Why Do Dogs Eat Grass?

By:  Loren W. Noblitt, D.V.M, M.S.

 

A lot of dogs (and some cats) eat grass.  I am commonly asked, "Why does [ENTER PET'S NAME] eat grass?" - I file this question under my "if I knew the answer and how to stop it, I'd have a million dollars", category of questions.  There seems to be multiple acceptable answers to this question - no one knows for sure in all cases. There are some very interesting theories to help explain our pets' 'fondness for forage', and they are as follows:

 www.thepetcentral.com

• Boredom behavior
• Dietary deficiency
• To induce vomiting
• Biologic/Ancestral influence

Let’s take a look at each of these individually now.

1)  Boredom behavior   
Some dogs flat out, just like to eat grass.  They like the taste and they like the texture.  Some particularly like certain types of grass, like fescue grass.  In these dogs there is no underlying pathology or illness causing them to eat grass.  This is not true of most dogs, and, for the most part eating grass is an inappropriate behavior and justifies some looking deeper to try to see why this habit is occurring.  Lack of stimulation during confinement in a particular environment, such as the back yard, can motivate a dog to eat grass or other various environmental substances. This condition, called pica is characterized by the consumption of non-nutritive material such as mulch, cat litter, grass, rocks, clothing, dirt, even feces.  Pica leads to vomiting, diarrhea, and intestinal obstruction or perforation.  Pica behavior can be reduced by providing your pet with stimulating and appropriate chew toys, more attention, and as a last resort: a basket muzzle. 

Try not to make it a “big production” if your pet puts an inappropriate item in their mouth, as this can eventually lead to attention-seeking behavior and can fuel a pica disorder.  Calmly walk over and remove the item from your pet’s mouth and replace it with an appropriate item, such as a Kong (available for both dogs and cats), Tartar Shield sticks, and Greenies.  Pica can be caused by underlying medical abnormalities, therefore veterinary examination, laboratory testing (blood/urine/fecal tests, radiographs, etc.) and dietary evaluation should be explored.  If your dog is eating his/her own feces (a subset of pica known as copraphagia) there are a wide array of anecdotal suggestions your veterinarian will likely have for you.  Contact the veterinarians at Zionsville Animal Hospital if your dog displays this unfortunate habit!

2) Dietary Deficiency

Veterinary behaviorists and nutritionists speculate that dogs eat grass to compensate for nutritional deficiencies, iron and fiber are among the most commonly sited suspected deficiencies.   A reduction in your dog’s grazing may be achieved by simply adding fresh greens and/or fibrous vegetables or fruits to their diets.  Leafy greens like kale, broccoli, and parsley and pineapple have all been reported to yield favorable results.  It should be noted that vegetables are most palatable (and digestible) when steamed and pureed or finely chopped before being incorporated into a dog’s meal.  Additionally, dogs that eat a diet based in whole foods (which requires owners to cook meals at home) instead of commercially available, processed, non whole-food based dry (kibble) or canned foods tend to exhibit less foraging behavior.

3)  To Induce Vomiting

Plant material is composed of insoluble fiber that is not readily digestible and irritates/inflames the stomach wall.  Dogs seem to “know” this instinctively.  Grass accumulates in the stomach instead of moving into the small intestine, like food normally would.  It also can pass through, undigested, and you'll see green blades in the feces (if you look carefully enough).  Underlying illnesses like Inflammatory Bowel Disease (IBD), stomach or intestinal parasite infestation, metabolic diseases of the kidneys, liver, or pancreas, and pica (discussed above) can stimulate the physiologic urge to vomit.  Therefore, dogs can eat grass as a means of facilitating their own vomiting and for reducing nausea.

4)  Biological/Ancestral Influence

Grass eating is a behavior exhibited by wolves.  An article in the Journal of Veterinary Behavior suggests that the grass eating traits of a nursing mother can influence similar behavior in her puppies. Your dog’s mother, grandmother, and so on may be partly responsible for imparting modern-day grass eating tendencies.   Conversely, another study looked at grass-eating dogs and no link was found to diet or history of gastrointestinal disease. Some dogs were reported to only eat grass if they already had an "upset stomach", and needed to vomit.  Most dogs seemed to eat grass because they liked it!

As a veterinarian, I see grass-eating dogs inadvertently ingesting toxins such as fertilizer, pesticide, and other unhealthy environmental debris (particularly rocks!).  Recently pesticides and some fertilizers have been linked to cancer in dogs and can cause temporary neurological problems (http://www.vet.purdue.edu/pcop/files/docs/CanineUrinaryBladderCancer.pdf). 

It's not surprising that the veterinarians at Zionsville Animal Hospital recommend dog owners take appropriate measures to deter grass munching, during all stages of life, and encourage owners to explore the possibility that there is an underlying reason for it.  However, there is a good possibility that the answer will be, “ Because he likes it," or, "Because the grass can't outrun him."

Nutraceuticals: The Good, The Bad, and the Worthless

        By:  Loren W. Noblitt, D.V.M., M.S.

     A question that I am asked very frequently (almost daily it seems), is, "Can I (safely) give my dog or cat the same over-the-counter (OTC) supplements that I take?" The answer is, "it's complicated." I mean, seriously -- EFAs, PUFAs, EFA, EPA, DHA, GLA, LPO -- What do all these letters and abbreviations mean? What do essential fatty acids do anyway? How should you use them? What dosage? What brands are available? Are they all the same? What about probiotics, cranberry extract, and appropriate liver support?

     Ok, Ok, Ok - it's REALLY complicated.
    
The term "nutraceutical" is defined as "a food or a part of a food that provides medical or health benefits."  Nutraceuticals and dietary supplements are commonly used in both veterinary and human medicine.
     
Since there is no regulatory body for the manufacturing of nutraceuticals, it becomes difficult to assess product quality.  Drugs regulated by the FDA must meet specific manufacturing standards. Nutraceuticals...not so much.  Studies have shown that nutraceuticals are commonly mislabeled; may contain impurities, such as heavy metals, toxins, bacteria, molds; may have variable quantities of active ingredients; may fail to dissolve (thereby remaining ineffective).  Though the label may say "X mg", it is possible that some capsules have less (even zero) and some may have more.

That's the clear advantage of Nutramax products:  What they say is in each capsule, really is. 

     Case in point:  Many of the OTC glucosamine and chondroitin products are made from shark cartilage or other hard-to-metabolize products.  They often pass through the gastrointestinal tract without reaching significant levels in the joints, largely because of stomach acid degradation.  Some of these products come from other countries (i.e., Mexico, China, Brazil, Malaysia, etc) and are not proven to be toxic free or even effective, at all.  It is for all of these reasons that the Veterinarians at Zionsville Animal Hospital consistently recommend products like Dasuquin, Cosequin, Proviable probiotics, Denosyl, and Welactin fish oils -- all of which are made by the Nutramax company.

