Laurie Anne Walden, DVM
Xylitol is a sugar substitute that is safe for humans but toxic to dogs. It is an ingredient in sugar-free gum and a variety of foods, especially products for people who have diabetes or need food with a low glycemic index. Xylitol is added to some oral care products because it slows the growth of bacteria that cause dental cavities.
Products that contain xylitol might or might not be labeled as being sugar free or low in sugar. Xylitol is found in products like these:
Effects in Dogs
Xylitol is safe for most animals, but dogs don’t metabolize xylitol the same way as other species. Compared with humans, dogs absorb more of the xylitol they ingest and process it more quickly. Xylitol causes dogs’ insulin levels to surge, resulting in rapid hypoglycemia (low blood sugar level).[1,2] Ingestion of larger amounts of xylitol can damage the liver and interfere with blood clotting.
Symptoms of xylitol poisoning in dogs can appear as soon as 30 minutes after ingestion but might be delayed for several hours. These are some of the common symptoms:
Other sugar substitutes and artificial sweeteners (sorbitol, aspartame, sucralose, and saccharin) should be safe for dogs. Xylitol does not seem to be toxic to cats.
What to Do
If your dog eats sugarless gum or another product that might contain xylitol, call a veterinary clinic or an animal poison control hotline right away. Keep the packaging if possible so the amount of xylitol your dog ingested can be estimated. Do not try to make your dog vomit. Induced (forced) vomiting can be dangerous for a dog whose blood glucose level is already dropping.
Treatment usually involves hospitalization, intravenous medications to correct hypoglycemia, and continued monitoring of laboratory values. Dogs with liver involvement and more serious symptoms need more intensive treatment.
Dogs that ingest small amounts of xylitol and are treated promptly tend to recover well. The prognosis is poorer for dogs that develop liver damage and blood clotting problems.
How to Keep Your Dog Safe
Keep candy, baked goods, and other products that might contain xylitol away from your dog (watch out for counter surfers!). If you keep gum or mints in your purse, don’t leave your purse where your dog can reach it. Don’t brush your dog’s teeth with toothpaste meant for humans. Read product labels to check for artificial sweeteners; sorbitol should be OK but xylitol is not.
1. DuHadway MR, Sharp CR, Meyers KE, Koenigshof AM. Retrospective evaluation of xylitol ingestion in dogs: 192 cases (2007-2012). J Vet Emerg Crit Care (San Antonio). 2015;25(5):646-654. doi:10.1111/vec.12350
2. Dunayer EK. New findings on the effects of xylitol ingestion in dogs. Vet Med. 2006;101(12):791-797.
3. Dunayer EK, Gwaltney-Brant SM. Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs. J Am Vet Med Assoc. 2006;229(7):1113-1117. doi:10.2460/javma.229.7.1113
4. Jerzsele Á, Karancsi Z, Pászti-Gere E, et al. Effects of p.o. administered xylitol in cats. J Vet Pharmacol Ther. 2018;41(3):409-414. doi:10.1111/jvp.12479
Photo by regipen
Laurie Anne Walden, DVM
Most wild mushrooms aren’t dangerous, but some are fatal if eaten. Keep your pets safe by removing wild mushrooms from their environment.
Because it’s not easy to know if a wild mushroom is poisonous, treat any wild mushroom ingestion as a medical emergency. If your dog or cat eats wild mushrooms, call an emergency animal clinic, your veterinary clinic, or a pet poison hotline right away. Don’t wait until your pet gets sick before you call. Some of the most toxic mushrooms don’t cause symptoms until hours after they’re swallowed.
Pet poison hotlines (fees might apply):
ASPCA Animal Poison Control: 888-426-4435
Pet Poison Helpline: 855-764-7661
Photos of toxic mushrooms in North Carolina:
NC State Extension Gardener Plant Toolbox: mushrooms
Symptoms of mushroom poisoning depend on the type of mushroom and the amount eaten. Toxic mushrooms can be categorized by the type of problem they cause: liver and kidney failure, central nervous system effects, muscarinic reactions, hallucinations, or gastrointestinal irritation.
