Passing soft or almost liquid foul smelling stool is very common in dogs. Dietary indiscretion is the most common cause of diarrhea. Our four legged friends have the inclination to eat too much and to eat things and substances that are not supposed to be eaten. Diarrhea can be due to a bad case of worm infestation or a side effect of taking medications. Diarrhea is not a disease in itself. The passing of soft stool is oftentimes an indication of an underlying illness. Diarrhea is the classic sign of coccidiosis.

Coccidia are small one celled parasitic organisms that live in the dog’s intestinal tract. Isospora Canis and Eimera are two genera commonly known as coccidian. Different species of these microscopic protozoal parasites cause diseases that are known collectively as coccidiosis. These intestinal diseases that vary in virulence infect dogs, cats, rodents and many other animals. Due to an undeveloped immune system, puppies that are less than 6 months old are most affected. Coccidiosis is also seen in adult dogs with immune system that is weakened by an existing illness or stress.

Stress, a change in environment, an illness or another parasitic infection can trigger coccidia infection. This is why puppies would commonly have coccidiosis after being weaned and transferred to a new home. Adult dogs can manifest clinical signs of coccidiosis if boarded in overcrowded kennels. The stress of long plane or car rides as well as unsanitary living conditions can spur the coccidia in the dog’s digestive tract to cause infection. This does not mean though that the puppy or an adult dog already has the parasite in its intestines. Coccidia protozoa are not present in the puppy’s intestines at birth. An infected mother dog that sheds infective cysts will transmit the organism to the puppies. Adult dogs can get infected by eating feces of infected dogs. These parasitic organisms can end up in the dog’s intestines, when coccidia carrying cockroaches and mice are ingested.

An infected dog would show clinical signs about two weeks after it was exposed to the parasites. These protozoal parasites multiply rapidly causing major damage to the intestinal walls when the cells of the dog’s intestinal lining rupture. A dog can have mild or severe diarrhea. In some dogs, coccidiosis would seem to have no effect at all. Passing loose stool would be over after a few days. Aside from diarrhea, the dog would show no other symptoms. On the other hand, a severely infected dog would pass watery stool that has considerable amounts of blood and mucus. Reduced food consumption will consequently result to weight loss. The condition will worsen if the dog refuses to eat altogether. Death from dehydration or from secondary diseases such as pneumonia is a possible outcome of severe infection.

Coccidia are opportunistic organisms. These organisms will take advantage of conditions that put the dog under stress. Coccidiosis is treatable but diagnosing the infection can be a challenge. Diagnosis is done through fecal examination. However, oocytes may not be found in the fecal sample even if the infection is severe. It may be necessary to examine a sample of the stools excreted for the last 48 to 72 hours. Sulfadimethoxine and trimethoprimsulfadiazine are the common drugs used for the treatment of coccidian. But instead of killing the organisms, these drugs would only hamper coccidia’s ability to reproduce. Rapid elimination of the parasite from the dog’s internal tract is not possible. The dog may have to go through several courses of the sulfa-based antibiotic to ensure that the organisms are totally wiped out. Supportive veterinary care in the form of IV fluids will be necessary if infection is severe. This highly infectious disease can be prevented with strict sanitation. Feces must be removed as soon as excreted. Dogs usually develop immunity to these parasites but while the pet is still a puppy precautionary measures against this infection will be necessary.