Laurie Anne Walden, DVM
Leptospirosis is a disease caused by infection with Leptospira bacteria. The disease is zoonotic, meaning that it can pass from animals to humans. The bacteria are spread through the urine of infected animals and can remain in water or soil for months.
Who’s at Risk
Many different animals can carry Leptospira. Rodents are the most common sources of infection in people. Farm animals, wild animals, and dogs can also be carriers. (Cats are very rarely infected.)
Leptospirosis is a public health hazard for people around the world. People are most often infected through contact with contaminated water, including recreational contact like swimming. Heavy rainfall and flooding increase the risk. Other routes of infection are direct contact with animal urine and contact with contaminated soil or food.[1,2]
Dogs are infected the same way as people: through contact with urine, contaminated soil, or contaminated objects. Dogs can also be infected by eating infected animals. Pregnant dogs can pass the infection to puppies through the placenta.
Dogs are at increased risk for leptospirosis if they have access to any of the following:
Leptospirosis was once considered a disease mostly of working dogs and other outdoor dogs. But small-breed dogs that live in cities and have no access to outdoor water sources are also at risk because rodents carry the disease.
Leptospirosis causes a wide range of problems, including kidney failure, liver failure, lung disease, eye damage, blood clotting disorders, and death. Some dogs infected with Leptospira have mild disease or no symptoms at all. The severity of disease depends on the Leptospira strain and the dog’s immune system, among other factors.
Symptoms of leptospirosis in dogs vary but can include the following:
Leptospira infection can be diagnosed with blood tests. Dogs suspected of having leptospirosis generally also need other tests, such as urinalysis, x-ray examination, and ultrasound.
Dogs with leptospirosis are treated with antibiotics. Most require hospitalization for supportive care and intravenous fluid treatment. The prognosis is good for most dogs that are treated early in the course of disease. Dogs with kidney failure that is not aggressively treated and those with lung complications have a poorer chance of survival.
Dogs with leptospirosis can infect people and other dogs. People handling infected dogs should take precautions like wearing protective clothing and avoiding contact with the urine.
Leptospira vaccines are available for dogs. Talk to your veterinarian about your dog’s risk for leptospirosis. In some geographic areas, veterinarians recommend leptospirosis vaccination for all dogs, including those that live mostly indoors.
Other precautions to reduce the risk of infection are washing hands after handling dogs, wearing gloves when cleaning or collecting dog urine, and using antibacterial solutions to clean surfaces that might be contaminated with urine. The Centers for Disease Control and Prevention recommends avoiding contact with contaminated water (don’t wade barefoot in floodwater!) or wearing protective clothing around potentially contaminated water or soil.
1. Leptospirosis. Centers for Disease Control and Prevention website. https://www.cdc.gov/leptospirosis/index.html. Accessed July 9, 2019.
2. Leptospirosis. World Health Organization website. https://www.who.int/zoonoses/diseases/leptospirosis/en/. Accessed July 9, 2019.
3. Sykes JE, Hartmann K, Lunn KF, Moore GE, Stoddard RA, Goldstein RE. 2010 ACVIM small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment, and prevention. J Vet Intern Med. 2011;25(1):1-13.
Photo by Matt Jones on Unsplash
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
Photo by Ian Badenhorst 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
Fleas don’t just cause itching. They also carry infectious diseases that can be contagious to people. Controlling fleas on your pets protects your whole family’s health.
Tapeworms are parasites that live in the intestines. They shed small body segments called proglottids that pass out of the host animal’s body in the feces. Tapeworm segments in the stool look like whitish rice grains.
Fleas transmit a type of tapeworm that commonly infects dogs and cats. Dogs and cats become infected by swallowing a flea. Tapeworms rarely cause significant disease in dogs and cats.
The dog and cat tapeworm that is carried by fleas, Dipylidium caninum, can also infect humans (usually children) who swallow a flea.
Bartonellosis (Cat Scratch Disease)
Bartonella species are bacteria that cause a variety of diseases in humans and other animals. Cat scratch disease and endocarditis (heart valve infection) are just 2 of the serious illnesses caused by Bartonella infection.
