Discover more from Healthy Pets
Life-Threatening FPV on the Rise, Despite the Vaccine
In decline for 50 years, the highly contagious feline panleukopenia virus is reemerging, even though it's included in all kitten immunization protocols. Learn which cats may be at highest risk...
Cases of the feline panleukopenia virus (FPV) are on the rise again this summer, with veterinary clinics and shelters in some locations finding it necessary to pause cat intakes to deal with outbreaks
FPV is highly contagious and life-threatening, and is reemerging despite the existence of a vaccine against it that’s included in all kitten immunization protocols
Severe cases of FPV are most often seen in very young kittens, pregnant, and immunocompromised cats, and cats living in shelters or rescue facilities
Symptoms of panleukopenia are similar to those seen in canine parvovirus, and include vomiting, diarrhea, life-threatening dehydration, and high fever
At-home care of a cat recovering from FPV requires a high level of supportive attention and strict adherence to proper hygiene practices to prevent the spread of the disease to other cats
A couple of months ago, during the first half of July, animal shelters in both Oklahoma City, OK and Charlotte, NC experienced outbreaks of feline panleukopenia. In Oklahoma City, veterinary clinics and shelters saw an “overwhelming” number of cases — more than they’ve seen in years.
At the Charlotte-Mecklenburg Police Department's Animal Care & Control (CMPD ACC) shelter, the situation prompted staff workers to temporarily halt the intake of adult cats.
"This is not totally unexpected – every shelter sees their cases every year,” Dr. Julie Holifield, an ACC veterinarian told WCNC Charlotte. “Like parvo virus in puppies, it is everywhere in the environment and not so easily eliminated. Vaccination is our strongest defense against this disease."
A second county in NC also faced a similar outbreak, with the added twist that in addition to panleukopenia in cats, there were also some cases of canine parvovirus, according to Gaston County Police's Animal Care and Enforcement division.
A year ago in July 2021, an animal shelter in Virginia was forced to temporarily stop accepting cats due to an outbreak of panleukopenia.The same animal shelter had also ceased taking in cats for several weeks in June due to an earlier outbreak.
Panleukopenia is a highly contagious disease that is especially dangerous for kittens and doesn’t occur in dogs.
Disease Was in Decline for 50 Years
The feline panleukopenia virus goes by many other names, including FP, FPL, FPV, feline infectious enteritis, feline parvo, and most commonly, feline distemper. But despite what some of these names suggest, the organism that causes FPV isn’t related to the viruses that cause canine distemper or parvovirus. And to further confuse the issue, feline panleukopenia is caused by a parvovirus and much of the information on canine parvovirus can be applied to FPV.
In 2019, the Morris Animal Foundation warned that panleukopenia was making a comeback following a sharp decline after the FPV vaccine (now part of the “kitten shots” series) was introduced in the late 1960s.The resurgence doesn’t appear to be the result of a new strain of the virus, however, researchers at the University of Sydney are investigating the reappearance of the disease by studying the intestinal virome (collection of gut viruses) of FPV-infected cats.
This would seem to indicate the disease is occurring in vaccinated cats, but that’s just an educated guess on my part.
Cats at Highest Risk for Infection
FPV is ubiquitous and extremely stable in the environment. The organism can live for years in contaminated environments and can survive freezing temperatures as well as treatment with common disinfectants such as alcohol and iodine. Fortunately, a mixture of 1-part bleach to 32 parts water effectively kills it.
The virus is highly contagious and potentially life-threatening. It attacks rapidly, dividing cells in the body — especially those found in the gastrointestinal (GI) tract, bone marrow, and the stem cells of kittens in the womb. Because the virus affects blood cells, FPV can lead to anemia. It can also make affected cats more susceptible to other viral and bacterial infections.
The worst cases of feline panleukopenia are typically seen in kittens between two and six months of age, pregnant females, and the immunocompromised. Cats living in groups, for example, barn and feral cats, and those living in stressful shelter and rescue situations are at highest risk for outbreaks of the disease.
In healthy adult cats, FPV is usually mild and can even go undetected because there are no observable symptoms. Kitties who survive the infection are immune to further infection with the virus. Panleukopenia can also infect wild cats, as well as minks, raccoons, and ferrets.
The virus is shed in the bodily secretions of infected animals for up to six months following exposure. Cats can become infected through direct exposure to infected feces, saliva, or viral particles left behind on food and water dishes, towels, bedding, or surfaces around the home or shelter.
FPV can also be transmitted in utero from an infected mother cat to her kittens, as well as to newborn kittens when mom grooms them.
Symptoms to Watch For
The virus enters through a cat’s mouth or nose. The lymph nodes in the throat are affected first, and then over the next two to seven days, the infection moves quickly to the bone marrow and intestine.
