Feline Upper Respiratory Infection
It’s true: our feline friends can get colds, too! As is the case with humans, the culprits to blame for these nasty colds are bacteria or viruses, sometimes both.
The bacteria and viruses that most commonly cause upper respiratory infections (URIs) in cats are:
- Feline herpesvirus type-1 (FHV-1); also known as feline viral rhinotracheitis (FVR)
- Feline calicivirus (FVC)
- Bordetella bronchiseptica (B. bronchiseptica)
- Chlamydophila felis (C. felis)
- Less commonly, Mycoplasma spp. (bacteria) or a feline retrovirus, such as FIV or FeLV, are contributing factors in an upper respiratory infection.
Bacteria and viruses are very contagious and are present in the saliva and discharge produced by the eyes and nose. Healthy cats can get infected when they come into direct contact with a sick cat. Cats with retroviruses are especially vulnerable to the contagions, both through direct contact or indirect contact with contaminated objects.
Unfortunately, some of the aforementioned diseases are still present in seemingly recovered cats (carriers) and are unknowingly passed on to other cats. Mothers can also act as carriers, passing on infections to their litters.
Cats that have contracted FVR are considered “chronic carriers,” meaning they will carry the virus for life and can become sick again in times of high stress (moves, new housemates, babies, etc.). About half of the cats infected with FVC will remain infected as carriers, sometimes for a few months after symptoms cease, and, in rare cases, for life.
Sniffling, sneezing, clear to pus-like discharge from the eyes and/or nose, coughing and lethargy are common symptoms of an upper respiratory infection in cats. On examination, your veterinarian may also check for oral ulcers, sometimes caused by FVR and FCV. Generally, a fever, poor appetite, and lethargy accompany the more specific symptoms of a URI.
Generally an infection will last for 7–21 days. There is an incubation period, the time period from point of infection to when clinical signs become apparent, of 2–10 days. It is thought that the incubation period is the time of highest contagion.
The clinical signs and symptoms are usually enough to make a diagnosis of feline upper respiratory infection. Diagnostic tests, however, are required to determine the cause of the infection. So your veterinarian may recommend the following tests:
- A complete blood count (CBC) to rule out blood-related conditions
- Chemistry tests to evaluate kidney, liver, and pancreatic function, as well as sugar levels
- Electrolyte tests