     To date, the Nutramax company has done virtually all of the available Veterinary studies in terms of effectiveness, batch variance, and bioavailability.  They have the research around their Cosequin product to prove it works, and better yet, the NEW! Dasuquin has added soybean and avocado extract, which has been found to reduce pain and inflammation, as well.  Does this mean that only their products are effective?  Likely not, but we can't say for sure.  The same holds true for the Omega 3's, probiotics, cranberry extract, and liver support (to name just a few). 

     Welactin has been extensively studied and remains the top additive of omega 3 essential fatty acid available to pets in the form of a supplement.  Of note here is the Hill's Pet food company and their j/d (Joint Diet) fortified with serious omega 3 fatty acids.  Hill's veterinary nutritionists say that you'd need to give ~two (2) dozen fish oil capsules to a large dog to approximate the omega 3's in a serving of Hill's j/d food.  These products are all promoted and sold at Zionsville Animal Hospital for these reasons.  Hill's j/d food is available upon request.

What's the BIG DEAL about Fish Oil (Omega-3 and 6 fatty acids) anyway?
Omega-3 and 6 fatty acids are classified as "essential"-- hence the term Essential Fatty Acids, or EFAs -- because humans and other animals are unable to synthesize them naturally.  Omega 3's have received much attention lately, and the important thing to know about them is they come in two varieties EPA and DHA, both are good!. 

Most EFAs are obtained from fish, crustaceans, and vegetables.  It was once thought that omega 3's were the better of the two because they were more anti-inflammatory than the omega-6's; however, this is no longer considered to be the case by Veterinary Dermatologists.  There is evidence that fish oil works to decrease the itching threshold, or "pruritic threshold", in dogs and cats with allergic skin disease (pollen allergy or atopy) and a recent clinical trial demonstrated a steroid-sparing effect of fatty acids due most likely in part to suppression of histamine and prostaglandin release.  Welactin fish oil is free of any proteins, which are the allergens in diets. Thus, theoretically, it should be safe to feed fish oils to animals with dietary allergies, so long as they're produced by reputable companies (i.e., Nutramax) that have repeatable quality control measures.  Your veterinarian may opt to withold fatty acids in the early stages of a dietary food trial (if a food allergy is suspected in your pet) in attempts to not "muddy the waters" in trying to arrive at a diagnosis. 

Fish oil is often used in cases of joint disease and osteoarthritis because of these inherent anti-inflammatory effects, and also a joint lubrication effect.

     When fatty acid supplementation is needed, it should be done at 180 - 200 mg of combined EPA and DHA fatty acids per 10 pounds of you pet's bodyweight.  The table below lists some of the preferred veterinary supplements on the market, and provides an omega-3 EFA dose per capsule or pump.  Zionsville Animal Hospital carries all 3 of these products and will be available via our online pharmacy coming soon:
            
        Product                                Omega-3 EFA Concentration/Dose         Amount per Pet
1)  Nutramaxlabs Wellactin                        270mg/capsule                             1 capsule per 20lbs
Omega3 Canine Gel-caps

2)  Nutramaxlabs Wellactin                        250mg/capsule                              1 capsule per cat
Omega3 Feline Gel-caps

3)  Nutramaxlabs Wellactin                      1300mg/5ml (1 tspn)                        5ml per 35kg
Omega3 Canine Liquid

     Ultimately, studies demonstrating the clinical benefits of a nutraceutical should be evaluated.  For example, several peer-reviewed studies exist documenting improvement in clinical signs with chronic osteoarthritis in dogs or horses given glucosamine or chondroitin sulfate (or combinations of these compounds). However, clinicians should examine how the studies were conducted, to determine their likely validity, because many studies are poorly designed or executed.
    
     In summary, neutraceuticals are not regulated by the FDA, as they are not considered to be "drugs." This means that they can be sold without scientific proof of effectiveness, without assuredness of safety and consistency from batch to batch, and without mandatory testing to determine the optimal dosage in target animals.  There are numerous anecdotal reports of these medications helping numerous individuals (both human and animal) but one should keep in mind that scientific investigation is continuing. 

     The best thing to do for your pet is to follow your veterinarian's advice and use reputable products when it comes to fish oil, glucosamine/chondroitin, or other supplementation, when possible.  If this cannot be done for whatever reason, try to keep the following suggestions in mind to help weed out inferior OTC nutraceutical products.

1.   Price.  Cheaper compounds are less likely to be of high quality. This has been the general observation with chondroitin sulfate.

2.   Pay attention to whether or not the product has a lot number and an expiration date.

3.  There is a general USP veterinary page (for veterinary drugs, requires free registration) and the USP Dietary Supplement Verification Program page, which provides a list of suppliers that have voluntarily submitted their products for USP verification and approval. These products carry the following mark:
                                                      
4. Claims of safety or efficacy.  If a nutraceutical claims a medical benefit on the label, there should be a New Animal Drug Application (NADA) number accompanying the product. While this is "mandated" by law, it is often ignored.  A NADA tends to suggest higher quality, because the manufacturer has bothered to abide by FDA regulations for drug manufacture.

5. Ingredient list. All ingredients should be listed by order of magnitude based on weight.

6. Scientific evidence supporting manufacturer's claims. Some manufacturers have begun providing data for their specific products through independent scientific studies. These studies should ideally be peer-reviewed and published. Importantly, they should be clinical studies, not in vitro studies. There are institutes, affiliated with universities and medical schools, who are beginning to investigate nutraceutical claims scientifically. These include The Nutraceuticals Institute, The Institute of Nutraceutical Research, and others.

7.   Testimonials in place of valid research.  Many companies provide testimonials from "satisfied clients".  These should be ignored, and companies that promote these instead of scientific research supporting their claims, should be viewed skeptically.

8.   Membership in National Animal Supplement Council (www.nasc.cc). This industry group has a close relationship with FDA and strict guidelines for member companies regarding quality control and adverse event recording. Member companies are likely to have better quality products.

Several websites exist that may help you investigate specific nutraceuticals:
1. www.quackwatch.com
2. www.herbalgram.org
3. http://nccam.nih.gov
4. www.navigator.tufts.edu/index.html
5. www.consumerlab.com
6. www.biovalidity.com

Photos coutesy of:  www.nutramaxlabs.com

Feline Diarrhea: Tritrichomonas and Giardia

                                          By:  Loren W. Noblitt, DVM, MS

Few conditions are more frustrating for veterinarians (and owners) than feline diarrhea.  I know that I always cringe a little inside when I'm confronted with these cases.  Primary causes of diarrhea, like gastrointestinal inflammation, infection, dietary changes, and cancer should all be considered, as well as secondary causes like liver, metabolic, and pancreatic disease.  The first diagnostic step (if the answer isn't obvious) is to obtain baseline blood work (CBC/Chemistry/Thyroid level), a fecal sample, and a urine sample.  Sometimes, a gastrointestinal (GI) blood profile test is indicated on a case-by-case basis.

