Toxoplasmosis is a parasitic disease of cats. It is the cause of severe diarrhea which can cause the death of young animals. It is an important disease because the parasite can infect humans and cause abortions in pregnant women. However, with good hygiene and a few simple preventive actions, the risks can be greatly reduced.

Toxoplasmosis is a disease caused by a protozoan parasite called “Toxoplasma gondii”. This parasite is part of the large family of coccidia. It has a particular life cycle, involving two animal species: the cat, and any other species.

Indeed, a toxoplasma egg can contaminate almost all living animal species. The parasite will then hatch and pass through the cells of the digestive tract. Once in the body of its host, it will diffuse everywhere via the blood and lymph and will be able to divide. This division of the parasite will produce cysts filled with parasite. 

The cat is the only animal species that can develop toxoplasmic coccidiosis, also called “toxoplasmosis of the cat”. It can become infected by ingesting a contaminated egg or meat containing a cyst. The parasite will then multiply sexually in the cat’s digestive tract and produce eggs, called oocysts. These eggs are then excreted in the cat’s faeces. They are extremely resistant in the environment and it is often difficult to get rid of them.

So, there are two ways to get infected:

• by eggs, present in the feces of the cat;
• by cysts, especially during the ingestion of undercooked meat of a contaminated animal.

Apart from the cat, contamination is asymptomatic in all animal species.

When it infects a young cat, the parasite will penetrate and destroy the cells of the intestine which will cause diarrhea by lack of absorption of nutrients and a fairly marked loss of water. At first, the diarrhea is mild, with a little mucus, and the stools appear “slimy”. As the infection increases, the diarrhea becomes sharp and hemorrhagic, with the appearance of “gooseberry jelly”. One then observes an attack of the general state of the cat which is slaughtered, and a rather marked dehydration. It is this dehydration linked to diarrhea that can be fatal in young animals. Often, secondary bacterial infections can be added which causes fever and darkens the prognosis of the animal.

In adult cats, the infection often goes unnoticed. Toxoplasmosis is then asymptomatic or manifests itself only by loose stools. However, the parasite reproduces anyway in these adults who then become real time bombs. They start to excrete a large number of oocysts which will then infect the young.

The diagnosis of toxoplasmosis is made by a veterinarian. Diarrhea in a young cat living in a community or having undergone stress (weaning, adoption) should make us think about it. Another evocative sign is the observation of heterogeneous litters, with animals of very different size and weight. Particular care should be taken in farms where cases of toxoplasmosis have already been reported because recontaminations are frequent.

Care should be taken not to confuse toxoplasmosis-related diarrhea with dietary diarrhea due to weaning, adoption, with viral, bacterial and other diarrhea of ​​parasitic origin. For this, coproscopy is an essential examination to make the diagnosis. When the animal is contaminated, we will then be able to observe oocysts present in number in the animal’s stool. The number of eggs present is directly related to the severity of the infestation.

There are two treatments for toxoplasmosis in cats. They need to be put in place as early as possible to be fully effective. Medicines are of two types:

• Coccidiostats, that is to say antiparasitic drugs that will block the development of new parasites. These are effective treatments, but relatively expensive, which are therefore recommended for treating a single animal.
• Coccidiocides, which are drugs that kill the parasite. At present none of these drugs are intended for cats. They are however occasionally used to treat flocks as they are sold in large quantities and are relatively cheaper than coccidiostats.

Symptomatic treatments must necessarily be associated with these drugs. In particular, it is necessary to treat the diarrhea with intestinal dressings and to be able to rehydrate the animal. It is also imperative to put in place health measures. In fact, toxoplasma eggs are extremely resistant and can cause relapse by recontamination from the environment.

In prevention, it is important to ensure the good hygiene of the premises in which the young animals are raised. In particular, it is necessary to be able to quickly remove all the excrement which is one of the main sources of contamination in breeding. It is also necessary to think about combating the intermediate hosts which can carry toxoplasma cysts and to avoid as much as possible their contact with cats (mice, birds, etc.). Finally, you should avoid giving raw or undercooked meat to animals to avoid contamination by cysts that may be present.

Pregnant women should be particularly careful not to come into contact with the parasite. Indeed, during a primary contamination on a pregnant woman, the parasite can be transmitted to the fetus and be the cause of an abortion. Once it has come into contact with the parasite, the human body will produce antibodies to defend itself. This is why the doctor often performs a serology in order to check for the presence of these antibodies to find out if the woman has already been in contact with the parasite. 

If antibodies are present then the body will have the capacity to defend itself against infection and the parasite does not pose much risk to the pregnancy. On the other hand, if no antibody is present then the parasite will be able to contaminate the woman and possibly migrate to the fetus.

If a pregnant woman has never been in contact with the parasite, it will be necessary to be vigilant to the different sources of contamination. However, it is not necessary to separate from your cat. Above all, care must be taken not to touch the cat’s excrement, and therefore its litter box. If this is necessary, then it should be done while wearing a mask and gloves to avoid contamination. It is also advisable to clean your vegetables well, especially if they must be eaten raw, because they sometimes carry oocysts. Finally, it will be necessary to cook its meat well to neutralize any cysts that may be present.