Though aspirin is not toxic to dogs, owners should not give aspirin to a dog except under the direct supervision and advice of a veterinarian, according to PetMD. Commonly used to treat short-term musculoskeletal pain, aspirin is known to cause gastric pain, bleeding and ulcers.
WebMD states that owners can give a dog an accidental aspirin overdose, causing organ damage or death. Even the correct dose can cause an unpredictable or life-threatening complication in some animals. The veterinarian knows the correct dosage, and whether the dog's pain can be effectively treated with aspirin. PetMD states that there are safer alternative treatments for managing pain, including medications developed specifically for dogs. Research and veterinarian experience show that aspirin must be used carefully, if at all.