Sudden aggression- please help

[mellongoose]

We have recently got a puppy. He is 4 months old. We have an older dog who is nearly 9 years old.

Everything has been going really well. Dogs get on and play. Dogs can be separated if pup becomes annoying etc.

The last couple of weeks the older dog has started to snap at some other dogs. He has never been like it before. I put it down to him being protective of pup. Today he and another dog (all spaniels btw) suddenly went into a proper dog fight. Really alarming. Teeth and saliva and snarling. It had to be broken up by me and the other owner, who was very understanding. I was really apologetic.

He has NEVER acted like this before.

He is still entire since he has never shown any signs of aggression. Not even close. The obvious thing seems to be to get him to the vet and have him done.

Is 9 too old/too traumatic?
Will it stop this behaviour?

I am a bit upset, so kind answers and constructive advice if possible.

Thank you 🙏

Are you walking the puppy at the time this is happening or is he being walked separately?

I would take him for a vet check to rule out a medical cause for this change in behaviour. I also wouldn't walk him for a good few days to give him time to decompress. When I started walking him again, I would walk him separately to the puppy and take him somewhere quiet where he won't see other dogs.

Neutering could make this behaviour worse if it is fear based, so I wouldn't consider that until I had ruled out a medical cause and potentially consulted a behaviourist.

@Leonberger

Are you walking the puppy at the time this is happening or is he being walked separately?

Together up until now. Tomorrow I will try separately.

@Happenchance

I would take him for a vet check to rule out a medical cause for this change in behaviour. I also wouldn't walk him for a good few days to give him time to decompress. When I started walking him again, I would walk him separately to the puppy and take him somewhere quiet where he won't see other dogs.

Neutering could make this behaviour worse if it is fear based, so I wouldn't consider that until I had ruled out a medical cause and potentially consulted a behaviourist.

I going to talk to the vet but was concerned they may suggest neutering regardless and I'm not sure it's definitely the answer.

Thank you.

I’ve had similar problems at times although not actual fighting as I don’t let mine greet strange dogs. It’s settled down over time with some training but it then flared up a little bit again when the puppy reached adolescence. Thankfully in the settled phase again so there’s plenty of things you can do! I would say overall it was about 3-4 weeks of misery to get to the other side and have the older dog ‘normal’ again.

Firstly it sounds like it’s either protective behaviour or perhaps an overload of everything going on causing him to have less tolerance for things? If he’s a bit stressed at home with the changes it can effect them a bit outside too as everything just becomes too much. My trainer explained it like having a glass of water, every time he feels some stress even small unnoticeable amounts without decompressing it’s filling the cup until eventually it bubbles over and you can get an outburst like what happened.

I also found my puppy getting excited/anxious in a situation made the other dog a bit more reactive, she could obviously pick up on the puppy emotions and reacted as she thought she should. I was also a bit more stressed dealing with two which probably rubbed off also.

I would walk them separately from now on and really work on getting him to focus on you when passing other dogs and at the same do the same with the puppy so when you bring them together both know the drill and can walk past calmly without winding eachother up.

In the nicest possible way I have found lots of spaniels grumpy with other dogs anyway so perhaps it’s a behaviour that you’ve not really noticed as much but now it’s escalated it’s become more obvious. Lots of dogs are quite happy to just ignore other dogs and that’s not a bad thing!

I wouldn’t rush to neuter either. It won’t help the behaviour unless it’s male dominance or sex hormone related aggression. If it’s something fear based your likey to make it worse. Mine was a spayed female and had similar behaviour to yours when the puppy came!

A qualified behaviourist opinion wouldn’t be a bad idea!

Any behaviour change requires a vet visit to rule out underlying pain. If he's playing with a much younger puppy at home, it's possible he may have injured himself or given himself aching joints by overdoing it a bit.

At 9 years old, it's possible he's struggling with a bit of arthritis and the pain could be causing him to lash out a bit. Remember, dogs mask pain really well so it could be that all the rough and tumble with pup has just exacerbated a long-standing problem.

I thought this might be a spaniel before you said it. Sounds like your older spaniel is jealous of the newer one and rather then take it out on the puppy is showing aggression to other dogs. Especially if both boys it’s a dominant thing.

I would try showing both dogs equal time and affection. Walk separately too. If it carries on take them to the vet to make sure it’s not something else.

My spaniel can get grumpy if I show too much affection to other dogs.

Thank you all for some really sound advice. We will start to walk them separately for a bit and see how that goes. He definitely gets plenty of space at home and plays nicely with pup when he feels like it. Loads of space outside. Room to get away when he's had enough. Baby gates to separate them inside and pup is crated at night.

He has been the most chilled spaniel I've ever owned and this was totally out of character.

Will also get him a check up to make sure he is not in pain. Mind you, he had his vaccination boosters in the spring and all was well then.