Respiratory Disease In Your Cat And Kitten = Rhinotracheitis, Cat Flu or Herpes 1
Ron Hines DVM PhD
It is very common for new pet owners to obtain a kitten or new cat with a crusty nose, weepy eyes and a sneeze. We call these problems upper respiratory disease (URI) or feline respiratory disease complex and it is the most common infectious disease that veterinarians deal with. . These problems usually resolve within a few weeks of good care and low stress but some cases linger. There are several organisms that can cause this disease. The most common is the rhinotracheitis virus. Rhinotracheitis is caused by a virus of the herpes group, Feline Herpes 1. The second most common organisms are Chlamydia psittaci (feline pneumonitis) and Calicivirus. Mycoplasma and Bordetella organisms make up the rest. None are dangerous to humans and only Bordetella and Mycoplasma can cross over to dogs. Often a combination of organisms causes the disease. These organisms reside in the upper respiratory tract, the nose, pharynx and trachea (wind pipe). The also affect the membranes covering the eyes causing tearing and crusty eyes. These pathogens are passed from mother to offspring and from cat to cat by sneezing, snuffling and on infected objects. They are all highly infectious and because rhinotracheitis is quite resistant to drying and time, it is most easily spread. Recovered cats can pass the virus on for many months. The majority of animals that carry these organisms look perfectly healthy. This explains how a newly arrived cat in a household or shelter of healthy cats comes down with the disease. The incubation period for rhinotracheitis is 3-6 days. The incubation period for Chlamydia psittaci is 5-10 days.
What Signs Of This Disease Might I See?
When cats first come down with these diseases they often run a fever, sneeze and become listless. Their appetite may wane. After the first few days of illness their body temperature returns to normal. A cat’s normal body temperature is 101.5-102.5F (38.6-.39.2C) Cats with respiratory tract infections can reach 106F (41.1C) during the first few days of illness. That is why adequate fluid intake is so important to prevent dehydration. Cats with Calicivirus often drool due to ulcers on their tongue, lips and roof of the mouth. These cats rarely show signs of pneumonia because with the exception of Calicivirus, these organisms usually spare the lungs. Nasal drainage is at first watery. With a time, the discharges become thick, tenacious and mucoid. Cat’s eyes become reddened, inflamed and weepy. These signs can last a week or so in mild cases and many months in stressed or frail pets. Mature cats almost never die from this disease. The disease is only life threatening in weak kittens that my stop eating or when a secondary pneumonia occurs in weakened patients. cat kitten lung respiratory nose eye
Is There Any Specific Treatment?
I have found that this disease complex responds better to simple T.L.C. than all the medications that I can dispense. Chicken soup is an excellent treatment for this disease. It can be fed through a dropper if need be to prevent dehydration and tempt depressed cats into eating. Sometimes pungent foods like sardines and tuna will be accepted when all else fails. Viruses are not killed by antibiotics so only in chlamydial, mycoplasmal and bordatella infections are antibiotics actually curative. I put most cats on antibiotics because I am never sure which pathogens are present and to prevent pneumonia and sinusitis in debilitated patients. I also place them on a multivitamin liquid because so many of them are stressed and not eating. Cats that are severely congested do well with vaporizers, steam and nasal decongestants. I also dispense tetracycline eye ointment to use in the eyes and crusted nostrils. When they have poor appetites, I dispense a high caloric past such as Nutrical®.
A small portion of cats infected with herpes virus rhinotracheitis will lapse into a chronic carrier state that lasts for years or a lifetime. Most of these carriers show no signs of the disease but some have intermittent eye inflammations, and draining nostrils. Others develop milky lesions of the cornea that come and go. In its inactive state, the eye lesions are milky white circular scars within the cornea. This disease is called herpetic keratitis. When rhinotracheitis flares as corneal ulcers the cat will squint and tear as eye membranes become inflamed. Usually these flare ups are associated with the stress of boarding, weather change, other disease or new cats in the family. If the problem is serious, I put the cat on one of the antiviral drugs such as acyclovir (Zovirax®), vitamin A and lysine, and tetracycline (Terramycin®) ophthalmic ointment or oral doxycycline (Vibramycin®).
The amino acid, l-lysine, has been found to help many cases of rhinotracheitis resolve. This amino acid reduces the amount of another amino acid, arginine, that is present in the cat’s body. Arginine is thought to be necessary for herpesvirus to reproduce. The suggested lysine dose is 250-500 mg per day sprinkled on canned cat food. I would give this suplement until the acute flare-up has resolved. But many cat owners continue the suplement indefinitely. Lysine can be purchased at health food stores. Pick a brand that is propylene glycol-free.
Are There Ways To Prevent This Viral Problem?
Good vaccines are available to prevent this disease. I give them to kittens at 9, 12 and 14 weeks of age. The problem is that many kittens are already infected with the virus of rhinotracheitis before they leave their mothers. The stress of pregnancy and more so nursing causes these carrier mothers to relapse and pass the virus to their kittens. Many cats from shelters are in the middle of an infection when I first see them. In these instances the vaccine will not work. Until recently, vaccinations were given yearly to cats in the United States. There is evidence that rhinotracheitis and Calicivirus vaccines do not need to be given that often. When they are given they should be administered through a 25-guage needle on the front or anterior side of a rear leg and the injection site vigorously massaged after injection. This is to decrease the very rare instances where a tumor forms at the injection site in cats.
Within the last few years,veterinarians have been given a tremendous tool for sorting out the various organisms that can cause respiratory problem in your cat.(ref) Sophisticated central laboratory services are now available throughout the United States to do this. All utilize a very sensitive test, the Polymerase Chain Reaction or PCR test to look for six of the most common causes of upper respiratory and/or chronic eye problems in cats ( Bordetella, Chlamydia, calicivirus, Herpes 1,influenza and mycoplasma). One limitation of the panel is that the most common cause of reoccur rent sneezing, the Herpes-1 (rhinotracheitis virus), is so stealthy that it can avoid detection with the PCR test when the cat is not experiencing a virus flare-up. So if the PCR test is positive for herpes-1, your cat is definitely a carrier of the virus. But if it is negative, the virus might still be sleeping somewhere deep in your cat’s nerve cells. So if the test found no likely cause reoccurring respiratory problems, it should be repeated at a later date – preferably during a flare-up.