Cats commonly suffer a respiratory disease, cat flu, in autumn and winter. This coincides with the mating season when male cats become more active and are probably responsible for transmitting the disease throughout their territory.
The disease is caused by a group of viruses and is highly infectious. Transmission is via droplets released into the air by sneezing or from the discharges from eyes and noses. The incubation period is quite short, usually about 5 to 7 days.
Two viruses are responsible for about 80 percent of respiratory infections. The Feline Rhinotracheitis (FR) virus and Feline Calicivirus (FC) have been isolated. Hence the disease is referred to by veterinarians as FRFC.
Cats of all ages can be infected, but very young kittens are most at risk. It is not unusual for a nursing cat to have a relatively mild “cold” but to lose all the kittens in the litter with an acute respiratory disease.
Cats may appear to recover completely from the disease but may carry the live virus lodged in a portion of their nasal cavities. These cats are probably responsible for the spread of the infection from year to year.
The first symptom of the disease is usually a watery discharge from the eyes and nose. The cat starts to sneeze, is reluctant to eat and drink, and can be quite depressed.
The severity of the disease is usually related to the degree of secondary bacterial infection which complicates the initial viral infection. In uncomplicated infections in healthy adults, the cat may throw off the infection unaided within a few days.
Unfortunately it is impossible to predict whether the cat’s natural defense mechanisms are going to resist the challenge. Probably the best guide is appetite. If the cat stops eating or is in obvious discomfort with mouth breathing and frequent sneezing, veterinary treatment should be sought at once.
The virus may attack the lining of the tongue and palate and produce painful ulcerations. It may cause a very painful swelling of the tissues of the throat, which not only prevents the cat from eating but makes it reluctant to meow or purr. Eating and swallowing are so painful that resistance will quickly decline if special feeding techniques are not begun.
Treatment is aimed at eliminating the secondary infection. Antibiotics are administered, firstly by injection, then continued by the owner in a palatable oral form.
If the cat’s nose is so obstructed that it is mouth breathing, decongestants are prescribed. Care should be taken to confine the animal so that treatment can be administered regularly but the surroundings should not be too hot, as this only further distresses the patient.
A vaccination is now available against FRFC infections. Initially two injections are necessary, three weeks apart. It is not until the second injection has been given that full immunity is achieved.
If the cat is to be placed in boarding kennels it is, therefore, necessary to start the vaccination program at least three weeks before the date of admission. A single yearly revaccination is then given and this can be combined with the feline enteritis vaccination.
Not all respiratory infections are caused by the FRFC virus combination. However the vaccination will protect the cat against the most common respiratory disease and is highly recommended.
The modern vaccine has very few side effects and can safely be given to kittens from 8 weeks. Of course the vaccine cannot be used if the cat is already showing signs of respiratory infections.