Fleas are the most common insect vector for Bartonella henselae, the species that causes cat scratch disease. Fleas can also carry other Bartonella species. Infected cats and dogs might or might not have any symptoms of infection.
Bartonellosis is a human health risk. Treating your cat with a cat-safe flea preventive reduces the risk of cat scratch disease for people in contact with your cat.
Rickettsiae are a group of bacteria responsible for diseases such as typhus and Rocky Mountain spotted fever. Rickettsiae are spread by arthropods, including fleas and ticks. The types of fleas that infest dogs and cats transmit Rickettsia typhi (which causes murine typhus) and Rickettsia felis. Both of these bacteria can also cause disease in people.[1,4]
Plague, including bubonic plague and the Black Death, is caused by infection with the bacterium Yersinia pestis. The Oriental rat flea (Xenopsylla cheopis) transmits the bacterium usually to rodents but sometimes to cats, dogs, other animals, and humans. Rat fleas in the western United States and other parts of the world still harbor Yersinia.
Cats infected with certain types of Mycoplasma bacteria develop anemia (low red blood cell count). Fleas are thought to be a source of infection for cats.
Fleas cause skin disease in animals that scratch or chew themselves to relieve the itch. Just a few fleas can set off intense itching in an animal with a flea allergy.
Because fleas feed on blood, animals with lots of fleas can develop anemia from blood loss. This anemia can be life threatening.
1. Fleas. Companion Animal Parasite Council website. https://capcvet.org/guidelines/fleas/. Updated September 19, 2017. Accessed May 7, 2019.
2. Bartonella infection (cat scratch disease, trench fever, and Carrión’s disease). Centers for Disease Control and Prevention website. https://www.cdc.gov/bartonella/index.html. Updated December 14, 2015. Accessed May 7, 2019.
3. Shaw SE. Flea-transmitted infections of cats and dogs. World Small Animal Veterinary Association World Congress Proceedings, 2008. Veterinary Information Network website. https://www.vin.com/doc/?id=3866578. Accessed May 7, 2019.
4. Little SE. Feline fleas and flea-borne disease (proceedings). DVM360 website. http://veterinarycalendar.dvm360.com/feline-fleas-and-flea-borne-disease-proceedings. Published April 1, 2010. Accessed May 7, 2019.
5. Lappin MR. Update on flea and tick associated diseases of cats. Vet Parasitol. 2018;254:26-29.
Photo of Oriental rat flea (Xenopsylla cheopis) by James Gathany, CDC
We all know that cats sometimes throw up hairballs. But hairballs aren’t the only reason cats vomit. Don’t assume that vomiting is normal for your cat, even if it’s been going on for months or years.
Consult your veterinarian if your cat has any of these symptoms:
Hairballs (trichobezoars in medical speak) are wads of hair in the digestive tract. Cats swallow loose hair when they lick their fur. Hair usually passes through the digestive tract without causing any problem. But sometimes hair packs together into a mass in the stomach or intestine.
A hairball is usually shaped like a cylinder. If you see one on your favorite rug, you might mistake it at first for feces. Hairballs are often about the same size and shape as a log of cat poop. But if you look at a hairball closely you’ll see that it’s made of tightly packed hair (and it doesn’t smell like poop).
We don’t really know how often cats normally vomit up hairballs. In an informal poll at a cat clinic in England, cat owners reported that nearly three-fourths of their cats had never vomited up a hairball. About 1 in 6 cats expelled a hairball once a year, and 1 in 10 cats expelled a hairball at least twice a year. Owners reported that long-haired cats brought up hairballs more frequently than short-haired cats did.
Hairballs that aren’t vomited up or passed in the stool can block the digestive tract. Symptoms include vomiting, decreased appetite, and signs of belly discomfort (which can be easy to miss in cats). Cats with intestinal blockages may need surgery.
Causes of Hairballs
Healthy cats occasionally bring up hairballs just because they’re cats and they groom themselves. But sometimes hairballs are a sign of another problem. Cats are more likely to have problems with hairballs if they swallow excessive amounts of hair or have a disorder that slows the movement of material through the digestive tract.
Fleas and itchy skin conditions can lead to excessive grooming. Cats also overgroom in response to pain or stress. More grooming means more hair swallowed and an increased chance of hairballs.
