What is wrong with Max?

*sorry, i missed the part about him biting his owner when I submitted this answer. It doesn't sound good. Please be careful and don't get your hopes up that you and the dog can be friends again. The kindest thing may be to let him go unless they can find a definite and treatable medical condition as the cause.

It's very sad to see this happen but at his age it could be dementia or some other neurological problem causing his change in behavior. I've seen this happen from time to time and unfortunately sometimes it's very difficult to determine what may be the cause and therefore, what the solution is. I've seen dogs who've gone through heartworm treatment do this, they even turned on their owners. Heartbreaking.

Regardless, it's a dangerous situation and likely to elevate. IF the dog isn't showing any problems with his owners, they should just put hiim in another room when you or other friends come over. Don't continue to subject him to the people that cause him distress.

But primarily, he should have a thorough examination by his vet first. Then, he will either need to be carefully managed, or if the behavior elevates, sadly he may need to be put down.

Max may sense your intimidation and he feels the need to act as top dog. Or something may be wrong.

Have the owners take Max to the vet to get the OK. If nothing is physically wrong, try and tap into an animal behaviorist to try and figure out what is causing this dog to turn on you and others.

YOur friend should have his dog seen by a vet. This kind of temoperment change can be a sign of sickness.

I know of 2 dogs that did htis and they both were found ot have brain tumors. Unfortunatly both owners waited to long and after they had bit over 5 people in a year for one and a year and ahalf for teh other. teh tumors had gotten to big.

Early diagnoses may have possibly saved them.

A sudden behavior change like that merits a trip to the vet. Sudden aggression could be his way of telling everyone he's not feeling right.

I would suggest to your friend to make an appt. with their vet. To start acting aggressive is a sign of illness.

he probably senses your fear so first he should be tethered when you come by so you can walk by without being afraid. when he behaves as you walk by, he should be rewarded. i'd ask your friend when max had a vet check up last, maybe hes not feeling well.

Could be related to him getting older.. Could be pain.. could be there is something wrong with him healthwise.. A vet will be able to better answer your questions.

i dont think you can but maby they can my dog had the same problem ask your vet or have it have the death shot

sudden aggression is a symptom of rabies