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My Older Dog is Aggressive to My New Puppy

I wrote about how I’m feeling overwhelmed with a puppy.

And then I received all these nice comments on how it gets easier and your puppy doesn’t have to be perfect and so on.

Only … my main concern is actually my senior dog Ace!

I’m worried my older dog is being too aggressive with my puppy when resources are involved like his dog bed, toys or … ME.

It’s normal for an adult dog to correct a puppy

Don’t get me wrong, it’s totally normal for an older dog to correct a rambunctious puppy. You can bet the older dog will growl or snarl or even lunge if a puppy is being a pest. This is how a puppy learns it’s rude to jump on a dog’s head while he’s resting, for example.

The older dog shouldn’t be scolded for doing this as long as he’s not physically hurting the puppy.

(Some puppies will yelp and squeal even if they are not hurt. I don’t react to this.)

It’s the owner’s job to re-direct the puppy away from the older dog

The dog owner needs to make sure to re-direct the puppy from being a pest so the older dog doesn’t have to correct the puppy most of the time. Call it a team effort for setting boundaries.

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Where it gets complicated … resource guarding

My older dog Ace is definitely showing some resource guarding around his bed, toys and, unfortunately, ME.

This is to be expected, to some degree. If a dog is calmly chewing on a bone, he’s going to growl if a puppy barges over to take it. Again, it’s always the owner’s job to manage these interactions.

However, in my opinion, my older dog Ace has crossed a line a couple of times. (And this still falls on me as the owner. Dogs are dogs.)

Older dog attacks new puppy

Should I let my older dog growl at my puppy? Well, in some cases a little growling is good, but my older dog’s aggression to my new puppy is more than what I find acceptable.

One example was when I was sitting on the floor petting Ace and he lunged at my puppy Remy for approaching us.

My older dog is aggressive to my new puppy

Ace used teeth on Remy’s head for a second and left marks (no punctures or scratches). Remy squealed and ran away.

I should have seen this coming and blocked Remy because, let’s be honest, he was BARGING his way onto my lap.

However, I thought Ace’s reaction was out of line.

It left me really stressed out about how I’m going to manage future interactions between my older dog and my puppy.

But on the plus side, Remy is totally fine. He’s happy go lucky and resilient. He likes Ace and he is not afraid of Ace in the slightest. They do have positive interactions with each other every day.

Other notes about Ace:

  • He has been sick for 7 months and has some pain. He’s also had to wear a cone collar which blocks his vision, hearing and movement.
  • I have seen some minor resource guarding from Ace over the years (Behavioral issues are rarely “out of nowhere.”)
  • Since he’s been sick, Ace has shown increased resource guarding around my cat Beamer, so it’s not just the puppy.
My dog Ace with his tennis ball

How to stop your older dog from being aggressive to the new puppy

Here are my recommendations for introducing dogs that will be living together.

In our case, these have helped things go as smoothly as possible for managing two dogs of different “generations.” Update: Unfortunately our senior dog has now passed away but the two dogs did learn to get along just fine!

1. Keep dog intros slow between the older dog and the new puppy.

That goes for the initial meeting but also the next couple of days and weeks. Slowly integrate them into each other’s lives. Don’t force them to play, interact, cuddle, pose for photos, etc.

The two dogs may or may not choose to interact naturally, but don’t force them to be best friends.

See my post: How to introduce your dog to a puppy. 

2. Prevention. Prevention.

Pick up all dog toys, bones, Kongs, food bowls, etc. Don’t give them opportunities to fight or guard these items. It’s wise not to sit on the ground petting one dog if there is any risk of “guarding” like my example with Ace. Use gates, crates and leashes as needed.

3. Re-direct the puppy away from your older dog.

The new puppy should not be allowed to bother the older dog. The older dog needs to know you have his back.

My dogs Ace and Remy!

4. Seek out positive experiences between the two dogs.

Do walks go well? Go for lots and lots of walks together as a pack if possible. Bring another adult along to help.

