If your dog has watery diarrhea that doesn't clear up with typical home care, you might be dealing with coccidia in dogs—a parasitic infection that's more common than you'd think. Here's what every dog owner should know about recognizing, treating and preventing this condition.

Coccidia are microscopic parasites that live in a dog's intestines. They're usually picked up when dogs swallow contaminated soil or water, or sometimes from eating infected prey like mice. Puppies between 4 to 12 weeks old are hit hardest, especially those in crowded environments like shelters or boarding facilities. Adult dogs with weak immune systems can get it too, but healthy adult dogs rarely contract it from infected puppies.

The main sign is watery diarrhea—anywhere from mild to severe. Some dogs show no symptoms at all but still shed the parasite in their stool, which means they can spread it to other dogs. Beyond diarrhea, you might notice vomiting, weight loss, reduced appetite or signs of dehydration. In puppies and small dogs, severe diarrhea from coccidia can become life-threatening if dehydration isn't managed.

Here's something important: if your dog has diarrhea that doesn't respond to home remedies, lasts more than a day or two, contains blood, or comes with other symptoms like fever or vomiting, get them to a vet. Coccidia symptoms can look similar to other serious conditions like giardia or parvo, so professional diagnosis matters.

Diagnosis is straightforward. Your vet will run a fecal float test on a stool sample—they mix it in a special solution to make parasite eggs float to the surface, then examine them under a microscope. There's no at-home test, so a vet visit is necessary.

Treatment typically involves sulfa-based medications like sulfadimethoxine that stop the parasites from reproducing, letting your dog's immune system clear the infection. Newer options like ponazuril and toltrazuril work faster because they directly kill the coccidia. Expect to pay around $40 to $70 for a vet exam, $30 to $50 for the fecal test, and $35 to $100 for medication. Severe cases might require hospitalization, IV fluids and anti-nausea meds, which can run $600 per night or more. Many pet insurance plans cover coccidiosis treatment if it's not pre-existing, so check your policy.

The good news? Most dogs recover well when caught early. The prognosis gets better the sooner you treat it.

Prevention comes down to hygiene and smart habits. Pick up after your dog on walks, avoid areas where other owners don't clean up, skip shared water bowls, and don't let your dog drink from puddles. Choose boarding facilities that maintain good sanitation standards. Annual checks for internal parasites help catch problems early. Dogs adopted from shelters should be tested shortly after coming home.

Coccidia in dogs is treatable and preventable—it just requires attention and basic precautions. If you notice persistent diarrhea in your puppy or dog, don't wait. Getting professional help early makes all the difference.