What are coccidian infections in dogs and should you be worried?

Actually, if you have a puppy with watery diarrhea, that won’t gain weight, and losing his appetite, then coccidian infections in dogs is definitely something to be concerned about.

Coccidia 101

You’ll be familiar with the concept of bacterial or viral infections, but what about coccidian infections? The latter are a tiny parasite, consisting of just one cell: A whole heap of trouble right there in a single cell!

This microscopic organism can adapt to survive in the environment for up to 12 months (given the right conditions) and is picked up by dogs when they snuffle around in the dirt.

Once infected, not all dogs become ill. An adult dog with a healthy immune system can often suppress the parasite and not show symptoms. However the downside is they may well go on to excrete the coccidian and pose an infection risk to other dogs.

However, puppies are a different matter. With their weak immune systems a coccidian infection often results in unpleasant diarrhea, stomach cramps, poor appetite, and weight loss. This isn’t great news for any pup, with the weakest ones at risk of developing potentially life-threatening dehydration as a complication.

Happily, once infection is identified it can be treated with antibiotics and a thorough cleansing of infected surfaces.

Now you have an overview of coccidian infections and why they matter, let’s consider it in more detail.

Who Is at Risk of Coccidiosis?

First things first, does your dog pose a risk to you or the family cat?

No.

Coccidian infections tend to be species specific, meaning dogs are infected by Isospora canis, which is a species only infectious to other dogs. Cats have their very own variety of Isospora species which is infectious to other felines but not to dogs or people. And we humans have our own species specific coccidian infections. (Not that this means you can be lax with personal hygiene, because you must always wash your hands before eating, especially after stroking or handling a pet.)

Isospora canis is passed out in the dog’s feces in a protected or ‘encysted’ form. Being made up of one-cell makes coccidia vulnerable, so to get around this they survive in the environment in a tough capsule, along with several hundred of their buddies for company. It is this cyst that, in the right weather conditions, can survive 12 months in the environment.

Dogs pick up infection when they consume a cyst containing the isospora. Once swallowed, the cyst can survive stomach acid, but breaks open in the intestine which is the target area for this coccidian parasite to set up camp.

Guess what? The Coccidia completes its lifecycle in the gut and excretes the next generation of encysted coccidian in the dog’s poop. Hey presto! Ongoing infection.

Dogs are most likely to swallow these cysts when they lick their fur (after walking on infected soil), eat dirt or accidental hosts such as rodents. It takes around 7 to 11 days from eating the cyst to develop symptoms such as diarrhea.

Signs of Infection

Coccidia disrupt gut function and most of the signs are gastro-intestinal, such as:

• Diarrhea: This is often water and streaked with blood or mucus
• Occaisional vomiting
• Poor appetite
• Weight loss
• Dehydration as a result of severe diarrhea

These dogs are often ‘under the weather’ rather than very suddenly sick, as happens with parvovirus. The diarrhea can drag on, despite sensible attempts to control it by feeding a bland diet and probiotics. Most otherwise healthy adult dogs will develop immunity after 2 or 3 weeks and the symptoms will then subside.

However, puppies are especially vulnerable as their weak immune systems and little body reserves to protect them against fluid are lost in diarrhea. Any puppy with diarrhea should see a vet promptly, since it is often the dehydration that is life-threatening, rather than the original cause of the diarrhea. Whereas an adult may be able to withstand three weeks of watery diarrhea, this could place a puppy at grave risk so treatment is essential.

Diagnosis and Treatment of Coccidia in Dogs

A positive diagnosis is made by analyzing a fecal sample and spotting the coccidian under the microscope. However, this isn’t foolproof as it depends on coccidian being present in that particular poop sample, whereas in reality coccidian are shed intermittently making false negative results a possibility.

Therefore, if your vet is suspicious of a coccidian infection based on the clinical signs, they may opt to treat it even though a fecal sample tests negative. This is especially sensible since treatment involves a five day course of antibiotic from the sulpha family and has few, if any, side effects.

In addition, from a control perspective it’s important to wash the pet’s bedding, food and water bowls, and steam clean any surfaces the dog contacts in the house. This is to prevent reinfection and eliminate the shed of coccidian cysts that are lurking on surfaces, ready to reinfect the dog.

With this in mind it’s also a good idea to bathe the dog at the beginning and the end of treatment, in order to cleanse away any cysts clinging to the fur.

Prevention is Better than Cure

Prevention is all about good hygiene and promptly removing poop from the yard so that it doesn’t pose an infection risk. Also, keep the dog’s bowls and bedding clean, helps reduce the risk of infection from cysts in the environment.

The take home message is that coccidian infections are common and easily treatable. However, any diarrhea in a puppy should be taken seriously, so always seek prompt veterinary attention. It’s also wise to remember that diarrhea is only a symptom, and not a diagnosis in its own right, therefore it’s wise to get any sick animal checked out by a vet.