Feline Leukemia Virus: Symptoms, Transmission, and Treatment - Everything You Need to Know
Feline Leukemia Virus: Symptoms, Transmission, and Treatment - Everything You Need to Know
Feline leukemia virus (FeLV) is one of the most dreaded diseases that can affect cats, accounting for nearly one-third of feline cancer deaths. First reported in 1964, this complex and commonly misunderstood disease remains one of the most studied feline health concerns, despite the fact that the incidence in healthy, free-ranging cats is reported to be as low as 1-3%, though estimates vary by geographic area. Treatment options have progressed, but no therapy can cure or eliminate the virus from a cat.
Feline leukemia is not rampant in shelters, but it is a concern because it can go undetected in healthy carriers, as it remains a fatal disease. One of the biggest debates surrounding the disease is whether or not feral cat trap-neuter-return (TNR) programs and shelters should routinely screen test for the virus, and how to handle obviously healthy cats that test positive.
1. What Causes Feline Leukemia?
Feline leukemia is caused by a retrovirus that only infects members of the Felidae family. It is not believed to be transmissible to humans. It is easily destroyed in the environment, readily inactivated by heat, soap, most disinfectants, and drying. Even in the right environment, it can only survive outside the cat for 24-48 hours. For these reasons, cats can be safely housed in shelters with minimal risk of disease transmission, but only if they are kept in individual cages and strict rules about proper hygiene and hand washing between handling cats are enforced. Additionally, a long waiting period does not need to be observed before adopting a new cat into a home where a previously infected cat lived.
2. How is Feline Leukemia Transmitted?
The most common way FeLV is transmitted is through direct nose-to-nose contact between cats, mutual grooming, sharing contaminated water bowls, and litter boxes. The virus is shed in many body fluids, including urine, saliva, milk, tears and blood, as well as feces. It is more concentrated in saliva than blood. It can also be transmitted through contaminated needles, footprints, surgical instruments, or blood transfusions, and from mother to kittens through the placenta. Healthy cats that are infected and considered viremic will shed the virus constantly at levels as high as those in sick cats.
When a cat is infected with FeLV, it will test positive within a few days to a week, but if the cat is healthy and has a strong immune system, it will clear the virus in about two weeks and then test negative. In the case of latent carriers, the virus sets up in the bone marrow and may escape detection through routine testing. Latent carriers do not spread the virus because they are not contagious, and they may eventually clear the infection. A third outcome is that the immune system does not mount a good response and the cat remains persistently positive (viremic) and eventually gets sick. According to Greene’s “Infectious Diseases,” the mortality rate for healthy, persistently infected cats in a multi-cat household is 50% within two years and 80% within three years, although there is also evidence that many cats with proper care can live for years.
3. Symptoms of Feline Leukemia
The symptoms of FeLV infection can be very vague and non-specific, including vomiting, lack of appetite and weight loss, lethargy, anemia, etc. As the infection progresses, symptoms related to the organ systems that are affected by the virus may be seen. For example, if the intestinal tract is affected, diarrhea may occur. The most common cancers include leukemia and lymphoma. Abortions and stillbirths may occur. Due to the immunosuppressive nature of the infection, these cats are also susceptible to infections with other organisms, and often die of secondary diseases. If routine FeLV screening is not performed, it is always indicated for cats who are unresponsive to treatment for disease or those presenting with recurrent fevers and other clinical signs of illness.
4. Diagnostic Tests for Feline Leukemia
The American Association of Feline Practitioners (AAFP) recommends that the FeLV status of every cat should be known. Shelters decide whether or not to determine a cat’s status before adoption, if resources are limited, is this the best use of shelter resources. Screening testing should be a priority when cats are housed together or neutered before adoption. Regardless of the decision made, healthy cats should not be euthanized based on the results of a single test. A positive test only indicates that the cat has been infected with the virus, and tests are not always 100% accurate.