Liver and Kidney Failure
The mushrooms responsible for the most deaths are in the Amanita, Galerina, and Lepiota genera. Examples are Amanita phalloides (death cap), Amanita bisporigera (destroying angel), and Galerina autumnalis (autumn skullcap).
The toxic compounds in these mushrooms are amatoxins, phallotoxins, or virotoxins. These toxins damage cells of the liver, kidneys, and intestines. The symptoms progress through stages:
Central Nervous System Effects
Mushrooms containing the compounds ibotenic acid and muscimol affect the central nervous system. The mushrooms most often involved in this type of poisoning are Amanita muscaria (fly agaric) and Amanita pantherina. Symptoms usually begin 30 minutes to 2 hours after ingestion (possibly earlier in cats) and include the following:
Muscarine is a substance that affects a specific metabolic pathway in cells of the body. Ingestion of muscarine-containing mushrooms—usually Clitocybe and Inocybe species—causes clinical signs related to part of the nervous system that regulates routine (not conscious) body functions. Symptoms appear a few minutes to a couple of hours after ingestion:
Hallucinogenic mushrooms include those in the genera Psilocybe, Conocybe, Panaeolus, Copelandia, Pluteus, and Gymnopilus. The toxic components are psilocybin and psilocin, which are similar to the drug lysergic acid diethylamide (LSD). Symptoms usually begin within an hour or two after ingestion:
Many mushrooms cause gastrointestinal (digestive tract) problems. The exact toxin in most of these mushrooms is not known. Some of the mushroom genera that cause this type of problem are Chlorophyllum (which often forms fairy rings on lawns), Omphalotus, and Scleroderma. Symptoms usually begin soon after ingestion and improve on their own within a few hours. Most symptoms are mild:
Diagnosing mushroom poisoning is difficult unless the animal is seen eating the mushroom or vomits up pieces of mushroom. Known access to wild mushrooms, compatible symptoms, and physical examination findings can put mushroom poisoning on the list of possibilities. Blood and urine tests are used to assess organ function in dogs with symptoms.
Treatment depends on the symptoms and type of mushroom (if known). Animals exposed to the most toxic mushrooms need early and aggressive treatment to survive. Unfortunately, early treatment isn’t possible if the ingestion was not witnessed and symptoms don’t begin until several hours later.
No antidote is available for mushroom poisoning. The best way to manage the risk is to prevent pets from eating wild mushrooms.
1. Hovda LR. Unfriendly fungi: five groups of mushrooms toxic to pets. DVM 360. Published October 20, 2015. Accessed July 23, 2020. https://www.dvm360.com/view/unfriendly-fungi-five-types-mushrooms-toxic-pets
2. Brownie CF. Poisonous mushrooms. Merck Veterinary Manual. Updated August 2014. Accessed July 23, 2020. https://www.merckvetmanual.com/toxicology/poisonous-mushrooms
3. Cope RB. Toxicology brief: mushroom poisoning in dogs. DVM 360. Published February 1, 2007. Accessed July 23, 2020. https://www.dvm360.com/view/toxicology-brief-mushroom-poisoning-dogs
Photo of Galerina species by Bernard Spragg
Laurie Anne Walden, DVM
Make plans now to keep your pets safe over the July 4 weekend. Large fireworks shows might be canceled this year, but fireworks stores across the state line are open and home fireworks pose risks for pets.
Fireworks in neighborhoods are traumatic for many animals. The loud bangs are random and sporadic, so they’re hard to predict. For pets at home, neighborhood fireworks are louder than big fireworks shows because they’re closer. And fireworks set off by individuals tend to continue for several hours, often over a few days, instead of being limited to the duration of a fireworks show.
