There are two reasons why it is unhealthy for a domestic cat to eat mice despite the fact that mice are the number one prey of the domestic cat. Of all the prey animals that the domestic cat wants to stalk, attack and kill, the mouse is at the top of the list.
The mouse is the perfect cat food
The mouse is made up of a perfect combination of protein, carbohydrate, fat and water plus a little bit of vegetation in the stomach as fibre. All domestic cat food should be based upon the nutrients in the humble mouse, the solid parts of which are 40% protein, 50% fat and only 3% carbohydrates. It is also 70% water.
- Do domestic cats prefer mice or birds?
- How do cats hunt mice?
- If five cats can kill five mice in five minutes, how long will it take 100 cats to kill 100 mice?
Normally, therefore, 95% of the time or more it is safe for cats to eat mice but I can think of two issues that need to be mentioned. Firstly, a mouse may be dying of a rodent poison. A cat might attack and eat that mouse and poison themselves. Clearly it would be unsafe for that individual cat to eat that particular mouse.
Secondly, mice are often infested with parasitic worms. A domestic cat who eats an infested mouse will ingest the worms and become infested themselves. This is not untypical. In fact it is commonplace for an outside cat to eat mice and get worms from this activity. Veterinarians prescribe deworming pills which you can buy from the clinic or you could take preventative measures yourself by ordering online and carrying out a home treatment without reference to a veterinarian. You can do this provided your cat is an outdoor cat and you know she is hunting mice and that you know what you’re doing when you buy the product. I think it cannot be stressed strongly enough how careful cat guardians must be when providing home treatments particularly when administering drugs to their cat.
The instructions must be read meticulously and you cannot give cat drugs that are manufactured for dogs. There are numerous instances of dog flea treatments, for example, killing domestic cats at the hands of their human guardians whose first responsibility is to keep their cats safe.
Mice can also carry fleas and these fleas can jump onto a cat. I have to say, though, that my cat is an avid mouser and he has eaten many mice but despite this exposure to fleas and very regularly flea combing I have never seen a flea on him. I think, therefore, that the hazard from getting a flea infestation from mice might be relatively slight.