Panleukopenia (Feline Distemper, FPLV, Feline Parvo, FPV)

Updated: Apr 8, 2020


Panleukopenia or FPV is a highly contagious virus that often affects kittens under the age of one. It is a very resistant virus that can be fatal (1, 2, 3).


This virus is most commonly seen in kittens under the age of one, once maternal antibodies are gone. It more commonly however affects those between the age of 3-5 months (4).


Initial symptoms include: Loss of appetite

Lethargy Diarrhea which may contain blood Vomiting (3, 5) Clinical Symptoms include: Low electrolyte and protein counts (indicative of dehydration from vomiting and diarrhea) Low white blood cell counts (leukopenia)

Low blood platelets (thrombocytopenia) (3,4)

Other symptoms can include: Fever Abdominal pain Nasal secretions Eye inflammation Other motor incoordination like drooping head or trouble walking

(5, 6) Extreme and poor prognosis Symptoms include: Low body temperatures Septic Shock Formation of blood clots (7)

Mothers who are pregnant can spread this virus to their unborn young. Unfortunately this often results in reabsorption of the fetus, mummification, abortion or stillborn young. In kittens that may survive this event, movement impairment can include loss of balance and muscle tremors in addition to neurological conditions affecting the cerebellum. This is extremely rare as mothers often pass immunity instead to their young. (6, 8, 9).


In general the incubation period (the period in which exposure to a virus occurs and the development of symptoms) is on average 5 days with a range of 2-7 days. In rare cases this period can be 10-14 days (6, 10, 11, 12).

FPV is a very hardy and resistant virus (7) that can be found in and around all environments that aren’t regularly disinfected (13). After the infection enters the body via the nasal or orally pathways, the virus then colonizes various tissues where it then moves to the blood, gastrointestinal tract, bone marrow and other bodily organs. Once this occurs virus symptoms develop within 3-5 days. It then rapidly spreads affecting the small intestine and white blood cells (11). There are many ways to contract FPV. While on the rarer side, some strains of canine parvo can pass to cats (14, 15, 16). More common routes of infection include:

  • Direct contact with fecal matter or urine from an infected cat

  • Nasal secretions/droplets including saliva and mucus

  • Urine

  • Fleas that have fed on an infected cat

  • Contaminated clothing, food/water bowls, litter boxes, toys, bedding etc.

  • It can be brought into your home on your shoes and clothing

  • Transmitted from family or friends who have visited another cattery, shelter, pet store, any place that allows animals who are/had been sick (6,10).

  • Vaccination (vaccine induced or from shedding)

  • Stress (due to surgery, moving, being in a new home etc.)

  • Use of immune depressing pharmaceuticals such as drugs (especially corticosteroids), vaccines, deworming products, flea, tick and parasite products etc. (9).

  • Mother to offspring

For a quick test the SNAP®Parvo from IDEXX Laboratories, while approved for dogs, can detect FPV in feline fecal matter quickly so treatment can occur ASAP. Furthermore it does take into account vaccinated cats who will test positive whether they have the virus or not (17). A complete blood count or CBC helps to determine the white blood cell levels, a primary indicator of panleukopenia. Numbers will be low. In a majority of cases FPV can present an infection without presenting symptoms or clinical signs evident in healthy unvaccinated cats with anti-FPV antibodies (3). In an unvaccinated cat if antibodies are detected this indicates that the cat is infected with FPV or has had it in the past (18). A Fecal Antigen test should also be performed. It should be noted that shedding only occurs for a few days so despite an active infection tests can be negative (5, 17, 19). Polymerase Chain Reaction (PCR) testing, while expensive, is a DNA based and cultured test that can identify FPV with impeccable accuracy (11).


