Should you be concerned if your pet eats a rat or mouse?

Whilst catching a mouse or a rat may be a natural activity for cats and in some cases dogs, eating rodents can have undesirable consequences. These can include contracting intestinal worms, the disease toxoplasmosis and secondary rat bait poisoning.


Cats and dogs can become infected with the protozoan organism Toxoplasma by eating rodents or rabbits that have the Toxoplasmosis cysts developing in their muscles. In dogs, Toxoplasma may make the dog quite ill and can cause various symptoms ranging from diarrhoea, pneumonia, liver disease, or diseases of the nervous system. In cats, the parasite lives in the intestinal cells, usually causing little harm. The adult parasite produces cysts that are passed out in the faeces of cats. It is these cysts that can cause harm if ingested by dogs, humans or cats with a weakened immune system. Read more about Toxoplasmosis here.

Intestinal worms

Cats and dogs can become infected with Roundworm by eating mice or rats infected with Roundworm larvae in their muscles. Roundworms are a common intestinal parasitic worm found in young dogs and cats. These worms feed upon the intestinal contents, competing with the dog or cat for food. Roundworms are approx 8-12cm long and spaghetti like in appearance. Read more about worms in dogs and worms in cats here.

Secondary poisoning

There is a small risk of secondary poisoning if a rodent has ingested rat bait and a pet then eats the rodent. The level of toxicity your pet will experience depends on the timing, amount and type of poison the rodent has consumed and the number of rodents your pet eats. For example, if a Jack Russel Terrier consumes 1-2 rats, this may be sufficient to cause symptoms. Cats, however, may need to consume many more rodents to be affected. If you suspect your pet has eaten a poisoned rat or mouse, please contact us directly for advice on what to do. For more information we recommend reading our article on rat bait poisoning for more information.

What you can do to help protect your pet and family

Obviously cats are natural hunters and some more so than others. If your cat is an outdoor cat consider installing a cat enclosure. Of course this will not stop rodents entering the enclosure but will prevent normal hunting activities. At the same time you will also help to protect our natural wildlife.

If there is an outbreak of rodents in your area, keep your cat inside. Whilst we understand this can be difficult task for outside cats, it is a time when neighbours will be more likely to use rodenticides such as Ratsak and Talon which means your cat may be at risk. Also, if you have a rat or mouse problem consider using more traditional forms of pest control as opposed to poisons.

Worm your pet on a regular basis, in most cases treatment in adult pets should be done once every three months. This will help protect you and your family.