Woman's 50+ cats being killed after kitten gets rabies

What a sad, and entirely preventable, situation.

After several kittens in a litter had died, this owner took a sick kitten to the veterinarian, where it bit one of the technicians. The technician followed the law and reported the animal bite and Animal Control was called to investigate. The unvaccinated kitten was tested for rabies and was positive.

This household had some indoor cats, and some indoor/outdoor cats, and only 15 rabies vaccine certificates - one reading only "a black cat" (there were 30 black cats in the household).

There are several important things to take away from this article:

1) It is a good idea to keep copies of your pets' current and up-to-date medical or vaccination records available, and make sure that your veterinarian accurately identifies each pet in your home on their medical records.

2) If your cat bites someone and the victim needs to seek medical attention, the bite will be reported to Animal Control and an investigation will occur. Depending on the circumstances, if your pet's rabies vaccine is not up to date, this could mean that your pet will be quarantined in a special facility at your expense, or it may mean that your pet will be euthanized and tested for rabies.  In fact, depending on the inflexibility of the law, your pet may be euthanized after exposure to a rabid animal as in this case in New Hampshire in which a dog that was two weeks overdue for a rabies vaccine was euthanized after being bitten by a rabid skunk.

3) Many people develop severe infections after cat bites, so medical attention after ANY cat bite is highly recommended - even if it is your own cat! 

4) The domestic animal most commonly reported to have rabies across the United States is the cat ( 247 cats, 89 dogs, 86 cattle, 31 horses/mules, 9 sheep/goats, 3 pigs, 2 llamas in 2013). It is also the most commonly affected domestic animal in the state of Michigan. The most common wild animal to test positive for rabies in Michigan in the bat, followed by the skunk.

Closer to home, Dr. Bailey's son, Christopher, was exposed to rabies while working with a cat at a veterinary hospital in Oakland County about 5-6 years ago (not ECats), about a year after our technician, Jennifer was exposed to a rabid kitten at another hospital in Oakland County (also not ECats) in 2007. Christopher had to receive rabies prophylaxis treatment, while Jennifer only needed to be re-vaccinated, since she had been vaccinated prior to travel to Africa back in 1998. Additionally, Dr. Bailey's good friend and colleague, Dr. Michael Ray had an encounter with a rabid cat at his feline hospital in Roswell, GA, two weeks ago.

 Drs. Scott Weese and Maureen Anderson of the Ontario Veterinary College's Centre for Public Health and Zoonoses comment on the situation: Cat Hoarding and Rabies

Disease Monograph: Feline Panleukopenia Virus

This little kitten was brought into our office because he had a poor appetite and a fever. Two days later, he had a severe drop in white blood cell numbers, and we suspected distemper. The next day, he started vomiting and having diarrhea and his parvo test was positive. We placed him on our isolation room on IV fluids and total parenteral nutrition (TPN) - since he wasn't eating and was severely dehydrated, we gave him all his nutrients through IV fluids - Plasmalyte (electrolytes), Procalamine (amino acids) and Intralipids (fats).

Distemper, Panleukopenia, Parvo, Infectious enteritis...whatever you call it, it's not good for cats.
For the purposes of this article, we will refer to this disease as Feline Panleukopenia Virus or FPV.

FPV is a disease that is highly contagious and almost always life-threatening. The virus that causes this disease is from the family Parvoviridae, which is the reason that one of its names is Feline Parvo. Others refer to the disease by some of its symptoms: Panleukopenia (a severe decrease in all types of white blood cells), Infectious enteritis (an inflammation of the intestinal tract that can be passed between cats), or Distemper (symptoms of Canine Distemper - a disease caused by an entirely different virus - are similar to many signs of FPV: fever, vomiting, diarrhea, seizures). The virus is a single strand of DNA inside a virus capsule that is extremely long-lived in the environment. It can survive freezing temperatures, is unaffected by alcohol, iodine, and general disinfectants, and is considered to be ubiquitous - or found everywhere in the environment. Just about the only thing that will destroy FPV is a 10 minute soak in a bleach solution.

Differences in structure in canine vs. feline Parvovirus

In the wild, the bobcat, the raccoon, and members of the Mustelid family (such as mink, skunk and otter) can carry the disease. Among other mammals, some species of monkey are susceptible to FPV. Despite the similar names and symptoms, FPV is not contagious to dogs, nor can cats contract Canine Distemper Virus or Canine Parvo Virus*. In fact, it is suspected by some scientists that Canine Parvo Virus is actually a sub-species of Feline Parvovirus - a mutation of the original, if you will - since some apparently healthy cats shed Canine Parvo Virus in their stool.


