I’ve heard of it and have friends with a cat who needed a nebulizer treatment daily.

If you can afford a second opinion, by all means, but it’s not unheard-of.

Licking the spot usually means it’s irritating in some way. I’d absolutely get him to the vet.

Ah, sounds environmental for sure. I’d just feed a decent grain inclusive food.

Also? Talk to a cardiologist in your area.

I would do trials of various proteins to verify the allergies are, in fact, environmental, and then feed a limited ingredient kibble based on that. There are several on the market if you’re in the US. I know someone whose greyhound couldn’t do fish or chicken and did exceedingly well on Natural Balance.

A friend’s golden lost his life to a cardiac event after several years on a grain free diet, confirmed by necropsy that he had a heart attack. The problem with grain-free diets is the substitution of legumes as fillers – this seems to be the contributing factor for dietary DCM. Did you have a necropsy done to verify it was the heart?

I’m so very sorry. Assuming your dog had dietary DCM, DCM is the absolute worst. We lost our Doberman in the same way, to sudden death, but in her case it’s endemic in the breed and she was diagnosed a little over a year prior. If it’s any consolation, the arrhythmic form of DCM – also called sudden death – does not allow the dog to suffer. It’s over like someone flipped a light switch. I know that’s the form I preferred for my dog – it SUCKED for us, but it was an easy departure for her, and that’s what matters most.

I would start researching raw, if you have a dog in need of a very restrictive diet that cannot easily be satisfied by mass produced options. Do a L O T of research into raw, as it’s more complicated than feeding a kibble diet.

Please get this puppy to the vet.

This seems acute. I sure hope you got him in when your vet opened today.

I would be looking for an exotics vet yesterday.

First: get a full “senior” bloodwork panel done. Rule out anything medical.
Second: hide all trash and all food. Counter and garbage surfing are self-reinforcing. Lock the trash away, get a locking can. Remove all food from all counters and put them in a secure cabinet. Lock the fridge with a child lock, if necessary.
Third: Crate when you can’t supervise.

This is usually medical if it’s sudden like this, but you need to be proactive in your prevention, and it’s always a multiprong approach.