In the bone marrow, the virus suppresses production of all white blood cells (“panleukopenia” means “all white shortage”), which are the immune cells required to fight the infection. Without white blood cells, the cat’s body can’t stop the progression of the virus.
In the intestine, the virus causes ulcers that lead to diarrhea, life-threatening dehydration, and overwhelming secondary bacterial infections. Death is usually caused by either dehydration or a bacterial infection that spreads from the gut to a cat’s systemic circulation. In infected cats, FPV causes symptoms much like those seen in canine parvovirus, including:
Refusal to eat
Significant weight loss
Neurologic signs if the virus attacks the brain
Your veterinarian will take a complete history, including your cat’s general health and whether he may have recently had contact with other cats or spends time outdoors. Since the virus causes symptoms also seen in several other conditions, including poisonings, feline leukemia (FeLV) and feline immunodeficiency virus (FIV), and pancreatitis, the vet will want to rule those things out first.
Routine laboratory tests include a complete blood count (CBC), a biochemistry panel, and urinalysis. In cats with FPV, bloodwork will typically show a dramatic decrease in white blood cells, and a low red blood cell count as well, indicating anemia. A fecal sample may also be taken to check for viral shedding.
Specific tests for FPV include immunofluorescent antibody testing, the polymerase chain reaction test, and virus isolation — however, they aren’t commonly used. As a rule, kittens with severe GI symptoms plus an extremely low white blood cell count plus anemia are considered probably infected with the panleukopenia virus.
Unfortunately, there are no antiviral protocols specific for FPV, so the only way a cat can survive is if she can be kept alive until her immune system is able to throw off the infection. At a minimum, this requires aggressive intravenous (IV) fluid therapy to prevent dehydration, and control of opportunistic intestinal bacteria.
Depending on symptoms, other medications may be required, including expectorants to help manage bronchitis or pneumonia, anti-emetics to help control nausea and vomiting, and whole blood transfusions for severely anemic patients. Sometimes nutritional support is required as well because the cat isn’t eating, and often pain management is necessary.
Patients with FPV must be hospitalized during this critical period and remain isolated from other cats. Integrative veterinarians may also use IV vitamin C therapy, ozone therapy, homeopathic FPV nosodes, as well as microbiome restorative therapy during this time to try to rapidly stimulating the immune system in a race to save the animal’s life.
Unfortunately, even with aggressive supportive therapy, FPV is almost always fatal in very young or immunocompromised kittens. Older cats with stronger immune systems have a much better prognosis, but even their chances of survival are not great.
Veterinary vaccine expert Dr. Ronald Schultz believes two well-timed panleukopenia vaccines given to kittens is the best way to protect most cats from the disease. Dr. Richard Pitcairn advocates the use of FPV nosodes instead. I use both.
At-Home Care for Panleukopenia Patients
For cats lucky enough to survive FPV, the good news is they’ll never catch it again. However, it can take weeks or even months for them to fully recover.
Once an FPV patient is released from the hospital, ongoing excellent supportive care at home will be necessary. Your cat will need plenty of rest in a quiet, warm area of your home, away from stressful situations and the daily household hustle and bustle. He’ll also need to be isolated from other cats until he’s fully recovered.
It's important that your cat eats well during recovery, and ideally, feeding a nutrient-dense, minimally processed fresher food diet is the best option for supporting the immune system. Adding in probiotics and medicinal mushrooms can also be beneficial.
It’s important to pet and cuddle your cat, because this disease has a particularly depressing effect both physically and mentally, and he’ll need attention and affection while he recovers. But with that said, you’ll need to practice very strict hygiene during his recovery from the infection.
It’s important to keep in mind that viral particles can remain around your home and on surfaces in the home for many months. Be sure you’re cleaning especially well anything that touches your cat and his belongings to avoid unintentionally spreading the virus to other kitties in the household.
Anyone coming into your home should use every precaution to prevent spreading the disease, including through contaminated shoes, and clothing. It’s also important to thoroughly disinfect hands and arms before coming in contact with non-infected animals.
Dilute household bleach can be used as an effective disinfectant. However, the best way to ensure you’ve truly eradicated the virus from your home is to replace all your cat’s belongings with new ones, including bedding, toys, dishes, towels, and litterboxes, once he’s recovered.
Healthypets Disclaimer: This information is for educational purposes only and is not intended to replace the advice of your own veterinarian or doctor. Dr. Karen Becker cannot answer specific questions about your pet's medical issues or make medical recommendations for your pet without first establishing a veterinarian-client-patient relationship. Your pet's medical protocol should be given by your holistic veterinarian.