*Correction: Canine Parvo virus subtypes have been isolated from both domestic and wild felids, but does not appear to result in the same level of virulence as FPV (the cats are not nearly as sick). However, there is one published case from March 2014 that reports of a cat that was infected with CPV2c that was critically ill with symptoms mimicking FPV. The feline vaccine appears to provide adequate protection from Canine Parvo Virus, but most agree that more research should be done before this presumption is relied upon.

Transmission

Any unvaccinated cat is at risk for contracting FPV, but those at highest risk are cats that are immunocompromised, such as kittens age 2-6 months, pregnant females, cats with immune-suppressing diseases such as FIV and FeLV, and cats who are being treated with immune-suppressing drugs.

The virus is shed from the body in the stool, vomit, urine, saliva and mucus, and a cat may remain contagious and shedding the virus for at least six weeks following infection. Since the virus is so long-lived, it can be transmitted by handling contaminated items (called "fomites") such as food bowls, towels, and litterboxes, or shoes, clothing and hands that have come into contact with the virus.

Additionally, the virus can be passed from mother to developing kittens, and can be spread by fleas.

Generally, the virus enters the cat through the mouth and then affects the lymph nodes. It takes about 2-7 days for the virus to make its way to the bone marrow and the intestinal tract. In the bone marrow, the virus interferes with cell production, and in the intestinal tract, the virus causes ulceration of the lining of the gut that is in charge of absorbing nutrients and prevents damage to the intestinal wall from digestive acids and bacterial growth. Once the intestinal lining is damaged, the cat is at risk for infection from normal bacterial flora, perforation of the bowel, and may suffer from dehydration, vomiting, diarrhea, and malnutrition, eventually leading to septicemia (severe bacterial infection in the bloodstream) and shock.

Mortality in kittens is 90%, though if the kitten survives 5 days of infection, the chances or survival and recovery begin to improve. If a cat is able to recover from FPV, they maintain lifetime immunity. If a pregnant female is exposed to the virus in early to mid-pregnancy, she will abort the kittens. If exposed during the last 2-3 weeks of pregnancy, the kittens will develop a condition called cerebellar hypoplasia.

Symptoms

FPV affects the rapidly dividing cells in the body, especially the bone marrow, which produces red and white blood cells, and the lining of the gastrointestinal tract (stomach and intestines). Since a lack of white blood cells occurs (a panleukopenia), the cat develops risk for other bacterial and viral infections to occur. A decrease in red blood cells may occur (anemia) and platelet numbers may also decrease (thrombocytopenia). Severe anemia results in a lack of oxygen to the cells of the body, and a lack of platelets can result in clotting problems. If white blood cells, red blood cells and platelets are all decreased, it is called a "pancytopenia" - literally, a lack of all cells in the blood.

• Vomiting
• Diarrhea, especially bloody diarrhea
• Fever
• Weight loss
• Depression
• Anorexia, loss of appetite
• Hiding
• Rough hair coat
• Anemia
• Weakness
• Neurologic signs
• Shock
• Abdominal discomfort, bloating, gas
• Elevated third eyelids

Diagnosis

In-hospital Parvo test

Any time that we see a kitten with a fever, vomiting, diarrhea and poor appetite, we will recommend a complete blood count. If the kitten has a low white blood cell count, we will likely recommend a special Parvo test. This test is marketed for dogs for the detection of canine parvo virus, but the feline parvo virus is similar enough that the test is accurate in cats, as well - though vaccination within 5-12 days of the test can occasionally result in a false positive. To run this test, a small amount of fresh stool is collected from the patient.

Additional tests, such as PCR testing and antibody level analysis can also confirm the diagnosis of FPV.

Unfortunately, many kittens will show mild signs of illness, such as fever and depression, before the white blood cells become affected, which can delay the diagnosis of FPV if conservative treatment is chosen over full diagnostic evaluation. If a kitten dies suddenly, a necropsy (the term for an autopsy, when discussing animals), may be recommended to collect samples to test for the virus - especially if there are other kittens in the home.

Because all the symptoms of FPV do not necessarily appear at once, it may be easy to confuse FPV with other conditions, such as poisoning or the ingestion of a foreign body (kittens love to eat toys, strings, hair ties, rubber bands, ear plugs...), Salmonella, Feline Leukemia (FeLV), feline immunodeficiency virus (FIV), feline infectious peritonitis (FIP), and pancreatitis.

Additional testing, such as urinalysis or blood chemistries may be performed to help rule out other diseases and conditions, or to assess the severity of the disease. X-rays may be recommended if blood tests are inconclusive or the cat does not have a known history - such as a stray or recently adopted cat.

