Aspirin is one of the most common and frequently used medicines for pain control and relief in human medicine, and dog aspirin is also quite popular among many veterinarians and pet owners. Aspirin, or acetylsalicylic acid, is considered an NSAID form of drug. NSAIDs, or non-steroidal anti-inflammatory drugs, are medicines that are designed to reduce pain and discomfort by eliminating inflammation and swelling from the affected parts of the body. Aspirin has not been approved for use in dogs, and the side effects can be somewhat unpredictable. Because of this, and especially because of the recent advances in pain relief medications that were designed specifically for pets and dogs in particular over the past two decades or so, most veterinarians avoid aspirin use in dogs. If you do give your dog aspirin, watch out for these potential side effects.
Vomiting and Diarrhea
One of the more common potential side effects of aspirin use in dogs is vomiting and diarrhea. Pay particular attention for any unusual substances contained in either your pet's vomit or his feces. If you notice any blood or if either is colored black, it may indicate that there is also internal bleeding going on. This is a much more severe sign of problems than simple vomiting or diarrhea, although neither of those are positive side effects.
Dizziness and Lethargy
Dogs that have taken aspirin are known to occasionally become disoriented and lethargic. These are perhaps more characteristic of standard changes to behavior and attitude that often come about as a result of the dogs having taken aspirin. Look out for changes to behavior including added aggression, refusal to want to play or move around, unusual walking and changed gait.
Liver Damage
Although it's not always easy to see in your dog's physical and outward appearance, extensive aspirin use can lead to severe liver damage. This damage is characterized by the death of liver cells and the eventual poisoning of your pet's liver. If you continue to provide him with aspirin in this condition, or if the aspirin use is prolonged for an extended period of time, more serious side effects like seizures, coma and even death may come up.
Changes in Diet and Weight
Dogs on aspirin may have significant changes to their diet and hunger patterns. It's not uncommon for dogs on this medicine to refuse to eat entirely, or to eat a huge amount at a time and continue to beg for food. With prolonged aspirin use, this can lead to dramatic and often unhealthy changes in weight.
Aspirin should only be used very sparingly in dogs. With the wide
range of much safer and specifically designed NSAIDs that exist today,
it does not make sense to continue to use aspirin as a sole source of
pain relief in pets. Speak with your vet for more advice.