New Principles of Immunology-Feline

Cat Health

Current Recommendations For Cats

Feline injection site Fibrosarcoma is a type of terminal cancer related to inflammation caused by rabies and leukemia vaccines.(12) This cancer is thought to affect 1 in 20,000 cats vaccinated. Mean disease free interval  time or survival time with surgical removal is about 3 months. Mean survival time with surgical removal plus radiation treatment plus chemotherapy is less than 3 years. Amputation of a rear leg plus radiation has resulted in a few cures.

Vaccines with adjuvant, an ingredient included to stimulate the immune system, have been implicated as a higher risk, although other injectable drugs have been incriminated as well. Adjuvanted  vaccines have been demonstrated to induce  mutation in cell cultures. Adjuvanted Rabies, Distemper and Feline Leukemia vaccines have been classified as Class II carcinogens by the World Health Organization. 

To minimize the risk of injection site fibrosarcomas, we now recommend all non-adjuvanted  vaccines for cats, including Merial PCR Purevac rabies vaccine. Testing by Dr. Dennis Macey, Colorado State University, has shown this vaccine to have the lowest tissue reaction.  Although there is no guarantee that an injection site fibrosarcoma will not develop, the risk will be much lower than with other vaccines.(12) After three years on the market there have been only two  injection site fibrosarcomas confirmed with Purevac rabies vaccine vs. over 70,000 caused by adjuvanted rabies vaccines.

Dr Rogers was instrumental in getting the Texas Department of Public Health and the New Mexico Department of Public Health to change the rabies vaccination requirement effective March 2003 to :

     Dogs and Cats should be vaccinated for rabies at four months of age, one -year later, and subsequently every three years. Alternatively, to prevent fibrosarcomas, cats can be vaccinated annually with a non adjuvanted product with a one year duration of immunity.

This law is retroactive. Patients vaccinated in 2002 are not due fro another rabies vaccine until 2005.

Scientists agree that three annual  vaccinations with a non -adjuvanted rabies vaccine is safer and less likely to cause a fibrosarcoma than one vaccination with a three year DOI adjuvanted vaccine. Three year DOI Licensing for the Purevac non-adjuvanted Rabies product is pending. 

Program injectable six month flea prevention for cats has been shown to be very tissue reactive and therefore has the potential of inducing an injection site fibrosarcoma.(12) Droncit injectable tapeworm medication also has the potential to be tissue reactive in some cats.
***If your cat develops a lump at the site of a vaccination, we highly recommend that it be removed ASAP, within 3-12 weeks, hopefully before it becomes cancerous.

Feline Leukemia Virus Vaccine: Feline leukemia virus (FeLV) is the leading killer of cats. The virus is spread from cat-to-cat through bite wounds, through extensive contact with infected cats, and from an infected mother cat to her kittens. The individuals most at risk of infection are young outdoor cats, young indoor/outdoor cats, and young  cats exposed to such individuals. Young cats living in households with FeLV-infected cats or with cats of unknown infection status are at  risk. Indoor-only cats with no exposure to potentially infected cats and adult cats are unlikely to become infected. 

FeLV vaccines are recommended for all cats less than 1 year of age at risk of exposure to the virus and those cats of unpredictable futures.

Approximately 30 % of cats that are exposed to the FeLV virus have a transient viremia. They are infected by the virus and they become naturally immune to the virus and eliminate the infection. Unfortunately this transient viremia can cause residual DNA damage which can cause a FeLV related cancer years later, the so called “hit and run phenomena. We recommend Leucat non -adjuvanted vaccine. Leucat FeLV vaccine is the effective in preventing transient viremia. 

Cats over one year of age are naturally 89% immune to FeLV (age related resistance) whether they are vaccinated or not, so annual vaccination of adult cats is not necessary.(10, 15-p5, 21-p681,23-p239) Age related immunity is actually better than vaccine induced immunity. (Cats infected at a younger age can still incubate the disease and come down with Leukemia for up to 8+ years.) (Some cats that are infected at a young age can spontaneously become immune and get rid of the virus. This transient viremia can cause residual DNA damage and result in FeLV related cancer years later although the virus has long been gone.)

If your cat is outside getting into fights and exposed to other cats you might want to err on the side of caution and vaccinate for FeLV every three years with a non- adjuvanted vaccine.