Animals startled by loud noises can bolt unexpectedly. Take these steps to keep your pets from getting lost and increase the chance of finding them if they run off:
Noise phobia, or irrational fear of certain noises, is common in dogs and is often triggered by fireworks. Noise phobia goes further than just disliking loud sounds. Animals with noise phobia have reactions that range from hiding under the bed to destroying parts of the house. Some symptoms, like seeking attention, are subtle. This anxiety condition often gets worse with time and can seriously affect an animal’s safety and welfare.
If you think your pet might have noise phobia, call your veterinarian. Your pet might need a combination of short-term treatment (like antianxiety medication) that you can use right away and long-term behavior modification measures. The sooner you address noise phobia, the better it will be for your pet.
Various therapies have been used to help dogs with noise phobia. Some work better than others. A survey published in May 2020 asked dog owners how they managed their dogs’ fireworks fears and how well various techniques worked. The most effective measures, indicated by at least 69% of owners, were counterconditioning (giving the dog something desirable when the noise occurred), prescription antianxiety medication, and relaxation training. Pressure vests and desensitization using fireworks recordings were less effective. Pheromones, nutraceuticals, and herbal remedies worked for the fewest dogs.
Fireworks contain hazardous substances like fuel, oxidizers (for combustion), and heavy metals. If swallowed, these chemicals can cause vomiting, diarrhea, seizures, liver disease, or kidney disease. Lit fireworks and smoke are obviously a risk to animals’ eyes and skin. Keep your pets completely away from new and used fireworks:
1. Riemer S. Effectiveness of treatments for firework fears in dogs. J Vet Behav. 2020;37:61-70.
2. Fireworks. Pet Poison Helpline. Accessed June 19, 2020. https://www.petpoisonhelpline.com/poison/fireworks/
Photo by Andy Thrasher
Laurie Anne Walden, DVM
It’s tempting to share some of the Thanksgiving feast with our pets. Not all human food is safe for dogs and cats, though. The best way to avoid a holiday trip to the emergency clinic is to give pets their usual food and keep table food out of their reach. If you (or your guests) do want to give your pets a little bit of holiday food, though, here are some suggestions that are fine for most dogs and cats.
Keep in mind a few rules of thumb. Don’t give them anything that’s dangerous to dogs and cats: fatty food, bones, raw meat, raw eggs, raisins, grapes, currants, onions, garlic, leeks, raw yeast dough, macadamia nuts, chocolate, and the sugar substitute xylitol. For more, see the posts on Thanksgiving safety for pets and human foods that are toxic to pets.
Unseasoned single-ingredient foods are safer than multiple-ingredient dishes because they’re less likely to contain hidden dangers like onion. Moderation is key; too much of any food can upset a pet’s stomach. And remember that these suggestions don’t apply to pets with food allergies or digestive problems.
A bite of cooked skinless, boneless turkey meat is safe for most dogs and cats. Keep portion size in mind; a 10-lb dog or cat does not need the same amount of turkey that a person would eat. Take these precautions:
Defatted turkey or chicken broth
Pan drippings and gravy are too high in fat for dogs and cats. But a spoonful or two of defatted broth is usually fine for dogs. Don’t give broth to your cat unless you can be absolutely sure it wasn’t made with onions, leeks, shallots, or garlic; try tuna juice instead.
Vegetables and fruits
Dogs like vegetables more than you might think. Avoid grapes, raisins, currants, veggies cooked with fat or butter, and vegetable casseroles (that green bean casserole with the crispy onions on top? no). Stick with plain veggies and fruits, either raw or cooked without seasoning. My own dogs highly recommend all of these:
A small piece of bread, cornbread, or biscuit is generally safe for dogs and cats. Keep unbaked dough out of their reach; raw yeast dough can cause ethanol poisoning. Watch for added fats and seasonings (no onion focaccia or garlic bread). A bite of plain bread is safer than dressing or stuffing, which is likely to contain fat, onion, and possibly raisins or currants. Also avoid store-bought baked goods that might contain artificial sweeteners like xylitol.