My dog Ace does much better with Remy when we’re outside. He tolerates Remy getting in his face for the most part as long as we’re outside. They can walk together, sniff the same bushes, touch noses. I’m using that to create positive interactions. “Yay! Such good boys! Treats for all!”

5. Calmly have both dogs sit and then give them treats.

Dog Behaviorist Dr. Patricia McConnell has an excellent post on dog-to-dog resource guarding. One idea she listed is to give both dogs treats one after the other for calm behavior. This is assuming you have no tension between the dogs and there is no risk of fighting while they’re sitting there.

In our case this works really well. I use a spoon of peanut butter, have both dogs sit (Remy tethered) and say their names one after the other giving them a few licks rotating back and forth. It teaches Remy to stay and teaches Ace fun things happen around Remy.

How to get your older dog to accept your puppy – a few reminders

Ace Remy and me

1. Dogs really do live in the moment.

Even if they fight or bite they generally move on from second to second. They can have many positive interactions in any given day.

2. Dogs adapt.

Even if two dogs have had a couple of bad interactions they can move on and live peacefully together if they’re set up for success. Usually anyway. There are exceptions.

3. Humans need to move on too. 

Dog owners have to move on and change their mindsets as well. Even if something bad has occurred, you have to move on.

For example, I need to stay light and positive (not tense). I can’t sit there predicting a reaction from Ace or it’s bound to happen. I may even cause a reaction.

4. It’s not personal.

My older dog is aggressive to my new puppy, but Ace is not capable of “hating” Remy or being upset with me for getting a new dog.

Those are human emotions. My dog is just being a dog, guarding what he feels is valuable and protecting his space. While we can make it complicated, it’s really pretty simple.

How long does it take an older dog to get used to a puppy?

It just depends on the dogs. In our case, things got a lot better once our puppy was about 5 months old. At that age, he was large enough where I wasn’t so worried my older dog would hurt him.

And, at that age my puppy seemed to have more common sense and awareness about my older dog’s limits.

My puppy would still push the limits, but he understood there would be consequences such as a ferocious growl or a snap. He knew to “proceed with caution.”

Remy and Ace often cuddled up on the same bed together

I still supervised them, of course, but I wasn’t as worried my puppy would get hurt. Around this time, my older dog seemed to have accepted our puppy and was pretty indifferent to him as long as the pup left him alone.

Then, once my puppy hit about 18 months old, they would even nap together on the same bed.

This was not because they were good friends but because my older dog would be sound asleep and Remy would sneak in for a cuddle. Once Ace woke up with Remy right there, he seemed to tolerate it as long as Remy was calm and quiet.

September 2016 update: Things are going much better! Ace is no longer showing aggression.

OK …

What do the rest of you have to add to this?

I love hearing from you! Let me know your experience or concerns in the comments.

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Older dog is aggressive to my new puppy


  1. Zuke’s minis treats.
    Zuke’s minis are treats almost all dogs are willing to work for and focus on!
  2. Treat bag.
    Carry your treats in a convenient treat pouch around your waist so you’re always ready to reward your dog for heeling, coming when called or paying attention to you.
  3. Gentle Leader.
    A Gentle Leader helps a lot of dogs learn not to pull on the leash.

Other resources:

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Lindsay Stordahl is the founder of That Mutt. She writes about dog training and behavior, healthy raw food for pets and running with dogs.

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Emily McCraw

Tuesday 2nd of March 2021

Thank you for this article. I just got a 12 week old standard poodle puppy and he is obsessed with his 3 year old rescue sister. His sister is dog reactive and was a stray so she has some resource guarding issues with unfamiliar dogs and people.

She has done the same as Ace, a bite on the head but no actual injury. It scared me and really discouraged me. But your article helped. They have gotten along super well in the backyard and I couldn’t figure out why! Then I realized there were no resources to guard in the backyard. So i took away food bowls, toys and such and we haven’t had any out of the ordinary corrections from my rescue dog. Your article gave me hope!

