(1997) The following is an extract from Steve Dean's column 'A Vet's View' in Dog World , and is reprinted here with his kind permission. "I noted a comment in Friday's World recently on leptospirosis. Dr JI Coates is reported as saying dog urine is potentially dangerous to man, the chief danger being leptospirosis, and that in people leptospiral infection results in meningitis. So what is the truth of the matter? Is dog urine so dangerous that we should all be wary of it? Well, apart from the normal hygiene precautions, I would not exactly panic. Leptospira bacteria are found in dog urine and they do cause kidney and liver infections. However, leptospira are also found in cattle, sheep, pigs and horses. In fact they probably exist in most domesticated and wild mammals. Thus, if we are to be concerned about dog urine, we would also be concerned about most animal urine, for man is susceptible to most variants of the leptospira family. In fact the biggest risk for leptospirosis infection in humans and their dogs is probably the rat. Not only does this animal carry heavy infections of leptospirosis but it urinates freely everywhere and thus manages to contaminate waterways, lakes and ponds. Even outdoor water dishes are at risk. In the domesticated dog, vaccines have been successful in limiting the worst of the disease symptoms but we know that the leptospirosis vaccines are not long lasting, nor are they particularly good at imparting a solid immunity. Despite this, regular annual boosters, along with occasional infection picked up from contaminated water, will keep most dogs' immunity reasonably effective. But, we know that many dogs still suffer from chronic kidney disease in middle and old age, and it is suspected that this is due to low levels of leptospira infection damaging the kidneys throughout a dog's life. It is also true that vaccination does not completely stop a dog becoming a carrier and so some dogs will excrete the bacteria in their urine, even when apparently healthy. So what of the risk of infection in man? Well it does exist but like toxocara infection it is relatively rare. Mostly it is an occupational risk and farm workers and water company employees are the most likely to suffer infection, but this probably came from infected cattle or rats, respectively. Dog owners' risks are very small by comparison unless they adopt poor hygiene. It is possible for the infection to enter through broken skin or via the mouth and nose, but normal cleanliness, such as wearing gloves or washing hands regularly, will do much to limit the risk. In fact if canine urine were a high risk, then I would expect vets to be a major group of leptospirosis sufferers but to my knowledge the profession does not suffer significantly from such symptoms. So, like so many of these scare stories, there is a basis in fact but the risk is small and providing you regularly vaccinate your dogs and bathe only in asses' milk (rather than dog urine), I am confident that few of you will suffer from leptospirosis caught from your canine companion."