There is always a big concern over the sharing of diseases between the species – that is why the big concern over Bird Flu. However, although the list of POSSIBLE diseases that a cat can share with its owner (this group of diseases are referred to as Zoonoses) is quite long, the actual number of diseases that a cat can infect a human with on a regular basis is small. Ironically, it works both ways. We can give cats some diseases too, and cats can even be infected by some strange things like tomato fungi. None of the viruses that cats get – except Rabies (which we do not have in Australia) can infect humans, so that lets us off the hook for most of the infections that a cat will get in its lifetime! That includes Feline Aids, Feline Leucaemia, Feline Herpes, Corona virus and Parvovirus. And several more!
The most common zoonosis to cause concern is Toxoplasma, especially for pregnant ladies. The details are complex, but the reality is – Toxoplasma is a small parasite that lives in the muscle of sheep, rabbits, rats and kangaroos and multiplies in the intestines of young cats if they eat that meat.
It is spread to the herbivores out on the fields and pastures contaminated by feral cats faeces. Only young cats pass contaminated faeces usually, so once past the kitten stage, very few cats will pass on the eggs (called oocysts) which can infect other mammals, including humans. The upshot of this is that most people in Australia become infected with Toxoplasma oocysts by gardening without gloves, and in France, by eating undercooked lamb or rabbit.
Being infected with the oocysts is only a problem for pregnant women if they have not been in contact with the Toxoplasma oocysts before they got pregnant, because then the baby gets infected as well, with debilitating effects. So, because cat faeces are involved, it is only right that pregnant women should not handle cat faeces. However, bear in mind it takes a few days for the oocysts to develop enough in the faeces for them to become infective, so daily cleaning of litter trays removes that risk as well.
Toxoplasma oocysts do not hang around on the cat’s coat either (in fact their skin has 30 percent fewer bacteria on it than yours because of all that grooming!). So the risk to an owner of an adult cat, with a regularly cleaned litter tray, is low. Interestingly, vets and vet nurses have no higher levels of exposure to Toxoplasma than the general population, which would indicate that cats are actually a low-risk source of infection. Precautions for women then, are to use gloves when gardening (and wash hands after handling any soil or sand outside) and to cook lamb, rabbit and kangaroo meat well, and wash hands after handlingthose meats raw.
Pretty simple really. Blood testing your cat for Toxoplasma is not going to be very revealing, as most cats will have been exposed and be immune from quite a young age. The ideal is to actually have both expectant mother and cat having high levels of toxoplasma antibodies prior to the pregnancy! That way, no one is going to be infected! An excellent read is on our website: www.catclinic.com.au
Ringworm is also a very common infection. It is not a worm but a fungus, which grows in a ring formation like mushrooms do! It is usually the fungus called Microsporum canis and it lives in the soil as well as on skin. It is as easy for children to get ringworm from another child (at preschool etc) as it is to get it from a kitten. Ringworm usually only infects the young, the pregnant and the elderly or those whose immune system is not working very well. It is easy to treat with creams (on humans) and shampoos and tablets in kitten. Again, adult cats rarely carry the fungus unless their immune system is compromised.
Giardia and Cryptosporidia, both of which cause diarrhoea, are often water-borne, and you can get them from the same source as your cat might. You can transmit them to your cat, too. However, once again, litter tray hygiene is usually sufficient to limit the problem. Similarly Salmonella comes from bad meat, same as for humans but then can be transmitted if hygienic methods are not practised.
So really, the biggest problem you can get from your cat is a cat bite, and these are not to be ignored. While the frequency of cat bites is much less than dog bites (after all, cats give lots of warning and will try to get away rather than bite), they are very infective and not to be taken lightly. Some people are very susceptible to blood poisoning from just one bite.
The bacteria in a cat’s mouth are actually not as toxic to people as the bacteria in other people’s or monkey’s mouths, but because the cat tooth injects the bugs under the skin, the bacteria have an ideal place to grow. Cat scratches can transmit a bacteria called Bartonella which causes lymph nodes to swell. It usually only inhabits young cats, and most people get over it without being treated specifically for it.
So, in a nutshell, there are lots of possible diseases, but few common infections that cats and their humans share. Most of the diseases are transmitted by young cats, in the same way as young children harbour most of the viruses and infections in the human population. Even once infected, most people can be cured of most of what a cat can give them, unlike some of the viruses we share between ourselves such as HIV, Herpes and Hepatitis. So think of it as your cat giving much more affection than infection!