Coccidia in Dogs and Cats
Laurie Anne Walden, DVM
Coccidia are tiny parasites that live in the intestines. Coccidia infection is common in dogs and cats, most often affecting puppies and kittens. Infection can cause severe disease and even death, especially in young animals, although some infected animals have no symptoms at all.
Coccidia are protozoa, which are single-celled organisms. They are not worms, and deworming medications do not remove coccidia. Different species of coccidia infect different animals. Coccidia that infect dogs and cats are in the genus Isospora. Other types of coccidia infect other mammals (including humans), birds, fish, reptiles, and amphibians.
Unlike some parasites, coccidia that infect dogs and cats are not contagious to humans. Coccidia are host specific: they cause disease only in their own host species, not in animals of other species. Dogs with coccidia spread the disease to other dogs but not to cats or humans. Cats with coccidia spread the disease only to other cats.
Coccidia that infect dogs and cats are transmitted through feces. Dogs and cats are usually infected by swallowing contaminated soil or other contaminated substances in the environment. They can also be infected by eating a small animal (like a rodent or insect) that serves as a transport host or vector for Isospora organisms.
Coccidia in the feces are not infective right away. The life stage that passes out of the body in the stool is immature (nonsporulated). After a few hours in the environment, this stage matures to the sporulated stage, which can infect other animals. Sporulated coccidia can survive in the environment for a year.
After sporulated coccidia are swallowed, they release other stages that invade cells of the intestines. Damage to the intestinal cells is responsible for the symptoms. Puppies, kittens, and adult animals with compromised immune systems are at most risk for serious illness. These are some of the symptoms:
Coccidia are diagnosed by examining a sample of feces under a microscope. Sometimes infected animals have false-negative test results (no coccidia seen even though the animal is infected), so animals with symptoms might need repeated fecal tests to diagnose the cause of illness. Coccidia can also be found in the feces of animals with no symptoms.
Coccidia infection is treated with medication from a veterinarian. Complete treatment may take a few days or a few weeks, depending on the severity of infection. Sanitation of the environment reduces the chance of reinfection during treatment, especially for animals in group housing.
Medications that remove hookworms, roundworms, and other common dog and cat parasites do not affect coccidia. Heartworm, flea, and tick preventives also do not remove or prevent coccidia.
Because coccidia in stool aren’t infective for a few hours, removing feces from the environment regularly (at least once a day) helps prevent infection. Keeping cats indoors reduces or eliminates their exposure risk. Preventing dogs and cats from hunting rodents and other animals also reduces their chance of infection from transport hosts. All dogs and cats—and especially puppies and kittens—should have periodic fecal tests by a veterinarian.
1. Coccidia. Companion Animal Parasite Council. Updated October 1, 2016. Accessed February 19, 2021. https://capcvet.org/guidelines/coccidia/
Photo by David Clarke
Periodontal Disease in Dogs and Cats
Laurie Anne Walden, DVM
Periodontal disease (disease of structures that support the teeth) is one of the most common medical problems of dogs and cats. This condition, which leads to bone loss around the tooth roots, causes the teeth to loosen and fall out.
Although periodontal disease can be painful, animals often don’t show any outward symptoms until the disease is advanced. Periodontal disease may also increase the risk of heart, liver, and kidney problems. Regular dental care at home and periodic dental cleanings under anesthesia are the best ways to prevent periodontal disease.
Periodontal disease is caused by bacteria in the mouth—or more specifically, the body’s immune response to bacteria. Oral bacteria produce plaque, a sticky substance that coats the teeth. If not removed, plaque hardens into tartar. Bacteria, plaque, and tartar near the gumline activate the immune system, causing inflammation.
The earliest stage of oral inflammation is gingivitis, or inflammation of the gums. Periodontal disease is more severe inflammation that affects the bone and other tissues around the tooth roots. Gingivitis is reversible with professional dental cleaning (including under the gums) and home dental care. Periodontal disease, which destroys the structures holding the teeth in place, is not reversible.
The biggest risk factor for periodontal disease is the presence of plaque and tartar on the teeth. Other things that increase the risk are genetics, older age, crowded teeth, thin bone around the teeth (for example, in toy dog breeds), poor nutrition, and possibly medical conditions that reduce resistance to infection. A study of 109 otherwise healthy cats found that all of them had some degree of periodontal inflammation.
Dogs and cats can have remarkably bad dental disease without showing any symptoms of discomfort. Unpleasant mouth odor might be the only symptom that pet owners notice. Because periodontal disease affects the tooth roots, it’s hidden from view in the early stages. It’s more obvious once bone has been lost to the point that the tooth roots are exposed or teeth start falling out.
The symptoms, if any, begin with symptoms of gingivitis and get worse as the inflammation becomes more severe:
Very advanced periodontal disease causes changes that can be seen on oral examination of an awake animal. Diagnosing earlier stages and assessing the extent of the disease require examination with the animal under anesthesia. The diagnosis is made by examining the entire mouth, probing the gums to find pockets of inflammation/infection, and taking dental radiographs (if available) to get a look at the tooth roots and the surrounding bone.
Treatment and Prevention
Gingivitis and early stages of periodontal disease are managed with dental cleaning under anesthesia followed by home dental care. Anesthesia is necessary because plaque and tartar must be removed from the parts of the teeth under the gums. Scraping tartar off the teeth of an awake animal is not enough. It makes the teeth look better, but it does nothing to treat the real problem and can make things worse by delaying a more thorough cleaning.
Teeth with later stages of periodontal disease are treated surgically. The procedure used depends on the stage of disease and the condition of the bone. Sometimes a tooth can be saved with an endodontic procedure like a root canal, but in many cases extraction of the tooth is the best option.
Plaque starts to form on teeth again soon after a dental cleaning, so regular home dental care is ideal. Brushing the teeth with pet (not human) toothpaste is the standard of care for animals that allow it. Many other products to help remove dental plaque are available. See the blog post on dental home care for some ideas and talk to your veterinarian about products that would work for your pet.
1. Wallis C, Holcombe LJ. A review of the frequency and impact of periodontal disease in dogs. J Small Anim Pract. 2020;61(9):529-540. doi: 10.1111/jsap.13218
2. Girard N, Servet E, Biourge V, Hennet P. Periodontal health status in a colony of 109 cats. J Vet Dent. 2009;26(3):147-155. doi: 10.1177/089875640902600301
Photo by Chris Smith
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.