Toxoplasma infections 

in Cats

Toxoplasmosis is a prevalent parasitic disease caused by a single-celled parasite called Toxoplasma gondii (T. gondii). This disease can infect almost all warm-blooded animals, including pets and humans. While cats are essential to the life cycle of T. gondii, they rarely exhibit clinical signs of the infection. It is important to note that toxoplasmosis can pose a significant risk to pregnant women and individuals with weakened immune systems.

• When a cat consumes prey or raw meat that is infected with the parasite, cysts containing the parasite are released into its digestive system.
• The parasite then multiplies and produces oocysts, which are excreted in the feces of the infected cat in large numbers, often in millions.
• Cats that are newly exposed to the parasite usually start shedding oocysts within three to 10 days after consuming infected tissue, and this shedding can continue for up to 14 days. It is worth noting that oocysts are incredibly resilient and can survive in the environment for over a year.

Clinical Signs
The symptoms of this infection can vary depending upon whether it is acute or chronic, and the location of the parasite in the body.

• The most common symptoms of toxoplasmosis include fever, loss of appetite, and lethargy.
• Infections in the lungs can lead to pneumonia, which can cause difficulty breathing that gradually worsens.
• Liver infections may cause jaundice, a yellowish tinge to the skin and mucous membranes.
• Toxoplasmosis can also affect the eyes and central nervous system (CNS), producing
• inflammation of the uvea or pigmented part of the eye (uveitis), the retina, or the anterior chamber.
• Other symptoms include abnormal pupil size and responsiveness to light, blindness, lack of coordination, heightened sensitivity to touch, personality changes, circling, head pressing, ear twitching, difficulty chewing and swallowing food, seizures, and loss of control over urination and defecation.



Diagnosis
To diagnose toxoplasmosis in cats, veterinarians usually rely on the cat's medical history, signs of illness, and laboratory test results. One of the most common diagnostic tests for toxoplasmosis measures the presence of two types of antibodies to T. gondii, IgG and IgM, in the cat's blood.

• High levels of IgG antibodies indicate that the cat has been previously infected and is most likely immune to the parasite and not shedding oocysts. This means that such cats are generally no longer a source of infection for other hosts.
• High levels of IgM antibodies suggest that the cat is currently infected.
• If there are no T. gondii antibodies detected in a healthy cat, it indicates that the cat is still susceptible to infection and may shed oocysts for up to two weeks following infection.
  

Treatment

• Toxoplasmosis is usually treated with a course of clindamycin, an antibiotic. 
• In some cases, corticosteroids may be added to the treatment plan if there is significant inflammation of the eyes or central nervous system.

It is important to start treatment immediately after diagnosis and continue it for several days even after the signs have disappeared. Diagnosis is often based on high initial IgM antibody levels, and treatment should lead to clinical improvement within two to three days. If no improvement is observed, the diagnosis of toxoplasmosis may be questioned.