Coccidia in Dogs – How They Get It And What You Can Do To Help

coccidia in dogs

Coccidia is a single-celled organism. When they infect the digestive tract of a dog, the resulting illness is called coccidiosis. Symptoms of coccidiosis in dogs typically include diarrhea and vomiting. There are actually several types of coccidia, but the type that tends to make dogs sick is the isospora species. It is interesting to note that coccidia can live in your dog’s intestinal tract without causing any illness at all. This is called a subclinical infection. However, if your dog becomes sick as a result of a coccidia infection, it is called a clinical infection.

Coccidiosis sounds a little scary, but with the right care and management, it is an illness that most dogs will get through. Practical measures, such as keeping your dogs surroundings clean and limiting your dog’s contact with other animals that may be carrying the infection, are ways you can help your pooch avoid the infection altogether.

How Do Dogs Get Coccidiosis?

Coccidia can infect your dog when the dog eats the spores of the parasite. And the most likely place for these spores to be lurking, is in the poop of other dogs. Or on surfaces that have been contaminated by poop.

Is Coccidia in Dogs Contagious?

Coccidia is contagious to other dogs in that an infected dog is likely to be passing coccidia spores. But not in the sense that your dog can catch it if another dog breathes on them.

Your dog needs to eat and swallow some spores in order to become infected.

Coccidiosis infections are more common in areas where many dogs are congregated in the one spot. Areas such as in boarding kennels or amongst populations of stray dogs are hot spots.

Coccidia can infect other pets too, such as cats or rabbits, but the parasite is species specific, so your dog won’t infect your cat, and vice versa.

What Are Coccidia Spores?

In this article we talk about ‘spores’ and the coccidian ‘oocyst’. This is the name given to one stage of the parasite’s life cycle. At this stage of the life cycle, the parasite has a thick, hardy outer wall, and is passed in the feces of infected individuals.

Coccidia Life Cycle

As coccidia multiply inside an infected dog, they begin to pass the coccidian oocysts in their poop. These oocysts are pretty tough and can survive for months exposed to the elements. But they are not infective immediately. In fact, these oocysts need to reach temperatures above 20˚C before they can sporulate (produce spores), so infected poop sitting out in the sun presents the perfect conditions for the oocysts to sporulate and spread.

A dog can ingest a sporulated oocyst in a couple of ways. They may pick up the oocyst as they forage and sniff around, as dogs like to do. For this reason, stray dogs are at a higher risk of picking up the infection as they must find food for themselves. Another way dogs can ingest the oocysts is by eating an infected paratenic host, such as a rabbit or a mouse. Paratenic hosts are animals that carry the infection but have no symptoms themselves.

Once the dog has ingested the oocysts, the oocysts ‘excyst’, and produce sporozoites which then take up lodging inside the dog’s digestive tract. From this point on, your dog still may not manifest clinical symptoms of coccidiosis unless they become stressed or have a severe infection.

Signs of Coccidia in Dogs

When a dog becomes infected with coccidia, the main sign is diarrhea. At times, there might also be some blood present in the stool. However, if the infection progresses, or the dog is already weak or immunocompromised, then the symptoms can become severe and the outcome can be fatal. In addition to watery diarrhea, at times with the presence of blood, more serious symptoms include anorexia, vomiting, and depression.

Often, a clinical manifestation of coccidiosis will occur when an animal is under stress, such as a change of ownership, moving to a new house, or a long journey which the animal does not enjoy.

How Do I Know If My Dog Has Coccidia?

Coccidia is one of many possible causes when a dog develops diarrhea. It is always advisable to see the veterinarian if your dog has severe or persistent diarrhea. Your veterinarian will be able to help with diagnosis and keeping your pet hydrated.

Coccidia can be identified under a microscope, which enables your veterinarian to prescribe the right treatment for your dog. So they will probably ask you to collect a stool sample from your dog, which will be sent off to the laboratory. You should have the results back in a few days.

Treating Coccidia in Dogs

Your vet may prescribe sulfonamides such as sulfadimethoxine to treat coccidiosis. This class of antimicrobials has been around for a long time. They have long been used by veterinarians to treat a variety of diseases found in animals. These medicines, sometimes in combination with other drugs, have been found to effectively reduce the number of oocysts present in the patient. And to help affected dogs gain bodyweight.

Aside from giving your pooch the medication your veterinarian prescribes, it is important to keep fluids up if your dog has been suffering from diarrhea. Your vet may recommend additional treatments to assist with rehydration. Another important step you can take is to keep the area your dog lives in clean. This helps avoid reinfection, which can happen if the oocysts are left hanging around.

Recovering From Coccidia

A diagnosis of coccidia is bound to be worrying, but the prognosis is usually pretty good. If your dog has become infected with coccidiosis but is otherwise healthy and is receiving the appropriate treatment, they should recover without any long term effects.

Coccidia in young dogs and puppies, is common. A severe coccidian infection is more concerning for both puppies and senior dogs. They may not have the immune system levels needed to bounce back if the infection is left untreated.

Clinical coccidiosis in adult dogs can be associated with other illnesses or stress. Therefore, if your dog has fallen ill with coccidiosis, it is worth checking that your dog is not suffering from another, unrelated condition that is causing them to become immunocompromised.

Prevention of Coccidia in Dogs

There are some practical measures that dog owners can take to reduce the risk of their dog contracting coccidiosis. Remember that your dog has to swallow infective oocysts in order to become sick. This means licking or eating poop or surfaces contaminated with poop.

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Be meticulous about picking up after your dog and disposing of their feces safely. Other measures include keeping your dog’s drinking water clean, and generally practicing good hygiene.

Coccidia is preventable with good hygiene practices. Keeping dogs contained and away from areas heavily contaminated with dog poop and from free ranging dogs will help to prevent infection. But keeping your yard clean and immediately scooping any poops is the number one method.

coccidia in dogs

References and Further Reading

The Labrador Site Founder

Pippa Mattinson is the best selling author of The Happy Puppy Handbook, the Labrador Handbook, Choosing The Perfect Puppy, and Total Recall.

She is also the founder of the Gundog Trust and the Dogsnet Online Training Program 

Pippa's online training courses were launched in 2019 and you can find the latest course dates on the Dogsnet website


  1. I was wondering if my puppy who is on medication for coccidia will reinfect himself? It’s day 2 of his medications and he just pooped and ate it back again. I’m wondering if he will need to stay on the medication for an extra day or 2 because of this? Please help. Thanks. Faith Scott

  2. My 2 Pyrenees/Husky mixes, both 5 years old, were just diagnosed with coccidia and one also with hookworm. They began treatment today. Both are very healthy and take monthly Heartgard and NexGard. We just boarded them for 4 days at a cageless open kennel; however they were also found eating feral cat feces on our country property. What I’m trying to figure out is how they got it – from the open kennel where at one point they were with 13 other dogs; or from the cat feces. Any ideas??

  3. My 8 week old puppy is suffering now of Coccidia. Assuming he had this when we bought him from the breeder. He’s at the vet now. Praying he pulls through

    • pamela Christian, my name is Denise Older. I am wondering if your 8 week old pup pulled through the Coccidia infection that he had last July. I am currently going through the same ordeal with my 6 week old Mastiff mix and I’m very concerned about him pulling through it. He has been a fighter so far but it’s been about 5 days now of sickness and I’m not sure how much more he can take