Coccidia in Dogs: Symptoms, Treatment, and Prevention

Does your dog tend to eat feces? While not a dinner-table topic, it’s a common behavior. Beyond being unpleasant, it puts your dog at risk of parasites.  

Feces can harbor many parasites, and some are more harmful than others. Coccidia are one such type of parasite, which are often seen in puppies and are a common cause of diarrhea.  

Let’s look at what this parasite is, how vets diagnose and treat it, and what you can do to protect your pup.  

What Is Coccidia in Dogs?

Coccidia infections in dogs are caused by a microscopic, single-celled protozoan in the genus Cystoisospora.  

These parasites are found throughout the environment and are host-specific—meaning the dog-affecting species infect other dogs rather than people. Infection (coccidiosis) damages the intestinal lining and can cause diarrhea and vomiting.  

After an infected dog passes parasite eggs (oocyst) in their stool, they develop into an infective stage in the environment within hours to days.  

When another dog ingests them, the parasite invades that dog and multiplies within the cells that line their intestinal tract. Eventually, infected cells rupture, releasing more coccidia into the intestines. Over time, so much damage occurs that symptoms develop.  

Coccidiosis is not usually a medical emergency, but in immunocompromised, small, or young dogs, it can become life-threatening. It’s important to have your dog examined by their vet once symptoms occur. 

Symptoms of Coccidia in Dogs

Often there are no symptoms of coccidia in dogs.  

However, pups that do experience symptoms often have mild to moderate gastrointestinal issues, such as: 

• Abdominal discomfort 

• Dehydration 

• Diarrhea, sometimes with blood and excess mucus 

• Decrease in appetite  

• Lethargy 

• Vomiting 

• Weight loss 

While rare, coccidiosis can cause anemia and even death in small or young dogs.  

Causes of Coccidia in Dogs

Dogs become infected with coccidia by ingesting contaminated feces, food, or water, or by eating infected rodents or insects.  

Puppies who are typically under 6 months of age are commonly affected and more likely to exhibit symptoms. Coccidiosis in healthy adult dogs is rare. 

Coccidia infections are also more frequent in overcrowded, stressful environments with poor sanitation and nutrition. Breeding facilities and shelters may see more cases than average.  

How Veterinarians Diagnose Coccidia in Dogs

Veterinarians diagnose coccidia in dogs using a fecal examination.  

A fresh fecal sample is mixed with a solution, centrifuged, and “floated,” allowing oocysts to rise to the top of the test tube to be placed on a microscope slide and examined.  

Because dogs may shed the parasites intermittently, frequent stool exams may be required to detect the oocysts. 

Alternatively, your vet may also submit feces to a diagnostic laboratory for a more comprehensive exam, including fecal culture and/or PCR panel to identify causes and rule out other potentially harmful parasites. 

Dogs presenting with severe illness may require additional tests such as blood work. 

Treatment of Coccidia in Dogs

Not every dog infected with coccidia requires treatment, but for many, medication is effective at clearing the infection. 

Your veterinarian may prescribe sulfadimethoxine (Albon) or ponazuril, which are commonly used to treat coccidiosis. 

Treatment typically requires a multi-day course of medication, and some cases may need weeks or even repeated treatments.  

Recovery and Management of Coccidia in Dogs

If your pet is seriously ill from coccidia in dogs, they may require hospitalization, IV fluids, and supportive care.  

Fortunately, most dogs can be treated on an outpatient basis, with their medications given at home. Your vet may require a follow-up exam and repeat fecal test to ensure the infection has cleared.  

Environmental control is important. Oocysts are resistant to most disinfectants and can survive for months (up to a year), including through freezing. In the home, steam cleaning of surfaces, and dilute bleach are effective disinfectant agents.  

It’s important to note that dogs can reinfect themselves. Bathing can reduce oocysts on the coat and help limit contamination of the environment.  

Additionally, all bedding material, food and water bowls, and toys should be disinfected or disposed of properly. 

Prevention of Coccidia in Dogs

As a pet parent, you can prevent coccidia in dogs by doing the following: 

• Pick up feces promptly. Oocysts require several hours to become infective; prompt removal of feces can prevent re-exposure and transmission of the parasite.  

• Wash your dog’s paws and behind before coming inside to reduce tracking into the house. 

• Prevent scavenging and hunting. Discourage eating feces and control access to rodents and insects. Maintain effective pest control.