Oh my goodness! I’m so sorry about your son and the dog. I’ve had to put down four old dogs in five or six years and it’s never easy. My old Jack Russell was put down six years ago at 14 after knee surgery at 13. They did ACL surgery and he recovered fine but a year later, he started limping again. The surgery caused autoimmune disease of the nervous system. Two of my JRT/Feists are his nieces. I’m down to three dogs now instead of six and the three are house dogs. Now, one of my small dogs has a slipped kneecap and one doctor said do surgery and one said don’t. She doesn’t seem to be in any pain but goes on 3 legs when it’s stiff. No surgery unless it’s to stop pain.
The size of the Coyotes here with the wolf mixed in makes them extremely dangerous and they don’t have natural fear of people like the smaller Western version.
After a while, adopt another dog. It helps. It will help you and the dog.
{hugs}
They wanted to do ACL surgery on our dog for about $2500., some people told us he might favor it and then you will have to do the other leg.
Friend suggested Absorbine Horse liniment, rubbed area twice a day.
He was fine after a few weeks.
https://absorbine.com/products/absorbine-veterinary-liniment-gel?variant=41063895236769
Hubby and I use it when we get sore spots, works great.
Have recommended to others with sore limbs, can’t thank us enough.