Is that goat afraid of your dogs now?
was it afraid of them before this alleged attack?
Does the owner of the goat have proof (like
video or other witnesses) that it was your dogs or are they just going on the presence of your dogs as their "proof"?
These things are important, especially if there are other dogs in the near area.
You can also check your dogs teeth for signs of fighting, there might be gum wounds or missing teeth, which would indicate they might be the culprits.
Goats will fight back, head butting is one of their defensive moves as well as kicking (both front legs and back legs), so there could be injury to the attacking dog(s) that would show up, and yes there could be blood on the muzzles or even chest area of the attacking dogs.
In cases such as this it is important to find out as many facts as you can, and if the neighbor didn't eye witness the attack, see if you can get them involved in helping to find out what really happened (especially if you don't think your dogs did or would do such a thing).
I've seen innocent dogs be put down as dangerous animals and then the real offender was found performing their second attack.
This is where you need to think like a detective and do the work to get to the facts, no matter what they are.
Redhawk