Why is my female dog aggressive towards my male dog after neutering?

I am very sorry to hear that you are experiencing these issues with Hazel and Daisy. I believe a couple of possibilities could be occurring. Though only behaviors that will be affected by spaying are those that are under the influence of female hormones, it could be possible that they are both still undergoing hormonal changes and so they need time to adjust. The hormone changes can take up to a few months to stabilator. When everything is stablized, a dog's temperament, training, and personality, are related to genetics and upbringing, not hormones, so should not be affected. Neutering does not “calm” an excitable dog, and unless a dog is overfed or underexercised, there is no reason for it gain weight or become inactive. The undesired traits which are related to hormones such as sexual behaviours, aggression, and urine marking will change over the course of a few days to a few months. It is also possible that Hazel is possibly not healing well and still experiencing some pain or discomfort. I would try gently palpating her abdomen to see if you get any flinching nor pain reactions. A check-up with the vet to confirm she is not in pain would also be a good idea. Pain can be expressed through changes in mood, which are often outwardly viewed as aggressive behaviour. I hope that is helpful information and I wish you the best of luck with Hazel and Daisy.

Hormonal changes that occur after being spayed or neutered can sometimes cause tensions. Keeping the dogs separated unless supervised may help reduce fights. If you notice one or both dogs becoming too excited or agitated, separating them and giving them a chance to cool off can help. Removing items of contention such as treats or toys can also help reduce fighting. If the fighting continues, or they are unable to be together at all, seeking out a local veterinary behaviorist or trainer in person that can observe their behavior may be useful for formulating a training plan to help both dogs get along again.

The lowered testosterone levels following the neuter could be making the pit less dominant and the lab is now trying to assert his dominance in the “pack”. There are some great resources on www.draophiayin.com that discuss aggression. You may also want to consider working with a veterinary behaviorist to resolve this issue. You can find one in your area on www.acvb.org.

Canine aggression is a complex behavior as it can stem from dominance, possessiveness, fear, anxiety, resource guarding or a combination. Most people are not familiar with reading canine body language and training. Because of this, I recommend to work with a professional trainer. Researching on your own will also be helpful. Familiarizing yourself with canine body language and dog training can help you to recognize what your pet is trying to say. You can find many books written on the topic and there is a trainer named Victoria Stilwell who I think is particularly helpful. Certainly male dogs who are not neutered are more prone to fighting and aggression. Neutering him may help but it will not likely solve all the problems. Best of luck.

Now is the best time to neuter them both. Neutered males are more docile and make better pets. When they reach sexual maturity at around 6 months and their hormones go into full swing so to speak, they may act aggressive toward other males and want to become dominant in the household. If you wait too long, neutering will not help. I suggest neutering all dog sin the house as soon as possible, then the hormones will die down in a few weeks. At this time, implement a training program with a trainer or by doing some research. The behavior will most likely get better, but that is not definite. Neutering with combined training is your best plan to change his behavior. .

Without being able to observe the behavior, it's impossible to know if this is true aggression or if this is play behavior. True canine aggression is a complex behavior as it can stem from dominance, possessiveness, fear, anxiety, resource guarding or a combination. Unless you are very familiar with reading canine body language and training, I recommend to work with a professional trainer. Researching on your own will also be helpful. Familiarizing yourself with canine body language and dog training can help you to recognize what your pet is trying to say. You can find many books written on the topic and there is a trainer named Victoria Stilwell who I think is particularly helpful. Rough play is a completely different behavior and will not generally be affected by neutering. I hope this helps and please feel free to post any additional questions.

Testosterone is mood balancing and very occasionally in timid dogs castration can heighten anxiety and aggression. I would recommend working with a certified behaviorist to try and work through this and possibly medications may be required if not settling