Final answer:
The main mode of transmission for feline leukemia virus is shedding of virus via saliva. It is transmitted through direct contact with an infected cat's saliva, such as biting, licking, mutual grooming, or sharing food and water bowls.
Step-by-step explanation:
The main mode of transmission for feline leukemia virus is shedding of virus via saliva. When an infected cat bites or licks another cat, the virus can be transmitted through the saliva. Direct contact with an infected cat's saliva is the most common route of transmission. It can also be transmitted through mutual grooming, sharing food and water bowls, or through casual contact like sharing litter boxes.