MEDICATIONS THAT MAY CAUSE AGGRESSION
Always check with your vet if your dog is taking any medication to see if the medication could contribute to aggression, or if the aggression may be a reaction to the medicine.
Some common medications that can contribute to aggression: Phenobarbital (required medication for seizures, Prednisone or other Corticosteroids (also known as Glucocorticoids), NSAIDs, including Rimadyl.
Corticosteroids are used for a number of different conditions that involve the inflammatory and immune systems such as arthritis, allergies, etc. They should not be stopped abruptly without talking to your vet, especially if your dog has been taking them regularly as it may cause dangerous side effects. If you think they are causing your dog to be aggressive, speak to your vet.
NSAIDs are also anti-inflammatory medications. They are often prescribed for treating pain.
Aggression is not listed as the most common side effects of these drugs, and can be prescribed to some dogs that are already aggressive without making their aggression worse, but it is a good idea to be aware that these medications can play a factor in aggression.