Treatment

There is no definitive cure for this disease, no medication that kills the virus that causes this disease. Cats affected with FPV must have immediate and intensive supportive care to help nourish and protect their bodies while the struggling immune system fights the virus. Since the lining of the intestine is being attacked, and nutrient absorption is decreased, most medications, if not all, will be given by injection - either into the vein (intravenously) or under the skin (subcutaneously). IV fluids will be necessary to protect the cat from severe dehydration due to poor nutrient absorption, lack of food and water intake and fluid loss from severe vomiting and diarrhea - TPN or total parenteral nutrition (IV fats and amino acids) will be administered this way, too, since affected cats are likely to vomit any food or water they eat or drink. Anti-vomiting medications will also likely be given.

Antibiotics may be given to aid the weakened immune system in preventing "opportunistic infections"  - exposure to bacteria that would not affect a normal, healthy cat, but that could be life-threatening to a cat with few white blood cells. In the case of FPV - the biggest concern is exposure to the normal bacteria living in the intestinal tract. As the protective lining of the gut is attacked by the virus, normally "friendly" bacteria may attack the unprotected cells and cause ulceration and eventually perforation of the intestinal wall, allowing bacteria to leak into the abdomen. In severe cases, the cat is given medication to help protect the intestinal lining from damage. Cats with severe depletion of both red and white blood cells (pancytopenia), or severely low blood proteins may require one or more blood or plasma transfusions.

Some suspect that treatment with immune-stimulation medications such as Interferon, or transfusion with antibody-containing serum may aid in fighting infection, but this therapy is not yet confirmed or considered to be routine.

An infected cat should be strictly isolated from other cats to prevent the spread of this extremely contagious disease.

Almost all recognized cases of FPV require hospitalization.

Prevention

If a cat in your home has been diagnosed with FPV, closely observe other cats in the home for signs of illness. You can use a bleach solution to clean any potentially contaminated toys, food dishes, beds, and litterboxes, but the safest way to ensure the virus has been eliminated from your home is to replace all possibly infected belongings with new ones. If your cat recovers from FPV infection, he or she will have lifelong immunity, but other cats in the home, or visiting cats (or visiting people) may come into virus contamination in the environment. If you have had a cat that has been infected with FPV in your home, any new cats should not enter the home for at least two weeks and should have a Distemper vaccination 1-2 weeks prior to entering the home.

To clean contaminated areas, use a bleach solution of 1:20 (1 part bleach in 20 parts water) and allow the solution to remain in contact with the contaminated item for 30 minutes before rinsing. Any dirt, feces, vomit or other biological fluid should be cleaned up before applying bleach. Fabric items such as carpets, rugs and cat beds or other areas that cannot be bleached, such as wood flooring, should be steam cleaned at 240-270 degrees F.

The best way to prevent your cat from contracting FPV is to have your cat vaccinated routinely every 2-4 weeks from the age of 8 weeks through the age of 16 weeks.  Maternal antibodies conflict with the vaccine's ability to help the body form immune responses. Since it is uncertain exactly when maternal antibodies no longer protect kittens after they stop nursing, routine re-vaccination until the age at which their risk factors are minimized is key to provide protection. After the first annual vaccine, a cat's future vaccination schedule should be determined based on the cat's age, health status and lifestyle by having a conversation with your trusted veterinarian, or at a minimum every three years.

References

Michigan DNR article on Canine and Feline Distemper

Isolation and characterization of feline panleukopenia virus from a diarrheic monkey 

High prevalence of non-productive FeLV infection in necropsied cats and significant association with pathological findings

Panleukopenia-like syndrome of FeLV caused by co-infection with FeLV and feline panleukopenia virus

Detection of Feline Panleukopenia Virus using a commercial ELISA for Canine Parvovurus

Evidence for recombination between Feline Panleukopenia Virus and Canine Parvovirus Type 2

Immunisation against Panleucopenia: Early Development of Immunity

Structural Comparison of Different Antibodies Interacting with Parvovirus Capsids

 Macintire DK, Smith-Carr S, Jones R, Swango L. Treatment of dogs naturally infected with canine parvovirus with lyophilized canine IgG. Proceedings of the 17th Annual Conference of the American College of Veterinary Internal Medicine. June 10–13, 1999, abstract 118, 1999: 721. 