For pets eating prescription or limited-ingredient diets
The best approach for pets with medical needs or food allergies is to close them in a room away from the kitchen and dining area. Guests might not realize that these pets have dietary restrictions. If your pet is eating a special diet and you’d like to give treats, ask your veterinarian for safe options. Some prescription diet manufacturers have developed treats that are compatible with their diets.
Photo by Charles 🇵🇭
Laurie Anne Walden, DVM
Chocolate is one of the top 10 animal toxins reported to the ASPCA Animal Poison Control Center each year. As you shop for Halloween candy and get ready for the holiday season, remember to keep the candy bowl and baking supplies out of reach of your dogs. (Chocolate is dangerous for cats too, but they’re less likely than dogs to eat it.)
What’s Toxic About Chocolate?
The main toxic components of chocolate are methylxanthine compounds, specifically theobromine and caffeine. Cocoa beans and their hulls have relatively high methylxanthine levels. Cocoa butter (the fat from the cocoa bean) contains very little methylxanthine.
Humans process methylxanthines in the body at a different rate than dogs do, so foods containing chocolate and caffeine that are safe for people can be very risky for dogs.
As far as toxicity goes, not all chocolate is created equal: some types of chocolate are more dangerous to dogs than others. Products with high concentrations of cocoa liquor, which is made from cocoa beans, are the most toxic for dogs.
In general, the darker the chocolate, the more dangerous it is for dogs. Dry cocoa powder is more toxic than dark sweet chocolate, and dark sweet chocolate is more toxic than milk chocolate. Mulch made from cocoa bean hulls contains theobromine and is unsafe for dogs. White chocolate has very low methylxanthine levels and doesn’t cause chocolate poisoning.
Chocolate-containing foods can be dangerous for dogs for other reasons too. Dogs that eat food with a high fat content—this includes white chocolate—can develop pancreatitis, a disorder of the pancreas. Baked goods and candies may contain raisins, macadamia nuts, xylitol (a type of sweetener), or other ingredients that are hazardous to dogs.
How Much Chocolate Is Dangerous?
The severity of chocolate poisoning depends on 3 factors:
These 3 factors determine the dose of methylxanthine that a dog has received. The higher the dose, the more severe the consequences.
Figuring out the amount of methylxanthine in a chocolate product isn’t always simple because cocoa content varies. You can get a general idea of your pet’s risk by using a chocolate toxicity calculator like the one at veterinaryclinic.com. The ASPCA Animal Poison Control Center has a mobile app that includes a easy-to-use chocolate calculator and information on other potential hazards.
Signs of Chocolate Poisoning
The signs of chocolate poisoning depend on the dose of methylxanthine. Dogs that eat chocolate can also develop pancreatitis (from the fat content) or have toxic effects from other ingredients. Signs of methylxanthine poisoning usually appear within 6 to 12 hours and include the following:
What to Do if Your Dog Eats Chocolate
If your dog eats chocolate or a caffeine-containing product, estimate how much she ate and make a note of the ingredients. Save the product label if possible. Call your veterinarian’s office if you’re not sure if the amount was safe. If your dog has symptoms of chocolate poisoning or if the amount or type of chocolate was dangerous (for example, if your Chihuahua ate a 2-oz bar of dark chocolate), seek veterinary care right away.
Dogs with chocolate poisoning may need to be hospitalized for treatment. Your veterinarian might induce vomiting or might recommend that you do this at home—but don’t try to make your dog vomit without checking with your veterinarian first (induced vomiting is not always the best or safest approach). The prognosis depends on the severity of the symptoms.
Image credit: CDC/Debora Cartegena
Laurie Anne Walden, DVM
Toxins from algae in a pond killed 3 dogs in Wilmington earlier this month. The same type of algae has been found in a public park pond in Charlotte. The only way to know if algae is harmful is by testing the water in a laboratory, so for safety, keep your dog away from all scummy or discolored water.