In the infectious category, usually the cause will be related to bacterial infection, either from stress (immunosuppression that allows low level anaerobic, "bad" bacteria to thrive), dietary indiscretion (introduction of "bad", foreign bacteria either from human food, trash, feces, or an animal carcass), or a very recent food change (malabsorption, food intolerance, or digestive problems).  When treatment for these more common causes fails to yield resolution of diarrhea, or if the diarrhea has been a chronic longterm issue for your cat, the veterinarian likely will discuss Tritrichomonas foetus (T. foetus) and Giardia.

T. foetus and Giardia are both protozoal diseases, meaning that they are neither bacteria nor virus, but rather a life-form in-between (so to speak); they are both transmitted by the fecal-oral route (through direct contact with feces), and Giardia can be found in unclean water.  Let's now discuss the salient features of each of these pathogens, focusing on risk factors, diagnosis, and treatment.

T. foetus is an emerging parasite in the feline world, however, it was first discovered in cattle as a cause of abortion (thus the species name: 'foetus'), and is spread as a venereal disease amongst cattle. Surveys have suggested that approximately 1/3 of all purebred cats are infected. It is rarely tested for and may be responsible for many of the cases of chronic diarrhea (e.g. inflammatory bowel disease) in cats.  A T. foetus organism looks very similar to Giardia so if viewed by in a fecal smear a misdiagnosis of Giardia is common. Fecal floats and Giardia snap tests are insensitive to it. T. foetus is a fragile organism whose life span out of the body is normally less than an hour. This lack of hardiness is due to the fact that T. foetus cannot form a cyst.  If T. foetus dries out, if it is refrigerated, or if it experiences temperatures above 105°F, it will die.  Good News!!! 

The protozoan lives in the intestinal lining of the large bowel.  It causes "cow pie" like stool that is often gassy and malodorous. The health of the cat is not usually adversely affected.  Cat breeders have commented that in symptomatic cats that the smell of the stool is a significant clue of an infection. It is important to note that an infected cat may or may not have clinical signs of tritrichomoniasis.

T. foetus is typically transmitted by an infected cat to other cats sharing the same litter box. Currently, the preferred and most reliable test to confirm diagnosis is a PCR test using the cat's stool sample.  Follow this link to see video of T. foetus and Giardia in action (Quicktime required): http://www.ncsu.edu/project/cvm_gookin/Tfoetusvideo.mov

Treatment of the T. foetus  infection is difficult due to drug resistance. Traditional antiprotozoal drugs such as Panacur and Metronidazole do not alleviate the symptoms, and as mentioned above, often is the first indicator that T. foetus infection may be present. Some antimicrobial drugs have been shown to improve symptoms but do not eradicate the parasite.  Ronidazole has had good efficacy in eradiation of the parasite in cats but has the potential for a variety of side effects, most notably, neurological side effects.  During treatment, the cat should be engaged in play activity regularly to ensure they are not experiencing neurological side effects, or motor skills impairment.  Two weeks of ronidazole, dosed at 30 mg/kg, once daily, is currently the recommended dosage. Care should be exercised (wearing gloves) while handling ronidazole, which can be toxic to humans.

During treatment, the cat should be keep isolated from other cats as to prevent the spread of T. foetus to another cat. Your cat should be fed a prescription high fiber food to help clear the organisms from the colon and to help heal the colon cells.  A common GI diet remedy in cats (boiled chicken breast and white rice) may be highly beneficial during and after treatment.

Treatment with ronidazole has shown good efficacy, and some positive results may be achieved after just two to three days of treatment, but completion of the two week cycle of drugs to avoid the risk of recurrence.  It is essential that a PCR test be conducted after treatment to verify that the organism has been completely eradicated.  It is also recommended that a follow-up test be performed a few months after the first.  Interestingly, cats that carry T. foetus and are not treated, usually cure themselves of the parasite within 2 years.

                                                                   
                                                    Giardia, in its motile Trophozoite form (above and below)

Photos courtesy of:  http://www.dpd.cdc.gov/dpdx/HTML/ImageLibrary/Giardiasis_il.htm

 

Giardia is a single-celled protozoan that affects the intestinal tract of mammals and usually causes diarrhea and can cause vomiting.  Definitive diagnosis comes from an enzyme-linked immunosorbant assay (ELISA) test using a stool sample.  Dogs and cats can become infected when they swallow Giardia that may be present in stagnant puddles of water or unclean drinking water. It is primarily contracted from the stool of infected animals, both wild and domestic.  Having giardiasis for a long time can cause weight loss, generally poor condition, and even death when the disease is serious. You might notice blood in your cat's stool from irritation that the Giardia parasite causes to the lining of the small and large intestines; however, many cats infected with Giardia do not show any signs of disease. The best way to prevent Giardia infection is to make sure that your cat has a safe, clean drinking water supply.  It is important not to allow cats to drink water from areas where other animals have left their feces.  Pick up soiled litter left by your cat or cats daily and place it in the trash.  Take care not to track animal feces into your house or environment where the cat will be.

The best treatment for Giardia is a six day course of an antiparasitic medication called Panacur (Fenbendazole), and on days #3 and #6 of the treatment, use wet wipes or soap and water to thoroughly clean your cat's rear end and tail.  This will cut down on the number of Giardia cysts that stick to the hair and will help prevent your cat from re-infection by normal cat grooming behaviors.  Bleach (diluted 1:20) or Lysol spray should be used to clean the litter boxes (allowing 10 minutes of good contact time before wiping), as these are both quaternary amines that are able to destroy the Giardia cyst lifeforms.  Importantly, a stool sample should again be checked in 1 month after the treatment was started to make sure the giardiasis is cured. 

As a veterinarian, I am often asked the question, "Can my cat (or dog) get Giardia from my dog (or cat)?"  The answer is Yes.  Either.  We typically recommend treating all the animals in the household when one animal is identified as being a Giardia carrier. 

Also of note, there is a chance that humans can be harmed by the same Giardia that affects their pets, but zoonotic infection (infection passed from animal to human) is extremely rare in this particular case.  It is likely that most people become infected with Giardia passed by other people rather than Giardia from pets.  Be sure to avoid contact with feces by using gloves, a bag over your hand, or a scooping device.  Also, be sure to thoroughly wash your hands after picking up feces.

Heartworm Disease: An Ounce of Prevention is Worth a Pound of Cure

By:  Loren W. Noblitt, DVM, MS

     Heartworm disease is a serious and potentially fatal condition caused by parasitic worms called Dirofilaria immitis.  These worms-heartworms-live in the arteries of the lungs and occasionally in the right side of the heart of dogs, cats and other species of mammals including wolves, foxes, ferrets, sea lions and, in rare instances, human beings!  Heartworms are classified as nematodes (roundworms) and are filarids, one of many species of roundworms. Dogs and cats of any age or breed are susceptible to infection.
    
     Naturally acquired heartworm infection in dogs and cats is identified as a worldwide clinical problem in veterinary medicine today. Despite improved diagnostic methods, effective preventives, and increasing awareness among veterinary professionals and pet owners, cases of heartworm infection continue to appear in pets around the world.  It occurs wherever the following four factors are found: i) a susceptible host population, ii) a stable reservoir of the disease, iii) a stable population of vector species, iv) a climate that supports the parasite's life cycle.
    
