CASE # 7 Feline Leukemia Chapter 9

What is Feline Leukemia? Feline Leukemia is a retrovirus and is associated with both neoplastic and non- neoplastic disease (Immunosuppressive diseases) Lymphoma is the most common neoplastic disease – tumors can occur in the thymus, GI tract, or lymph nodes throughout the body Neoplastic: abnormal cell growth (could be tumor, example is Lymphoma, which is cancer), Non-neoplastic: other clinical signs, not abnormal cell growth Attacks the immune system

Feline leukemia: Transmission is vertical & horizontal Exposed cats may experience: Regressive infection(transient) Progressive infection(persistent viremia) Active infection with c/s Regressive: they are exposed to FELV but later clear the infection (Transient: lasting short time) Progressive: The virus is actively being replicated by the body and is being shed (not showing clinical signs) Viremia: virus within the blood stream Active: Showing signs, full blown infection.

Transmission: The most likely route of infection is through continued intimate contact such as grooming, sharing food and water bowls (virus sheds in saliva, urine, tears, blood) – this is horizontal transmission The virus can also be transmitted to neonates in utero and through the milk of infected queens – this is vertical transmission Uncommon Vertical is when it is passed from the mother. Vertical is passed from mother to baby either before or after birth. * Transmission can also depend on host factors: Age, Immune system, other diseases, viral strain and duration of exposure

Clinical signs: Fever Anorexia Weight loss Anemia Secondary infections(weakened immune system) Vomiting/diarrhea Spontaneous abortion Renal disease Tumors of lymphoid origin Neurologic signs (example: enlarged popliteal lymph node)-back of the hind limb Neurologic signs: Paresis to paralysis. Hyperesthesia: sensitive when touched.

DIAGNOSTIC TESTS CBC/SERUM CHEMISTRIES RADIOGRAPHS FeLV/FIV Test(Feline antigen) All cats that go outdoors or come from unknown backgrounds should be tested for FeLV and FIV when first examined by a veterinarian IFA(Immunofluorescent antibody)- This should be done if cat tested positive(3-4 months after initial test) Radiographs: check for tumors. CBC will show nonregenerative anemia. FeLV/FIV snap test: We test at 8 weeks old. IFA is done at the lab and it test for antibodies (antigen=active infection, antibody=exposure to infection: could indicate patient is in later stages) If the ELISA test is positive and you retest after 3-4 months, cat is negative for the antibodies, that is known as regressive. Essentially, they cleared the virus. (They built immunity). If they are positive, this would indicate that they do have Felv and are in the later stages of the disease.

DIAGNOSTIC TESTS Abdominal radiographs (if masses are palpated) CBC Nonregenerative anemia Leukopenia – this virus can affect the bone marrow resulting in feline panleukopenia-like syndrome FeLV ELISA positive Leukopenia: low WBC (weakens immune system). Test takes 10 minutes. FELV: antigen test. Snap test (DOVE 2 minutes) Bone marrow helps with RBC, cartilage, fat and bone production

DIAGNOSTIC TESTS TUMOR OF THE THYMUS – WOULD OCCUR IN THYMUS: helps with immune response TUMOR OF THE THYMUS – WOULD OCCUR IN A YOUNG ANIMAL INFECTED WITH FeLV

DIAGNOSTIC TESTS Intestinal mass

POSSIBLE OUTCOMES OF FeLV INFECTION 1. REGRESSIVE INFECTION - Cat may mount an immune response, clear the virus, and become resistant to future infection 2. PROGRESSIVE INFECTION - some cats fail to mount an effective immune response, become persistently viremic, but with no clinical signs Viremia: Virus goes into the blood stream.

POSSIBLE OUTCOMES OF FeLV INFECTION 3. Active infection – with clinical signs Outcome depends on: Age, immunocompetence, concurrent disease, viral strain, duration of exposure

TREATMENT NO CURE for FeLV Supportive care IMMUNOMODULATING DRUGS (none have proven efficacy in cats with FeLV) Human interferon-α – interferes with viral replication; given orally Acemannan – known to have antiviral, immunostimulant, and antineoplastic properties; given intraperitoneally (IP) Proprionibacterium acnes – killed form of this bacteria can be given to stimulate the immune system to fight disease IMMUNOMODULATING: modifies immune response