Harmful Algal Blooms
Algae are tiny plantlike organisms that live in water. Some algae produce toxins that cause serious illness. Under certain conditions, algae grow quickly into collections called algal blooms. Algal blooms are most likely to form in warm water that is high in nutrients like nitrogen. Hot weather and stagnant water increase the chance of algal growth.
Algal blooms can form in either fresh or salt water. The most common type of harmful algae in fresh water is cyanobacteria, or blue-green algae. Another type of algae causes red tide in salt water.
Avoid water with signs of potentially harmful algal blooms:
Symptoms of Exposure
People and animals can be exposed to algal toxins through skin contact with contaminated water, by drinking contaminated water or eating contaminated food (like fish), or by inhaling water droplets in windblown spray. Dogs are typically exposed when they play or wade at the edges of bodies of water with algal blooms.
Not all algal blooms are toxic. But with some types of algae, exposure to only a small amount of toxin can be fatal within hours or days. Algal toxins can damage the liver, nervous system, kidneys, and digestive tract. Symptoms depend on the type of toxin and the amount of exposure and include the following:
What to Do if Your Pet Is Exposed
If your dog comes in contact with questionable fresh or salt water, bathe or at least rinse him off with clean (tap) water right away, before he licks his fur. Take precautions to avoid exposure to yourself; wear gloves or wash your hands after rinsing your dog.
Take your dog to a veterinary clinic if she has swallowed water containing algae or has licked her fur after wading in water with an algal bloom. Symptoms of toxin exposure constitute a medical emergency, so seek veterinary care immediately if your dog is vomiting or stumbling after water contact.
The Centers for Disease Control and Prevention (CDC) and the NC Department of Health and Human Services (DHHS) recommend these precautions:
Cyanobacteria: Protecting Children & Dogs (NCDHHS): https://epi.dph.ncdhhs.gov/oee/algae/protect.html
Harmful Algal Bloom (HAB)-Associated Illness (CDC): https://www.cdc.gov/habs/index.html
Photo source: https://www.usgs.gov/media/images/harmful-algal-blooms-6
Laurie Anne Walden, DVM
A recent study of 114 recipes for homemade diets for cats found that all of the diets were nutritionally inadequate in some way. Most of the recipes, which were either posted online or published in books, were deficient in at least 1 nutrient. Some recipes included ingredients (like onions and garlic) that are toxic to cats. Other studies have found similar problems in recipes for home-cooked diets for dogs.[2-4]
Some pet owners choose to make their own dog or cat food because of a pet with food allergies, a desire to feed natural products, a distrust of commercial pet food, or another reason. Preparing dog and cat food at home is time-consuming and expensive, and owners who undertake it generally just want to take good care of their pets. Dogs and cats rarely require home-prepared diets, but if you decide to make your pet’s food yourself, check the resources for safe recipes at the end of this article.
Potential Problems With Homemade Pet Food
Recipes for home-prepared dog and cat diets are often not nutritionally complete and balanced. Deficiencies in nutrients like iron, taurine, and calcium can lead to anemia, heart disease, and bone disease. Because many recipes are deficient in the same nutrients, rotating among different diets and ingredients won’t necessarily balance the diet.
Home-prepared diets must be supplemented with the right mix of vitamins and minerals. General-purpose multivitamins for dogs or cats are usually not sufficient for pets eating homemade diets. Some vitamin supplements are made for pets eating fortified commercial diets, not those eating homemade diets with lower vitamin and mineral levels.
Oversupplementation is also a possible problem. Too much vitamin D, for example, can damage the kidneys. The choice and amount of nutrients to include in a supplement depend on the ingredients of the chosen diet.