De Mari K, Maynard L, Eun HM, Lebreux B. Treatment of canine parvoviral enteritis with interferon-omega in a placebo-controlled field trial.Vet Rec2003;152:105–8

Genetic complexity and multiple infections with more Parvovirus species in naturally infected cats

Feline Host Range of Canine parvovirus: Recent Emergence of New Antigenic Types in Cats

Isolation of canine parvovirus from a cat manifesting clinical signs of feline panleukopenia.

Canine parvovirus 2c infection in a cat with severe clinical disease.

Canine parvovirus in asymptomatic feline carriers.  

Disease Monograph: Feline Leukemia - Part 2: Diagnosis, Prevention and treatment

Diagnosis of Feline Leukemia

To diagnose this disease, there are two types of blood test. One is called an enzyme-linked immunosorbent assay (ELISA test) and the other is called an immunofluorescent antibody (IFA) test. It is highly recommended to test cats prior to giving the leukemia vaccine to ensure that the cat is not already positive. If your cat is positive for FeLV, the vaccine will not help your cat fight the infection. The ELISA test is a quick and readily-available color change test that detects FeLV virus presence in the blood by testing for a protein that the virus creates when it replicates. This test can detect the virus at any stage of infection and can display positive results within a few days of infection. False positives can occur, due to the nature of this disease, so if your cat has only been tested once and tests positive, it may be a good idea to wait 2-3 months and re-test. Additionally, if you test a cat immediately upon bringing it into the household, you should test again about 60 days after its last possible exposure to the disease (whether it came from a shelter, was outdoors as a stray, or came from a breeder or friend).

In some cases, the tears or saliva of a cat can be tested with the ELISA method, but it turns positive only in late stages of infection and can return a false negative result. It can also return false positive results due to the nature of the testing procedure, so it is not commonly performed.

The IFA test is a test for FeLV proteins (antigens) in blood cells that appear at a later progression of the disease. This test may return a false negative result if the cat is in the early stages of the disease. If the IFA test is positive, it generally means that the cat will be unable to fight off the virus. This test is usually sent to a reference lab to confirm positive test results from the veterinary hospital laboratory.

A third type of blood test exists, but is not commonly used for regular screening. This third test is a PCR test and indicates whether there is any FeLV DNA present in the blood.

According to the American Association of Feline Practitioners (AAFP), the recommendation is that the FeLV status of ALL cats should be known, because Feline Leukemia Virus is responsible for the illness and death of more cats than any other disease condition.  Cats who have had a recent known or possible exposure, or cats that are ill should be tested before entering into a home with other cats.

The Six Stages of FeLV infection

1. The virus enters the cat and infects the white blood cells in the tonsils which then travel to the lymph nodes and copy themselves

2. The virus enters the blood stream and spreads throughout the body

3. They lymphoid system (the root of antibody response) becomes affected and further spreads the virus

4. The virus takes over the immune system and the intestinal tract becomes infected.

5. The bone marrow becomes infected if the cat cannot fight off the infection. At this point, the virus has become a part of the cat for the rest of its life. The virus is now carried in newly-made white blood cells that are produced by the marrow. Red blood cell production may be affected, as well.

6. The infection spreads to the cells that line the body cavities and organs, including salivary glands, stomach, esophagus, intestines, trachea, kidney structures, bladder, pancreas and lungs.

The outlook for cats infected with FeLV is grim. Eighty to ninety percent of cats that test positive do not live more than 4 years after diagnosis (on average, about 2.5 years). The other 17% are carriers that may be outwardly healthy, but can spread the disease to other unvaccinated cats. Cats that test positive and appear healthy should be kept in a low-stress environment to help the body conserve energy to fight the disease, but there are no other definitive preventive measures that will stop the disease progression.

Prevention:

This disease is extremely contagious in kittens. Neonatal kittens are 100% susceptible to contracting the virus after one exposure. By 8 weeks, their risk of infection drops to 85% from one exposure. Only about 30-40% of cats become immune after exposure. This means that 60-70% of unvaccinated cats (6 of 10) will contract the virus.

Several different vaccines exist for feline leukemia virus prevention: inactivated virus, recombinant canarypox vector and genetically engineered subunit vaccines. Once a cat has been vaccinated, it takes about 2-3 weeks before the cat develops immunity, so vaccination for Feline Leukemia is best done well before a cat will be at high risk for exposure. Most Feline Leukemia vaccines only provide immunity for 12 months, and therefore need to be boostered annually. The vaccine used at Exclusively Cats Veterinary Hospital is a vaccine that only needs boostering every 2 years, to help reduce the risk of negative side effects. Some cats vaccinated with feline leukemia virus vaccines have had negative side effects - usually mild, but up to and including vaccine induced sarcomas. Your cat is not at risk from contracting FeLV from the vaccine. Since 1992, none of the FeLV vaccines available are capable of causing active infection. Additionally, the vaccine will not cause your cat to test positive on a Feline Leukemia test. While no vaccine is 100% effective, use of this vaccine in high risk cats is highly protective (80-90%) and strongly recommended.

