by Dr. Jean Hofve, DVM
Yes, cats can get the flu. In the last couple of years, a hyper-virulent virus has been hitting shelters and other high-density housing of cats [catteries, rescues, veterinary clinics, pet stores]. And while nicknamed “cat flu”, it is most commonly caused by Feline Herpes Virus-1 [also known as Feline Virus Rhinotracheitis], or Feline Calicivirus. And then, there was also the startling news recently of a documented case of the H1N1 virus in a cat.
How is cat flu spread? Much the same way a cold is spread in humans – from cat to cat contact, and from contact with the nasal and eye discharge from an infected cat.
Most kitten vaccines for feline distemper (panleukopenia) also include rhinotracheitis and calicivirus. There is also a vaccine for virulent calicivirus, but it is unlikely to protect against different strains. Like human flu viruses, feline calicivirus often mutates, making older vaccines ineffective. Vaccination does not prevent illness, and infected cats can still shed these highly contagious viruses; but vaccines are thought to minimize symptoms and reduce viral shedding. Fully vaccinated adult cats are still susceptible; in the case of virulent systemic calicivirus, adults actually fare worse than kittens.
Signs of cat flu (calicivirus, herpesvirus)
• Conjunctivitis with red, puffy eyes
• Corneal ulcers
• Nasal discharge
• Poor appetite
Virulent, systemic strains of calicivirus cause more severe problems:
• Painful ulcers in the mouth and sometimes on the paws
• Unwillingness to eat
• Joint pain and swelling
• Skin lesions
• Systemic vasculitis
Cats have been known to contract non-feline influenza viruses, including avian flu (H5N1), and earlier this month a case of “swine flu” (H1N1) was diagnosed in a cat. Cross-species viral infections are rare, but can occur. There is no evidence that cats can infect humans with either influenza virus.
Supportive care is all that’s needed for most cases of cat flu. In severely affected cats, IV fluids or even a feeding tube may be necessary. If there is evidence of a secondary bacterial infection, such as pneumonia, antibiotics should be given.
In cases where one or more cats is already sick, taking precautions against disease spread (strict isolation of infected cats, meticulous cleanliness) is vital. Bleach is one of the few reliable disinfectants that can kill calicivirus; mix 1 ounce of bleach in a gallon of water.
The best defense against any contagious disease is a healthy immune system. Good nutrition (with an emphasis on low-carb, high moisture foods), maintaining optimal weight, regular exercise (with interactive cat toys such as Da Bird), and immune-boosting supplements will help keep viruses and other invaders at bay.