Buffered aspirin, an analgesic drug used to relieve pain, is better for dogs than regular aspirin because it is less likely to create ulcers in dogs' digestive tracts. Aspirin is suitable only for short-term use in dogs, and only in veterinarian-recommended dosage.
Buffered aspirin has a corrosive effect on the cartilage of the joints, so aspirin is seldom used for long-term treatment of arthritis in dogs. Aspirin thins the blood -- so if anemia or other blood disorders are issues, aspirin shouldn't be given. Liver or kidney problems are sometimes side effects of giving buffered aspirin to dogs. Aspirin toxicity can cause loss of appetite, vomiting, diarrhea and ulcers as well as central nervous system disorders causing lack of coordination, weakness or sudden death.