The Chinese New Year is the Year of the Rat. Although most of the cases in our database concern dogs and cats, we have over 100 cases involving rats exposed to a wide variety of substances including drugs, pesticides, chemicals, plants and household products. Two of the most common agents we are contacted about in rats are anticoagulant rodenticides and permethrin.

Anticoagulant rodenticides are a particular concern since rats are one of the target species for these pest control products. Treatment is recommended in most cases of anticoagulant rodenticide ingestion in rodents and rabbits because the amount ingested is generally unknown and it will be impractical to monitor clotting parameters due to small body size and low blood volume. In addition, rabbits and some rodents can be re-exposed to rodenticides through caecotrophy. Although preventing this may be impractical in most cases, rabbits, guinea pigs and chinchillas can theoretically be collared for the first 72 hours with monitoring of access to food and stress levels. Assisted feeding with a supplement diet can also help to reduce consumption of toxin contaminated caecotropes. Vitamin K1 dosing in very small animals can be a problem as the doses recommended are parenteral and therefore not practical for long-term therapy outside a veterinary surgery. Vitamin K1, however, can be given orally by either breaking up the tablets or oral administration of the injectable liquid. The liquid can be given with fatty food such as peanut butter or given on a favourite treat.

As in cats, permethrin causes neurological signs with tremor, twitching and seizures in rats. Treatment will require dermal decontamination, if applicable, and anticonvulsants.

We also have a few cases of rats eating oral contraceptives. This does not seem to be a concern as in the cases where we have follow-up the rats have remained well.