My kitten just got his first vaccine few hours ago. At first he seemed ok but now is lethargic and just wants to sleep. When i picked him up he started hissing when i touched his right shoulder i first thought he injured himself while playing and jumping around but then i also noticed a slight limp on his right side where the painful shoulder is and if i remember correctly thats the area where the vet gave him the shot. He ate but now just keeps sleeping. Is this normal ?