Aspirin has been used by dog owners in the past although it is not recommended by most vets, as a range of drugs with fewer side effects are now available. The standard dose of aspirin is 5mg/lb of body weight (so for a 100lb dog that would be about one and a half standard aspirin) twice a day and should always be taken with food. Aspirin, like many NSAID (non-steroidal anti-inflammatory dugs) can cause many serious side effects including include vomiting, loss of appetite, depression, lethargy, and diarrhea, kidney and liver problems and ulcers. It can also interact with other prescription medication so you should always consult with a vet before administering aspirin.

There are several NSAIDS which are more suited for dogs such as meloxicam, caprofen and deracoxib. If your vet does recommend asparin or any other NSAID for your dog then you should watch closely for symptoms such as changes in urination habits, odor or colour, loss of appetite, vomiting and black or tarry stools. Other human painkillers such as panadol and paracetamol have also previously been used in animals but can have even more serious side effects than aspirin.