     Dogs are considered to be the definitive and "susceptible host" for the heartworm parasite, meaning that even though the disease is not transmitted directly from one dog to another, untreated dogs provide a "stable reservoir" for the disease for mosquitoes. Mosquitoes of several different species are the "stable vectors" and are considered to be intermediate hosts for the developing microfilariae (baby heartworms).  Development of the microfilariae in the mosquito requires a temperature at or above 80 degrees F for about two weeks.  Interestingly, no larval development takes place in the mosquito below 57 degrees F.
    
     In the United States, heartworm disease continues to be a problem.  It has been reported in all 50 states, all countries, and all continents except Antarctica. The map below shows particularly endemic areas in the United States based on the number of cases reported by clinics.  Note that Indiana is in the "26-50 cases" of Heartworm disease reported per Veterinary clinic, and that on average, the Zionsville Animal Hospital treats 10-15 cases of heartworm disease per year.


The Life Cycle

     Adult female heartworms bear live young - thousands of microfilariae in a day-released into an animal's bloodstream. Then, while taking a blood meal from the infected animal, mosquitoes become infected with these microfilariae.  During the next 10 to 14 days, the microfilariae mature to the infective larval stage within the mosquito. After that, the mosquito bites another dog, cat or other susceptible animal (see above), and the infective larvae actually burrow into the animal through the mosquito's bite wound and undergo several changes to reach adult form.  They then travel to the right side of the heart through a vein and await the opportunity to reproduce.
    

Heartworms in the Pulmonary Artery of a dog

    
    
     Microfilariae cannot mature into adult heartworms WITHOUT first passing through a mosquito.  It then takes a little over six months for the infective larvae to mature into adult worms. In dogs, the worms may live for up to seven years if there is no treatment given.  Adult heartworms can reach twelve inches in length and can remain in the dog's heart for years.  In cats, by contrast, heartworms live only several years.  In both cases, there can be tremendous, long-term damage to the lungs as a result of heartworms.

What Are the Signs of Heartworm Disease?

     For both dogs and cats, clinical signs of heartworm disease may not be recognized in the early stages, as the number of heartworms in an animal tends to accumulate gradually over a period of months and sometimes years and after repeated mosquito bites.  The first sign of heartworm infestation is often a soft cough that increases with exercise, and commonly may be dismissed as being trivial or unimportant by the owner.  But often the cough worsens and the dog may actually faint from exertion, tires easily, becomes weak and listless, loses weight, and may cough up blood.  Breathing becomes more difficult as the disease progresses because the worms are multiplying in the lungs and heart. The progression is traumatic: the dog's quality of life diminishes drastically and he/she can no longer retrieve a ball or Frisbee; can no longer take a nice walk in the park without respiratory distress.  Congestive heart failure ensues, and the once-active family pet is in grave danger.
    
     Cats may exhibit clinical signs that are very non-specific, mimicking many other feline diseases.  Chronic clinical signs include vomiting, gagging, difficulty or rapid breathing, lethargy and weight loss.  Signs associated with the first stage of heartworm disease, when the heartworms enter a blood vessel and are carried to the pulmonary arteries, are often mistaken for feline asthma or allergic bronchitis, when in fact they are actually due to a syndrome defined as Heartworm Associated Respiratory Disease (HARD).  Chest x-rays and objectively measuring the cat's heart, in conjunction with heartworm blood testing, should be done to look for heartworm disease.  These tests are recommended even if a cat has been on heartworm prevention reliably.
Detecting Heartworm Disease
    
     Heartworm infection is usually detected with blood tests for a heartworm substance called an "antigen" (found only on the adult female's body) or actually seeing the microfilariae under the microscope on a routine blood smear.  Neither test is consistently positive until about seven months after infection has occurred.  An antibody test is the preferred blood test for cats because the worm burden is usually smaller in cats versus dogs and there may not be significant antigen (e.g. significant number of female worms) in an affected animal's blood to make the test positive. Heartworm infection may also occasionally be detected through ultrasound and/or x-ray images of the heart and lungs, although these tests are usually used in animals already known to be infected.
Prevention
    
     Because heartworm disease is preventable, the American Heartworm Society (AHS) recommends that pet owners take steps now to talk to their veterinarian about how to best protect their pets from this dangerous disease.  Heartworm prevention is safe, easy, and inexpensive; however, treatment for heartworm disease is a complicated and expensive process, taking weeks for infected animals to recover and, during the recovery period, STRICT exercise restriction is mandatory. Recently the drug used to treat heartworms in dogs, Immiticide (melarsomine), has become increasingly hard to obtain, resulting in some animals with heartworm disease having to wait for treatment to be available. Thus, the expression, "an ounce of prevention is worth a pound of cure" is truly apropos. There is currently no effective treatment for heartworm disease in cats, so it is imperative that disease prevention measures be taken for cats, especially for at-risk, outdoor cats in particular.  For more information on this, please ask your veterinarian.
    
     There are a variety of options for preventing heartworm infection in both dogs and cats, including monthly tablets (Interceptor, Sentinel, and Trifexis) and chewables (Heartgard Plus), monthly topicals (Revolution and Advantage Multi) and a recently re-released, six-month injectable product called ProHeart available only for dogs.  Some of these preventives also kill gastrointestinal parasitic worms and fleas, as well.  All of these methods are extremely effective, and when administered properly and on a timely schedule, heartworm infection can be completely prevented. These medications interrupt heartworm development before adult worms reach the lungs and cause disease.  Veterinarians recommend a year-round heartworm prevention program to guard against the occasional mosquito flying about in areas with mild winters, such as Indiana.

Treatment

     The first step is to evaluate the dog and treat any secondary problems of heart failure, liver or kidney insufficiency, so that he/she can withstand the treatment. The next step is to kill the adult worms with Immiticide (an arsenic compound).  This compound is carefully injected deep into the muscles adjacent to the lower spine through a series of treatments. Treatment may be administered on an outpatient basis, but hospitalization is sometimes recommended, depending on a number of variables such as energy level, attitude, home environment, other pets or not, etc.  When the dog returns home, strict exercise restriction must be enforced to decrease the risk of partial or complete blockage of blood flow through the lungs by dead worms ("worm plugs" or "worm mats").  Importantly, re-infection during treatment is prevented by administration of a heartworm preventive, as described above.  Usually, all but the most advanced cases of heartworm disease can be successfully treated in dogs.  Again, there are no products in the United States currently approved for the treatment of heartworm infection in cats-the disease just has to run its course.  Veterinarians will often attempt to treat an infected cat with supportive therapy measures to minimize immune reaction; however it is always best to prevent the disease.

     For more information on heartworm disease or if you have specific questions about this disease or specific preventives for your dog or cat, please contact the veterinarians or staff at the Zionsville Animal Hospital.