The virus does not survive long outside of the body, only lasting 2 hours at most, and in reality probably only a few minutes, in a dry environment, keeping the litterbox clean and dry is important if there is a feline leukemia positive cat in a multi-cat environment. The virus is also easily killed with bleach and household detergents.

Treatment

Many times, a cat diagnosed with FeLV infection is already feeling sick, and in these cases, a pet owner may opt for euthanasia to end the cat's suffering. Since there is no cure for FeLV infection, and since 80% or more of positive cats will die within three years (most of which occur within 6 months) this may be the most humane option in cases where the cat is severely ill.

Propionobacterium acnes - a potential FeLV treatment

If a cat is diagnosed with FeLV infection and is apparently healthy, the best course of action is to limit the cat's exposure to other cats, keep the cat indoors, limit and prevent stress in the cat's life, feed a high quality diet, and keep her (non-FeLV) vaccinations up-to-date (remember that this disease decreases the effectiveness of a cat's immune system, making her more susceptible to other diseases). Quick response to secondary infections or conditions will help keep the infected cat healthy, longer, as well, so a close relationship with a veterinarian is important. For example, if an infected cat's red blood cell count begins to drop, the cat can receive various treatments aimed at stimulating red blood cell production or circulation - B12 or iron injections, erythropoetin treatment, or even a blood transfusion, if needed.

Additionally, there has been some development of experimental treatment protocols combining the

Polyprenyl immunostimulant - a potential FeLV treatment

use of immunostimulants, antivirals such as interferon and drugs that are in development for human AIDS treatment (these are usually tested in cats before moving on to human trials). However, there have not been many clinical use trials for these treatments, so information about their general effectiveness remains vague and anecdotal. Chemotherapy for FeLV associated cancers is available, but FeLV positive cats do not respond to chemotherapy as well as non-FeLV positive cats, and survival time once cancer develops is usually only about 6 months, despite chemotherapeutic treatment.

FeLV versus FIV

Some people confuse Feline Leukemia Virus (FeLV) and Feline Immunodeficiency Virus (FIV) because they are both retroviral diseases that affect the immune system. Feline Leukemia Virus infection, however, is almost two times more common than FIV. There are two very significant differences between the two diseases:

1) FeLV frequently causes severe illness, especially in young cats, while FIV tends to remain latent or non-illness-causing in the body for 8-9 years or so. It may never cause illness in some cats.

2) FeLV is much more easily transmitted. FIV tends to cause disease primarily following a bite wound, while FeLV can be transmitted through casual contact.

References and Further information:

Disease Information Fact Sheet: Feline Leukemia Virus

http://jfm.sagepub.com/content/suppl/2013/08/14/15.9.785.DC1/5_Fact_sheet_5.pdf

Journal of Feline Medicine and Surgery (2013) 15, Supplementary File

Disease monograph: Feline Leukemia Part 1: What is it?

Feline Leukemia Virus is a disease is transmitted between cats by a virus. The Feline Leukemia virus is a retrovirus from a family of viruses called oncornaviruses - viruses that cause the development of cancers (among other effects). A retrovirus is a virus that interacts with the genetic material of its host in order to reproduce. Feline Leukemia Virus (FeLV) causes immunosuppression, or failure of the body's natural defenses, in many feline species - the domestic cat is most susceptible, but large cat species such as lynxes, Florida panthers, cheetahs and lions have also been reportedly infected. This virus is not known to pass between non-feline species, so humans and dogs appear to be safe.

How is Feline Leukemia transmitted?

Electron micrograph of FeLV - from Wikipedia

The virus is shed in the saliva of an infected cat, and to some degree in respiratory secretions. Most cats receive the virus through the mouth. Generally, it is considered that the virus is transmitted through long term contact with an infected individual - such as sharing litterboxes and food bowls, mutual grooming, or through a bite. Mating behavior may also transmit the virus. Additionally, kittens can contract FeLV from their mother in utero and be positive from birth, or they can contract the virus through their mother's milk. Petting a feline leukemia positive cat and then petting a non-infected cat will not transmit the disease.

The frequency of FeLV positive cats varies greatly between areas. In some areas, the incidence can be as high as 70% in large multi-cat homes where cats have outdoor access. In single-cat, indoor homes, the prevalence is around 3% (3 in 10 cats). FeLV tends to be more common in urban cats (up to 40%) than in rural cats (up to 6%), because cats live in higher population densities and therefore have more contact with each other.

