Symptoms & Treatments for Cat Leukemia: A Comprehensive

What is Cat Leukemia?

When it comes to cat leukemia, the American Animal Hospital Association (AAHA) has provided a clear definition:

Cat leukemia is a widespread, incurable disease that suppresses the immune system of cats. It is one of the most common causes of cancer in cats, accounting for over 30% of all cancers in felines.

Cat leukemia is caused by retroviruses, which produce a reverse transcriptase enzyme. This enzyme allows the virus to copy its genetic material into the host cells. Once the leukemia virus's RNA is transcribed into doublestranded DNA and inserted into the host DNA, it splits into DNA containing the virus, completing the transmission process.

Cat leukemia viruses are categorized into three subtypes: FeLVA, FeLVB, and FeLVC. Only FeLVA can be transmitted and suppress the immune system under natural conditions. FeLVB and FeLVC can only infect cats through recombination with FeLVA, meaning that if a cat has developed antibodies to FeLVA, it can combat all FeLV subtypes.

Cat leukemia viruses are specific and do not infect humans or dogs. However, due to the compromised immune system of infected cats, they may trigger a series of zoonotic diseases. Therefore, individuals with weakened or compromised immune systems should avoid contact with cats suffering from leukemia.

Currently, the infection rate of FeLV is approximately 2%3% worldwide, with a significant number of untested cats not included in the statistics. Therefore, the actual infection rate is likely higher. The mortality rate of cat leukemia is very high, with young kittens and kittens whose immune systems have not fully developed being more susceptible to infection, while adult cats have a lower chance of infection, less than 30%. There is currently only a vaccine for prevention, but no cure exists.

How Cat Leukemia Spreads

Cat leukemia viruses belong to enveloped viruses, which have a low survival rate in the natural environment, surviving for no more than three hours outside the body. However, due to their diverse modes of transmission, the spread can be quite extensive.

Saliva Transmission

Cats' social behaviors, such as grooming each other and sharing food and water bowls, provide excellent vectors for the virus's spread. This is also the primary mode of transmission. The amount of virus in saliva is significantly higher than that in plasma, so avoiding contact between infected and healthy cats can effectively prevent transmission.

MothertoOffspring Transmission

The virus can be transmitted directly through the embryo and during breastfeeding.

Blood Transmission

If a flea bites an infected cat and then a healthy cat, there is a chance that the leukemia virus will be transmitted. Blood transfusions can also lead to transmission.

Secretion Transmission

If healthy cats come into contact with infected cats by touching noses, the virus may be transmitted through the nasal secretions (wet noses). Other secretions like tears can also cause the virus to spread.

Feces Transmission

Cats may transmit the virus if they defecate in the same litter box or area.

Three Phases of Virus Infection

In the early stages of FeLV infection, some healthy cats can rely on their immune systems to fight the virus, but they may struggle against secondary infections, which is a major reason for the high mortality rate in infected cats.

There are generally three types of infection in infected cats:

Abortive Infection

This occurs in the initial three weeks of infection. If the cat quickly produces antibodies and eliminates the virus within three weeks without developing secondary viral sepsis, the antibodies can continue to protect the cat and lead to recovery.

Regressive Infection

This occurs after three weeks of infection. The immune system is unable to combat the leukemia virus, leading to secondary sepsis, and the virus may have already inserted itself into the cat's DNA. If the cat can rely on its immune system to defeat the virus, but the virus in the DNA can be reactivated during stress or a weakened immune system, the symptoms may reappear.

Cats in this stage generally do not transmit the virus.

Progressive Infection

This occurs after thirteen weeks of infection. At this point, the leukemia virus has started to replicate and infect other tissues in the cat, leading to persistent sepsis. If the virus is not cleared within thirteen weeks, it will accompany the cat for life, and cats with persistent infections will typically die within 23 years.

Symptoms of Virus Infection

When a cat's immune system is strong, there may be no significant symptoms in the early stages. However, as the immune system weakens, symptoms will gradually appear, including immune suppression, anemia, and lymphoma. These may lead to autoimmune hemolytic anemia, glomerulonephritis, uveitis, polyarthritis, and other immunemediated diseases.

Immunemediated diseases are rare in cats, especially in very young cats. If such diseases occur, it is advisable to consider whether the cat has FeLV.

Specific symptoms of cat leukemia, as summarized by the Cornell University College of Veterinary Medicine website, include:

Lack of appetite, weight loss, severe emaciation in the later stages, dry hair, enlarged lymph nodes, persistent fever, pale gums or mucous membranes, gingivitis and stomatitis, skin, bladder, and upper respiratory infections, persistent diarrhea, seizures, changes in behavior, and other neurological disorders, various eye problems: unequal pupil size, dilated pupils, Horner's syndrome, difficulties with pregnancy or abortion.

Many other diseases can also present with these symptoms, so it is best to conduct a blood test for feline leukemia or feline AIDS.

Treatment and Prevention of Cat Leukemia

There is no medication available to treat cat leukemia. The main treatment approach is to address the secondary symptoms caused by leukemia.

Secondary infections are treated with antibiotics, cat interferonΩ, or azidothymidine, depending on the specific situation. Cat interferonΩ and azidothymidine may reduce the virus and improve symptoms, extending survival time, but they cannot treat viral sepsis.

Of course, prevention is always better than treatment. The best way to prevent cat leukemia is to limit the cat's outdoor activities, spay or neuter at the appropriate age, maintain a balanced diet, and schedule regular checkups.

If your cat has unfortunately contracted the disease, please do not abandon it. Spend more time with your furry friend and ensure they have no regrets before they journey to the stars.