Some homemade diet recipes include potentially unsafe ingredients. Others are based on misconceptions about dog and cat nutrition. Dogs and cats don’t need to eat raw meat, which poses a risk of bacterial contamination for the pet eating it and also for people in the household.[5,6] Bones in the food can damage the digestive tract unless they are ground up. Many recipes (and commercial diets) promote the mistaken idea that there is something wrong with feeding grain to dogs. In fact, grain-free diets might be linked to heart disease in dogs.
Where to Find Recipes
The safest homemade diets for dogs and cats are formulated by board-certified veterinary nutritionists. These specialist veterinarians have extensive training in animal nutrition. Veterinary nutritionists develop recipes for healthy animals and can also customize diets for animals with diseases or specific nutritional needs.
If you use a recipe from a veterinary nutritionist, be sure to follow the recipe and feeding instructions exactly. Ingredient substitutions can change the nutritional balance of the diet.
1. Wilson SA, Villaverde C, Fascetti AJ, Larsen JA. Evaluation of the nutritional adequacy of recipes for home-prepared maintenance diets for cats. J Am Vet Med Assoc. 2019;254(10):1172-1179.
2. Heinze CR, Gomez FC, Freeman LM. Assessment of commercial diets and recipes for home-prepared diets recommended for dogs with cancer. J Am Vet Med Assoc. 2012;241(11):1453-1460.
3. Larsen JA, Parks EM, Heinze CR, Fascetti AJ. Evaluation of recipes for home-prepared diets for dogs and cats with chronic kidney disease. J Am Vet Med Assoc. 2012;240(5):532-538.
4. Stockman J, Fascetti AJ, Kass PH, Larsen JA. Evaluation of recipes of home-prepared maintenance diets for dogs [published correction appears in J Am Vet Med Assoc. 2014;245(2):177]. J Am Vet Med Assoc. 2013;242(11):1500-1505.
5. Freeman LM, Chandler ML, Hamper BA, Weeth LP. Current knowledge about the risks and benefits of raw meat-based diets for dogs and cats. J Am Vet Med Assoc. 2013;243(11):1549-1558.
6. van Bree FPJ, Bokken GCAM, Mineur R, et al. Zoonotic bacteria and parasites found in raw meat-based diets for cats and dogs. Vet Rec. 2018;182(2):50.
Photo by Caroline Attwood on Unsplash
Laurie Anne Walden, DVM
Microchips are a type of permanent identification that helps families reunite with lost pets. Pets should also have visible forms of identification like collar tags, but microchips can’t be pulled off by accident and are an important backup. Microchips are also required in some situations, like transporting animals.
Microchips connect owners to lost pets only if the owner’s contact information is registered in a microchip database. The United States does not have a central microchip registry. Microchip manufacturers and pet recovery services maintain their own databases. It’s essential to keep your contact information up to date in your pet’s microchip database.
If you’re not sure where your pet’s microchip is registered, enter the microchip number in the American Animal Hospital Association microchip lookup tool:
If you don’t know the microchip number, your veterinarian’s office can scan your pet if the number is not already entered in your pet’s medical record.
What Are Microchips?
Microchips are radiofrequency identification transponders about the size and shape of a grain of rice. Microchips are implanted under the skin. In dogs and cats, they are implanted between the shoulder blades. You can’t usually feel a microchip under your pet’s skin, but you can see it on an x-ray image.
A microchip is not a GPS device and can’t be used to track your pet.
How Are Microchips Implanted?
A microchip is injected under the skin through a needle, similar to the way a vaccine is injected (although the needle is a bit larger). Animals do not need anesthesia during microchip insertion. Your veterinarian can implant a microchip during an office visit.
How Does Scanning Work?
Shelters and veterinary clinics routinely scan stray dogs and cats for microchips. If the animal has a microchip and the owner’s information in the database is accurate, the staff can contact the owner.
A microchip scanner emits a low-power radiofrequency signal that activates the microchip. When a microchip scanner passes over a microchip, the chip transmits a number that the scanner displays on a screen. The number is unique to that microchip, so once you’ve registered it, it’s also unique to your pet.
