What is his respiratory rate per minute?
Heart rate per minute?
Is he heartworm negative?
Do you keep him separate from the other dogs?
To get pulse, feel inside of his back leg up near his groin. Count beats for 15 seconds and then multiply by 4. I would not expect to see a big dog's over 60 even if excited.
Respiration should not be over, say, 30ish, except if panting.
Is he neutered?