Feline Distemper in Cats: Infection, Symptoms, and Treatment
What Is Feline Distemper or Panleukopenia?
Feline distemper is a serious disease that affects domestic cats as well as wild ones. It’s caused by a virus that is extremely widespread in the environment and is very contagious among cats. In fact, it’s thought that almost all domestic cats are exposed to the virus during their lives. The disease that develops is frequently life threatening and often fatal, especially in kittens. It is possible for a cat to recover from feline distemper, however. The good news is that a vaccine that provides excellent protection from the disease is available
Feline panleukopenia is the official name for feline distemper. The virus that causes the disease is called the feline panleukopenia virus, or FPV. It’s a member of the parvovirus family. The word “leukopenia” means a low white blood cell count, which is one of the major signs of feline distemper. "Pan" means that all types of white blood cells are reduced in number.
FPV can cause disease in house cats, wild cats, raccoons, mink, and coatimundis. It may also infect ferrets, although this isn't certain. The feline distemper virus isn't the same virus that causes canine distemper and it doesn't infect humans.
The Feline Panleukopenia Virus
A virus is a microscopic particle made of DNA (or a very similar molecule known as RNA) surrounded by a coat of protein. DNA contains the genetic code of an organism. It's found in the cells of animals, plants, and bacteria as well as in many viruses. Virus don’t consist of cells, however, and operate differently from cellular organisms.
In order to reproduce, a virus must send its DNA (or RNA) into a living cell. Once this happens, the cell makes new virus particles. The particles then escape from the cell, often destroying it in the process. The feline panleukopenia virus has a special affinity for cat cells that are in the division stage of their life cycle.
Transmission of the Virus
There are several ways in which FPV can be transmitted from one cat to another. The process can happen directly when a healthy cat inhales or swallows substances released from an infected one. These substances include saliva, mucus, urine, feces, vomit, and blood. An infected cat is said to “shed’ the virus, which means that it releases virus particles from its body. A distemper infection lasts for five to seven days, but the cat may shed virus particles for up to six weeks after it’s no longer experiencing symptoms of the infection.
The virus can also be transmitted on fomites, which are inanimate objects that carry infectious organisms such as viruses and bacteria. Fomites include cat bedding, cat litter, toys, food bowls, and water bowls. Viruses can exist without water, oxygen, or any of the other requirements of life. FPV is an especially hardy virus and is resistant to temperature extremes. The virus is still in an active state after being outside a cat's body for a year or more.
A female cat can transmit the distemper virus to her kittens while they are still in her uterus. Humans can transfer the virus from one cat to another on their shoes, clothing, and hands. Fleas may transmit the virus through their bites. Feline distemper is most common where unvaccinated cats live in close proximity, such as in a pet store, an animal shelter, or a feral cat population.
A cat may not become ill when the distemper virus enters its body. If it has developed an immunity to the virus its body will be able to destroy the virus particles. Cats develop immunity due to a vaccination or due to a previous, non-fatal exposure to the virus.
Cells divide to make new cells. The new cells repair damaged tissue and enable a body to grow. The feline distemper virus attacks and kills rapidly dividing cells in a cat’s body. Cells in this condition are found in the bone marrow, the lining of the intestine, and the nervous system of a kitten which is developing inside its mother's uterus.
Bone Marrow Effects
The dividing cells in the bone marrow produce white blood cells. These cells fight invaders like bacteria and viruses, so when their number is reduced by the distemper virus a cat is vulnerable to other infections. This is why cats with feline distemper may suffer from a bacterial infection as well. The bacteria are able to produce a “secondary” infection because the cat's immune system is weakened by the virus.
The bone marrow also produces red blood cells, whose main function is to transport oxygen to the body's cells, and platelets, which play an important role in blood clotting. The distemper virus may reduce the number of red blood cells, a condition known as anemia. The number of platelets is sometimes decreased as well, a condition known as thrombocytopenia.
Just as in humans, the lining of a cat's small intestine is frequently replaced by a fresh lining made by rapidly dividing cells. This replacement is necessary because the intestine is a passageway for food and digestive chemicals. The lining is damaged by these materials as they pass through the intestine.
The distemper virus prevents a new intestinal lining from being made and injures the old one. As a result, ulcers form and the cat may produce diarrhea containing blood. Feline distemper is also known as feline infectious enteritis. "Enteritis" means inflammation of the small intestine.
Nervous System Effects
If a pregnant cat is infected by the distemper virus her developing kittens may be killed or injured. The virus affects certain parts of a kitten's developing nervous system, including the cerebellum in the brain and the retina at the back of the eye.
The cerebellum is responsible for balance and for coordinating muscle movements. The distemper virus can cause cerebellar hypoplasia in a kitten, a condition in which the cerebellum doesn't develop properly. As a result the kitten has problems controlling its movements.
The retina contains the light receptors. When these receptors are stimulated by light, they send a message along the optic nerve to the brain, which then creates an image. Kittens affected by the distemper virus while they are still inside their mother's uterus may suffer from retinal dysplasia, a disorder in which the retina develops abnormally.
Sailor, a Cat With Cerebellar Hypoplasia
Cerebellar Hypoplasia and Cerebellar Ataxia in Cats
Kittens who have cerebellar hypoplasia are born with movement problems, a condition known as cerebellar ataxia. These problems include lack of coordination and balance, jerky movements, and muscle tremors.