Healthy cats that test positive should not be allowed to roam outside, because they can infect other cats they come across. Additionally, other cats that live in the same household should be vaccinated, and it is recommended that the FeLV positive cat not have contact with the other cats because no vaccine is 100% effective, and the FeLV positive cat may spread other diseases that their weakened immune system allows them to contract.

Signs and symptoms

Not all cats that contract the feline leukemia virus actually develop "leukemia" (cancer of the white blood cells - specifically in the bone marrow), but leukemia is one of the cluster of diseases and symptoms that can develop when a cat is infected with this virus. Common symptoms of FeLV include poor appetite, poor coat and skin condition, fever, lethargy, weight loss, and anemia. Anemia is present in about 25% of all FeLV-related illness. Fifty percent of infected cats that become ill develop immunosuppression, or immune system failure, to some degree.

Various organ diseases can develop, such as liver or intestinal disease. Many cats may experience prolonged healing times after surgery or wounds. Additional signs may include uneven pupil size (anisocoria), swollen lymph nodes (lymphadenopathy), various secondary infections (bladder, skin, respiratory tract - bacterial or viral origins), gingivitis, stomatitis, diarrhea, jaundice, and a type of cancer called lymphosarcoma. Cats that are infected with FeLV are 50 times more likely to develop lymphosarcoma than non-infected cats. Lymphosarcoma (sometimes called lymphoma) is a cancer that consists primarily of a type of white blood cell called "lymphocytes". It can affect almost any organ in the body, but in young cats, it often appears in the chest cavity. In older cats, lymphoma of the intestinal tract is more common. Often in intestinal cases, there is no obvious mass or lump to find, but instead a generalized thickening of the intestine.

• Pale gums (or pale nail beds)
• Jaundice - yellow color to eyes, mouth, ears or other exposed skin and/or extremely dark, staining urine

  

  Jaundice coloring the roof of a cat's mouth

• Enlarged lymph nodes
• Chronic infections of respiratory tract, bladder or skin
• Gingivitis
• Weight loss/poor appetite
• Fever
• Poor coat
• Progressive weakness/sleepiness/lethargy/reclusiveness/hiding
• Diarrhea
• Vomiting
• Dehydration
• Breathing difficulty
• Reproductive problems - sterility, miscarriage

There are four possible paths the disease can take in an infected cat. These potential outcomes depend on the amount of virus the cat is exposed to, the strain of the virus (there are 4 unique strains of FeLV), the cat's initial health level (the effectiveness of his immune system and the presence of any other health complications), and age.

If a cat tests positive for FeLV, one of the following will occur:

1) IMMUNITY - Some cats are able to fight off the virus and become immune. Some of these cats completely eliminate all traces of the virus from their bodies. The cat may have some mild signs of illness - fever, poor appetite, large lymph nodes, lethargy for up to 10 days and then recover. This outcome occurs about 40% of the time, and is more likely in adults than in kittens.

2) PROGRESSIVE INFECTION - The second possibility is that the cat may become infected and develop a compromised immune system. The cat may have a short illness and recover enough to be outwardly healthy for 2-3 years in 50% of the cases. This outcome occurs about 30% of the time, and is more common in kittens than in adult cats. The bone marrow, which produces new blood cells, becomes infected and each new blood cell that is produced will contain more virus, creating a "persistent viremia" or constant presence of virus in the bloodstream. The infection is progressive, gradually taking hold in various body organs. Lymphoma is the final stage of the disease.

3) LATENT INFECTION -  Up to 30% of the time, cats will develop a latent infection. These cats may test positive at first, and then test negative 3-4 weeks later. The virus does not kill the cat's cells once it is inserted into the cellular DNA, but sits in wait. Eventually the body may reject these abnormal cells or the cat will become sick. While healthy, these cats will continue test negative on FeLV tests, but if vaccinated, will not be protected. Pregnant cats with latent infection may test FeLV negative but produce FeLV positive kittens. A latent infection may eventually result in immunity or may develop into active infection at some point in the future. Many cats with lymphoma (a common end-stage of FeLV) do still carry some FeLV DNA and are suspected by some to be latently infected with Feline Leukemia Virus.

4)  CARRIER STATE - Others may experience a "regressive infection" and continue to harbor the virus or particles of virus in a few cells, but the virus cannot replicate. In these cats, there is rarely any sign of illness, and they do not shed the virus. This outcome is extremely rare, occuring only about 1-2% of the time. These cats will test positive on ELISA test but negative on IFA tests. They may remain asymptomatic for a long time, even years. These cats are considered "carriers", and while they may never get sick, they can infect other cats. Eventually, these cats may develop active infection or develop latent infection. 