The symptoms of digestive tract diseases like inflammatory bowel disease and intestinal lymphoma (a type of cancer) can be mistaken for hairballs. In one study, some cats with hairballs blocking the intestines also had serious intestinal disease. These diseases affect the way food and hair move through the digestive tract and may put cats at higher risk of hairballs. Hairballs can also irritate the digestive tract, causing inflammation.
Ask your veterinarian before treating your cat’s vomiting or hacking with over-the-counter remedies or hairball diets. Hairballs might not be responsible for the symptoms.
Brushing the coat to remove loose hair is safe and might be all that’s needed to reduce hairballs in healthy cats. Long-haired cats that regularly bring up hairballs may benefit from having their fur trimmed.
If you’re noticing more hairballs than usual, ask your veterinarian to check your cat for underlying problems. If the symptoms point to an intestinal disease, your cat might need a series of diagnostic tests (such as bloodwork, ultrasound, and possibly a biopsy of the intestines).
1. Cannon M. Hair balls in cats: a normal nuisance or a sign that something is wrong? J Feline Med Surg. 2013;15(1):21-29.
2. Norsworthy GD, Scot Estep J, Kiupel M, Olson JC, Gassler LN. Diagnosis of chronic small bowel disease in cats: 100 cases (2008-2012). J Am Vet Med Assoc. 2013;243(10):1455-1461.
Photo by Karin Laurila
Laurie Anne Walden, DVM
Adult heartworms grow up to a foot long, block blood flow around the heart, and cause inflammation within blood vessels. The damage continues as long as the heartworms remain in the body.
Heartworm treatment protocols for dogs are designed to remove the worms while reducing the risk of treatment complications. No safe heartworm treatment exists for cats and ferrets. Your veterinarian can recommend appropriate heartworm preventives for your dog, cat, or ferret.
Heartworm infection is diagnosed with a blood test. Your veterinarian might confirm the diagnosis with another test before proceeding with treatment.
Other tests, like x-ray imaging, echocardiography (heart ultrasound), and other blood tests, are used to assess the extent of damage. The results can affect the treatment plan, so your veterinarian might recommend these tests even if your dog isn’t showing any symptoms of infection. Dogs with blood clotting problems or signs of heart disease need a full diagnostic workup before treatment starts.
Any activity that increases the heart rate and blood pressure can worsen the problems caused by heartworms. Dogs with heartworms need to stay as quiet as possible to limit the damage. Once treatment begins, pieces of dead worms can break off and lodge in small blood vessels, potentially causing serious problems and even death. Strict exercise restriction is the best way to reduce the risk.
The American Heartworm Society (AHS) recommends restricting activity from the time heartworms are diagnosed until 6 to 8 weeks after the last dose of heartworm treatment. Dogs should ideally stay indoors in a small area where they can’t run or jump. Some dogs need to be confined to a crate. They should go outdoors on a leash only long enough to pee and poop. Ask your veterinarian about the level of confinement your dog needs.
Before Killing the Heartworms
Before dogs begin receiving adulticide (medication that kills adult heartworms), they may need treatment for heartworm-related problems. They should receive a certain type of heartworm preventive to remove larvae, or immature worms, from the bloodstream. They also benefit from a monthlong course of doxycycline, an antibiotic, to eliminate a bacterium that lives inside heartworm cells. This bacterium is partly responsible for the inflammation that occurs when heartworms die.
The AHS recommends that dogs start adulticide treatment 2 months after receiving a heartworm diagnosis (30 days after the last dose of doxycycline). Dogs should have limited activity during these 2 months.
The only adulticide currently approved for use in the United States is melarsomine. This drug is given by injection in a veterinary hospital. Your dog may need to stay in the hospital for observation after a melarsomine injection.
The number and timing of injections may vary depending on the situation. The current AHS recommendation is to give a series of 3 injections: 1 injection followed by a 30-day wait, then 2 injections given 24 hours apart. Your veterinarian will suggest a protocol that’s appropriate for your own dog.
Complete exercise restriction is crucial during adulticide treatment and for several weeks after the last dose. Your veterinarian may also prescribe medications to reduce adverse effects of treatment.
