You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.

Cats are excellent hunter-killers and - even though they are fed more than enough food - they will still instinctively stalk and kill rodents and other small animals

Domestic cats often bring home the partly eaten remains of mice, voles, rats, birds and other animals. But is this behaviour harmful ?

The short answer is YES - catching small mammals, and rodents in particular, does present a potential health risk for domestic cats.  Rodents (mice and rats) carry several diseases which can be transmitted to cats and even to humans.

Two of the most common diseases transmitted from rodents to cats are :

• Tapeworms - eg Taenia, Diplopylidium, Echinococcus, Hymenolepis and Spirometra. These worms can live in the intestine of cats without causing any signs of disease although very heavy worm burdens cause weight loss, abdominal distension and discomfort. The type of worms carried by rodents varies in different geographical regions of the world. They can be diagnosed by finding worm eggs or segments in the cats faeces, or when tapeworm segments or whole worms are passed out per rectum. Tapeworm segments often appear like contracting "rice grains" attached to the hair around the anus and tail base. Some of these tapeworms can be transmitted to humans, so they present a human health risk as well.
• Leptospirosis - this bacterial infection is common in rodent populations, and blood tests show that many cats have been exposed to leptospires, however very few cats develop clinical signs so cats are naturally resistant to this disease. On the other hand, leptospirosis is an extremely serious infection for other species such as dogs and humans and it can cause kidney or liver disease.

So, whilst catching prey does not present a serious health risk for the cats themselves - it can be a serious risk for other members of the family - including humans and pets which are susceptible to the infections eg dogs. 

In conclusion :

• catching and eating rodents does present a health risk to cats, but they are quite resistant to most of the infections they may contract, and they may not show any signs of disease even if they do become infected
• infections contracted by cats from rodents can present a serious health risk if they are transmitted on to other species including dogs and humans
• rodent populations should be kept under control (eg in a cattery) to reduce exposure to infectious diseases
• cats that frequently catch prey should be wormed regularly
• when handling the remains of prey humans should use protective gloves and equipment which should be disposed of afterwards
• rodent-catching cats that are even slightly  "off colour" should be examined by a veterinarian in case they have contracted a disease that could be transmitted to humans

You might also be interested in

• Leptospirosis
• Tapeworms
• Toxocara cati

Updated October 2013