The calicivirus has mutated, but now there’s a way to prevent it.
By Jennifer Hayes, Best Friends NetworkAlthough many people may not be familiar with the disease itself, the calicivirus is fairly common and its prevention has been a part of the normal FVRCP vaccination given to cats annually. However, a new strain of this virus called the VS-FCV (Virulent Systemic Feline Calicivirus) was discovered less than a decade ago, but unlike its original form of a standard upper respiratory infection, this strain is often fatal.
The VS-FCV disease has previously been thought to be rare, occurring only occasionally. However, Dr. Gary Norsworthy, DVM, Diplomate ABVP (Feline Specialty), has said that at his many speaking engagements around the United States and Canada, when he discusses the VS-FCV, invariably a vet comes up to him after the lecture to state that he or she has witnessed cats with the symptoms, but was just not able put a name to the disease. Dr. Norsworthy therefore believes this strain to be far more common than previously thought, just not properly diagnosed, due to lack of knowledge and awareness.
The symptoms of this new strain include not only sores on the tongue, fever, sneezing, and nasal discharge from the original strain, but also swelling under the chin or leg joints. Hair loss then follows on the swollen areas and open sores then begin to appear as well. Cats can exhibit fevers in excess of 105 degrees F, become jaundiced, and internal organs, such as the liver and pancreas, may even begin to become affected. This new mutated virus is very dangerous and has proven lethal to approximately 60% of adult cats that contract it and 15% of kittens. Those that do recover, continue to shed the virus (potentially infecting other cats) for about 4 months after recuperation.
However, a new vaccine has come to market that protects cats from VS-FCV, in addition to those diseases prevented by the FVRCP; feline rhinotracheitis, panleukemia, and the common calicivirus. However, a booster shot is needed to be administered to the cat 3-4 weeks following the initial shot for the greatest protection. Thereafter, only one annual vaccination will be necessary. As with all vaccinations, none are 100% effective; however, in vaccine studies, 75% of cats exposed to the virus had complete protection and the remaining 25% showed minor symptoms for a day and subsequently recovered.
Obviously cats that are allowed to roam outdoors should be protected against this new virus strain, but indoor cats should be as well. Contamination can potentially occur with exposure to
any other cats; that includes through a window screen or even at your veterinarian’s office for its annual exam. The virus spreads easily and can even be transmitted by people via clothing or household objects. Many regular disinfectants do not destroy it; only a bleach mixture (bleach to water with a 1:32 ratio) will kill the virus, which can live up to four weeks in the environment.
What You Can Do:If you have cats, it is highly recommended that you speak with your own veterinarian to discuss the VS-FCV and this new vaccine. You may just be saving your cat’s life!
For more information about VS-FCV and this new vaccine, see:• Dr. Norsworthy’s article from the January issue of
Cat Fancy Magazine • Dr. Norsworthy’s
New Vaccine Handout, attachment on Resources tab
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ShelterMedicine.com Sources: Dr. Gary Norsworthy, Cat Fancy Magazine, and Dr. Gary Norsworthy’s New Vaccine Handout
Photo credit: healthy cat photo taken by Jennifer Hayes, the photo showing swelling and open sores under the chin reprinted with permission by Dr. Norsworthy
A special thank you to Dr. Gary Norsworthy of the Alamo Feline Health Center in San Antonio, for his assistance with this story.