Toxoplasmosis in my cat

Toxoplasmosis is seen in cats and is a microscopic parasite that can affect all mammals, including man, as well as birds, amphibians and other reptiles. Certain species appear to be more likely to transmit the disease (the pregnant sheep at the time of birth, is an example). Living in proximity with our domestic pets leaves us a little more exposed than a non-pet owner. The cat is the definitive host. Between 30% and 60% of humans have evidence of contact with Toxoplasmosis.

How do people catch Toxoplasmosis?

• Eating raw or undercooked meat
• Contact with cat faeces from litter tray or flower beds.
• Vegetables, salad or fruit contaminated by infected material and not sufficiently washed.

CAT FAECES ARE NOT INFECTIVE FOR 24 HOURS AFTER LEAVING THE CAT

How does Toxoplasmosis affect humans?

It is very rare for Toxoplasmosis to have any adverse effect on healthy humans. There are two ‘at risk’ groups of people:

• People whose disease defence is weakened by AIDS, chemotherapy and some types of cancer.
• Pregnant women, especially in the first, two-thirds of pregnancy where disease can be passed to the unborn child causing blindness, epilepsy and brain damage.

Mild cases of Toxoplasmosis show as ‘flu-like’ symptoms with swollen glands, temperature rise and general ill health lasting up to a couple of weeks.

How do cats catch Toxoplasmosis?

As cats are fastidious cleaners, it is unusual for contact to be from another cat. More commonly it is from eating infected prey, raw meat fed by owners or contact with infected cat faeces in the garden or dirty litter trays.

How can you tell if your cat is carrying Toxoplasmosis?

This can be very difficult and often inaccurate. If your cat has a high blood antibody titre, then it will have been in contact and may be a carrier. Paired antibody blood tests a month apart with increasing antibody levels probably means the cat has the disease but may not be excreting the disease. Evidence of the disease in the faeces is diagnostic but rare to achieve. False negative results are common. It may be better to assume that disease may occur in your cat and take preventative measures to safeguard your family’s health.

What is the risk to humans?

If you are pregnant or an ’at risk category patient’, go and see your doctor and ask him or her about the risks concerned. A blood test may show evidence of contact with Toxoplasmosis in many cases, and this may mean that your immune system has produced antibodies to protect you. A very low antibody titre will mean minimal exposure and no protection, and you must take additional precautions against the disease.

When do cats excrete Toxoplasmosis?

Cats shed Toxoplasma cysts in their faeces when they first contact the disease, often when very young and on their first hunting expeditions. Shedding of cysts is unlikely except when the cat has ill health such as feline leukaemia, cat AIDS, severe diarrhoea or other debilitating illnesses. Do remember that it takes 24 hours for the Toxoplasma cysts to become infective after they leave the cat and so good hygiene will prevent human infection.

How to avoid getting Toxoplasmosis

This advice relates particularly to pregnant ladies and other ‘at risk’ people. By all means blood test and faecal sample your cat. Do NOT rely totally on these results.

• Eat only well-cooked meat.
• Keep surfaces on which raw meat has been handled, scrupulously clean and wash hands thoroughly after handling raw meat.
• Avoid unpasteurised goat milk and cheeses.
• Garden with gloves on and wash hands afterwards.
• Wash soil covered vegetables very well and clean kitchen afterwards.
• Clean out your litter tray every 12 hours. Get your partner to do this and put contents into a sealed bag.
• If there is nobody to help you, use rubber gloves and a face mask and clean the tray out thoroughly with disinfectant every time. Wash your hands thoroughly.
• Do not allow the cats on work surfaces or in bedrooms. If they are ill, do not handle. At other times wash your hands well after handling. If the cat’s blood test is ‘sero-negative’ (no evidence of exposure) keep the cat indoors at all times and feed only commercial cat food. This will significantly limit the risk. If the cat has positive spores in the faeces, the cat should be hospitalised and treated until no signs of shedding are present.
• Do not acquire any new cats.