My two Doberman puppy sisters fight aggressively. What can I do?

Aggression among Dobies of the same sex is well-documented and believed to be a breed specific trait with a genetic component. However, there has not been any research that has proven any one theory over another beyond a reasonable doubt. The reason they do not fight with the opposite sex is simple survival of the fittest. Obviously the breed could not continue to live on if the males and females were not able to coexist with one another. Hope this helps.

A certain amount of rough play is normal in puppies. If they get too rough, simply separate them until they calm down. Praise and reward them when they behave. Correct any negative behavior immediately. A pheromone product, such as the Adaptil collar or DAP plug in diffuser, may also help to calm them down some.

It can take dogs awhile to get used to each other, and the best thing to do is to make sure hat they each have their own space to retreat to if they don’t feel like interacting. If either one is starting to act aggressive you should separate them. They should have separate water bowls and eat food separately for awhile as well. Even though there haven’t been any injuries yet it would be safest to keep them separate while unsupervised until they are getting along. That being said it can be very normal for dogs to growl during play and sometimes vigorous play can seem similar to fighting. If you’re not sure it might be helpful to talk to a trainer or behaviorist - your vet can make a recommendation.

If they are not spayed then you should start with that. Hormones can certainly cause aggression. After the surgery it takes about 30 days for the hormone levels to decrease to a level that may change aggressive behavior. If that does not help then you should consult with a professional in-home dog trainer to help you sort out the root of the problem. I see you are in Puerto Rico. There is a HUGE free spay/neuter campaign coming there in November. I suggest you check it out if you want to get your dogs spayed. Search "Spayathon for Puerto Rico" on Facebook to find their page. Hope this helps. Best wishes.

When you have two bitches together, they will show aggression to compete for territory and intact males especially if they are in heat. The best thing to do is to have both of them spayed. This will reduce the aggression between them as it is most likely hormonally related. It will also eliminate the risk of a pyometra, which is a life threatening infection of the uterus. Without spaying them, you will have a very hard time reducing the aggression because it's hormonally related. Removing the source of the hormones is the best way to stop the aggression.

This sounds like puppy play to me. When they bite, is there any blood or wounds visible after play? If so, it may be best the separate them. If not, let them work it out! I would be more concerned if the biting was occurring on the hind or along the legs. I would also be concerned if there were other signs of aggression, such as during feeding time or potty time. If you are uncomfortable with the puppies play biting each other, try to throw some puppy toys in the mix, maybe even some that have treats inside to distract them.

At this stage you are not likely to correct this behavior. It is not uncommon for two female dogs that are not spayed to fight. You can have one or both of them spayed - that might help but there is no guarantee. The best thing to do is keep them separated at all times. If they have to be in the same room together then I suggest you keep basket muzzles on them so they can't hurt each other. ( https://www.amazon.com/Baskerville-Ultra-Basket-Dog-Muzzle/dp/B0051H45GC )