Cat Diarrhea and Cat Cryptosporidium

Cat diarrhea, or gastroenteritis, is an all too common of a problem in our four legged friends and although many cases are simply an upset intestinal tract, a cryptosporidium infection could be the cause.

A nasty parasite, cryptosporidium is a single celled organism that causes diarrhea by reproducing within the intestinal cells. This eventually kills the intestinal cell and as the number of cryptosporidium increase, the number of intestinal cells killed increases as well, resulting in sometimes severe bloody diarrhea.

Cryptosporidium is based in contaminated water and is in the same family as giardia. Symptoms of cryptosporidium infection include mild to severe watery diarrhea with or without blood, poor appetite, weight loss, abdominal cramping, and lethargy.

The most common diagnosis is a fecal exam but the cryptosporidium oocysts are so small, they are difficult to detect under normal testing and the magnification of microscopes in the average vet clinic. Instead of the usual 'in house' fecal exam, samples should be carefully sent to the lab for special staining and examination. Blood work to detect serum antibodies can often detect exposure to the infection and in rare cases, an intestinal biopsy may be necessary to confirm the presence of the parasite.

Treatment of Cryptosporidium

How severe the disease becomes is dependent on the overall health and immune function of the patient. Some infected individuals will not show any clinical signs of the cryptosporidium infection and are considered carriers. Eventually, the healthy immune system will kill the parasite and you may not have been aware your pet was ever sick.

For young kittens, older cats and cats suffering from a suppressed immune system, the severity of the condition can become life threatening and it is strongly recommended to hospitalize your pet. Dehydration from the diarrhea is as dangerous as the disease and IV fluids may be necessary to balance fluid levels and replace electrolytes.

There are antibiotics that slow down the reproduction of cryptosporidium protozoa, however, the only 'cure' is for the animal's immune system to fight off the disease. In healthy, immunocompetent cats, the disease is self-limiting and a full recovery is possible without medication. Some veterinarians prescribe antibiotics to prevent secondary infections although this practice is controversial as the medication kills the healthy bacteria and intestinal flora, leaving the body less capable of fighting off the parasite.

Life Cycle of Cryptosporidium and How Cats become Infected with Cryptosporidium

Like most parasites, cryptosporidium has a life cycle that involves multiple stages. The non-infectious oocysts are sloughed off in the intestinal tract and then eliminated in the feces. Once the environmental conditions are right, the non-infectious oocysts mature and become infectious (sporulated oocysts). Other cats, dogs, humans, livestock, or rats then accidentally swallow the infectious oocysts and another infection develops. Outdoor cats are more likely to be exposed to infected feces then indoor cats.

The oocysts contain sporozites and sporocysts and once in the intestinal tract, the 'zoites' attack and invade the intestinal cells. These develop into schizonts that release more zoites, then compromising more intestinal cells. These zoites then form gametocytes. The male gametocyte release gametes that fuse with the female gametocytes to form oocysts and the cycle continues.

Cryptosporidium Infection in Humans

Cryptosporidium is easily transferred to humans and, like cats, the immune system normally fights off the infection without any problems. For someone who is immunosuppressed, however, the infection can become life threatening and hospitalization is recommended.

Infected animals should be kept isolated from young children, the elderly and anyone suffering from an immunosuppressed condition such as HIV/AIDS.

How Common is Cryptosporidium Infection

In a study done by on stray dogs and cats in the San Bernardino City and County animal shelters, it was found that 2% of the 200 dogs were carriers, shedding the infectious cryptosporidium oocysts while 5.4% of cats were similarly infected. In itself, it is not a conclusive study as the detectable oocysts are only one part of the life cycle of the parasite and animals may have been infected but the disease was in an undetectable stage. Estimates of 15 to 20% of animals as carriers are considered more realistic.

Cryptosporidium transmission is possible to humans from cats, dogs and livestock. Cryptosporidium, a coccidian protozoon, is the cause of 2 to 6% of self-limiting diarrhea in pediatric cases.

Preventing Cat Diarrhea and Combating a Possible Infection of Cat Cryptosporidium

Cryptosporidium oocysts, the infectious stage of the life cycle, are hardy, resisting bleach and most normal cleansers. Extreme temperatures and prolonged exposure to ammonia is the only effective way to kill the oocysts.

If your cat is diagnosed as a carrier, keep them inside to prevent further infection of other animals. Clean their kitty litter and water dishes regularly with ammonia. Rinse well after cleaning.

Feeding high quality, high fiber food helps regulate the diarrhea associated with cryptosporidium in cats and always provide fresh, filtered water.

Supplements to help support the immune system will shorten the length of the infection and help reduce the impact or severity of the disease. A vital part of your pet's immune system is a healthy digestive tract and will reduce the impact of the cryptosporidium oocysts on the intestinal walls. Adding soil-based probiotics to your cat's daily regime can help prevent this common parasite from infecting your beloved pet.

Cryptosporidium is a common problem amongst outdoor cats and although it can be devastating, supporting your cat's immune system and always feeding her the best quality food can help lessen the overall impact.