Synonymous to feline infectious respiratory disease and feline upper respiratory disease complex (URD), feline upper respiratory infection (URI) refers to a respiratory infection caused by one or more viral or bacterial agents, explained Cheryl Yuill, DVM, MSc, CVH of VCA Hospitals, an operator of over 750 animal hospitals in the US and Canada.
The most common viruses that cause URI in cats are FHV-1 (Feline Herpesvirus Type-1) and FCV (Feline Calicivirus), while the most common bacteria that cause this disease are B. bronchiseptica and Chlamydophila felis. About 90% of all feline upper respiratory tract infections are caused by Herpesvirus and calicivirus. However, other lesser-known agents that may be involved in URI in felines are mycoplasma or feline reovirus.
Evaluation of Cat Health Following the 2011 Great East Japan Earthquakes
A retrospective cohort study was conducted at a temporary shelter in Ihno, Fukushima prefecture, where animal control officers from the Fukushima Daiichi Nuclear Power Station—a restricted zone—brought 189 cats between April 27, 2011 to December 31, 2012, said Aki Tanaka and colleagues of biomedical and life sciences journal portal PMC. During 2011, 95 cats were impounded and 94 felines were impounded during 2012.
In 2011, 71% of cats had incident diarrhea and the following year, 54% had this infectious disease. On the other hand, upper respiratory infections were seen in over 95% and about 80% of the casts in 2011 and 2012 respectively. About 96% (91 of 95) of cats showed symptoms of URI or diarrhea in 2011 and about 80% (75 of 94) in 2012. 63% of cats (60 of 95) in 2011 and about 30% of the felines (28 of 94) in 2012 suffered from URI and diarrhea.
Corticosteroids were given to approximately 30% of cats with URI and over 40% of cats with diarrhea in 2011 and over 40% of URI incidences and about 30% of diarrheic incidences in 2012. Antibiotics were given to 67.4% of felines in 2011 and over 40% received over three different antibiotics. 755 of cats were administered less than four drugs in 2012.
Interferon was given to about 66% of cats to treat URI in 2011. However, interferon and antihistamine, including the number of antibiotics and drugs administered, were associated with prolonged duration of URI. To date, there is no evidence supporting the effectiveness of interferon in treating the clinical signs of URI. Tanaka and colleagues suggested to minimize stress, reduce population density, and avoid using interferon or multiple antibiotics.
Upper Respiratory Infection/Disease and Associated Risk Factors In Cats In Canada’s Animal Shelter
Nadine Gourkow and colleagues of PMC studied 250 cats at an animal shelter in coastal western Canada to find out whether age, source, gender, and sterilization status contribute to the risk of shedding at intake, transmission of infection, and development of URI. At intake, 28% of the samples were carriers for one or more pathogens.
Of those, M. felis, FCV, FHV-1, and B. bronchiseptica were present in 22%, 2.8%, 2.0%, and 2.4% in cats, respectively. Gender was not associated with the development of URD, but neutered cats (39%) had a greater prevalence of URD than intact cats (26%). This is due to neutered cats being owner-surrendered, meaning they had likely not been exposed to URD pathogens, making them more susceptible.
The risk of developing URD was 2.6 times greater for carriers (53%) than for non-carriers (23%) when all pathogens were all taken into account. Compared to 28% of cats without subclinical infections, all FHV-1 carriers (100%) developed URD. The risk was not significantly higher for FCV carriers (43%) and only 28% of FCV non-carries had URD.
The prevalence of M.felis shedding (21%) was higher than for all pathogens, but the risk of developing URD was not significantly higher. However, cats with subclinical B. bronchiseptica (181 cats, 83%) were more likely to develop URD than non-carriers (181 cats, 28%).
Risk Factors and Symptoms of Feline URI
Typically, URI involves your cat’s nose and throat, which causes sneezing, nasal congestion, conjunctivitis, and eye or nasal discharges. The discharges may be clear or become cloudy in appearance and contain pus. With FVR and FCV, your cat may have ulcers in its mouth.
Other less specific signs of URI are anorexia, lethargy, fever, squinting, and enlarged lymph nodes. In severe cases, your cat may have trouble breathing. URI usually lasts for seven to 10 days. Kittens and shelter cats are more likely to have URI.
It commonly occurs in cats that have regular contact with other cats in places where they are housed together such as shelters, stated Lianne McLeod, DVM, of The Spruce Pets, a website dedicated to publishing pet-related content.
Unvaccinated cats, stressed cats, and those that are immunosuppressed due to feline leukemia virus (FeLV) or feline immunodeficiency virus (FIV) are also more susceptible to URI. Persians and flat-faced cats seem vulnerable to URI. Your cat may get URI through direct contact with infected cats or by contact with contaminated objects such as dishes or bedding.
Diagnosis and Treatment of URI
Diagnosis is mostly based on the characteristic clinical signs. If URI is caused by a virus, your vet can identify it by collecting samples of cells discharges from your pet’s nose, eyes, or back of the throat. Treatment is aimed at managing the symptoms of URI. Hence, antibiotics may be prescribed to combat bacterial infections that usually happens following viral infections.
Medications to control nasal congestion and discharge may be given to your cat as well. Your vet will provide you with treatments you can do at home, but if your cat does not eat or drink or have difficulty breathing, hospitalization may be needed. Your vet may give intravenous fluids to prevent dehydration and may even provide oxygen therapy if necessary. If your cat suffers from prolonged or repeated bouts of URI, you may need to have it checked for FeLV and FIV even if it tested negative before.
URI Prevention and Home Care
Vaccinate your cat against herpesvirus and calicivirus. Minimizing stress and preventing contact with infected cats can reduce the incidence of URI. If you live in a multi-cat household, consult your vet about any precautionary measures you should take to reduce the risk of URI such as isolating sick cats or disinfecting objects.
If your cat suffers from URI, be sure to keep it in a quiet and comfortable area. Carefully wipe away eye or nasal discharges and administer all prescribed medications. In case of reduced appetite, you can try feeding your cat their gourmet canned food or a veterinary diet for nutritional support.
From the above-mentioned studies, stress, viruses, and bacteria are some of the main causes of URI in cats. Owners living in multi-cat households should take precautionary measures to reduce the risk of URI.