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
Roundworms are some of the most common internal parasites in dogs and cats. They can also infect humans. According to the Centers for Disease Control and Prevention (CDC), 13.9% of people in the United States have antibodies to roundworms, meaning they have been exposed to the parasite at some point in their lives.
How dogs and cats are infected
Almost all puppies are born with roundworms. The type of roundworm that most often infects dogs, Toxocara canis, transfers from a mother dog to unborn pups through the placenta. T canis can also pass to puppies through the mother’s milk. Infected animals excrete roundworm eggs in their stool, so dogs can be infected by eating feces or swallowing roundworm eggs in the environment. Dogs can also become infected by eating a small animal (like a rodent) that is carrying roundworms.
The most common roundworm in cats is Toxocara cati. Cats and kittens are usually infected by swallowing roundworm eggs in the environment or by eating an infected animal. T cati does not pass to unborn kittens through the mother’s placenta.
Ingested T canis and T cati eggs hatch into larvae in the intestines. The larvae migrate through body tissues to the lungs, are coughed up and swallowed, grow into adult worms in the intestines, and begin producing eggs that pass into the environment through the feces.
Roundworm larvae can remain dormant in body tissues of adult animals instead of maturing in the intestines. These arrested-development larvae can’t be detected by fecal tests for worm eggs because they don’t produce eggs. Dormant larvae in a pregnant dog can become active and move through the placenta to the pups. In other words, a female dog with a negative test for roundworms can pass roundworms to her puppies anyway.
Signs of infection
Infected animals often have no symptoms at all. Dogs and cats (especially puppies and kittens) with lots of roundworms may develop a potbelly, vomiting, diarrhea, weight loss, or dull coat. Heavily infected animals sometimes vomit worms, which look a bit like spaghetti noodles, or pass worms in the stool.
Treatment and prevention in pets
Young puppies and kittens should receive multiple doses of deworming medication. The Companion Animal Parasite Council recommends deworming puppies and kittens every 2 weeks starting at age 2 weeks for pups and 3 weeks for kittens, continuing until they are about 2 months old, and then beginning monthly parasite preventives. Many heartworm preventives also prevent roundworm infection.
To reduce the chance your pets will be infected, remove feces from the environment and try to keep them from eating rodents or other wild animals. Have your veterinarian regularly test your pets for parasites, and give them parasite preventives all year round.
Infection in humans
People can be infected by T canis or T cati if they ingest contaminated dirt or feces. Toxocara eggs can survive in the soil for years. Children and people who own dogs or cats have an increased risk of infection, says the CDC.
Many people with Toxocara infection don’t develop serious disease and have no symptoms. But T canis and T cati larvae can migrate through the bodies of humans, as they do in dogs and cats. Larvae that migrate to internal organs (such as the liver) damage these tissues, a disease process called visceral larval migrans or visceral toxocariasis. Symptoms depend on the organs affected. Sometimes larvae migrate to the eye, causing a disease known as ocular larval migrans or ocular toxocariasis. People with this condition may develop retinal inflammation and vision loss.
Prevention in humans
The CDC recommends these steps to prevent toxocariasis:
For more information
Ascarid (Companion Animal Parasite Council)
Cat Owners: Roundworms and Dog Owners: Roundworms (Pets and Parasites)
Toxocariasis FAQs (CDC)
Photo by Berkay Gumustekin
Laurie Anne Walden, DVM
Tooth root abscesses are painful and need prompt treatment, but the signs can be easy to miss. Dogs don’t always show that their mouths hurt, and tooth abscesses can mimic other conditions.
Tooth root abscesses are pockets of pus caused by bacteria that invade the deep structures of the tooth. They often occur in teeth with severe periodontal disease or gingivitis (gum disease), especially if the gum has receded around the tooth.
Teeth that are cracked or fractured are also at risk for root abscesses. Teeth can fracture when a dog chews on something hard, like a bone, cow hoof, ice cube, hard nylon toy, or rock. Fractures that expose the pulp cavity (the inner part of the tooth) give bacteria a route to the tooth root.
The upper fourth premolar—the large cheek tooth on each side of the upper jaw—is a common site of root abscess. This tooth, also called the carnassial tooth, is used to crush food. When a dog crunches something hard, a carnassial tooth can sustain a slab fracture (shearing off a slab from the side of the tooth) or can crack down the center. The roots of the carnassial tooth reach nearly to the eye, so an abscessed root causes swelling just below the eye.
Root abscesses can occur in any tooth. The large canine (fang) teeth are frequently broken and are also common sites of root abscesses.
Although tooth root abscesses are very painful, dogs’ signs of mouth pain can be subtle. Some dogs don’t show any symptoms at all. Signs of a tooth root abscess can include the following:
A veterinarian may be able to find evidence of a tooth root abscess during examination of an awake patient. However, dogs with tooth root abscesses sometimes have too much mouth pain to allow much of an oral examination without sedation.
Diagnosis often requires dental radiographs (x-ray images) or at least a full oral examination with the patient under anesthesia. Dental radiographs sometimes reveal tooth root abscesses that can’t be seen any other way.
Untreated tooth root abscesses cause prolonged pain and tooth loss. The infection can spread to other tooth roots and to the face, potentially even affecting the eye.
Dogs with tooth root abscesses need antibiotics and pain relief. The source of the infection must also be removed. There are 2 options for treating an abscessed tooth root:
If you think your dog might have a tooth root abscess, make an appointment with your veterinarian as soon as possible. Your veterinarian will examine your dog and, if the signs indicate an abscess, will probably prescribe an antibiotic and an analgesic (pain reliever).
The next step will be either another appointment with your veterinarian for tooth extraction or referral to a dental specialist for possible root canal therapy. Both extraction and root canal therapy require general anesthesia.
If you would like your dog to keep his tooth, root canal treatment is the best option. Antibiotics alone are rarely enough to treat a root abscess. However, not all teeth are candidates for root canal therapy. The dental specialist will evaluate dental radiographs to see if root canal treatment is a good option and will extract the tooth if necessary.
Sometimes tooth root abscesses are unavoidable. But you can take some measures to reduce your dog’s risk:
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