Photos Courtesy of:  The American Heartworm Society
http://www.heartwormsociety.org/pet-owner-resources/heartworm.html

                      

 

Brachycephalic Airway Syndrome: What You Need to Know

                                                By Loren W. Noblitt, DVM, MS

The old phrase, "variety is the spice of life," is truly exemplified by the canine species as a whole.  Case in point: the dog's head.  As we all know, dog heads come in all shapes and sizes, but did you know that there are technically three major categories that they fall in to?  They are as follows: 1) Mesaticephalic-a skull of intermediate length and width.  This classification includes dogs like the Beagle, the Labrador Retriever, and the Rottweiler; 2) Dolichocephalic-a relatively long skull.  This classification includes dogs like the Greyhound, the Whippet, and the Collie; and finally, 3) Brachycephalic-a skull that is broad and short.  This includes dogs like the Pug, Boston Terrier, Boxer, Bulldog and Shi tzu.  The brachycephalics have been bred to have compressed faces, shallow eye sockets, and narrow nostrils (or nares) which, although making them all-the-easier to love, also seriously predisposes them to difficulty recruiting fresh oxygen into their lungs. 

Brachycephalic Airway Syndrome (BAS) is any combination of the following abnormalities: a) Narrowed (stenotic) nostrils, b) Elongated soft palate, c) Laryngeal saccule (the useless soft tissue masses adjacent to the vocal cords) eversion, d) Collapsed larynx, and e) Hypoplastic (narrow) trachea (windpipe).  Of these, the elongated soft palate, narrowed nostrils and trachea are considered to be present at birth.  The everted saccules and laryngeal collapse occur secondarily to the effects of the congenital defects (explained below).  Because any of the 5 components of BAS abnormalities can lead to obstruction of oxygen flow into the lungs, the condition often progresses to include inflammation and fluid accumulation of other important upper respiratory tissues like the epiglottis and tonsils, making it even harder for the animal to breathe-BAS is, in this way, very much a vicious circle.
 
     Let's now look at each component of BAS individually.  Nostril narrowing usually occurs on both sides, and when present, contributes to the severity of dyspnea (difficult breathing) making the dog work harder to pull air into his or her lungs-this increase in negative pressure draws the soft palate deeper into the larynx.  The normal function of the soft palate, in conjunction with the epiglottis, is to prevent food from entering the nasal cavity during chewing and swallowing.  In normal animals, the border of the soft palate is near the tip of the epiglottis and if the soft palate is longer than this, it frequently will obstruct airflow through the larynx creating friction with the epiglottis.  Friction results in inflammation during each respiration, further lessening air flow into the lungs.  As increased breathing effort continues in an effort to overcome these anatomical handicaps, increased negative pressure in the airway develops and encourages eversion of the laryngeal saccules, further blocking airflow.  Anxiety from the labored breathing occurs and often leads to excessive panting.

    There are several components of BAS that can be addressed surgically. Surgical correction or widening of stenotic nares may be desirable as part of an overall strategy to decrease upper airway airflow resistance in animals with multiple upper airway abnormalities.  Shortening an elongated soft palate is routinely done by cutting the excess tissue with surgical scissors at the level of the tonsils and stitching the remaining palate back together.  Correction of the nostrils and palate can be done together and as early as 3 to 4 months of age.  Similarly, the laryngeal saccules can be excised with a curved scissor if they are obstructing air flow to make the dog more comfortable and further reduce resistance to air flow; however, this often does not need to be done because once air flow is improved by either/or trimming the soft palate and widening the nostrils, the saccule swelling goes down in most breeds of dog and are no longer everted.  The recent exception to this rule appears to be the Norwich terrier, where everted saccules are felt to be a primary condition.

    As an owner of a brachycephalic dog, there are steps that you can take in lieu of (or in conjunction with) surgical correction, to help prevent severe BAS from occurring.  First of all, animals with severely compromised upper respiratory tracts due to congenital conditions should not be bred, as they will only perpetuate the BAS situation.  Obesity is a big risk factor for BAS so a healthy and controlled diet is imperative.  Along these same lines, exercise and excitement can trigger panting, subsequent airway inflammation, and obstruction, so as an owner be cognizant not to overdo it on walks or runs, especially in hot weather.  Cooling will help minimize panting, so some good suggestions are to place your dog in a quiet air-conditioned room or kennel after a long walk or bout of increased respiratory effort and always make sure that they have access to fresh, cool water.  Finally, the use of sedatives and analgesics in conjunction with your veterinarian may be used to help calm a distressed animal and to decrease severe panting episodes that come secondary to anxiety. 

    Your vet, or the vets at the Zionsville Animal Hospital can discuss with you whether or not your dog is a good candidate for any of the aforementioned surgical procedures. He or she probably will recommend doing a laryngeal exam under sedation to assess these structures.

Pancreatitis: 'Tis the Season

                                               By Loren W. Noblitt, DVM, MS

     Scrumptious leftover Thanksgiving turkey, Mom's famous Christmas gravy, and other fatty leftovers like turkey and chicken skin, or ham from holiday meals - all have the potential to cause pancreatitis in dogs (and cats, too!). 
Pancreatitis is, by definition, inflammation of the pancreas caused by inappropriate release of pancreatic enzymes that are normally pre-formed and tucked away for use during normal everyday digestion.  These pancreatic enzymes literally digest and eat away at the pancreatic and surrounding tissues - an extremely painful and dangerous process.  In addition to fatty food ingestion - trauma, underlying endocrine diseases like Hypothyroidism, Diabetes Mellitus, and Cushing's Disease, high amounts of triglycerides in the blood, and breed predispositions (Miniature Schnauzers, Shelties, and Yorkshire Terriers, in particular)...all are well-known risk factors for pancreatitis in dogs.

     The pancreas is a very delicate organ [comparatively speaking], nestled up closely between the first part of the small intestine (duodenum), the stomach, and adjacent to the liver in the right upper quadrant of the dog and cat's abdomen.

    Pancreatitis manifests in dogs most commonly by vomiting, abdominal pain (tenseness), restlessness, diarrhea, depression, and unwillingness to eat their normal food.  A fever is commonly present, as well, but is only present in roughly 50% of cases.  A "prayer stance" is often observed in dogs with pancreatitis - this stretching is done presumably because their abdomen is uncomfortable.  Cats are not immune to pancreatitis by any means, and although eating [unaccustomed] fatty meals is definitely a trigger, there is generally less known about causes of pancreatitis in cats, compared to dogs.  Decreased appetite, hiding, and extreme lethargy are the most common signs to look for in cats suspected of having pancreatitis.  The anatomy of the cat's intestinal tract is unique and, as a result, intestinal and liver diseases can often lead to bouts of feline pancreatitis.

