Wee “Buttercup” was a lovely, petite tortoiseshell cat. She was a frequent visitor to the clinic, as she had chronic rhinitis symptoms. “Buttercup” had contracted “cat flu” as a kitten before her owner had acquired her, and ever since she had been prone to flare ups of her debilitating runny nose and sneezing symptoms.
There are many causes of upper respiratory tract disease in cats. Feline viral rhinotracheitis (feline herpesvirus) and feline calicivirus are the main primary cause. These respiratory viral diseases are common in young cats and are highly contagious. They are transmitted through air droplets, or by direct contact with an infected cat through contact with nasal or ocular discharges, or via contaminated bedding and food bowls. The viruses may survive in a favourable environment for up to 24 hours for herpes virus, and up to 10 days for calicivirus. Over 85% of respiratory diseases are caused by the feline herpes virus 1, which causes the respiratory infection known as rhinotracheitis. These upper respiratory viruses can persist in some cats, known as carriers, for weeks, months, or even years. Some cats that have been infected with the herpesvirus or the calicivirus will remain carriers for life.
These viral infections can cause severe respiratory mucous membrane inflammation and damage, leaving the cases then susceptible to secondary bacterial infection. The viral infection damages the protective mucous membranes of the respiratory tract and eyes, and allows bacteria to invade these damaged tissues, thereby causing persistent clinical signs. This can lead to chronic persistent or intermittent recurrent signs with sneezing, eye and nasal discharges, and nasal congestion. In severe cases this may then lead to chronic infection of the nasal turbinate bones, an osteomyelitis, a bacterial infection of the fine bones within the nasal sinuses.
Vaccinated cats that have not been given the appropriate annual booster vaccines may become infected with one or more of these viruses, and then later in life may exhibit chronic post-viral rhinitis and conjunctivitis symptoms. Or, if they have been previously exposed to respiratory viral infection as kittens, they may have chronic or recurrent symptoms.
There are other pathogens. Chlamydophila Felis and Bordetella are bacteria that can also cause primary respiratory infections in cats. A group of organisms called Mycoplasma can cause primary respiratory and eye infections, or play a secondary role, along with other bacteria such as Pasteurella, Streptococci and Staphylococci. Some fungal infections can also cause chronic upper respiratory tract disease. Also, cancers affecting the upper respiratory tract are rare but may also need to be ruled out in certain cases. In a few cats, benign, non-cancerous, nasal polyps may cause chronic sneezing and discharge. Other causes of upper respiratory tract inflammation may need to be ruled out with further investigations and imaging, such as allergic rhinitis, trauma, foreign bodies trapped in the nose, or even dental disease.
A runny or “stuffed-up” nose is the most common clinical sign in cats with chronic upper respiratory tract infections. The nasal discharge tends to be thick and often is greenish yellow, and it may also be blood tinged. Because smell is so important to them, affected cats have a poor appetite and lose weight. There may also be inflammation in the throat, making swallowing uncomfortable and this can lead to salivation. Affected cats can also have a chronic discharge from one or both eyes. In severe cases, facial swelling and resentment of handling or touching the face may occur due to pain or soreness. Flat-faced cat breeds, such as Persians, find this congestion extremely debilitating. In other cases, these chronic signs are relatively mild, such as episodes of sneezing accompanied by a clear nasal or ocular discharge. Cats with mild symptoms usually have normal appetites.
Some of the common symptoms are:
- Runny nose and sneezing
- Difficulty breathing
- Runny painful eyes and conjunctivitis
- Eye ulcers
- Gingivitis and mouth sores
- Lack of appetite
- Fever and lethargy
These symptoms will be more severe in immunocompromised cats and kittens. If the infections are chronic or recurrent, then tests for the presence of feline immunodeficiency virus, or feline leukaemia virus are advised, both of which may weaken the immune system and predisposing the case to recurrent respiratory infections.
Investigations for chronic cases may involve blood sampling, swab samples of nasal and eye discharges and throat swabs for Laboratory examination, and in some cases imaging, endoscopy and tissue biopsies may be required.
Post-viral chronic rhinitis cases are extremely difficult to manage, and realistically controlling rather than curing the disease is often the primary goal. Antibiotics typically give an initial dramatic improvement that is frustratingly often short lived. Anti-inflammatory treatments can sometimes be of some benefit. Targeted nutritional supplements that aid in mucous membrane repair and maintenance and general immune system stimulation can be helpful, especially in chronic viral infections. And anti-viral and immune-stimulating medications may be beneficial in some severe recurrent cases.
Despite best efforts, some cases often remain chronic or recurrent. The treatment goal in these cases is to reduce the cat's discomfort through long-term or periodic required medication to improve their quality of life. Good home nursing care is also extremely important, keeping the cat’s face clean and clear of discharges, and encouraging them to eat by providing nutritious warmed up food that is strong smelling, such as fishy flavours.
“Buttercup” thankfully responded well to a course of anti-inflammatory and antibiotic treatments, and her owners were always extremely vigilant in watching out for any recurrent respiratory symptoms.
If you are concerned about any upper respiratory disease symptoms in your cat, then do contact your Vet practice for an initial check-up appointment.