How can I make my old dog comfortable with my new dog?

Is the pup 8 weeks or 8 months? you said both… He’s jealous! Are you neutering just because of the new dog issues? IMO it won’t help for that, although there are many good reasons to neuter anyway. I’ve had a multi-dog household for years; you have to expect some friction. (Also, older dogs HATE the puppy teeth!) It’s as though your mom brought home a stranger and told you, “Here’s your new BFF!” You won’t automatically get along wonderfully! You should treat the older dog as the #1 dog, even though he’s smaller. For example, pet him first, give him treats first, give him more attention. The younger dog won’t have her feelings hurt, she knows he’s an adult and she’s a baby. Eventually they should get along fine… but don’t rush it. And you may need to protect your older dog from the young one as she grows; she might hurt him accidentally due to the difference in size. My rule for my dogs is, they don’t have to like each other, but they do have to get along. And they do pretty well, most of the time; like people, sometimes they will have a difference of opinion. But they have learned from puppyhood that I don’t tolerate fighting so there is rarely a problem, (Notice I didn’t say ‘never’!:-/) You should google it; there are loads of sites with advice for this. Good luck!

The puppy is 8 weeks old, the dog is 3 years old. The neutering we were planning on doing anyway, but now we want it done soon because the new puppy is female. When the dog bit the puppy, she didn’t even attempt to bark or fight back, she just ran away and hid. The puppy is surprisingly mellow and calm. She’ll play with you, but makes little noise, never shows her teeth, or growls. It’s my older dog that is the major aggressor.

Just wait until the new puppy starts teething. She’ll show her teeth….on everything and everyone. It just feels soooo good to bite stuff! Make sure there are plenty of chew toys around, and don’t let her gnaw on your older dog or anything else.

I once had a dog that for a week that my dog didn’t like at first. She shaked like a leaf. I put her in a kennel for the first 3 days. It was the only time she wouldn’t shake and my dog didn’t bark at her. But I would take her out and love her and put my dog to my side and let them sniff each other without touching. With a little time he started going near her kennel to just sniff her and he started to let her sniff him. When he did bark at her in the first 3 days, I would go between him and the kennel and firmly tell him know. He got the idea she was my possession and stopped barking. As she got comfortable she started to walk around and he started following her. Then they started playing and then I had to start keeping a really close watch because they were getting tooo friendly. I think a nervous dog makes them anxious. Puppies tend to be anxious in a new environment. A kennel can help her feel safe for now and give both dogs some time to get to know each other safely. Could be the older dog has frighten her and she has already had accidents around the house and he has smelled it and has taken it that she is trying to claim his home. Is he sniffing around areas she has walked? If he is, than he is looking for spots to reclaim. At 3 neutering won’t change much of his behavior but it may at least keep her from getting knocked up or him going into heat. He will still be territorial. You need to teach him your home is your home. Your sofa, your room, your new dog. (I’m not saying piss your stuff) There are web sites that give advice on how to retrain your territorial dog. He bit her so that really isn’t good. You may want to take him to go to an actual dog trainer.

Well, tbh, it was quite rude of you to bring a new puppy home without an introduction outside the home in neutral territory. That step is highly recommended when introducing a new family member.

That being said, now you have to make peace between them and the new pup being big is not going to help the old dog feel more secure, but it’s gentle nature may be the only saving grace in this situation.

Personally, I would take them to a neutral outside area, not your yard maybe a park, and allow them (while on leashes) to smell each other, ‘talk’ a little and see how it goes. If your old dog is still agressive you have to try to understand a new younger and bigger dog has invaded his turf and behave accordingly.

I have also heard that sometimes a baby gate will allow them to get to know each other without damage…and don’t trust the new baby, they can get aggressive towards older dogs very easily, especially if she’s bigger…be very careful you don’t leave your old dog open to life-ending damage.