     Diagnosing pancreatitis is often a challenge for veterinarians, regardless of species.  There is a relatively simple blood test that can be run in-house, called CPLi (canine pancreatic lipase immunoreactivity).  This test is not as routinely available for cats (FPLi) and has to be sent to an outside laboratory - thankfully, results are available 12-24 hours later.  Unlike humans, the enzymes lipase and amylase are very unreliable in dogs and cats.  Occasionally, lipase and amylase values that are elevated three or four-fold can assist the diagnosis, but seldom are relied upon solely by the veterinarian to make the diagnosis.  X-rays can be helpful in some cases, but the PLi test is really the gold standard for making the diagnosis.

    
     The treatment of pancreatitis varies somewhat between dogs and cats, but there are two cornerstones of therapy, regardless of species:  Pain Control and Intravenous Fluid Therapy.  In fact, there is an old adage in Veterinary medicine that has served many veterinarians through the years: "the pancreas is a prima donna when it comes to pain and perfusion." 
Other important facets to consider are nausea-control and giving the pancreas a rest (not offering food or water for a short time).  Antibiotics are sometimes indicated, but only in advanced cases.  It is important to note that once your pet has had a bout of pancreatitis, he or she will be more likely to have another in the future.  A low fat diet is generally recommended long term to help prevent future episodes.
    
     The prognosis is generally very good if pancreatitis is caught early, but not always.  It can run the gamut from mild, with no or minimal vomiting, all the way to life- threatening-disease-status and can be the cause of rapid death.

    
     So, in summary, safe guard your trash cans and empty them frequently when table scraps are lurking in them, do your very best to discourage "counter-surfing", and DO NOT give-in to your dog when he or she begs you for those tasty leftovers (easier said than done - I KNOW!).  Your pet will thank you in the long run!  For more information or if you feel that your pet may be experiencing an episode of pancreatitis, please contact the Veterinarians at Zionsville Animal Hospital immediately.

 

Top 16 Common Toxicities In and Around Your Kitchen

By Loren W. Noblitt DVM, MS

1) Chocolate:  Chocolate contains theobromine and caffeine (both methylxanthines), a chemical that is toxic to dogs' and cats' hearts, causing it to beat too fast and subsequently can cause arrhythmias (unorganized heart beats) that can be fatal if ingested in significant doses.  Other signs of ingestion include seizures, tremors, hyperactivity, lethargy and vomiting.  Call your veterinarian with the specifics of the ingestion-amount of chocolate ingested in ounces, information about the type of chocolate (milk chocolate vs. dark, semisweet chocolate vs. baker's chocolate), whether or not wrappers were consumed as well, and when the ingestion occurred.  Pancreatitis (inflammation of the pancreas) can occur as a consequence of chocolate ingestion, especially if your pet has had an episode of pancreatitis in the past.  Often time, treatment will consist of induction of vomiting and coating the stomach with activated charcoal or similar compound to prevent absorption of the theobromine into the blood.  Theobromine cause central nervous system and muscular stimulation, including the heart muscle.  In some cases, beta-blockers or lidocaine to control problematic fast and irregular heartbeats. 

2) Cocoa Bean Mulch:  When planting your garden or landscaping your yard this year, pay close attention to the type of mulch that you buy.  There is a type called Cocoa Bean Mulch and can lead to toxicosis if your dog (or cat) ingests it.  A retrospective study released by the ASPCA Animal Poison Control Center (APCC) confirms that this commonly used fertilizer may deter slugs and snails, but it also attracts dogs, who can be poisoned by eating it.  Made from spent cocoa beans used in the production of chocolate, cocoa bean mulch still contains caffeine and theobromine.  Comments Dr. Steven Hansen, the APCC Senior Vice President, "Since the updated data confirms that dogs can exhibit certain clinical effects after consuming cocoa bean shell mulch fertilizer, the ASPCA advises pet owners that they should avoid using this fertilizer around unsupervised dogs, and dogs with indiscriminate eating habits."

3) Grapes and Raisins: Although the mechanism is unknown, fruits of Vitis vinifera cause kidney impairment and failure in dogs.  Reported fatal doses are widely variable and there appears to be no dose-response relationship, and hence any ingestion should be considered dangerous. Vomiting is a frequent early sign. Prognosis is poor in animals with oliguria (small amounts of urine) or anuria (inability to urinate).

Management should be aggressive and include decontamination, aggressive IV fluid therapy, and monitoring kidney function closely. What exactly the toxic component of grapes and raisins is is currently unknown, but it is felt to be water-soluble, and within the flesh of the grape/raisin, not the seed.  The prognosis remains guarded once renal failure develops.



4) Xylitol/Sugar-free Gum and Candy: Xylitol is an artificial sweetener and sugar alcohol. In people, xylitol generally has no effect on blood insulin or blood sugar levels.  Dogs metabolize xylitol much differently than people. In dogs, xylitol triggers a large release of insulin that causes a sudden drop in blood sugar (hypoglycemia) and is evidenced by unsteadiness, depression, dilated pupils and, in severe cases, seizures. If ingested in high enough quantity, xylitol may lead to liver failure. Signs are subtle and include lethargy, vomiting, loss of appetite, and diarrhea. 

The toxic dose of xylitol for dogs is 75-100 mg/kg of body weight.  That being said, actually knowing how much xylitol the dog ate is another matter completely because most gum manufacturers consider the level of xylitol in their products to be proprietary information and refuse to disclose it.

The amount may differ not only from manufacturer to manufacturer, but from flavor to flavor.  The xylitol in one piece of gum ranges from 0.9 mg to 1,000 mg-obviously a HUGE difference.  That being said, products that list xylitol as the first ingredient tend to be the most toxic to dogs. 

Treatment typically consists of IV fluids, close blood glucose monitoring, and/or glucose/dextrose administration to correct low blood sugar.  S-adenosyl-L-methionine (SAMe) has been used as a liver protectant in some cases.  Also, the form of xylitol used in a product affects its toxicity.  For instance, xylitol used in candies and mints is in a powder form that's absorbed quickly into the blood stream, causing signs of illness in ~30 minutes.  Gum is different because it has to be chewed to release the xylitol.  Dogs tend to swallow gum whole without chewing it. The xylitol still leaches out into the stomach but it takes much longer.  If no side effects have been seen by 8-12 hours of ingesting gum, toxicity shouldn't be an issue, according to one veterinary toxicologist.  This same toxicologist commented that "ABC-gum" (already-been-chewed-gum :)) poses much less risk to dogs and that the more thoroughly chewed up the gum is, the less sweetener is present.

5) Fatty Table Scraps:  Fatty foods and scraps from the table can lead to an extremely painful and scary condition in dogs and cats called Pancreatitis (see previous Pancreatitis blogspot).

6) Onions and Garlic: The toxic dose of onions in dogs is about 5 g/kg and garlic is ~ 5 times more potent, so 1 g/kg-and cats are far more sensitive. Unfortunately with these supplements, the levels can vary considerably and be well above or below what's listed on the label. ANY amount of garlic is going to cause some RBC damage-it's only when the amount of garlic is sufficient to damage enough RBCs that we see clinical signs.  We know that onions and garlic will decrease an important enzyme which then leads to low levels of glutathione, a critical antioxidant and enzyme. These and other changes in the RBC lead to decreased deformity of the erythrocyte membrane and increased microviscosity. Since these cells lose the ability to "flex," hemolysis (rupture) results.  Unfortunately, there is no low-end dose published. We know that most animals will not have issues with small amounts of onions/garlic, but they do become more susceptible with other underlying disease processes.

