If you need a more accessible version of this website, click this button on the right. Switch to Accessible Site

WARNING

You are using an outdated browser. Please upgrade your browser to improve your experience.

Close [x]
(207) 846-6515 H
H

(207) 846-6515

INFECTIOUS DISEASE: FELINE LEUKEMIA VIRUS INFECTION


Feline Leukemia Virus Infection


Basics
Overview
-A retrovirus that causes inability to develop a normal immune response (known as "immunodeficiency") and development of tumors in domestic cats
Genetics
-No genetic susceptibility to infection by feline leukemia virus (FeLV)
Signalment/Description of Pet
Species
-Cats
Breed Predilections
-None
Average Age and Range
-Number of cases highest between 1 and 6 years of age
-Average - 3 years of age
Predominant Sex
-Male-to-female ratio-1.7:1 (that is, males are 1.7 times more likely to have feline leukemia virus infection than are females)
Signs/Observed Changes in the Pet
-Onset of feline leukemia virus-associated disease-usually occurs over a period of months to years after infection
Associated diseases-may be related to inability to develop a normal immune response (immunodeficiency) or to development of tumors or cancer
-Clinical signs of FeLV-induced inability to develop a normal immune response (immunodeficiency) cannot be distinguished from those of feline immunodeficiency virus (FIV)-induced immunodeficiency
-Signs depend on the type of disease (inability to develop a normal immune response [immunodeficiency] or tumor/cancer) and occurrence of secondary infections
-Enlarged lymph nodes (known as "lymphadenomegaly")-mild to severe
-Upper respiratory tract disease-inflammation of the nose (known as "rhinitis"), inflammation of the moist tissues of the eye (known as "conjunctivitis"), and inflammation of the cornea (known as "keratitis"; the "cornea" is the is the clear outer layer of the front of the eye), seen in 18% of cases
-Persistent diarrhea
-Inflammation of the gums (known as "gingivitis"), of the mouth (known as "stomatitis"), and/or of the tissues surrounding and supporting the teeth (known as "periodontitis")
Long-term (chronic), nonresponsive or recurrent infections of the external ear and skin; abscesses
-Fever and wasting (seen in 42% to 53% of cases)
-Lymphoma (a type of cancer that develops from lymphoid tissue, including lymphocytes, a type of white-blood cell formed in lymphatic tissues throughout the body)-most common FeLV-associated cancer
-Leukemia
-Fibrosarcomas (cancer that develops from fibrous tissue)-in pets co-infected with mutated sarcoma virus; most frequently in young cats
-Disorders usually affecting the nerves to the legs and paws (known as "peripheral neuropathies"); progressive wobbly, incoordinated or "drunken" appearing gait or movement (known as "ataxia")
Causes
-Cat-to-cat transmission-bites; close casual contact (such as grooming); shared dishes or litter pans
-Transmission of the virus from the mother cat (known as a "queen") around the time of birth-fetal and newborn kitten death from 80% of affected queens; transmission across the placenta or through the milk in at least 20% of surviving kittens from infected queens
Risk Factors
-Age-kittens are much more susceptible to infection than are adults
-Male-result of behavior
-Cat allowed outside; free-roaming cats
-Multicat household


Treatment
Health Care
-Outpatient for most cats
-Inpatient-may be required with severe secondary infections, low red-blood cell count (known as "anemia"), or extreme weight loss with muscle wasting (known as "cachexia") until condition is stable
-Blood transfusions-emergency support; multiple transfusions may be necessary
-Management of secondary and opportunistic infections-primary consideration; "opportunistic infections" are infections caused by organisms that usually do not cause disease, but are able to cause disease because the cat's body and/or immune system has been weakened, in this case by the feline leukemia virus infection
-Supportive therapy (such as fluids and nutritional supplements) may be useful
Activity
-Normal
Diet
-Normal
-Diarrhea, kidney disease, or long-term (chronic) wasting-may require special diet
Surgery
-Biopsy or surgical removal of tumors
-Dental cleaning, tooth extraction, biopsy of the gums
Medications
-Medications presented in this section are intended to provide general information about possible treatment. The treatment for a particular condition may evolve as medical advances are made; therefore, the medications should not be considered as all inclusive
-Zidovudine (Retrovir)-antiviral agent; may lead to clinical improvement, but does not clear virus
-Medications to alter the immune response (known as "immunomodulatory drugs")-may alleviate some clinical signs; interferon (Roferon) may increase survival rates and improve clinical status; Propionibacterium acnes (ImmunoRegulin); acemannan (Carrisyn)
-Mycoplasma haemofelis infection-suspect in all cats with low red-blood cell counts due to the destruction of red-blood cells, in which the body is producing new red-blood cells (known as "regenerative hemolytic anemia"); oxytetracycline or doxycycline; short-term use of steroids, administered by mouth, if needed
-Lymphoma (a type of cancer that develops from lymphoid tissue, including lymphocytes, a type of white-blood cell formed in lymphatic tissues throughout the body)-management with standard combination chemotherapy protocols; periods of remission average 3-4 months; some cats may remain in remission for much longer
-Blood disorders or disease and leukemias-less responsive to medical treatment; for low red-blood cell count (anemia), try erythropoietin (Epogen); for low neutrophil count (known as "neutropenia"), try Neupogen
-Yearly vaccination for respiratory and intestinal viruses with inactivated vaccines recommended


Follow-Up Care
Patient Monitoring
-Varies according to the secondary infections and other manifestations of disease
Preventions and Avoidance
-Prevent contact with feline leukemia virus--positive cats
-Quarantine and test incoming cats before introduction into households currently with one or more cats
Vaccines
-Several commercial feline leukemia virus vaccines are available
-Test cats for FeLV before initial vaccination; if prevaccination testing is not done, advise clients that the cat may already be infected
-Vaccinate kittens at 8-9 weeks and 12 weeks of age; administer booster FeLV vaccine at 1 year of age; revaccinate every 2-3 years thereafter


Possible Complications
-Exposure of non-feline leukemia virus-infected cats to infection
-Development of disease related to inability to develop a normal immune response (immunodeficiency)
-Development of tumors or cancer
-Death


Expected Course and Prognosis
-Cats that persistently have feline leukemia virus in their blood (known as "FeLV viremic cats")-more than 50% succumb to related diseases within 2-3 years after infection


Key Points
-Keep feline leukemia virus-infected cats indoors and separated from FeLV-negative cats, to protect them from exposure to secondary disease-causing agents and to prevent spread of FeLV to other cats
-Good nutrition is important
-Control secondary bacterial, viral, and parasitic infections

Office Hours

DayOpenClose
Monday7:306:00
Tuesday7:306:00
Wednesday7:306:00
Thursday7:306:00
Friday7:306:00
Saturday8:0012:00; Also, 4 pm Boarding Pick-up
Sunday4:00pmBoarding Pick-up
Day Open Close
Monday Tuesday Wednesday Thursday Friday Saturday Sunday
7:30 7:30 7:30 7:30 7:30 8:00 4:00pm
6:00 6:00 6:00 6:00 6:00 12:00; Also, 4 pm Boarding Pick-up Boarding Pick-up