Cats and Vaccinations - Frequently Asked Questions

"Thank you" kisses for Dr. Demos!

The most important reason that your cat should visit the veterinarian 1-2 times yearly is for the expert physical exam your pet's doctor performs. A proactive approach to your cat's health, focused on wellness and preventive care can be beneficial because illness and disease can be detected earlier, when treatments may be more successful and less costly. In addition to physical examinations and discussing your cat's diet and litterbox habits, when your veterinarian discusses your cat's health with you, he or she will likely recommend updating your cat's vaccinations.

What are vaccinations?

Vaccinations are injections of a substance that stimulates a cat's immune system, preparing the body to fight disease-causing organisms. Most vaccinations are developed for viral infections - diseases that cannot be treated with antibiotics. Some vaccines are developed for severe bacterial diseases, too.

Types of Vaccines -

• Inactivated vaccines or "killed virus" vaccinations are vaccines that contain viruses that are unable to reproduce in the body. The majority of this type of vaccine contains adjuvants.
• Modified-live vaccines contain viruses that can replicate, but do not cause clinical disease. While it is unlikely, it is theoretically possible for this type of vaccine to revert to virulence and cause disease.
• Recombinant vaccines do not contain the whole virus, but specific parts of the virus DNA that the body's immune system recognizes as an invader, but that don't actually cause disease. These strings of proteins are either inserted into a non-disease-causing virus (vectored vaccine) or are inserted into bacterial DNA (called plasmids) so that antigens can be harvested and purified for use in vaccines (subunit vaccine).

Why do cats need vaccinations?

Vaccinations are very important to the health of your cat - the diseases we vaccinate for are diseases that do not respond well to treatment, and in most cases are deadly or produce life-long complications. Diseases like distemper are extremely long-lasting in the environment, lasting for years and can be brought into your home on your hands, feet or clothing if you come into contact with the virus particles in the environment. Additionally, the virus that causes distemper is resistant to disinfectants, can be passed to kittens through breast milk from the mother and can be acquired in utero. During the summer, cats that go outdoors are at higher risk because they are more likely to spend a longer or more frequent amount of time outdoors. Other diseases that we vaccinate for can be transmitted through the air. Rabies virus is transmitted by the bite of an infected animal, and despite common misconception, an infected animal is not always the raging, frothing creature that you see in the movies. Most skunks do not show signs or symptoms of infection, and any skunk that you encounter should be considered to be a carrier of rabies. In  companion animals, signs of infection may not show up for 10 days after the animal begins shedding the virus - so if your cat gets into a fight with a stray cat that seems healthy, that cat could be rabies positive, but may not be recognizably so until it has disappeared into the woods again.

But my cat doesn't go outside he doesn't need vaccinations!

Indoor cats are definitely at lower risk for communicable diseases, however there are many factors that still create risk for these cats. If you bring a new cat into the house from a rescue or shelter, you may be bringing disease into your home. A trip to the pet store to buy cat food may result in virus particles on your clothing that you can bring home to your cat. A friend with a sick pet may bring virus particles into your home while visiting. Airborn viruses can travel into your home through open windows and doors. You may bring virus particles in on your shoes after working in the yard. A stray cat may visit your screen door. Your cat may need to be boarded in an emergency situation, and would require vaccinations to do so.

In the case of rabies, the major carrier of this disease in Michigan is the bat. We very frequently receive phone calls from people telling us that they found a live or dead bat in their home, and most people do not know that a bat has access to their home until it is inside. Most bats are able to squeeze through extremely narrow openings; the little brown bat can enter a space (5/8" by 7/8") and the big brown bat can squeeze through an opening (1-1/4" by 1/2"). Bat bites are almost microscopic, so you would be unable to tell if your cat had been bitten by the bat. If your unvaccinated cat were to escape from your home and get bitten by an unknown animal, vaccination after the fact would not be guaranteed protection, and Michigan Public Health officials must proceed as though the animal that bit your pet was positive, euthanizing and testing your cat. If your unvaccinated cat bites a person, it could result in a 10 day quarantine at an animal shelter at your expense.

Rabies is a life threatening disease and in companion animals, there is no cure. The only definitive test for rabies requires euthanasia of the animal in question and examination of the brain tissue. By the time your pet starts showing signs of disease, you could already have been exposed. While rabies vaccinations are not required by law for cats in the state of Michigan, the safest thing to do for you and your cat is keep your pet's vaccines up to date.

