Final answer:
The true statement regarding FeLV is that the FeLV vaccine is recommended only for cats at risk. The virus is primarily transmitted through saliva and blood, and while it can lead to various symptoms and diseases in cats, these are not limited to tremors and lethargy. The vaccination schedule can differ based on the vaccine and the cat's risk factors.
Step-by-step explanation:
The question asks which statement regarding Feline Leukemia Virus (FeLV) is true. The correct answer is that the FeLV vaccine is recommended only for cats that are at risk. FeLV is a retrovirus that causes an immunosuppressive illness in cats, and it is transmitted through saliva, blood, and, to a lesser extent, urine and feces. Cats at higher risk of exposure, such as outdoor cats or cats in overcrowded shelters, should be vaccinated. The vaccine is not generally recommended for all cats.
The statements that clinical signs of FeLV are associated with tremors and lethargy, and that the virus is spread via urine and feces are partially true but incomplete. While FeLV can cause a variety of symptoms, including a weakened immune system leading to various other conditions, it's not spread solely through urine and feces but also through more direct means like saliva and blood. As for the vaccination schedule, whether it's annual, biannual, or triennial, it can vary depending on the vaccine used and the risk factors of the individual cat, making this a nuanced topic.