Vaccination or maternal antibodies do not interfere with testing so it can be performed in cats of any age. Queen cats and every member of a litter should be tested individually. It is best to test at least one week after exposure to FeLV. If a cat tests negative, it should be retested, with the final test occurring 90 days after exposure to confirm that the cat is truly negative. Any healthy cat that tests positive should have a confirmatory IFA test performed, which is considered gold standard. Discrepancies between ELISA and IFA test results should be resolved before making a final decision about a healthy cat.
5. Treatment and Management of Feline Leukemia
Treatment options are beyond the scope of this article. Treatment is not recommended in a shelter environment due to the stress of a shelter and the opportunity for these immunocompromised cats to become infected. Healthy FeLV-positive cats should be vaccinated (FVRCP and rabies), dewormed, neutered, kept indoors, and monitored closely for the development of other disease symptoms. They should be housed separately and not with FIV-positive cats. If adopted, they should go to a home with no other cats or a home with vaccinated cats. Kittens are at much higher risk of contracting the disease than adult cats, so homes with kittens should be avoided. Owners should be educated about the disease, its risks, and the cat’s prognosis, take their cat to their veterinarian twice a year for check-ups, feed a complete and balanced feline diet, and check the cat’s mouth regularly for dental disease. Stress should be avoided such as feeding raw, uncooked, or unpasteurized foods. Antiviral and immune therapies may be initiated if they become sick, but it should be remembered that while they can prolong and improve quality of life, they cannot offer a cure.
There is an FeLV vaccine. Cats should be tested before being vaccinated. Avoid vaccinating FeLV-positive cats. The vaccine is generally considered effective but not recommended for routine use in shelters. The vaccine has been associated with vaccine-associated sarcomas (tumors) and should be administered in the left lateral thigh to avoid amputation if a sarcoma develops.
Conclusion
Feline leukemia is a serious disease, but it doesn’t necessarily mean a death sentence for your cat. Early diagnosis and treatment can significantly increase a cat’s chances of survival. Understanding the transmission, symptoms, and treatment of feline leukemia, as well as how to prevent and manage the disease, is crucial for all cat owners.
Feline leukemia virus (FeLV) is one of the most dreaded diseases that can affect cats, accounting for nearly one-third of feline cancer deaths. First reported in 1964, this complex and commonly misunderstood disease remains one of the most studied feline health concerns, despite the fact that the incidence in healthy, free-ranging cats is reported to be as low as 1-3%, though estimates vary by geographic area. Treatment options have progressed, but no therapy can cure or eliminate the virus from a cat.
Feline leukemia is not rampant in shelters, but it is a concern because it can go undetected in healthy carriers, as it remains a fatal disease. One of the biggest debates surrounding the disease is whether or not feral cat trap-neuter-return (TNR) programs and shelters should routinely screen test for the virus, and how to handle obviously healthy cats that test positive.
1. What Causes Feline Leukemia?
Feline leukemia is caused by a retrovirus that only infects members of the Felidae family. It is not believed to be transmissible to humans. It is easily destroyed in the environment, readily inactivated by heat, soap, most disinfectants, and drying. Even in the right environment, it can only survive outside the cat for 24-48 hours. For these reasons, cats can be safely housed in shelters with minimal risk of disease transmission, but only if they are kept in individual cages and strict rules about proper hygiene and hand washing between handling cats are enforced. Additionally, a long waiting period does not need to be observed before adopting a new cat into a home where a previously infected cat lived.
2. How is Feline Leukemia Transmitted?
The most common way FeLV is transmitted is through direct nose-to-nose contact between cats, mutual grooming, sharing contaminated water bowls, and litter boxes. The virus is shed in many body fluids, including urine, saliva, milk, tears and blood, as well as feces. It is more concentrated in saliva than blood. It can also be transmitted through contaminated needles, footprints, surgical instruments, or blood transfusions, and from mother to kittens through the placenta. Healthy cats that are infected and considered viremic will shed the virus constantly at levels as high as those in sick cats.