For the health and safety of all of our patients and staff, all cats that come into our hospital for surgical or dental care or boarding must be up to date on vaccinations.

How often do cats need vaccinations?

The number and frequency of vaccines recommended for a cat is often a complex and individualized plan based on each cat's age, lifestyle, risk assessment and health status. However, there are some general guidelines that have been established by scientific study and experts in the field that are upheld by professional groups that specialize in feline medicine, such as the American Association of Feline Practitioners (AAFP) and the International Society of Feline Medicine (ISFM).  In some states, certain vaccinations and schedules are required by law.

Kittens are more susceptible to disease because their immune systems are not fully developed. Kittens raised by their mothers receive antibodies from their mothers, but these antibodies can interfere with vaccinations. Since we do not know for certain how long maternal antibodies remain active, or if every mother cat provides antibodies to all the major diseases, kittens need a series of vaccines to provide immunity. This series should continue until the kitten is at least 16 weeks of age. Additionally, any cat receiving a vaccination for the first time, no matter how old they are, will usually need a series of two vaccinations to ensure adequate protection.

You can find the Exclusively Cats Veterinary Hospital wellness care recommendations here.

It is recommended that even if a cat is not due for vaccination in a given year, they should be evaluated by a veterinarian at least annually, to ensure that health and risk status has not changed.

Cats should be tested for Feline Leukemia before starting the series of Feline Leukemia vaccinations because there is no medical benefit in giving a Leukemia vaccine to an infected cat. There are no negative side effects to vaccinating an infected cat, but this also eliminates the possibility of failing to recognize vaccine failure. If a previously untested cat who has been vaccinated for Feline Leukemia is later tested and is positive for Feline Leukemia, there is no way to tell if the Leukemia virus has been present long term or if the cat was recently exposed and the vaccine did not protect him. 

What are the possible side effects of vaccination?

The currently available feline vaccines do have an excellent safety record, however negative events following vaccination can occur. It is important to report these events to your veterinarian if they do occur, as veterinarians are requested to report adverse events to the manufacturer, as well as the USDA. It is also important to note that not all negative events that may follow vaccination can be directly said to be caused by the vaccine with 100% certainty. 

During the years 2002 - 2005, more than 1.25 million vaccines were given to cats at Banfield Hospitals across the US. In that time period, 51.6/10,000 cats had reactions within 30 days of vaccination (0.52%). Of these reactions, 54% experienced lethargy (weakness/tiredness) with or without fever, 25% experienced pain at the injection site, 10% experienced vomiting, 6% experienced facial swelling, 2% experienced generalized itching. Death occurred in 4 cats (0.04%) - two of these deaths were related to anaphylaxis (allergic reaction). Vaccines containing a Chlamydophila component were more likely to cause lethargy and fever than those without. Several other vaccine reaction studies report a rate of adverse reaction between 0.23% and 3% depending on the type of vaccination, the number of vaccinations given at one time, and the type of reaction being monitored.

Anaphylaxis or "allergic reaction" occurs rarely (about 1-5/10,000 cats).  It can be identified as vomiting, diarrhea, respiratory distress, facial itching or swelling, and collapse. Often, this type of reaction can be adequately controlled with the use of antihistimines or steroid medications or a different vaccine formulation.

Vaccine-associated sarcomas are a known problem, but the exact reasons that they form is not yet understood. Many suggest that the development of these tumors may result from inflammation or trauma at the injection site. Feline injection-site sarcomas (FISS) are rare, occurring in fewer than one out of every 10,000-30,000 cats, but the severity of this side effect is frightening to many people. In recent years, many precautions have been taken to minimize the trauma and inflammation caused by vaccination, and the frequency of this problem has significantly decreased. At Exclusively Cats, we give vaccinations in insulin syringes, to decrease the needle trauma associated with vaccination. We allow the vaccines to warm to room temperature before giving them, and we choose to use primarily non-adjuvanted vaccines. In addition, we vaccinate cats only as frequently as medically necessary to provide immunity, and we avoid vaccinating cats that have other compromising health issues (which is why we do not administer vaccinations without a physical exam). In addition, we use recommended vaccination sites low on the leg so that, in the eventuality that a sarcoma does develop, the limb can be amputated if necessary, to prevent the spread of the tumor to the rest of the body and prolong the life of your cat.

More about the diseases that we vaccinate for:
Feline Panleukopenia (also known as Feline Distemper, Feline Parvo, or Infectious Enteritis)
Feline Leukemia
(more to come...)