While there is supportive care, and antibiotic treatment for secondary infections, while self-limiting like any virus there are no direct treatments. NATURAL: Because there is no set therapy to remedy FPV there are many methods to support a cat or kitten with the virus. FPV is very similar to canine parvovirus so many natural therapies are modeled after those used for CPV. According to RJ Jamieson a long standing natural rearing dog breeder, it is best to be prepared ahead of time, especially as a breeder to have the following on hand: Several bags of Lactated ringers (5-10 would be ideal) -a heating pad or other way to safely and evenly heat the fluids. Cold fluids can put an already ailing animal in shock and also causes the body to work harder since it must warm the fluids first. This is also to keep the ill animal warm again without wasting valuable healing energy to keep the body temperature maintained. 2-3 IV Administration Lines 20 and/or 22 gauge hypodermic needles Various sized needleless syringes or eye droppers to administer oral fluids or medications (I prefer 1 mL, 3 mL and 10 mL syringes) Electrolyte solution (ES) or Coconut Water (in a pinch) 3 Sisters Colloidal Silver (CS) Herbal Tinctures (oregon, grapefruit seed extract, cat's claw, astragalus and echinacea) - a mixture will be made of 50% electrolyte solution, 50% colloidal silver and 4 drops of each tincture) and given orally. -Should the kitten or cat not keep this down than the 50/50 ES and CS mix will be given as an enema -Finally, if that fails proceed to administer subcutaneous fluids using the lactated ringer solution Homeopathic Remedies:

  • Aconite

  • Arsenicum Album

  • Baptisa

  • Belladonna

  • Carbo Vegetabilis

  • China

  • Ipecac

  • Mercurius (Sol or Viv)

  • Phosphorus

  • Podophyllum

  • Sulphur

  • Veratrum Album

For a complete description of each presented by Kathleen Borys view


Australian Bush Flower Emergency Essence

Administered 2-3x a day for mild cases, or every 1-2 hours if more ill. There is little to no guideline for the above as EACH CAT OR KITTEN IS DIFFERENT. You need to know when fluids are needed and how aggressive you need to treat your cat or kitten. A combination of the above supplies will be needed during this intensive period. Dr. Susan Wynn DVM provides a protocol as well. You will need: Aconite 30 C Phosphorus 30 C Arsenicum Album 30 C Administer a dose (3-5 pellets) every hour for four doses. After any kind of vomiting has stopped administer one dose of liquid bentonite clay.

Amber Naturalz also has several products and a protocol as well for FPV. This includes combining their product Kitty DT with hydration and antibiotics (such as colloidal silver or the company’s Vibactra Plus) Kitty DT at the extreme should be given every hour orally or as an enema for 1-2 days straight. NOTE: Hydration is one of the most important aspects of FPV therapy. Without it you can lose a kitten faster to dehydration than FPV. Dehydration also causes the body to work harder, shut down faster and lead to mortality. Hydration can be done Subcutaneously (sub-q), Intravenously, orally and as an enema. IV, Orally and Enema should be considered first for faster absorption but if they are not tolerated Sub Q fluids would be the next option.

NOTE: Enemas should be performed after checking hydration by first looking at the gums and performing the skin pinch test. Enemas can be performed with a clear standard syringe. Make sure the kitten’s spine is straight and the syringe is lubricated when administering. If an enema is performed and the fluids leak out either it was given too fast (must administer slowly) or the intestines have twisted. If the second is the case, immediately seek veterinary attention. Do not use 24 hours straight, only use it if the kitten is obsessively vomiting. The end goal is keeping them hydrated enough to keep oral fluids down (9).

Other products to use and have on hand include:

Vira-X, a natural anti-viral from The Two Crazy Cats Ladies CONVENTIONAL TREATMENT

Most companion owners opt to seek emergency veterinary care for FPV. This often involves:

  • Continuous hydration therapy via IV fluids

  • Nutritional therapy via tube feeding and vitamin administration

  • Restoration of electrolytes, blood sugar

  • Prevention of secondary infection with IV antibiotics (such as amoxicillin/clavulanic acid, piperacillin + aminoglycosides, fluoroquinolones, cephalosporins or piperacillin/tazobactam)

  • Blood transfusions (25)

While not approved for use by the FDA for felines (approved for canines), recombinant feline interferon omega (rFeIFN; 1 MU/kg/day SC for 3 days) has been shown to be a very effective treatment (6). If there is an outbreak, unvaccinated kittens or cats can be given anti-FPV serum containing FPV antibodies. This can provide 2-4 weeks of protection (26,27).