Your dog can be retested for heartworms several months after the last melarsomine injection. The goal of treatment is to remove all stages of heartworms.
Protocols to manage heartworm infection without using melarsomine are sometimes called “slow-kill” treatments. These protocols consist of giving doxycycline for a month and beginning a specific type of heartworm preventive to remove larvae. Heartworms take from several months to a year or more to die with these protocols.
The disadvantage of slow-kill treatment is that it allows adult heartworms to remain in the body for much longer than with adulticide treatment. The worms continue to damage the heart and blood vessels during this time. For this reason, the AHS does not recommend this method as standard treatment. Dogs receiving slow-kill treatment should also have exercise restriction for as long as adult heartworms remain in the body.
The advantage of slow-kill treatment is that it costs much less than melarsomine. Slow-kill methods have been proposed for dogs that would otherwise go untreated or be euthanized, like those in shelters or in areas where melarsomine is not available. Slow-kill treatment also offers an option for dogs at high risk of complications from adulticide treatment.
For More Information
See these resources from the American Heartworm Society:
Battling Boredom: Tips for Surviving Cage Rest (PDF)
Heartworm Positive Dogs: What Happens if My Dog Tests Positive for Heartworms?
Heartworm Treatment Guidelines for the Pet Owner (PDF)
Photo by Ryan McGuire
Laurie Anne Walden, DVM
Hypertension (high blood pressure) is fairly common in older cats. The condition can cause serious health problems but is treatable. Senior cats and cats with kidney or thyroid disease benefit from routine blood pressure screening.
High blood pressure is silent; it has no symptoms of its own. But high blood pressure damages organs of the body, causing symptoms that cat owners might notice.
In cats, hypertension is usually caused by another disorder. The most common causes in cats are chronic kidney disease and hyperthyroidism (overactive thyroid). Sometimes high blood pressure in cats seems to develop on its own with no known cause, as can happen in humans. Older cats are more likely than younger cats to have hypertension.
Blood pressure measurement
Current guidelines recommend measuring blood pressure in cats in these categories [2,4]:
In cats, blood pressure is usually measured with an inflatable cuff similar to the cuffs used in people (but much smaller!). The cuff is placed around a leg or the tail. During the procedure cats can lie down or sit upright, whichever is more comfortable for them. Most operators try to position the cuff at the level of the heart, but forcing a cat to lie down can cause agitation and raise the blood pressure.
Blood pressure readings are most accurate in calm cats. You might be asked to wait with your cat in the examination room for a few minutes to give her time to settle down and get comfortable. Consider bringing a cat bed, blanket, or towel from home so your cat can rest on something familiar during the procedure. Blood pressure is typically measured several times during each session to account for variation from motion or anxiety. Cats tend to tolerate the procedure well.
A systolic blood pressure below 140 mm Hg is considered normal in cats. (In blood pressure readings like “110/70 mm Hg,” systolic pressure is the first number and diastolic pressure is the second number). A systolic blood pressure of 160 mm Hg or higher indicates hypertension and an increased risk of organ damage.
Veterinarians often measure blood pressure on more than 1 clinic visit before making a definite diagnosis of hypertension. Cats’ blood pressures can vary from visit to visit depending on their stress levels. However, signs of organ damage can confirm the diagnosis and justify starting treatment after only 1 measurement session. Cats with hypertension (or at risk for hypertension) should have blood pressure checks every few months.
The goal of treatment is to reduce the risk and extent of organ damage. The underlying problem causing the high blood pressure is treated at the same time. Most cats with hypertension receive daily oral medication. The dose is adjusted as needed after blood pressure rechecks. Medication is usually effective in reducing the blood pressure, especially if the underlying disease is also controlled.
1. Syme H. Systemic hypertension: World Small Animal Veterinary Association World Congress Proceedings, 2013. VIN website. https://www.vin.com/doc/?id=5709837. Accessed March 25, 2019.
2. Taylor SS, Sparkes AH, Briscoe K, et al. ISFM consensus guidelines on the diagnosis and management of hypertension in cats. J Feline Med Surg. 2017;19(3):288-303.
3. Quinn R. Cardiovascular effects of systemic hypertension in cats. MSPCA Angell website. https://www.mspca.org/angell_services/cardiovascular-effects-of-systemic-hypertension-in-cats/. Accessed March 25, 2019.
