If you’ve ever had a kitten or gone to a shelter, you’ve probably seen the sneezing, runny noses and watery eyes typical of upper respiratory tract infections in cats. Most of these infections are like colds in people – annoying, but not life-threatening – but occasionally they become much more serious.
What causes upper respiratory infections?
Two viruses cause most upper respiratory infections in cats: feline herpesvirus type 1 (FHV-1) and feline calicivirus (FCV). They’re highly contagious, spreading rapidly from cat to cat, and are especially problematic where lots of cats are housed together, like shelters or long-term sanctuaries.
Almost all cats are exposed to FHV-1 during their lifetime, and kittens often get infected by their mothers shortly after birth. Since FHV-1 is a herpesvirus, cats become life-long carriers after they’re exposed. Stress can reactivate this dormant feline herpesvirus, causing upper respiratory signs to reappear. Stress-induced shedding helps explain why shelter cats are prone to upper respiratory infections.
Like FHV-1, FCV is highly contagious. But unlike FHV-1, FCV is not linked to stress. Some cats are healthy carriers of FCV, where they don’t show any signs but can still spread the disease. This virus also has been linked to some chronic diseases in cats.
In the last decade, veterinarians have discovered a new, highly virulent form of calicivirus in cats: virulent systemic feline calicivirus. The signs of this form vary, but infection usually leads to multi-organ failure and death. Ongoing studies are uncovering more about this unusual and rare FCV infection, which tends to occur in isolated outbreaks.
What are the signs of upper respiratory infections?
Think of the signs of a human common cold, and you’ll be able to spot an upper respiratory infection in cats. Sneezing, watery eyes and watery nasal discharge are common. Others include loss of appetite, lethargy, oral ulcers and fever. Upper respiratory infections can lead to bacterial infections, which can be very serious. Coughing and eye and nose discharge are signs of more serious infections.
Sometimes the viruses responsible for infections never completely clear, so cats can have periodic relapses throughout their lives.
How are upper respiratory infections treated?
The good news is that, like the common cold in people, many cats recover from upper respiratory infections without treatment. Severely affected cats may need supportive care with fluids, nutritional support and antibiotics for secondary infections. Other treatments include special eye drops, antiviral drugs and nebulization (moist steam). One of the most important therapies is stress reduction, especially in cats housed in groups, such as rescue facilities and shelters.
Cats that have chronic upper respiratory infections are more difficult to treat. However, newer therapies like injectable interferon and intranasal administration of vaccines show promise in preliminary trials. Your vet can guide you on the best treatment options for your cat.
How do you prevent upper respiratory infections?
Routine vaccinations protect your cat from upper respiratory diseases like FCV and FHV-1. While vaccination doesn’t prevent infections, it does help diminish the seriousness of signs if a cat is affected.
Morris Animal Foundation has been supporting research into the causes and treatment of feline upper respiratory infections since 1964. The foundation has invested more than $1 million in just the last 10 years, looking at all aspects of the disease, from diagnostic tests to reducing stress in shelter cats.
Morris Animal Foundation is committed to continually looking for new ways to address important infectious diseases, and you can help us. For more information, I encourage you to visit Morris Animal Foundation.