Toxoplasmosis in Cats

Cats have long been cherished as beloved companions to millions of people worldwide. These furry feline friends bring joy, comfort, and companionship to our lives. However, like all animals, cats can carry diseases that may pose risks to both them and their human owners. One such disease is toxoplasmosis, a parasitic infection that has garnered attention due to its potential implications for pregnant women and individuals with compromised immune systems. In this article, we will explore toxoplasmosis in cats, its causes, symptoms, and how to manage and prevent it.

What is Toxoplasmosis?

Toxoplasmosis is a disease caused by a protozoan parasite known as Toxoplasma gondii. This microscopic parasite is capable of infecting a wide range of warm-blooded animals, including birds and mammals, but its primary host is the cat family (Felidae), which includes domestic cats.

How Common is Toxoplasmosis in Cats?

While T. gondii seldomly causes significant symptoms in healthy adults either (see below for exceptions), the Centers for Disease Control and Prevention (CDC) has recently identified toxoplasmosis as one of five neglected parasitic infections of people due to its high prevalence. More than 60 million people in the U.S. are thought to be infected.

It is estimated that a significant percentage of domestic cats have been exposed to Toxoplasma gondii at some point in their lives. This exposure can vary by region and environmental factors. Cats can shed Toxoplasma oocysts in their feces for a short period (usually 1-2 weeks) after they are first infected. After this initial shedding, most cats develop immunity and no longer shed the parasite. The risk of transmission to humans is highest during this shedding phase. In some areas, a higher percentage of cats may be infected due to environmental factors, while in others, the prevalence may be lower.

What Causes Toxoplasmosis in Cats?

Cats become infected with Toxoplasma gondii through various means, including:

• Ingesting infected prey: Cats that hunt and consume small mammals, birds, or other infected animals can contract toxoplasmosis. The parasite's life cycle depends on the cat as its definitive host.

• Ingesting oocysts: Toxoplasma gondii can also be transmitted through ingestion of oocysts, which are the environmentally resistant forms of the parasite. Cats can shed oocysts in their feces, contaminating the environment. Humans and other animals can become infected by accidentally ingesting oocysts through contact with contaminated soil, water, or food.

Signs of Toxoplasmosis in Cats

Most healthy cats infected with Toxoplasma gondii do not exhibit any noticeable symptoms. In some cases, mild gastrointestinal issues like diarrhea or vomiting may occur, but these symptoms are generally transient and self-limiting.

However, toxoplasmosis can be more serious in cats with weakened immune systems, such as kittens, elderly cats, or those with concurrent illnesses. In such cases, symptoms may include:

• Loss of appetite

• Lethargy

• Difficulty breathing

• Jaundice (yellowing of the skin and eyes)

• Neurological signs such as tremors or seizures

• Inflammation of the eyes

It's important to note that while cats can be infected with Toxoplasma gondii, they are not the primary source of human infections. Human infections typically occur through ingestion of oocysts from contaminated food, water, or soil, or through consumption of undercooked or raw meat containing tissue cysts of the parasite.

Can You Get Toxoplasmosis From Breathing in Cat Litter?

Toxoplasmosis is a disease caused by the parasite Toxoplasma gondii. While it is commonly associated with cats, especially their feces, the primary mode of transmission is not through inhalation but rather through ingestion of the parasite.
While it is possible to get Toxoplasmosis from handling cat litter, the risk is relatively low. The oocysts in cat feces take at least one to five days to become infectious after being shed, so if you clean the litter box daily and maintain good hygiene practices (e.g., washing your hands thoroughly with soap and water after handling cat litter), the risk of transmission is minimized.

To reduce your risk of Toxoplasmosis when handling cat litter:

• Clean the litter box daily to reduce the time oocysts have to become infectious.

• Wear disposable gloves while cleaning the litter box.

• Wash your hands thoroughly with soap and water after handling cat litter or soil that could be contaminated with cat feces.

• Avoid ingesting contaminated soil, water, or food.

• If you are pregnant or have a weakened immune system, consider having someone else handle cat litter, if possible.

Toxoplasma Gondii Life Cycle

Toxoplasma gondii has a complex life cycle involving multiple stages and hosts. The life cycle of Toxoplasma gondii can be summarized as follows:

• Definitive Host: Cats are the definitive host of Toxoplasma gondii.

• Intestinal Reproduction: Inside the cat's intestine, the parasite undergoes sexual reproduction, leading to the formation of oocysts.

• Oocyst Shedding: Oocysts, which are environmentally resistant, are shed in the feces of infected cats.

• Environmental Survival: Oocysts can survive in soil, water, and other environments for months to years.

• Intermediate Hosts: Various warm-blooded animals, like rodents, birds, and livestock, can become intermediate hosts by ingesting oocysts from the environment.

• Tissue Cyst Formation: Inside the intermediate host, the oocysts release sporozoites, which invade the host's cells and develop into tissue cysts. These cysts primarily contain bradyzoites.

• Transmission to Cats: If an intermediate host is consumed by a cat (through predation or scavenging), the tissue cysts are digested in the cat's digestive system.

• Transformation in Cat: In the cat's intestinal epithelial cells, the bradyzoites transform into tachyzoites, the rapidly dividing form of the parasite.

