Understanding Coccidia: Causes, Symptoms, Diagnosis, and Treatment

Coccidia are intestinal parasites that can cause significant health issues, especially in young or immunocompromised animals. Knowing how to identify, treat, and prevent coccidia is crucial for your pet’s well-being.


What Are Coccidia?

Coccidia are tiny, single-celled organisms classified as protozoa—not worms. This distinction is important because common deworming medications are ineffective against them. The species of coccidia that infect dogs and cats are primarily from the genus Isospora.

Coccidia are host-specific, meaning they can only infect their specific host species. For example:

  • Dogs with coccidia spread it to other dogs, not to cats or humans.
  • Cats with coccidia spread it only to other cats.

While some animals show no symptoms, untreated coccidia infections can lead to severe complications, particularly in puppies, kittens, and animals with weakened immune systems.


Symptoms of Coccidia Infection

Coccidia damage intestinal cells after they are swallowed, releasing stages that invade and harm the lining. Symptoms of infection include:

  • Diarrhea: Often slimy and sometimes with traces of blood.
  • Weight Loss: A noticeable decrease in body weight.
  • Loss of Appetite: The animal may eat less or refuse food entirely.
  • Vomiting: This can occur in more severe cases.
  • Slimy Stool With Blood: A common and concerning symptom (see pictured example if applicable).

How Coccidia Are Transmitted

Coccidia spread through feces, making proper hygiene crucial to preventing infection. Transmission occurs when:

  • Animals swallow contaminated soil, water, or other substances.
  • Dogs or cats sniff or inhale near feces from an infected animal.
  • Animals eat infected small prey, such as lizards or rodents.

Sporulated coccidia (the infectious form) can survive in the environment for up to a year, which makes reinfection a persistent concern in shared spaces or outdoor areas.


Diagnosing Coccidia

Coccidia infections are diagnosed through a fecal examination:

  • A stool sample is examined under a microscope for the presence of coccidia.
  • False negatives can occur, meaning the parasite may not be detected even if the animal is infected.

For this reason, veterinarians may recommend treating ongoing symptoms even if initial fecal tests come back clear. Some animals with coccidia may also appear asymptomatic but still carry the parasite.


How to Treat Coccidia

Treating coccidia requires specific medications that target protozoa, such as:

  1. Toltrazuril: This effective treatment can be ordered online. Many breeders and pet owners keep it on hand for preventative care.
  2. Veterinary Prescription Medications: Drugs like sulfadimethoxine (Albon) may be prescribed by your vet or ordered online as well.

Key Points About Treatment:

  • Treatment duration can vary from a few days to several weeks, depending on the severity of the infection but will most often be a course of 5-10 days
  • Reinfection is common if the environment is not thoroughly sanitized during and after treatment so clean thoroughly with cleaners that kill coccidia. Most average cleaners will not 

Sanitation Tips:

  • Remove feces promptly from yards and litter boxes.
  • Disinfect hard surfaces with a pet-safe cleaner.
  • Use hot water and soap to wash bedding, toys, and food bowls.

Preventing Coccidia

Because coccidia are resistant to many preventives, regular treatment and environmental hygiene are essential. Here’s how to protect your pets:

  • Preventative Treatment: Treat every few months with Toltrazuril or other recommended medications.
  • Clean Environment: Sanitize areas where pets eat, sleep, and play to reduce contamination.
  • Monitor Symptoms: Keep an eye out for diarrhea, weight loss, or other signs, especially in puppies and kittens.

Where to Find Coccidia Treatments

You can easily order effective treatments like Toltrazuril online. For convenience, I’ve included links to trusted sources in my Shopping List. These are products I’ve used and recommend to ensure your pets stay healthy and happy.


By understanding the risks of coccidia and taking proactive measures, you can protect your pets from this common yet potentially harmful parasite. If you have any questions or need further advice, don’t hesitate to reach out—I’m here to help!