Watching an affected cat as it tries to move is very sad for someone who isn't familiar with cerebellar hypoplasia, but the condition doesn't get any worse once a kitten is born and isn't painful. The cat learns to compensate somewhat for its disability and has a normal lifespan, providing the owner protects it from possible dangers caused by its inability to fully control its movements. Owners of cats with cerebellar hypoplasia and ataxia say that the animals can lead happy lives if they are part of a loving family. The mental development of the cats is normal.
Possible Symptoms of Feline Distemper
Fever, depression, loss of appetite, and dehydration are generally the first distemper symptoms to appear. A cat may sit in front of its water bowl for long periods but be unable to drink.
One or two days after the first appearance of the fever more symptoms may appear. These include the following:
- vomiting, even when the cat hasn't been eating or drinking
- diarrhea, which may be bloody
- abdominal pain, especially when someone touches the abdomen
Additional symptoms may include:
- a nasal discharge
- hypothermia (a low core body temperature)
In severe cases there may be seizures and septic shock, a condition in which the body is overwhelmed by an infection and the blood pressure falls to a dangerously low level. Kittens can develop distemper so rapidly that a kitten may die before the owner is even certain that it’s sick.
It's vital that cats with any of the above symptoms see a vet as soon as a possible for a diagnosis and treatment. Time is of the essence when treating feline distemper.
Getting a Diagnosis
The signs and symptoms of feline distemper can be caused by other disorders. Sometimes the symptoms resemble poisoning. In order to arrive at a correct diagnosis, a vet will probably perform a blood test to look at the level of white blood cells and perhaps a stool test to look for the presence of the virus.
The vet may be able to feel thickened intestine and swollen lymph nodes in the cat's abdomen. Lymph nodes are small structures in the immune system that are connected by lymphatic vessels. The lymph nodes fight infections and sometimes become inflamed when a cat's body is being attacked by viruses or bacteria.
A Cat That Recovered From Feline Distemper
A cat has a better chance of surviving distemper if treatment is begun quickly. A cat owner should therefore take their pet to the vet very soon after noticing abnormal behavior so that a diagnosis can be made and treatment begun as soon as possible.
At the moment there is no drug that can kill the feline distemper virus. A vet has to provide supportive care, which treats the symptoms of the infection rather than the infection itself. The care may include the administration of intravenous fluids, electrolytes, and nutrients if the cat is dehydrated and needs nourishment. It may also include the administration of anti-nausea medication and medication to fight pain. Antibiotics may be given if the cat has developed a bacterial infection. Sometimes a blood transfusion is performed if a cat is suffering from anemia.
In addition to receiving fluids and medications, a cat with feline distemper needs to be kept warm. Frequent petting, personal attention, and hand feeding may help prevent a very sick cat from losing the will to live. The goal of supportive treatment is to make the cat feel comfortable and help his or her immune system fight the virus. If the cat manages to survive for five days while it receives treatment the chance that it will recover is much improved.
The likelihood of an individual cat recovering from an FPV infection depends on several factors, including the age of the cat, the health of the animal’s immune system, and the amount of time between the start of the infection and the start of the treatment. The American Veterinary Medical Association reports that without supportive medical treatment up to 90% of cats infected by the feline distemper virus die. Kittens are more likely to die than adults, but even for adults the disease is very serious.
Preventing Distemper in Cats
The most effective method to prevent feline distemper is vaccination. In this process an inactive or altered form of the distemper virus is injected into the cat's body. The cat's immune system then makes antibodies to attack the virus, just as it would do if the virus was active and in its normal form. The antibodies will protect the cat if it's infected with the distemper virus in the future.
Kittens born from a mother who is vaccinated against distemper will receive antibodies to fight the disease when they drink the first milk that their mother produces. This special milk is called colostrum. The antibodies are effective in the kittens' bodies for about six to eight weeks after birth. At this point the kittens will need to receive the first of a series of vaccinations.The number and timing of these vaccinations will depend on the schedule recommended by a vet. Even indoor cats need to be vaccinated, since it's so easy for the distemper virus to be passed from one cat to another, directly or indirectly.
If a cat has been diagnosed with feline distemper, the area where it's been living must be disinfected thoroughly to prevent infecting other cats in the family. FPV is resistant to many disinfectants, but according to the Merck Veterinary Manual a ten-minute soak in diluted bleach kills the virus. The bleach should be diluted by adding 1 part of bleach to 32 parts of water.
If you're faced with the problem of removing the feline distemper virus from your home, ask your vet for his or her advice. It's very important to remove all traces of the virus from the home, not only to protect the cats that live there in the present or that will live there in the future, but also to prevent transmitting the virus to cats outside the home.
Vaccinating pets in a controversial topic. People disagree about the types of vaccinations that should be given and about how frequently the vaccines should be administered. However, the feline distemper vaccination is very important in order to prevent a horrible and painful experience for the cat and a heartbreaking situation for the owner.
Vaccinating my three cats against distemper is important to me. I don't want them to experience the illness or to have a tragic outcome from the infection. Preventing feline distemper is much easier than treating it.
© 2012 Linda Crampton