• Multiplication: Tachyzoites can multiply and form new tissue cysts inside the cat's intestine, completing the cycle.

• Oocyst Shedding (Again): Oocysts are then shed in the cat's feces, starting the cycle over again.

Treatment of Toxoplasmosis in Cats

Before treatment, the cat needs to be diagnosed. Toxoplasmosis in cats can be challenging to diagnose because clinical signs are often non-specific. Diagnosis typically involves a combination of clinical signs, blood tests (serology), and occasionally, fecal or tissue sample analysis. In more severe cases of toxoplasmosis, or when clinical signs are evident, veterinarians may prescribe medications to treat the infection. The primary drug used for treating toxoplasmosis in cats is clindamycin. This antibiotic can help control the parasite and reduce its impact on the cat's health.

Treatment for toxoplasmosis in cats typically involves medications that target the protozoan parasite. The choice of medication and the duration of treatment depend on the severity of the infection and the cat's overall health. Common medications used to treat toxoplasmosis in cats include:

• Clindamycin: Clindamycin is an antibiotic that is often used to treat toxoplasmosis in cats. It can help reduce the multiplication of Toxoplasma gondii within the cat's body.

• Sulfadiazine and Pyrimethamine: This combination of medications is sometimes used in severe cases of toxoplasmosis. Sulfadiazine inhibits the growth of the parasite, while pyrimethamine interferes with its ability to reproduce.

• Trimethoprim-Sulfamethoxazole: This combination antibiotic is another option for treating toxoplasmosis in cats and can be used as an alternative to clindamycin or in combination with it.

Ingredients Sulfadiazine

Does Toxoplasmosis Go Away in Cats?

Yes, in many cases, a cat's immune system will mount a response to the Toxoplasma gondii parasite, and the infection will go into a dormant or chronic phase. In this state, the cat may carry the parasite for an extended period without showing any symptoms or with mild, intermittent symptoms. The cat's immune system can keep the infection in check, preventing it from causing illness.

In some instances, particularly in cats with weakened immune systems, the infection may not resolve on its own, and the parasite can remain active, leading to ongoing health issues. Kittens and cats with compromised immune systems (e.g., due to Feline Immunodeficiency Virus or Feline Leukemia Virus) are at a higher risk of developing severe forms of toxoplasmosis.

Long-Term Effects of Toxoplasmosis in Cats

If treatment is not finished or if the cat owner fails to recognize the symptoms and does not promptly initiate treatment, the prolonged neglect may result in lasting consequences.

Here are some potential long-term effects of toxoplasmosis in cats:

• Chronic Infection: Cats that have been infected with Toxoplasma gondii may carry the parasite in a dormant or chronic state for an extended period. While many cats with chronic infections remain asymptomatic, some may experience intermittent or mild symptoms, such as diarrhea or weight loss.

• Immune System Effects: Toxoplasmosis can affect a cat's immune system. Cats with weakened immune systems, such as those with Feline Immunodeficiency Virus (FIV) or Feline Leukemia Virus (FeLV), may be more susceptible to severe or recurrent toxoplasmosis infections.

• Ocular Toxoplasmosis: In some cases, toxoplasmosis can affect the eyes of infected cats, leading to a condition known as ocular toxoplasmosis. This can result in inflammation of the retina, leading to vision problems or blindness in severe cases.

• Neurological Effects: Toxoplasmosis can affect the central nervous system in cats. Neurological symptoms may include seizures, lack of coordination, and behavioral changes. These symptoms can occur as a result of the parasite affecting the brain and spinal cord.

• Reproductive Effects: Toxoplasmosis can have implications for pregnant cats. If a pregnant cat becomes infected with Toxoplasma gondii, the parasite can potentially infect the developing fetuses, leading to congenital toxoplasmosis in kittens. This can result in stillbirths, birth defects, or kittens born with clinical signs of toxoplasmosis.

How to Prevent Toxoplasmosis in Cats?

Preventing toxoplasmosis in cats involves several measures

• Feeding commercial cat food: Feeding cats commercial cat food instead of allowing them to hunt for prey can reduce their risk of infection.

• Keeping cats indoors: Indoor cats have a lower risk of contracting toxoplasmosis compared to outdoor cats, as they are less likely to hunt and ingest infected animals.

• Providing clean litter boxes: Regularly cleaning and disinfecting litter boxes can reduce the chances of oocyst contamination.

To prevent human infection

• Cook meat thoroughly: Cooking meat to a safe temperature (at least 160°F or 71°C) can kill the tissue cysts of Toxoplasma gondii.

• Wash fruits and vegetables: Thoroughly washing produce can help remove any potential oocysts.

• Practice good hygiene: Wash hands with soap and water after handling cat litter, soil, or raw meat.

Conclusion

Toxoplasmosis in cats is a concern for both feline health and human health, particularly for pregnant women and individuals with weakened immune systems. However, with proper prevention measures and awareness of the disease, the risks associated with toxoplasmosis can be minimized. Responsible cat ownership, including keeping cats indoors and practicing good hygiene, can help protect both our feline friends and ourselves from this parasitic infection.