There are several types of parasites, but here are the most common ones.

What is Coccidiosis?

Coccidiosis is a parasitic infection caused by the coccidia parasite. It is an intestinal infection caused by a one-celled organism, or protozoan, called coccidia. In cats and dogs, the most common coccidia are Isospora felis and Isospora rivolta.

Coccidia are not parasitic intestinal worms; they are microscopic parasites that live within the cells of the intestinal lining.

Because they live in the intestinal tract and most commonly cause diarrhea, they are often confused with worms. They most commonly cause watery, mucus-based diarrhea in animals.

If left untreated, it can damage the lining of a cat’s intestinal tract over time. However, with appropriate and prompt treatment, the prognosis is good.

Oocysts, or immature coccidia, are passed in the stool of an infected cat. They persist in the environment and eventually sporulate and mature into a more developed oocyst capable of re-infecting the cat or dog. Other cats, dogs, and rodents in the household might also become infected.

This process can occur in as little as six hours, but it usually takes 7 to 10 days.

If the sporulated oocysts are ingested, they mature in the animal’s intestine to complete the life cycle. If a mouse ingests the oocysts, a cat may become infected by eating the infected mouse.

Giardia spp.

Giardia spp. are single-celled parasitic protozoa found in the intestines of cats and many other animals. These microscopic parasites either attach to the intestinal wall or swim freely within the mucous lining of the intestines.

Approximately four percent of pets in North America are expected to be infected with Giardia. Cats under three years old are more frequently infected than older cats.

Life cycle of Giardia

Giardia occurs in two forms:

A motile feeding stage, known as a trophozoite, lives in the intestine alongside a non-motile stage.

The cyst forms as the parasite is swept through the intestine, just before it is excreted in the faeces. Cysts are fully developed when the enclosed protozoan divides, producing two daughter organisms.

Daughter trophozoites are released when cysts are accidentally ingested.

Once the parasites are released, they repeatedly increase their numbers by dividing in half.

What is giardia?

Giardiasis is an intestinal infection affecting both humans and animals, caused by the protozoan parasite Giardia intestinalis (also known as Giardia lamblia). Giardia is a simple, single-celled parasite; it is neither a worm, bacteria, nor a virus. This parasite is found worldwide and is a common cause of “traveler’s diarrhea” in people.

Outdoor enthusiasts who inadvertently drink contaminated water may develop “beaver fever,” another name for giardiasis in humans. Other protozoan parasites that can cause enteric (intestinal) diseases include coccidia, cryptosporidium, and toxoplasma.

The Giardia organism has two forms. A fragile, feeding form exists in the infected person’s gut. A hardy cystic form is shed in faeces and can survive for several months in the environment, particularly in water and damp conditions.

Giardiasis can be a significant cause of diarrhoea in both animals and humans. However, many cats are infected without showing clinical signs, or their diarrhoea is treated as non-specific.

Giardia infection in pets is undoubtedly more common than recognized or diagnosed cases.

The parasite has a one- to two-week incubation period. Most cats are asymptomatic, although they may continue shedding cysts for months or years. Clinical signs are most likely to be seen in younger animals from multi-cat households.

Tritrichomonas Foetus

Tritrichomonas foetus is a microscopic, single-celled, flagellated protozoan parasite long recognized as a cause of reproductive disease in cattle, including infertility, abortion, and endometritis.

Tritrichomonas foetus is another infectious organism that causes diarrhea in feline patients, typically those with a history of group living. This organism was once believed to infect only cattle, where it causes miscarriage and fertility issues; however, in 2003, T. foetus emerged as an infectious agent in cats. Information and recommendations regarding this organism have evolved over the last several years, and we aim to provide the most up-to-date summary of what is known and recommended for the prevention and treatment of this infection.

1. The fetus is shed in the feces of an infected cat. Transmission most commonly occurs when cats share a litter box, as the organism can survive for up to three days in fecal material. Whenever a cat steps in the feces of an infected cat, the organism can adhere to its paws and later be ingested during grooming.