As I understand it (and I’m NOT a vet, but I’ve had conversations with a few veterinary nutrition experts about this since my dog has a food sensitivity), dogs are more likely to be allergic to the protein source than the grains. Chicken, beef, and lamb seem to be the most common protein allergens.
I’m a fan of waiting. If you can be 100% certain to keep him contained in the event he smells a bitch in heat in the neighborhood, it’s good to let him keep his hormones until fully grown.
(People who neuter for behavioral reasons are lazy trainers. Marking is a training issue, unmanaged attitude problems are due to lack of engagement, etc.)
I know someone who lost her puppy to distemper after a series of shady vaccinations using only what was available at Tractor Supply.
If you love your pets, don’t use vax from Tractor Supply.
Are you wearing his brain out prior to bedtime? I don’t mean a run in the yard – I mean puppy push-ups (sit/down/sit/stand, rinse repeat for a good 15 minutes) or something similar at this age.
If she’s pulling while on a prong, it’s likely not positioned correctly. It might also have a larger link size than she should have. Go with a smaller link and position it right behind the jaw. Make sure to have a backup slip lead on, just in case. Work on this in the yard before going on a walk.
I suspect she has far too much freedom and too few rules. You’ve gotta go back to square 1 with obedience. Utilize trades (not food) instead of just taking things from her. Crate her if she’s chewing something. Consider umbilical training to prevent bad behavior, and praise the heck out of good behavior. Since group classes are not a thing in most places right now, look into Fenzi Dog Sports Academy. It’s an online-only school, and they might have something that will work for you.
Beyond that, try looking here for trainers: https://www.canineprofessionals.com/find-a-professional
I feed the food the dog does best on. If that means Victor, or some other grain free brand, then that’s what it means. (Though I’m really not a fan of Victor.)
I have been a fan of Merrick for a long time. Try them, or Castor + Pollux, their other brand. If you think your dog is allergic to chicken, make sure you read labels carefully – LOTS of brands use chicken fat in formulations which do not list chicken as a main ingredient, and even a little of it will make our girl break out in hives and have loose stool. I can feed grain-inclusive foods as long as they’re limited ingredient.
Then I would look at the neighbors’ homes. Because unless she’s contained in a cage of some sort, she can and will get away from the house for a while. It happens with every outdoor cat.
First, and most importantly, I’m very sorry for your loss. It’s hard when we don’t know the cause of our pets’ death.
Unless you’re watching her at all times – literally 24 hours a day – or you keep her inside, where she should be, there’s no way to say she isn’t going away from your home.
That said…due to the blood from the mouth, I would wonder if this is the result of rat poisoning. Is there ANY chance of rat poison around your home?