Microchip manufacturers around the world make microchips that use different radiofrequencies. Not all scanners detect all microchip frequencies. Universal scanners read multiple frequencies. Microchips that meet the International Standards Organization (ISO) global standard transmit a specific radiofrequency that can be read by an ISO-standard scanner. Some countries require ISO-compliant microchips for imported animals.
Are Microchips Safe?
The benefits of microchipping are generally far greater than the potential risks. Adverse reactions to microchips are rare. Animals could bleed a little or have mild, short-lived discomfort at the injection site. Infection and swelling at the injection site are possible but not common. Microchips can theoretically cause inflammation that leads to cancer, but almost all reports of cancer near a microchip implantation site have been in laboratory rodents. Only a few cases in cats and dogs have been reported, and in most it was not clear if the cancer was linked to the microchip.
Are Microchips Reliable?
It’s possible for an animal to have a microchip that isn’t found on a scan. A microchip might use a different radiofrequency than the scanner can detect (if the scanner isn’t universal). Microchips occasionally migrate under the skin, usually to the side of the shoulder or front leg. People scanning for microchips typically scan a wide area of the body for this reason. And a microchip might not work at all (or stop working). Ask your veterinarian to check your pet’s microchip at the next clinic visit.
For more information, see Microchipping of Animals FAQ on the American Veterinary Medical Association (AVMA) website.
The AVMA Microchipping of Animals backgrounder page was also a source for this article.
Laurie Anne Walden, DVM
Antifreeze is toxic to animals and people. Even a small amount of antifreeze licked from a paw or lapped from a puddle could kill a cat or dog. If you think your pet has been exposed to antifreeze, contact a veterinarian immediately.
The main ingredient of most types of antifreeze is ethylene glycol, a type of alcohol. Ethylene glycol has a naturally sweet taste.
Protect your pets by keeping them away from fluids that have leaked out of cars. Store antifreeze in sealed containers out of the reach of animals and children. Consider using antifreeze made of propylene glycol instead of ethylene glycol; it’s safer for pets.
Sources of ethylene glycol
Antifreeze (radiator coolant) is used in the engines of cars and other motor vehicles. The risk of exposure might be higher when seasons change and people change the antifreeze in their cars. Dogs have also been poisoned by drinking toilet water that has had antifreeze added to keep it from freezing.
Although antifreeze is the most common source of ethylene glycol poisoning in dogs and cats, ethylene glycol can be present in other products:
Signs of poisoning
The earliest symptoms are caused by the ethylene glycol itself. Symptoms that appear later are caused by toxic substances produced when ethylene glycol is broken down in the liver. The symptoms of poisoning occur in 3 stages.
Stage 1: During the first 12 hours, symptoms are similar to those of alcohol intoxication:
Stage 2: From about 12 to 24 hours after ingestion, the animal may seem to improve as “drunken” symptoms go away. But toxic products of ethylene glycol begin to alter the body’s acid-base balance and damage the kidneys. Signs include the following:
Stage 3: Between 12 and 24 hours after exposure (cats) or 36 and 72 hours (dogs), the kidneys stop working. The patient shows symptoms of acute kidney failure and other problems:
Diagnosis and treatment
A blood test can detect ethylene glycol in the first few hours after ingestion. After a few hours, blood and urine tests begin to show evidence of acid-base disturbances and kidney damage. Diagnosing ethylene glycol poisoning can be tricky if no one saw the pet swallow antifreeze and the pet doesn’t arrive at the veterinary clinic until it is showing signs of kidney failure.
The sooner treatment begins, the better the prognosis. An antidote to ethylene glycol is available and should be given soon after exposure. This drug stops ethylene glycol from being converted to toxic substances. After most of the ethylene glycol has been metabolized by the liver, the antidote is less likely to be effective.