The incubation period of Feline leukemia can be  3 -8 years, so if your cat is in the incubation stage of the disease prior to vaccination, the vaccine will not prevent the disease. We highly recommend testing every cat or kitten for FeLV

Feline Panleukopenia Virus Vaccine: Feline panleukopenia (also called feline distemper) is a highly contagious and deadly viral disease of kittens. This disease is rare.  Feline panleukopenia virus is extremely hardy, is able to survive extremes of temperature and humidity for many months, and is resistant to most available disinfectants. Similar to canine parvovirus, it causes bloody, watery diarrhea and is rapidly fatal. Although an effective treatment protocol is available, it is expensive to treat. Because of the serious nature of the disease and the continued presence of virus in the environment, vaccination is highly recommended for all kittens. Cats vaccinated at 6 months of age or older with will produce an immunity good for life.(15, 20, 21)  Adult cats do not need this vaccine. We recommend MLV non- adjuvanted vaccine. 
 Dr. Pedersen’s Duration of Immunity Studies demonstrated immunity by  serology & challenge  for 7 1/2 years after immunization.(24) This study was reproduced by Dr Michael Lappin. Longer Duration of Immunity studies are pending. Most immunologists feel the protection is lifelong. 
 Feline Calici virus / Herpesvirus Vaccine: Feline calicivirus and rhinotracheitis (feline herpes virus type I) are responsible for 80-90% of infectious feline upper respiratory tract diseases. Most cats are exposed to either or both of these viruses at some time in their lives. Both indoor as well as outdoor cats are easily exposed to this airborne virus. Once infected, many cats never completely rid themselves of the virus. These “carrier” cats either continuously or intermittently shed the organisms for long periods of time — perhaps for life — and serve as a major source of infection to other cats. The infection can also relapse with stress.  The currently  available vaccines do not completely protect against infection, but will minimize the severity of upper respiratory infections. Because there are over 65 types of Calici virus, no vaccine will prevent disease in all situations.(6, 7 15, 19, 21) Intranasal vaccines used in conjunction with parenteral vaccines  may be more effective at preventing the disease entirely(23-p239), and intranasal vaccines will be safer.

 A rare side-effect to the intranasal vaccines is sneezing for one or two days post-vaccination. This is normal and nothing to worry about. Because intranasal vaccines produce an immunity of shorter duration,  tri-annual vaccination is recommended.

Vaccines not Recommended For Cats

Chlamydia or pneumonitis: This is a rare ocular disease of cats and kittens accounting for less than 5% of upper respiratory infections in cats.(13, 15, 21) It is a mild easily treated disease. The vaccination produces only a short (2 month) duration of immunity.(19)

Reactions to this vaccine can be serious including fever, loss of appetite, polyarthritis or anaphylaxis. It is estimated by the AAFP that the reaction rate to this vaccine is 3%. This vaccine is not recommended because the risk outweighs the benefits. This vaccine is only useful in a cattery or multi-cat household with an ongoing problem with chlamydia.

Feline Infectious Peritonitis  Most kittens (85%) become infected with the non pathogenic Enteric Corona virus during the first 3 months of life. This virus does not produce any disease.  The FeCoV very rarely mutates to the virulent, disease producing FIP virus. Just like no two snow flakes are alike, no two FIP viruses are alike. There is no cross protection by the  vaccine between different viruses. Therefore the vaccine cannot possibly work.

The vaccine is labeled for use at 16 weeks. If the objective of the vaccine is to prevent infection, there is no advantage to vaccination after the infection has occurred.(21)

A report by Dr. Fred Scott at Cornell University did not confirm the efficacy claims of the manufacturer.(13, 15, 21) 

 In a study at Texas A & M and in Dr. Scott’s study, cats that were vaccinated and developed FIP actually died faster from FIP than unvaccinated cats. This  suggests  that the vaccine could actually enhance the disease caused by  FIP (vaccine enhanced disease). There is no good data to suggest that this vaccine is effective.

The risks and benefits of vaccination for  FIP should be weighed carefully. Avoiding  over crowded and poor sanitation as well as avoiding exposure of kittens less than 16 weeks of age  to adult cats other than their mother is recommended.  

There is no test that is specific for the FIP virus. All available tests will detect normal FeCoV as well. There is no correlation between a high titer FIP Test and FIP disease. 

All 27 veterinary schools in North America do not recommend FIP vaccine or Testing. .(13)

Bordetella A new vaccine for feline bordetella has recently been introduced. Although bordetella can cause serious infection in kittens, Dr. Wolfe of Texas A&M University says that bordetella is a normal flora and does not likely cause disease in adult cats. Dr. Lappin of Colorado State University agrees & says that a review of the Colorado State medical records reveals not one case diagnosed in 10 years. This vaccine is only applicable for kittens in a shelter where the disease is a proven problem.

This vaccine has been reported to cause sneezing in up to 15% of cats vaccinated. 

Giardia Vaccine: A newly introduced vaccine for Giardia has shown poor efficacy. Immunologists say it would be necessary to produce secretory mucosal  IGA antibodies to protect against an intestinal parasite and a parenteral (injectable) vaccine does not do this. Independent studies have failed to support the efficacy of this vaccine.