Lindsay Stordahl

Tuesday 2nd of March 2021

So glad I could help and best of luck! Hang in there!

Julie Pear

Monday 28th of December 2020

I have a 6 year old springer Finn and have just adopted a puppy cocker spaniel Eddie who is 11 months old now. We have had him 7 weeks now and they are generally ok but every now and them my springer will attack him and we are slowly learning it tends to be when the puppy comes to us when Finn is there. He seems to be recourse guarding us and Eddie has learnt to keep away. He is not feeling comfortable coming into the front room and will go and sit on his own upstairs or in the kitchen. We have taken advice and are trying to stop Finn owning the sofa and us by keeping distance between us. I am just worried that Eddie will get too nervous and not want to come anywhere near us with Finn around. How can we stop Finn doing this and how should we react when he does do it? Will it subside when Eddie grows up? Also Eddie has not been castrated yet and we are wondering if this will help Finn not want to attack him. Eddie has a crate we use when we want to give them treats or go out but he does not go in there on his own accord.


Monday 30th of November 2020

Thank you so much for your response. Since the weekend the puppy has gone to my son's home. It got to be too much for the older one. Thank you again!!

Lindsay Stordahl

Tuesday 1st of December 2020

Oh I'm glad you found a solution.


Wednesday 18th of November 2020

Hello, I have a female 4 year old lab/pit mix that is having some aggression issues when the new lab puppy comes in the house. She growls and shows her teeth when the puppy gets to close. She does not like sharing my husband and I at all. They both went outside yesterday and with my back turned my older dog bit the puppy right by the eye and on her mouth. Of course natural reaction is to scold the older dog and hug on the crying puppy. We truly adore the puppy and love our older girl bunches. Can anyone give some advice as to what to do or how long this may last? Thank you

Lindsay Stordahl

Wednesday 18th of November 2020

I'm so sorry to hear that, I'm sure it's so stressful for you all. For our situation, it got better once the puppy was about 6 months old and not so little. The older dog was still grumpy, but I didn't have to worry as much because the puppy was not so tiny. Also, the pup seemed to learn how far he could "push" the older dog. But I would suggest you supervise and do all you can to prevent the puppy from bothering your older dog for now. Keep the puppy leashed quite often when they're together and use toys or your voice to keep your puppies attention away from the adult dog when she's not leashed.

Good luck! I hope things get better. If you're able to take them for walks together, that often helps them bond and there's usually less aggression since the adult dog is focused on the walk and moving/exploring.


Monday 16th of November 2020

Hi there! so glad I found this article. My 3 year old shih tzu ( Jax )has been showing aggression towards our new shih tzu pup ( Shadow ) who is 8 weeks old. They are father and son. A little backstory: we had a shih tzu who was also Jax's son he was 6 months old when he passed earlier this year unfortunately to parvo. We were devastated because we all lost our best friend. We decided to mate Jax one more time because we did not want him to be alone and wanted the father son dynamic. We recently got Shadow but he has NOT been taking to shadow as well as he took to Loki. Which is so strange to me. Jax and Loki were best friends, played all dayyyy, and got along so well they shared toys and all. Of course, there was an occasional redirection here and there but best friends nonetheless. Jax and Shadow spend most of the day at my parents ( we call it daycare) and has one issue there and one issue in our home. We keep them separated for the most part and they have played before and have had good interactions. We watch them like hawks and feed them separately because i am afraid jax might hurt shadow. Shadow is still a baby so he sleeps most of the day in his crate but what happens when he gets older. Jax has been aggressive towards humans before and bit us plenty of times but he got a long so well with Loki i thought it would be the same with Shadow.

Lindsay Stordahl

Monday 16th of November 2020

So sorry to hear you lost Loki. Congrats on your new puppy. I think if you give it time they will get better. I would walk them together once Shadow is able to do so (not sure on vaccinations). Walking seems to be a time when dogs will work together, usually anyway.

Best of luck and I hope it all works out!