I left my cat with my dad while i was on vacation, and the first day the cat was there he escaped outside. My dad found him asleep on a car. The cat started squirming when he picked him up, at which point my dad grabbed him by the scruff of the neck. Then the cat began attacking my dad. He said the cat was startlingly agressive and bit my dad about 15 times before my dad was able to shake him off. This is very uncharacteristic behavior.
A bit of background. I live in a house with another cat, who is also a 2 year old neutered male. The other cat in very aggressive, and viciously attacks my cat, therefore they must be constantly separated. The few times that they have interacted with eachother the ensuing fights re frightening and completely one sided (the other cat is a bengal, and much stronger than my cat). Despite the situation, my cat has always seemed very calm and relaxed and I havent noticed any changes in his behavior. He is a very passive, relaxed, sociable cat. he likes being picked up, petted, and allows me to rub his belly. He is playful, he has never shown any behavior like this before.
I am wondering what I should do about this attack. I am taking this very seriously, because I cannot have a cat who may randomly attack. Could the aggression toward my dad have stemmed from the situation at my house with the other cat? Could it have been stress from being at my dads house? Could my cat have been angry cause he hadnt been outside in 4 months, and was mad that my dad wanted to capture him? Also, my dad said that the aggression only started when he grabbed his neck, which makes me think he thought my dad was attacking him. Could this be an underlying aggressive streak that may not go away? Could he have some sort of medical condition? Im not sure what to do, i feel like I either need to move away from the bad cat situation at home, or put him down. Im going to make an appointment with a vet tomorrow, however I would appreciate any advice.