7) Lillies:   Did You Know that Lilies are poisonous plants for cats? 

The lily leaves, petals, flowers, and pollen can cause a type of kidney failure in cats which is nearly irreversible a few days after the ingestion of the plant. It may be treatable if the cat is brought in shortly after the plant eating has been discovered so do not wait until the cat is sick. Or better yet, decorate for Spring in other ways. In dogs, Easter Lilies cause a nasty upset stomach but no kidney failure.  Asiatic Lilies, Day Lilies, Tiger Lilies, and Stargazer Lilies are ALL TOXIC.

                                                                                                                         Easter Lily

8) Macadamia Nuts:  The exact cause of the clinical signs of toxicosis resulting from macadamia nut ingestion by dogs is unknown. Since toxicity has only been seen in dogs, the actual mechanism of action could be specific to the dog and may involve constituents of the nuts  themselves, contaminants from processing, mycotoxins, or other unidentified causes.  In most cases-and for an unknown reason-dogs develop an inability to stand or use their hind limbs within the first 12 hours, post-macadamia ingestion. Depression, vomiting, ataxia, tremors, and fever can also be present. The prognosis in most cases is extremely good, as most dogs return to normal within 24 to 48 hours. Potential complications could be GI obstruction, pancreatitis, gastritis (inflammation of the stomach) or enteritis (inflamed intestines).

9) Cigarettes:  Tobacco products contain varying amounts of nicotine, with cigarettes containing 13-30 mg of nicotine and cigars containing 15-40 mg.  Clinical signs often develop quickly (usually within 15-45 minutes) and include excitation, tachypnea, salivation, emesis, and diarrhea. Muscle weakness, twitching, depression, tachycardia, shallow respiration, collapse, coma, and cardiac arrest can follow the period of excitation.

10) Pennies:  Ingestion of coins by pets, especially dogs, is not uncommon. Of the existing US coins currently in circulation, only pennies pose a significant toxicity hazard. Pennies minted after 1983 contain 99.2% zinc and 0.8% copper, making ingested pennies a rich source of zinc. Other potential sources of zinc include hardware such as screws, bolts, nuts, etc., all of which may contain varying amounts of zinc. In the stomach, gastric acids leach the zinc from its source, and the ionized zinc is readily absorbed into the circulation, where it causes red blood cells to rupture. The most common clinical signs of penny ingestion are vomiting, depression, anorexia, hemoglobinuria, diarrhea, weakness, collapse and icterus/jaundice. Secondarily, acute kidney failure may develop. Laboratory abnormalities will be suggestive of ruptured RBC's (hemolysis)-including elevated bilirubin, hemoglobinemia, hemoglobinuria, and regenerative anemia) and may also indicate the development of kidney failure. X-rays of the abdomen may reveal the presence of coins within the stomach or intestine.

Treatment for recently ingested pennies should include induction of vomiting. Activated charcoal is not indicated, as it is of little benefit in binding metals. Removal of zinc-containing foreign bodies via endoscopy or gastrotomy/enterotomy may be required. Treatment for symptomatic animals should include blood replacement therapy as needed, intravenous fluids, and other supportive care. The use of metal chelators (binders) may not be necessary in cases where prompt removal of the zinc source is accomplished. If chelation therapy is instituted, careful monitoring of kidney parameters is important for the duration of therapy.

10a.) Knives:  Don't let your animals play with knives!

11) Bread Dough:  Raw bread dough made with yeast poses mechanical and biochemical threats to animals ingesting it. The warm, moist gastric environment stimulates yeast growth, resulting in expansion of the dough mass, resulting in gastric distention, which, if severe, can result in respiratory and vascular compromise.  Perhaps more significant is the release of alcohol from yeast fermentation, resulting in profound blood acidosis, central nervous system depression, and even death.  Early clinical signs may include unproductive attempts at vomiting, abdominal distention, and depression. As alcohol intoxication develops, the animal becomes ataxic and disoriented. Eventually, profound CNS depression, weakness, recumbency, coma, and hypothermia may occur. Management includes decontamination and treatment for alcohol toxicosis.  Because emesis is often unsuccessful, gastric lavage is initially recommended. The veterinarian should be prepared to perform gastrotomy should the lavage fail to remove the bulk of the dough mass due to the glutinous nature of the dough. Treatment for alcohol intoxication should proceed as previously described.

12) Human/Animal Prescription Medications.  The most commonly seen group of medications that animals seem to have a propensity to "get in to" around the house are their owners.'  "Serotonin Syndrome" is the term used to describe behavioral changes seen when toxicity is seen.  Clinical signs are typically rapid (within 1-2 hours of ingestion) and are behavioral and/or neuromuscular in nature.  The exception being some of the extended release products (i.e., Effexor XL) in which signs are seen 8-12 hours later, typically.  The behavioral changes commonly seen are agitation and depression/lethargy and neuromuscular signs include ataxia (drunken walking), muscle jerking, tremors, erratic eye movements and increased sensitivity to pain.  Elevated temperatures (due to excessive muscle activity and a resetting of the brain's thermoregulatory center), vomiting, diarrhea, panting, accelerated heart rate, and increased blood pressure are all common, as well. Treatment must be prompt.  Decontamination is sometimes possible, but regular monitoring and cooling measures are vital. Cyproheptadine, a non-specific serotonin antagonist, has been used successfully in many cases and is the treatment of choice.

The following is a compiled list of drugs known to be associated with elevated Serotonin levels.  If you have/use any of these medications at home, take every precaution when storing them:

Amphetamines	Buproprion (Wellbutrin)	Buspirone
Chlorpheniramine	Clomipramine	Robitussin
Venlafaxine (Effexor)	Fentanyl	Fluoxetine (Prozac)
Ginseng	L-tryptophan	Lithium
LSD	Methamphetamine	Metoclopramide (Reglan)
Ondansetron (Zofran)	Paroxetine (Paxil)	Pentazocine
Selegiline	St. John’s Wort	Tramadol
Trazadone	Tryptophan	Mirtazapine (Remeron)

(Note:  A handful of these medications are used in Veterinary medicine very frequently so take precautions when storing these medications as well (i.e., tramadol, mirtazapine, metoclopramine, selegiline, and clomipramine (Clomicalm))

13) Anticoagulant Rodenticides:  These are coumarin and similar compounds that inhibit the critical enzyme, vitamin K1-2,3-epoxide reductase, thereby depleting the body's vitamin K1 supply needed for synthesis of blood clotting factors II, VII, IX and X-the 4 factors required for clot formation. Clinical signs of clinical coagulopathy (bleeding) develop usually 3-5 days post ingestion.  Diagnosis is generally possible before signs of coagulopathy develop (bleeding from orifices or hemorrhaging seen under the skin).  Lethargy and/or respiratory distress upon exercise are both important early visual signs.

