I would like to talk about one of the well-known viral diseases in cats, “Feline Leukemia.”
Feline Leukemia Virus (FeLV) and Modes of Infection
FeLV is an RNA virus that belongs to the Gamma retrovirus genus. It is transmitted through the saliva, tears, urine, and feces of an infected cat, entering the body through the mouth or nose.
Specifically, cats can become infected through biting during fights, grooming each other, or sharing dishes and litter boxes.
Additionally, an infected cat can transmit the virus to her kittens via the placenta or milk, and infection can also occur from the saliva during grooming.
FeLV is very unstable in the environment and loses its infectivity within minutes to hours at room temperature.
However, it can retain infectivity for a longer period in moist places like pet pads.
Furthermore, in 2002, a research team from Nihon University reported that cats infested by fleas have a higher tendency of FeLV infection (Maruyama, 2002).
Symptoms of Feline Leukemia (FeLV)
Early symptoms include fever, lethargy, lymph node swelling, and anemia, which last from a week to several months before temporarily subsiding.
Since the virus is not eliminated from the body, many cats experience recurrent symptoms, and some develop tumors like lymphoma or leukemia within a few years.
When the virus affects the bone marrow, it can cause aplastic anemia and leukopenia, leading to weakened immunity, making secondary infections more likely.
FeLV infection can also cause glomerulonephritis, progressing to renal failure, characterized by increased drinking and urination, loss of appetite, weight loss, and anemia.
If a mother cat is infected, it can lead to miscarriage or stillbirth, and kittens born may die early.
The virus remains latent and doesn’t manifest, making complete recovery difficult, leading to death within months to years.
FeLV infection is classified into four types based on the progression speed and characteristics.
1. Progressive Form
This is the most severe type.
The virus proliferates in tissues like lymph tissues, bone marrow, mucosal layers, and glandular epithelial tissues, compromising immunity. Most infected cats die within 3-4 years.
2. Regressive Form
The cat’s immune response suppresses viral proliferation before it invades the bone marrow, clearing the virus from the body.
The virus doesn’t replicate or get excreted.
3. Abortive Form
Although the cat is infected, tests cannot detect the virus, antigen, viral RNA, or proviral DNA. This type is rare after artificial infection.
4. Localized Form
The virus is confined to specific areas like the spleen, lymph nodes, small intestine, and mammary glands, but this is a rare case.
Risk Factors for FeLV Infection
– Male cats (2.4 times more likely than females)
– Adult cats (2.5 times more likely than kittens over seven months old)
– Free-ranging cats (8.9 times more likely than indoor cats)
Stray cats have a higher prevalence of FeLV than house cats, so it is crucial to check for the virus when rescuing stray cats.
Testing for FeLV
A blood test can determine infection status.
However, it cannot be detected immediately after infection.
The test can identify infection approximately one month post-exposure.
If the initial test after rescue is negative, a retest should be conducted after one month since a retest may yield negative even if initially positive.
Repeated tests confirming positive indicate definite infection.
When symptoms like lymphoma and leukemia are observed and tested positive, a single test may suffice for diagnosis.
For kittens, the presence of maternal antibodies may prevent accurate test results. Therefore, it is recommended to conduct tests one month after taking the kitten in and when the kitten is over three months old.
Treatment for Feline Leukemia Virus
Unfortunately, current veterinary medicine cannot eliminate the virus from the body.
Symptomatic treatment is provided to alleviate discomfort according to each symptom.
Main Symptomatic Treatments
– Interferon
– Antibiotics
– Anti-inflammatory drugs
– Antineoplastic agents
– Blood transfusions
– Intravenous drips
Impact on Other Species
Since it is a virus specific to cats, it is believed not to infect humans or animals other than those of the Felidae family.
How to Deal with Household Cats
As mentioned earlier, the Feline Leukemia Virus is a frightening infectious disease that can easily spread through grooming and fighting.
Therefore, if you have other cats living with a cat that is positive for the Feline Leukemia Virus, it is important to isolate them.
There is also a risk of transmission through food dishes and litter boxes, so ideally, it is recommended to keep the infected cat and other cats in completely separate rooms.
If you are unsure whether a new cat has the virus, it is recommended to isolate it until it tests negative for the virus.
However, if isolation from the infected cat is not possible and they have to share the same space, there are combination vaccines that include the Feline Leukemia Virus. For cats that test negative, vaccination can be considered.
However, it is important to note that even combination vaccines do not provide 100% protection against infection.
They help to create a state where the infection is less likely to establish and the disease is less likely to develop. Therefore, creating an environment where the infected cat does not come into contact with other cats is still considered crucial to prevent infection.
Vaccines are not only ineffective for cats that are already infected, but their safety is also not established. Make sure to get a test before vaccination.
Preventing Onset of Feline Leukemia
If the immune system is functioning properly, it is expected to prevent the onset of the Feline Leukemia Virus.
Conversely, stress can disrupt the immune balance and result in the onset of the disease.
Regardless of the Feline Leukemia Virus infection status, stress disrupts the immune balance and can lead to infections, autoimmune diseases, and tumors. Therefore, it is important to provide a stress-free lifestyle.
Take another look at your cat’s living environment and diet.
Maintaining a healthy gut environment is also essential for a proper immune system. There are tests available to examine gut bacteria, and it might be beneficial to have such a test done to check your cat’s gut flora, even if they are currently producing good stools.
The fundamental measure to prevent the Feline Leukemia Virus is to keep the cat entirely indoors to avoid exposure to the virus.
However, even if a newly adopted cat tests positive for the Feline Leukemia Virus, it does not mean that the cat will necessarily develop the disease 100%.
To ensure that your beloved cat lives its life to the fullest until the very end, strive to provide a stress-free lifestyle and enjoy “Nyan Life” with your entire family.