Treatment continued: ANTIVIRAL DRUGS -*can be toxic to bone marrow in cats AZT – antiretroviral ANTIBIOTICS POSSIBLE CHEMOTHERAPY You can also provide appetite stimulants. Cats might not want eat, especially if going through chemotherapy. Chemotherapy really only if the cat has a tumor (Lymphoma) Antiviral is used for both Felv and FIV: remember that. Antiretroviral: helps fight off retroviruses

CLIENT INFO & PROGNOSIS FeLV positive cats should be retested 3-4 months after initial test-just to see if still positive FeLV cats should be isolated from all other cats FeLV cats should be kept indoors FeLV cats should have reduced stress and regular vaccination and veterinary check-ups Life expectancy is approximately 2 years after diagnosis Healthy cats do not need to be euthanized Retest in case cat clears infection or if false reading. Stress could lead to virus flare ups. Basically, you will treat clinical signs until the patient shows no more or stops responding Only lives about 2 years. NO NEED TO RUN BLOOD WORK EVERY YEAR. https://www.youtube.com/watch?v=xiae6-mFL8w (FeLV video)

Feline leukemia vaccine: Vaccine can be given at 8 weeks of age Boosted one time 3-4 weeks later Even if an indoor cat, good idea to at least have this vaccine done every year for a couple years This is beneficial just in case the kitten were to get out of the house and risk exposure

CASE #8 Feline Immundeficiency Virus Chapter 9

What is feline immunodeficiency? FIV (Feline AIDS) Lentivirus associated with immunodeficiency Similar to HIV Species specific (Feline-derived cells) Acquired by horizontal transmission Intact males living outdoors are at greater risk Horizontal: direct contact. HIV attacks the bodies immune system. Humans can not get this.

Clinical signs: Gingivitis, stomatitis Pale mm Chronic fever Vomiting Diarrhea Chronic URI cachexia Chronic, unresponsive skin/ear infections Cachexia: weakness and wasting of the body.

TRANSMISSION Most infections are acquired through horizontal transmission among adult male, sexually intact cats Fight and bite wounds appear to be the major route of transmission. It is possible to transmit the virus vertically to neonatal kittens, but the virus is not easily transmitted this way(through milk) Although, antibodies against FIV can be passed and protect the kitten. This is important because the test checks for antibodies, therefor kittens should not be tested until 6 months of age. This way you don’t mistaken the antibodies from the mother. Once the maternal antibodies clear out you will get an accurate test.

DIAGNOSTIC TESTS CBC/SERUM CHEMISTRIES FeLV/FIV ELISA All unvaccinated outdoor cats should be tested for these diseases as they are contagious and without cure Kittens should not be diagnosed with this test until 6mths of age

DIAGNOSTIC TEST RESULTS CBC Nonregenerative anemia, lymphopenia ELISA positive THIS IS AN ANTIBODY TEST, not antigen – there will be interference by maternal antibodies and vaccination! Lymphopenia: low lymphocytes(immune compromised), If vaccinated, they can test positive. The FIV vaccine is not a very common vaccine. Vaccine has antibodies so test will be positive.

TREATMENT SEE FELINE LEUKEMIA VIRUS DENTAL SURGERY Whole mouth extraction of teeth may be necessary in cats with chronic stomatitis and gingivitis Just like Felv, Antiviral drugs are a form of supportive therapy for cats with FIV.

CLIENT INFO & PROGNOSIS Although FIV is morphologically and biochemically similar to HIV, it poses no threat to humans Infected cats may survive for prolonged periods before experiencing advanced stages of the disease Some may be asymptomatic for 10+ yrs Keep FIV+ cats indoors and free of stress and concurrent disease Prevention: vaccination, which will cause a positive antibody test! Show no signs for 10 years. https://www.youtube.com/watch?v=UW06wBpiaWI (FIV) Stop at 6 minutes

Review:FELV Retrovirus Could be cancer or not (masses) Direct contact(grooming)-horizontal Passed from mother-vertical Snap test: Antigen CBC: non-regenerative anemia WBC: leukopenia (all WBC low) Vaccine Snap test: Antigen

Review: FIV Lentivirus Chronic stomatitis Horizontal (cat bites) Vertical (From mother) Could help prevent disease with antibodies Snap: Antibodies (Kittens 6mths) CBC: non-regenerative anemia WBC: Lymphopenia (Lymphocytes low) Vaccine could lead to false positive (Not common vaccine) BOTH FIV AND FELV CAN BE TESTED WITH A SNAP TEST! BOTH FIV AND FELV: USUALLY WILL BE SEXUALLY INTACT BOYS LIVING OUTDOORS.