
I am crying with you right now because I know this is an enormous and heart piercing decision.
If it helps, then speak with your vet and get an opinion if need be from another vet in the practice. Ask them outright what they would do if this were their own dog. It's awful, I know, but vets went into their amazing profession because of their love for animals and they are heartbroken too when the time comes to make this type of choice. They will be honest with you I'm sure in what's best for your little lad.
Should it be they agree it is time to say your goodbyes, were this me I'd be with my friend to the end. I had the choice taken from me once and would never want that again.
It is very personal - you should deal with it how best you feel able. I found that my pets were comforted by my holding them gently and talking to them. I somehow manage to hold back tears to be brave for them but it's hard to do, yet I feel very important that they don't sense our own fears and emotions.
I wish you strength of mind and soul in reaching a decision and peace in your heart whatever that may be.
Teri x