Upper respiratory infections (sometimes called “cat flu” or URIs) are common in cats of all ages, from kittens to seniors. Young cats often have a viral or bacteria infection as the first cause. An older cat may have a chronic bacterial, viral URI. However, this is not the end of the story.
Normal bacteria is found in the skin, noses, and respiratory tracts of all cats, as well as humans. These bacteria are not usually harmful to healthy animals, but if there is an underlying illness, they can become the source of a URI. This is called a secondary bacterial infections, which means that the infection is secondary to another underlying cause. Your veterinarian is responsible for diagnosing and treating the underlying cause of the URI.
How to determine the source of your cat’s upper respiratory infections
Your vet will first determine if your cat has a simple viral upper respiratory infection or if she has an underlying condition for which the URI is merely a symptom. The latter is more common in older cats. A thorough physical exam will be performed by your vet. This may include radiographs and blood tests, as well as radiographs of the mouth and nasal tissue.
It is crucial to perform a thorough exam on a cat suffering from chronic URIs. The list can be quite long. There are many possibilities, including a foreign object (such a grass awn or foxtail) that has become lodged in a sinus, an abscess of the tooth root (the upper teeth are very near the sinuses), an underlying fungal disease, allergies, or a type of irritating growth called a nasal polyp. These can all occur in the throat or nose of cats. Tumors and underlying diseases can lead to severe immune suppression in your cat. If your vet has not done so recently, they will need to check for feline immunodeficiency viruses (FIV) or feline leukemias (FeLV).
Remember that even if you have a simple URI, most bacterial infections associated with bacterial respiratory infections are caused by an underlying viral infection. These viruses are common causes of upper respiratory infections in kittens and are frequently seen in stressed cats living in shelter situations.
Cats that are able to recover from one of these viruses in their youth can be chronic carriers. It is not always possible to tell if your cat is a chronic carrier of the virus because viruses cannot be tested in all cats. A cat that has a history of chronic or repeated URIs may be the sign of a multi-cat household. This could be a possibility if one of your cats has had a history of being in shelter or has an unspecified medical history.
Cat URI treatment options
Veterinarians routinely use a variety of antibiotics to treat URIs in cats. Antibiotics can only be used to treat bacteria. You will soon learn that chronic bacterial respiratory infections in cats are often secondary to other conditions. The underlying cause of the respiratory infection must be addressed. Otherwise, it will likely recur or not resolve at all.
Tooth extraction may be necessary if there is underlying dental disease. Your vet will need to remove or flush out any grass awns that have become lodged in your nose. Antiviral and antifungal medication may be used to treat a primary viral or fungal infection. Your vet can remove a polyp in a quick and painless manner. Some tumors can be treated with chemotherapy or surgery.
There is no one best treatment for chronic URIs in cats. The key to success is proper diagnosis and treatment of the underlying problem. Sometimes, the treatment is insufficient. In these cases, the symptoms may be managed but not the entire infection.
Bottom line: Your vet may need to spend some time to determine the root cause of the problem. Effective treatment is dependent on thorough diagnosis, diligent home treatment, and a consistent, ongoing treatment, even if it takes several weeks.