When a cat is infected with FeLV, it will test positive within a few days to a week, but if the cat is healthy and has a strong immune system, it will clear the virus in about two weeks and then test negative. In the case of latent carriers, the virus sets up in the bone marrow and may escape detection through routine testing. Latent carriers do not spread the virus because they are not contagious, and they may eventually clear the infection. A third outcome is that the immune system does not mount a good response and the cat remains persistently positive (viremic) and eventually gets sick. According to Greene’s “Infectious Diseases,” the mortality rate for healthy, persistently infected cats in a multi-cat household is 50% within two years and 80% within three years, although there is also evidence that many cats with proper care can live for years.
3. Symptoms of Feline Leukemia
The symptoms of FeLV infection can be very vague and non-specific, including vomiting, lack of appetite and weight loss, lethargy, anemia, etc. As the infection progresses, symptoms related to the organ systems that are affected by the virus may be seen. For example, if the intestinal tract is affected, diarrhea may occur. The most common cancers include leukemia and lymphoma. Abortions and stillbirths may occur. Due to the immunosuppressive nature of the infection, these cats are also susceptible to infections with other organisms, and often die of secondary diseases. If routine FeLV screening is not performed, it is always indicated for cats who are unresponsive to treatment for disease or those presenting with recurrent fevers and other clinical signs of illness.
4. Diagnostic Tests for Feline Leukemia
The American Association of Feline Practitioners (AAFP) recommends that the FeLV status of every cat should be known. Shelters decide whether or not to determine a cat’s status before adoption, if resources are limited, is this the best use of shelter resources. Screening testing should be a priority when cats are housed together or neutered before adoption. Regardless of the decision made, healthy cats should not be euthanized based on the results of a single test. A positive test only indicates that the cat has been infected with the virus, and tests are not always 100% accurate.
Vaccination or maternal antibodies do not interfere with testing so it can be performed in cats of any age. Queen cats and every member of a litter should be tested individually. It is best to test at least one week after exposure to FeLV. If a cat tests negative, it should be retested, with the final test occurring 90 days after exposure to confirm that the cat is truly negative. Any healthy cat that tests positive should have a confirmatory IFA test performed, which is considered gold standard. Discrepancies between ELISA and IFA test results should be resolved before making a final decision about a healthy cat.
5. Treatment and Management of Feline Leukemia
Treatment options are beyond the scope of this article. Treatment is not recommended in a shelter environment due to the stress of a shelter and the opportunity for these immunocompromised cats to become infected. Healthy FeLV-positive cats should be vaccinated (FVRCP and rabies), dewormed, neutered, kept indoors, and monitored closely for the development of other disease symptoms. They should be housed separately and not with FIV-positive cats. If adopted, they should go to a home with no other cats or a home with vaccinated cats. Kittens are at much higher risk of contracting the disease than adult cats, so homes with kittens should be avoided. Owners should be educated about the disease, its risks, and the cat’s prognosis, take their cat to their veterinarian twice a year for check-ups, feed a complete and balanced feline diet, and check the cat’s mouth regularly for dental disease. Stress should be avoided such as feeding raw, uncooked, or unpasteurized foods. Antiviral and immune therapies may be initiated if they become sick, but it should be remembered that while they can prolong and improve quality of life, they cannot offer a cure.
There is an FeLV vaccine. Cats should be tested before being vaccinated. Avoid vaccinating FeLV-positive cats. The vaccine is generally considered effective but not recommended for routine use in shelters. The vaccine has been associated with vaccine-associated sarcomas (tumors) and should be administered in the left lateral thigh to avoid amputation if a sarcoma develops.
Conclusion
Feline leukemia is a serious disease, but it doesn’t necessarily mean a death sentence for your cat. Early diagnosis and treatment can significantly increase a cat’s chances of survival. Understanding the transmission, symptoms, and treatment of feline leukemia, as well as how to prevent and manage the disease, is crucial for all cat owners.
This article is original, please keep the link when forwarding:https://www.5zo.net/showinfo-3-87694-0.html