While coryza is often compared to the simple “cold” we are familiar with, it is actually a more complex disease. Its severity can vary, and it can even be fatal in kittens and immunocompromised cats. It should not be underestimated… This disease is a real scourge when it affects cats living in communities (pet stores, breeders, boarding houses…), because it is then very difficult to get rid of it. Nevertheless, coryza is not only found in catteries and it is important to know the disease in order to react quickly.
What are the symptoms of coryza?
The symptoms of coryza can be of varying nature and intensity: some forms, discreet, are bearable in everyday life for the animal. Others, known as “hyper virulent”, are life-threatening. In addition, coryza can be fatal in young kittens that are still fragile and immunocompromised animals (this is the case of cats infected with FIV or feline leukosis for example).
After an incubation period of 2 to 4 days, the disease breaks out by targeting :
- The upper respiratory tract: the cat is slaughtered, sneezes, coughs, has a runny nose (the discharge may be transparent or purulent, or even slightly bloody). This is very uncomfortable for him, who, unlike humans, hates to breathe through the mouth! In addition, the destruction of the nasal mucous membrane can lead to a loss of sense of smell; the cat, no longer being able to smell its food, sometimes stops eating. He becomes weak and dehydrated very quickly …
- Eyes: Some cats may have conjunctivitis. The eyes are then dirty and purulent. In more serious cases, ulcers may appear on the cornea.
- Oral cavity: in some cases, especially when the virus involved is a Calicivirus, ulcers appear on the tongue or gums. The cat drools, has difficulty eating. If you gently open its mouth, you will observe bright red patches with sharp edges. Be careful, the reactions can be violent! Indeed, they are very painful wounds …
Watch out! These symptoms are very general and can be a sign of other diseases! Thus, their appearance should always motivate a consultation with your veterinarian, because only he will be able to confirm or not the coryza attack.
What is coryza due to?
It is primarily a syndrome; this means that several pathogens can cause coryza. They often even act in combination. They are mainly viruses of different families (Herpesvirus, Calicivirus and Reovirus to a lesser extent). Bacteria often play a role as secondary agents, by superinfecting the already weakened nasal mucosa. However, one bacterium, Chlamydophila felis, is also considered a primary agent of coryza. It mainly causes conjunctivitis and relatively few respiratory disorders.
After a simple clinical examination, it is impossible for the veterinarian to determine with certainty the agent(s) involved in coryza for a given cat. For this purpose, some laboratory tests exist. They are generally used to target treatment in communities, or during frequent recurrences in the same cat. These tests are rarely offered as first-line treatment.
How do cats get infected?
Your cat can catch coryza from its fellow cats, whether they are sick or asymptomatic carriers: the disease is transmitted through saliva, nasal or eye secretions. Sneezing, sneezing, burning, or mutual grooming are as many opportunities to become infected. But contamination can also be indirect: Caliciviruses can resist a whole week under the soles of your shoes, in a basket or at the bottom of a bowl.
People and objects that have been in contact with a sick cat can also be a source of infection. This is why the disease is so difficult to eradicate in a cattery. It is just as difficult to control the infection when several cats live in the same household…
Does a cat sick with coryza heal “on its own”?
Symptoms can regress in about ten days. Afterwards, some cats will spontaneously eliminate the virus, while others will remain chronic carriers and will excrete the virus for the rest of their lives, sometimes asymptomatically. In any case, when a cat is sick with coryza, it is better not to leave it lying around and take care of the problem quickly! Indeed, a badly treated coryza can leave after-effects (for example, an excessively damaged nasal mucous membrane, or even damage to the bony structures of the nose). The disease then takes on a chronic aspect, which is more difficult to treat. Breathing becomes noisy (snoring, wheezing) and the nose frequently runs.
In addition, contamination by a virus of the Herpes family can be latent: the virus remains “hidden” in the body, and reappears as a result of stress or a drop in the immune system (other disease, childbirth…), as would a fever blister. The cat then appears to be cured, but in reality it has not eliminated the disease, which can reappear at any time in a recurring manner.
What is the treatment for coryza?
There is no specific treatment against the viruses responsible for coryza. The first thing to do at home is to daily clean the crusts around the nose and eyes with a cotton pad soaked in warm water or saline solution. At the same time, a symptomatic treatment will be implemented by your veterinarian to relieve the cat. This treatment is adapted on a case-by-case basis, depending on the symptoms your cat presents. This often involves the prescription of anti-inflammatory drugs or aerosol therapy.
The main objective is to decongest the nose and moisten the secretions to improve comfort and, if necessary, help regain the cat’s appetite. Some veterinary clinics are equipped with special aerosol therapy devices to administer antibiotics or anti-inflammatory drugs through the nose. It is sometimes possible to rent them in some pharmacies. These devices can be difficult to use in less docile cats because they are noisy and therefore a source of stress. More simply, some inhalations can be done at home. This is less difficult than it sounds, as long as you have a large towel and a transport box that closes properly.
How do you get a cat to do inhalations?
- Place the cat in its transport basket. In front of the cage, place a bowl of very hot water into which you will have poured a few drops of active ingredient (this is often a decongestant product, some specialties of which are available in pharmacies). Then cover it with a large towel. Beware of the risk of burns! Make sure that the basket is well closed, and that it is placed on a stable surface. It is best to stay around to make sure that everything is going well.
- An inhalation session lasts on average 10 to 20 minutes. To obtain a convincing result, 2 to 3 daily sessions are necessary, for about 5 days. A good dose of patience…and a little trickery is required, because after 2 or 3 sessions, some cats refuse to go back in the basket.
- If necessary, your veterinarian may decide to prescribe antibiotics, to treat bacterial superinfections, or to prevent their occurrence. Finally, if your cat categorically refuses to eat, it may be necessary to hospitalize it. He will then receive a liquid food by tube and rehydration by infusion.
Depending on your cat’s symptoms and any complications that may be present, the treatment may be completed by other more targeted measures (administration of eye drops in case of eye damage, healing ointments if the nose is very damaged….).
In serious cases, interferon is sometimes proposed. This is a very expensive antiviral agent. To date, there is little data on its effectiveness.
What can I do to protect my cat?
Kittens are protected in the first weeks of life by antibodies transmitted by their mother. Thereafter, they become particularly susceptible to infections. This is why it is necessary to “take over” through vaccination.
Coryza vaccines currently on the market protect against Calicivirus, Herpesvirus, and sometimes also Chlamydophilosis. Beware, they are not intended to prevent the cat from becoming infected or to prevent the disease from occurring, but to reduce the severity of the symptoms. They will not prevent your pet from being a carrier of coryza, but it will be less sick, will heal faster, and will be less contaminating for its fellow cats. Vaccination is therefore recommended from the age of 8 weeks. In some cases, vaccination is possible from 6 weeks of age. The vaccination schedule may be different from one vaccine to another, but generally two to three injections are needed in the first year. After that, a booster shot should be given every year. Do not hesitate to ask your veterinarian for advice.