4. Acierno MJ, Brown S, Coleman AE, et al. ACVIM consensus statement: guidelines for the identification, evaluation, and management of systemic hypertension in dogs and cats. J Vet Intern Med. 2018;32(6):1803-1822.
Photo by Hunt Han
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
Chronic kidney disease is common in cats. It can affect cats at any age but is most common in older cats. The disease has no cure. The goals of treatment are to slow the progression of the disease and maintain a good quality of life for the cat.
Functions of the Kidneys
The kidneys filter the blood and excrete waste products into the urine. When the kidneys don’t work properly, these waste products accumulate in the body. The kidneys balance the body’s water level by adjusting the urine concentration. Kidney disease impairs the ability to concentrate the urine and retain water in the body, so animals with kidney disease become dehydrated. The kidneys also help regulate blood pressure, red blood cell production, and acid-base balance.
Signs of Kidney Disease
Kidney disease is already advanced (at least two-thirds of kidney function lost) by the time signs of illness appear. Cats typically have the following signs:
Keep an eye on the size of the urine clumps in your cat’s litter box. Enlarging urine clumps can mean that urine volume is increasing, which is one of the earliest signs of kidney disease. Other disorders (like diabetes) can also increase the urine volume, so larger-than-usual urine clumps warrant a visit to the veterinarian.
As chronic kidney disease progresses, the loss of kidney function leads to further problems:
Causes of Kidney Disease
Acute kidney injury is a rapid loss of kidney function over hours to days. Some of the many possible causes are toxins, infections, and shock. Depending on the cause and severity, acute kidney damage can sometimes be reversed with treatment.
Chronic kidney disease is more common than acute kidney injury in cats. In chronic kidney disease, kidney function gradually decreases over time. The cause is usually not known. The same entities that cause acute kidney injury can lead to chronic kidney failure. Other possible causes are high blood pressure, abnormal kidney development, infection or inflammation of the kidneys, disorders that alter blood flow to the kidneys, and cancer.
Tests are used to diagnose kidney disease, assess the stage of the disease, identify metabolic problems caused by the disease, diagnose other disorders (like thyroid disease) that cats with kidney disease sometimes also have, and possibly reveal the cause of the kidney problem.
Blood tests and urinalysis (analysis of urine) are typically the first diagnostic tests for cats with suspected kidney disease. Blood pressure measurement, urine culture to test for bacterial infection, and ultrasound or x-ray imaging of the urinary tract are also commonly performed for cats with kidney disorders.
Cats with chronic kidney disease benefit from regular testing to monitor disease progression and adjust treatment. In general, these cats should see a veterinarian for blood tests, urinalysis, and blood pressure measurement every 3 to 6 months.
The stage and substage of chronic kidney disease are evaluated with specific tests:
Chronic kidney disease can’t be cured, but it can be managed. The prognosis is variable; some cats can live with the disease for years. If your cat has kidney disease, work with your veterinarian to craft a treatment plan that will give your cat a good quality of life.
Treatment strategies are based on the stage of disease and the individual cat’s needs and may include the following[1,4]:
1. Sparkes AH, Caney S, Chalhoub S, et al. ISFM consensus guidelines on the diagnosis and management of feline chronic kidney disease. J Feline Med Surg. 2016;18(3):219-239.
2. Brown SA. Renal dysfunction in small animals. Merck Veterinary Manual website. https://www.merckvetmanual.com/urinary-system/noninfectious-diseases-of-the-urinary-system-in-small-animals/renal-dysfunction-in-small-animals. Accessed February 26, 2019.
3. International Renal Interest Society. IRIS staging of CKD. http://www.iris-kidney.com/pdf/IRIS_2017_Staging_of_CKD_09May18.pdf. Updated 2017. Accessed February 26, 2019.
4. International Renal Interest Society. Treatment recommendations for CKD in cats. http://www.iris-kidney.com/pdf/IRIS_2017_CAT_Treatment_Recommendations_09May18.pdf. Updated 2017. Accessed February 26, 2019.
Photo by Nicolas Picard on Unsplash
Laurie Anne Walden, DVM