NOTE: While a long lasting immunity is mounted, post treatment shedding can occur in the feces for up to 6 weeks. So it is best to keep the recovered cat or kitten isolated from others. (6, 28).

TREATMENTS: ENVIRONMENT NATURAL A Mixture of distilled vinegar, water, and hydrogen peroxide (9) can be used as a spray, mopping solution etc. CONVENTIONAL You can use a 1:32 dilution of household bleach (6% aqueous sodium hypochlorite), 4% formaldehyde, and 1% glutaraldehyde for 10 minutes at room temperature. (MAKE SURE YOU HAVE GOOD VENTILATION)

FPV is very resistant to common disinfectants however peroxygen disinfectants and those containing peracetic acid, formaldehyde, sodium hypochlorite, or sodium hydroxide can also be effective (29).

In addition make sure you are rigorously cleaning your shoes and clothing. You can pour the bleach mix in a bucket or container with a towel so you and others can disinfect your shoes when entering the home or cattery (9). After any treatment it is important to isolate your companion from others for at least 2 weeks to prevent any spread of the virus. In addition it is important to bathe your companions to remove the virus from the skin, fur, feet, face etc (11).


Many factors influence the prognosis of those infected with FPV including:

  • Age

  • Overall health

  • Diet

  • Strain of FPV

  • Immunity from mom

  • Previous vaccinations

  • Prior exposure to the virus

  • Stress

  • Individual predispositions (5, 6, 13)


Survival rate taking into these factors is between 40-90% (11). Mortality of affected litters are between 20-100% (20). In cats with quick onset and short duration a mortality rate of 25-90% is expected. Those with peracute or severe onset is often a 100% mortality rate (21, 22). In one study survival of infected cats was 51.1% but concluded that there was no correlation between survival and age, vaccination status or degree of the presenting symptoms (3). Supportive care greatly increases the chances of survival (23). In addition if a cat or kitten survives the first five day, recovery is further increased (24). After infection most cats not only have a strong immunity to the virus, but suffer no long term effects (11) and there is also absolutely no evidence that a cat is a carrier after recovery (4).

While there are FPV vaccines, not only are there few sources for single FPV vaccines (there mainly exists combo vaccinations like the FVRCP vaccine) most FPV vaccines are modified live vaccines. This means they contain a small amount of the live virus. You can choose an injectable product (Subcutaneous) or intranasal (in the nose or eyes) product. Intranasal vs. Injectable The intranasal vaccine is administered in the eyes or nose. There is some debate if the intranasal vaccine should be used. It is recommended only to use intranasal vaccines for respiratory viruses since the mode of acquisition is through the respiratory tract. In addition, the intranasal vaccines often cause sneezing and watery eyes after administration as well as oral lesions (that eventually resolve). Finally, they seem to be less effective than injectable vaccines. (34, 35, 36). Alternatively they have no risk of injection site sarcomas nor kidney damage like the injectable vaccine. It is also a beneficial administration method in catteries with herpes or calicivirus because it supposedly stimulates an immunity quickly without interfering with maternal antibodies allowing them to be administered in kittens younger than 8 weeks (37). Unfortunately this also increases the risk of shedding. About 2 weeks from administration, the virus can be shed in the feces of your companion and can infect another animal. This is uncommon but due to various factors can occur (9). Many vets including Lisa A. Pierson, a well know feline vet, recommends only using modified live vaccines with NO adjuvants (these are ingredients that cause an inflammation reaction in the body to stimulate the immune system). Due to the specific ingredients of adjuvants and inflammatory response, malignant tumors or injection site sarcomas are not uncommon. SIDE EFFECTS OF VACCINATION MINOR/MODERATE SIDE EFFECTS Itching at injection site Swelling at injection site Vomiting Diarrhea Lethargy Fever Lameness (38)


MODERATE SIDE EFFECTS Swollen features Itching Allergic reactions SEVERE SIDE EFFECTS Shock to the lungs causing Coughing (potentially involving blood) Difficulty breathing Collapse Death Shock of the Intestinal Tract Violent vomiting (potentially involving blood) Violent diarrhea (potentially involving blood) Immune Mediated Hemolytic Anemia Immune Mediated Thrombocytopenia (platelets)