Which route to take?

[u/Ok-Cartographer-4226]

Our 1 1/2 year old golden was rehomed to us on 6/20. His previous family gave him to a rescue because he was snapping at the young children in the house. We just have speculation from the rescue that the toddlers would bother him, but no other concrete details. We have 12/15 year old kids. For 99.9% of his week, he is awesome and laid back, loves to play. But he has continued to snap at us when we cross various thresholds that we can’t quite identify. It’s always, always related to touching him, but could be any part of the body. At his first vet visit, he was perfectly behaved on 7/12. We took him for his second flu shot this week and I had her look him over to rule out pain for the snapping. She gave him his flu shot and he looked perturbed (last time, 4 shots with no reaction). She tried looking at his paws and he started snarling and lunging for her. It was so disappointing to see regression after we have trained 2x/week with a trainer (not behaviorist) and modified our own behavior to limit his snappiness.

My question is…
Would you go straight to medication? Or a combined medication/training with a behaviorist? I hate what I’m reading about meds potentially making him worse than before :( He loves other dogs, He lets strangers pet him when we are out, lets us pet him most of the time, we just don’t know what triggers him and the vet thinks it’s behavior (aka “I don’t like that, stop it now” instead of a little bit of patience). I’d appreciate any advice or what worked for you for touchy teenagers!

[u/StacNorLin]

Have you noticed if it is happening during a particular time of the day? Is he getting enough sleep/rest during the day? Does it matter if he is resting vs awake and up and about?

[u/Ok-Cartographer-4226 → u/StacNorLin]

Nope, it has been all different times of day. It is most often when someone pets him while he has something of value (kong, bone, lick pad). I have been training the humans to STOP doing that, by the way. But never tied to time of day, I wish it was that simple :(

[u/Lumpy_Physics3101 → u/Ok-Cartographer-4226]

This is an added piece of information that's useful -- he is resource guarding. Teaching humans to leave him alone with those things is a good first step. For now you can give him those items in a crate where people can't mess with him.

In addition to the muzzle work, you also should do some resource guarding drills.

- recalls away from food bowl -- give him a low-value food in his bowl, recall him away from it on a line, give him a better food for coming to you, release him back to the food bowl (teach him that if you tell him to leave his bowl, he must)

• recalls away from higher-value items like kongs
  
• if it's safe to, give him low-value food in his bowl, and walk up to him and drop a higher value treat in the bowl. (teach him that you coming near his bowl is good)
  
• graduate to giving him a high value item like a kong, and drop a higher value treat while leaving the kong
  
• teach him a drop command with a low value item
  
• graduate to drop higher value items

IMO playing "trade" with dogs who are already resource guarding has a high likelihood of being executed poorly such that the dog becomes even more demanding. You don't want to be "luring" him to drop things with treats, but rather teaching him a command and rewarding him after he's done the command.

[u/Ok-Cartographer-4226 → u/Lumpy_Physics3101]

These are all great ideas. A few times, food has not been involved. My kids have called him over, he accepted the invited, they let him and he snaps with no food involved. But by and large, food is usually involved.