Another test called the "PIVKA" ("Proteins Induced by Vitamin K Antagonism") test is more specific.  The PIVKA test detects inactive serine proteases.  If an unusually high amount of inactive serine proteases are circulating that would indicate something is wrong with Vitamin K recycling.  Long-term (3-4 weeks) oral vitamin K1 therapy is not needed in all cases, and should only be instituted once coagulopathy is confirmed analytically, unless hemorrhage is already evident. Cases already presenting with severe bleeding will require fresh whole blood transfusions to deliver activated clotting factors, and many units of fresh (or frozen) plasma may be needed.

Follow this link to see why clotting factors are so important:
http://youtu.be/uBvpE5ia2LE

14)  Vitamin D analogues (Human Psoriasis medications:  Vectical, Dovonex, Taclonex):  The toxicity of vitamin D compounds to dogs has long been known. However, some analogues used in the management of psoriasis and also hyperparathyroidism in humans have been found to be extremely toxic. These include calcipotriol, calcitriol and tacalcitol.  It is the metabolite calcitriol that mediates the toxicity by enhancing absorption and retention of calcium leading to elevated calcium levels, tissue deposition of calcium, and related secondary effects.  Measurement of serum phosphorus, calcium, blood urea nitrogen (BUN), creatinine, and urine specific gravity, together with good history-taking, can confirm the diagnosis.  Management is aimed at early decontamination, promotion of calcium excretion with IV saline and furosemide, together with the use of bisphosphonate drugs.

15) Non-Steroidal Analgesics-NSAIDS (Aleve, Advil, Ibuprofen, etc):  The propensity of these human-intended drugs to cause gastric irritation, ulceration, and also kidney toxicity is well known. Even drugs with widespread veterinary use such as meloxicam (Metacam) or carprofen (Rimadyl) have toxic potential. Appropriate management includes decontamination measures, short-term use of misoprostol and medium-term use of other gastroprotectant drugs including proton-pump inhibitors (e.g., omeprazole) or Pepcid AC.  Fluid therapy is vital for high dose exposures, as are frequent monitoring of kidney (including urine production and specific gravity) and liver values.

16) Mycotoxins:  This poisoning syndrome arises through ingestion of fungal metabolites present in moldy foods, silage and compost. Several tremorgenic mycotoxins have been identified including penitrem A and roquefortine, though their mechanisms of action have not been elucidated. Clinical signs are rapid in onset and include vomiting, ataxia, rigidity, tachycardia, tremors and convulsions. Mainstays of management include decontamination, close monitoring, control of convulsions and cooling measures.  Full recovery may take 48 hours or longer. Tremorgenic mycotoxins produced by molds on foods are a relatively common, and possibly under-diagnosed, cause of tremors and seizures in pet animals.  Because of their relatively indiscriminate appetites, dogs tend to be most commonly exposed to tremorgens. These toxins are produced from a variety of fungi, however tremorgens produced by Penicillium spp. are the most commonly encountered. These molds grow on practically any food, including dairy products, grains, nuts, and legumes; compost piles may also provide a source of tremorgens.  Tremorgens have several different mechanisms of actions: some alter nerve action potentials, some alter neurotransmitter action, while others alter neurotransmitter levels. The overall affect is the development of muscle tremors and seizures. Clinical signs include fine muscle tremors that may rapidly progress to more severe tremors and seizures. Death generally occurs in the first 2 to 4 hours and is usually secondary to respiratory compromise, metabolic acidosis or hyperthermia. Other signs that may be seen include vomiting (common) hyperactivity, depression, coma, behavior alterations, tachycardia, and pulmonary edema.

     Asymptomatic animals exposed to moldy foods should be decontaminated via emesis or lavage followed by activated charcoal and cathartic. In symptomatic animals, control of severe tremors or seizures has priority over decontamination. Supportive care should include IV fluids, thermoregulation, and correction of electrolyte and acid-base abnormalities. In severe cases, signs may persist for several days, and residual fine muscle tremors may take a week or more to fully resolve. Testing of stomach content, suspect foods, or vomitus for tremorgens is available through the Animal Health Diagnostic Laboratory at Michigan State University (517-355-0281).

If your pet has been exposed to, or known to ingest any of the above items, contact your local veterinarian or the Zionsville Animal Hospital for advice and/or treatment.

OTHER MISCELLANEOUS HOUSEHOLD HAZARDS:

a) Ant Baits:  Ant and roach baits are common objects found in households. They are also referred to as hotels, traps, or stations. The insecticides used most commonly in these baits are chlorpyrifos, sulfluramid, fipronil, avermectin, boric acid, and hydramethylnon. The baits usually contain inert ingredients such as peanut butter, breadcrumbs, sugar and vegetable or animal, which could be attracting to pets.  Exposures to these types of ant baits usually do not require decontamination or treatment.  Most often, if signs are seen at all, they are mild in nature and self-limiting and are usually attributed to the inert ingredients instead of the active ingredient.

b) Silica Gel Packets:  Silica gel is used as a dessicant (drying agent) and often come in paper packets or plastic cylinders. They are used to absorb moisture with leather, medication, and in some food packaging. Silica is considered "chemically and biologically inert" upon ingestion. However, with ingestion, it is possible to see signs of GI upset, such as nausea, vomiting, and inappetence.

c) Toilet Water and Tank Drop Ins:  Tank "drop in" products typically contain corrosive agents (alkali or cationic detergents.) However, when a tank "drop in" cleaning product is used in a toilet, the actual concentration of the cleaner is very low in the bowl. With dilution by the bowl water, the cleaning agent is just a gastric irritant. Common signs seen with ingestion include mild vomiting and nausea.

d) Birth Control Pills:  Each packet of oral contraceptives contains 21 tablets of estrogen and/or progesterone and possibly 7 placebo pills. Estrogen could cause bone marrow suppression at levels greater than 1 mg/kg. Some oral contraceptives also contain iron.  Decontamination is not necessary unless the level of estrogen is greater than 1mg/kg or the level of iron is greater than 20mg/kg.

e) Liquid Potpourri:  Liquid potpourri may contain essential oils and cationic detergents; because product labels may not list ingredients, it is wise to assume that a given liquid potpourri contains both ingredients. Essential oils can cause mucous membrane and gastrointestinal irritation, central nervous system depression, and dermal hypersensitivity and irritation. Severe clinical signs can be seen with potpourri products that contain cationic detergents. Dermal exposure to cationic detergents can result in redness, intense pain, and ulceration. Ingestion of cationic detergents may lead to tissue necrosis and inflammation of the mouth, esophagus, and stomach. Treatment is symptomatic and supportive.

Blog Information Sources:
Veterinary Information Network www.vin.com
Poison Control Center  http://www.apcc.aspca.org/
Marvistavet:  www.marvistavet.com
Veterinary partner:  www.veterinarypartner.com