Why is my dog fixated on my other dog?

The simple answer is that most other dogs that want to play with your dog will be offering your dog a great deal of fun. That dog playmate provides your dog with bodily contact, physical play, perhaps chase elements, mouthing and interaction – so your dog has learnt that other dogs = where the fun is at. The other reason can be for some older dogs or rescue dogs, is that other dogs can provide them with a safe space. If they have grown up on the streets, in shelters or travelling with them, being around dogs is familiar and how they have been raised so it feels safe and they may gravitate to them to help themselves. They are scanning the horizon for other dogs all the time. They bolt off and don’t come back to you when they see one. They will run off and into any dog they see, even if its on lead and does not want to play. Your dog isn’t listening or looking to you for any direction or help, they just have one thing on their mind – other dogs.

Your dog is obsessed with other dogs because your pup either wants to play with the other dog, is fearful, or has created a bad habit of trying to interact with every dog your pup sees. If your dog obsessed with other dog, there is a reason for it and can stem from a variety of different situations. This can vary from a dog that reacts from fear or lack of exposure to a young pup that just built a habit of having to play with every dog he encounters. Many dog behaviors begin as a voluntary response than with enough practice and repetition the response then becomes involuntary. For instance, the first time you let your dog greet another pup on a leash, your dog made the voluntary decision to interact with another dog. After enough repetitions of you allowing your dog to “say hi” to other dogs on a walk, your dog’s response every time he sees another dog becomes involuntary because up to that point you let your dog make a habit of saying “hi” to every pup your dog sees. Another reason your dog obsessed with other dog is that your pup is fearful of another dog. The 3rd main reason your pup is obsessed with other dogs is because your pup lives to play. A dog that is obsessed with other dogs because he wants to play most likely has either had too much time playing with other dogs to the point where it created the obsession or the complete opposite the dog rarely plays and when he encounters another pup is gets flooded with excitement the key is about balance.

The 3 year old dog is a nurturing dog to begin with. He has always been interested in sticking his nose in all of their asses. My cat will swat at him and he stops. He always humps the other dog and the pig though. As of late he has become obsessed with the 2 year old dog. Following him around with his nose in his ass, humping him periodically throughout the day. I'm wondering if one of them or both could be sick. My results when looking it up online just says "Possible UTI and full anal glands that need to be expressed".