Pet owners who have more than one dog may have noticed aggressive behavior in one or both of the animals. Some aggression in dogs is not uncommon in dogs that live together, as there is typically a "dominant" canine and a "submissive" canine. However, conflicts can arise over a number of different issues, even in animals that previously got along.
VCA Animal Hospitals recommends owners get their veterinarians involved in the issue as soon as possible. Owners should provide a full medical history of both dogs, and keep a record of times they fought and what exactly happened. This can help narrow down the cause of the conflict. The vet can also check for any possible medical conditions that could be contributing to the aggression.
Many times, a younger and more athletic dog will challenge an older dog for dominance. This can occur even if the relationship between the two animals was normal in the past. Another common situation occurs when two dogs begin to fight after an older dog becomes ill or dies.
An owners first instinct may be to intervene in this scenario, but it's not always a good idea. Trying to keep things equal between the dogs may exacerbate the problem, emboldening the "submissive" dog and leading to more conflict. The best course of action is to have one dog begin to defer to the other. Ultimately, this may mean that owners will have to control access to food, toys, attention and other resources until the hierarchy is re-established.