Other treatment is given to correct the body’s acid-base balance and support kidney function. Pets with ethylene glycol poisoning will probably need to stay in the hospital for a few days, even if the poisoning is caught early.
The prognosis is good for animals that begin treatment soon after ingesting antifreeze. For those that develop kidney failure, the prognosis is guarded to poor.
1. Antifreeze poisoning in dogs & cats (ethylene glycol poisoning). Pet Poison Helpline website. https://www.petpoisonhelpline.com/pet-safety-tips/antifreeze-poisoning-in-dogs-cats-ethylene-glycol-poisoning/. Accessed March 11, 2019.
2. Grauer GF. Overview of ethylene glycol toxicity. Merck Veterinary Manual website. https://www.merckvetmanual.com/toxicology/ethylene-glycol-toxicity/overview-of-ethylene-glycol-toxicity. Accessed March 11, 2019.
3. ToxFAQs for ethylene glycol. Agency for Toxic Substances and Disease Registry website. https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=85&tid=21. Published November 2010. Accessed March 11, 2019.
4. Brownie CF. Managing ethylene glycol toxicity (proceedings). DVM360 website. http://veterinarycalendar.dvm360.com/managing-ethylene-glycol-toxicity-proceedings. Published August 1, 2010. Accessed March 11, 2019.
Photo by Ana Silva on Unsplash
Laurie Anne Walden, DVM
Are you tempted to skip your pets' heartworm and flea medicines during the winter? Dogs and cats actually need parasite prevention all year round. Year-round parasite control for pets helps keep the whole family safe from parasite-transmitted disease.
Warm spells during the winter are common in North Carolina, so we can’t count on cold temperatures to suppress insects that carry disease. Mosquitoes, fleas, and ticks can also live through the winter in areas that are protected from the cold.
Heartworms are transmitted by mosquitoes. Mosquitoes become active when the temperature rises above about 50°F (which happens routinely in North Carolina during the winter). But occasional warm winter days aren’t the only reason pets need year-round heartworm prevention.
Heartworm preventives work by killing tiny heartworm larvae that are already in an animal’s bloodstream. These larvae came from mosquitoes that bit the animal in the past month or more. Skipping a month of heartworm prevention could mean that your dog isn’t protected from heartworm larvae that he was exposed to when it was warmer. The American Heartworm Society recommends giving heartworm preventives all year round.
Intestinal parasites (worms)
Some heartworm preventives also control intestinal parasites like hookworms and roundworms. These parasites can infect humans too. Giving parasite prevention to your pets throughout the year is a sensible safety measure.
Fleas don’t just causing itching. They also transmit diseases like cat scratch disease, tapeworms, and plague.
Fleas lay eggs that drop off the infested animal into the environment. This means that flea eggs are present everywhere the animal has been, including inside a home. After the eggs hatch, the larvae and pupae (intermediate stages) can stay dormant for weeks to months before becoming adult fleas.
Because fleas can go through their life cycle indoors, they don’t need to wait for warm weather to develop into adult fleas. Flea infestations are easier to prevent than to treat, so the best chance of avoiding a flea problem is to give your pets year-round flea prevention.
Ticks carry many diseases that affect both pets and people. Some tick species, including the type that transmits Lyme disease, are active during the winter when the temperature is above freezing.
Ticks tend to live in leaf litter, crevices of buildings, and underbrush. When they’re ready to take a blood meal, they move to grassy areas or shrubbery near paths and latch onto a passing animal or person.
Ticks can be hard to see through fur, so you might not realize that your dog has picked up a tick. Because of the risk of serious disease, the safest approach is to limit tick exposure: control ticks around your home and give your pets tick preventives recommended by your veterinarian.
Photo by Justin Veenema
Laurie Anne Walden, DVM
The contents of this blog are for information only and should not substitute for advice from a veterinarian who has examined the animal. All blog content is copyrighted by Mallard Creek Animal Hospital and may not be copied, reproduced, transmitted, or distributed without permission.