I was wondering whats the length of time a cat can have cancer? My cat would shake her head and saliva would fly. Thats been going on for at least a year. We told the vet that and she thought it could've been a symptom. We thought nothing of it till she started slobbering. Could they have it that long and not know it? I read someone had a cat with cancer 9 months before they really had to take it to the vet because of noticable symptoms. Please help. Thanks