The truth about cats, toxoplasmosis and pregnancy

When you are pregnant, once you have got over the excitement and elation of the news, you start to worry and there is a lot you can worry about. One thing I often get asked about as a vet, and which I was very concerned about myself, was toxoplasmosis.

Toxoplasmosis is a parasite which, if picked up for the first time just before you conceive or while you are pregnant, can cause significant harm to your unborn child. It is possible to contract it from many sources, one of which is cats, and this causes their owners great anxiety. I have even heard of midwives advising owners to give up their beloved pets, which, in my opinion, is very much an over-reaction.

It is difficult to know how many cats are infected with toxoplasma. Studies suggest between 20% and 60%, with those that hunt or are fed raw or undercooked meat being more at risk. However, even if your cat does have it you probably won't know as most show few outward signs.

The parasite causes the cat to pass oocysts (microscopic spores that will eventually develop into toxoplasma) in the faeces for about a fortnight. These then take between one and five days to sporulate (become infectious). After about two weeks, the cat's immune system fights the infection and although the parasite will likely remain permanently in their body, they will no longer pass any spores.

Only cats with poor immune systems or other illnesses (for example, feline lymphoma or feline AIDS - and if they have these you will probably know about it already), will actually get sick or shed the oocysts for longer than two weeks.

I was tested when I was pregnant with both my children and have been negative each time. This means I have never been exposed to toxoplasmosis, despite working with cats every day. In fact owning a cat has been shown not to increase the risk of a toxoplasma infection at all and vets are no more likely to be infected than the general population.

Those most vulnerable are actually gardeners because the cats use the soil as a litter tray and while the faeces quickly decompose, the toxoplasma oocysts can survive for years.

It is also possible to pick up toxoplasma from sheep, particularly around lambing time, so pregnant women are advised to steer clear if they do work in farming; you can also get it from eating raw or undercooked meat or unpasteurised dairy products.

With your cat, as long as you ensure you are careful when emptying litter trays (or better still, avoid it altogether when you are pregnant), make sure you do it at least daily and always wash your hands afterwards, the chances of the infection passing on are very slim. In addition, using litter tray liners and periodically cleaning them with detergent and scaling water is a good idea. Also, the toxoplasmosis can only be caught from direct ingestion of the oocysts from faecal matter; you cannot get it from simply stroking your cat.

Toxoplasmosis is a disease which can be serious and sadly does cause complications in around five in every 1,000 pregnancies in the UK. However, the vast majority of those are not caused by the family's pet cat.

Cat Henstridge, BVSc MRCVS, is a vet specialising in pets and is based in Sheffield, UK. She is passionate about her job and healing the animals in her care. She also loves to write about her experiences and pet health issues at catthevet.com.