Cat Flu Season: What You Need To Know

Cats are susceptible to a variety of viruses and diseases, some of which can be transmitted to humans. Feline calicivirus (FCV) is a highly contagious RNA virus that causes respiratory and oral infections in cats. It is particularly common in multi-cat environments such as shelters and pet stores. Symptoms of FCV include sneezing, eye discharge, mouth ulcers, and fever. Most cats recover from FCV, but it can be fatal in rare cases. Another common virus affecting cats is feline distemper, which is highly contagious and life-threatening, especially to kittens and unvaccinated cats. It can cause various symptoms, including a painful abdomen, decreased appetite, and bruising. In addition to these viruses, cats can also be infected with influenza, which can spread between cats and from cats to humans. While influenza in cats is usually mild, it can sometimes lead to severe illness or death, especially with avian influenza.

Feline calicivirus

The virus spreads through direct contact with the saliva, nasal discharge, and eye discharge of infected cats. It can also be transmitted through aerosolised sneeze droplets and contaminated objects, such as food bowls, bedding, and grooming tools. FCV is highly contagious and can survive on surfaces for up to a month, making it easy for the virus to spread in multi-cat environments.

Symptoms of FCV include sneezing, nasal congestion, fever, drooling, eye and nasal discharge, inflammation and ulcers in the mouth, lethargy, mild lameness, and loss of appetite. These symptoms can last from 5 to 10 days in mild cases and up to 6 weeks in more severe infections. Some cats may also develop a chronic form of gingivitis, making eating painful.

In rare cases, a more virulent strain of FCV can cause FCV-associated virulent systemic disease (FCV-VSD) or virulent systemic feline calicivirus (VS-FCV), which is characterised by severe symptoms such as high fever, swelling of the head and legs, crusting sores, hair loss, jaundice, and multiple organ dysfunction. This strain has a high mortality rate, with up to 67% of infected cats succumbing to the disease.

There is currently no specific treatment for FCV. However, supportive care and symptomatic treatment can be provided, including keeping the nose and eyes clean, using vaporizers and saline nose drops, and administering anti-inflammatory medications to reduce fever and mouth pain. Broad-spectrum antibiotics may also be used to prevent secondary bacterial infections.

Vaccines are available for FCV and can help reduce the severity of the infection if a cat is exposed. The FVRCP vaccine is a core cat vaccine that provides protection against FCV and other respiratory agents. However, due to the mutating nature of the virus, vaccinated cats can still be infected with new strains. Therefore, it is important to keep cats up to date with their vaccinations and to minimise their exposure to other cats, especially in high-risk environments.

Feline herpesvirus

Cats become infected with FVR through direct contact with viral particles. The virus spreads via saliva and discharges from the eyes and nose of an infected cat. Therefore, an infection occurs when a susceptible cat comes into direct contact with an infected cat or contaminated objects such as clothing, food and water dishes, or furniture. The virus can survive on contaminated surfaces for up to 18 hours if the secretions remain moist, but it typically dries up within a few hours.

The incubation period for FVR is two to five days, during which the cat can infect other cats. Once symptoms appear, the active infection typically lasts about 10 to 20 days. All cats infected with FVR become carriers of the virus, and most carriers are latent, meaning the virus remains inactive within the cat's body. However, stress and illness can cause the virus to reactivate, making the cat infectious again.

Symptoms of FVR include sneezing, nasal congestion, conjunctivitis, excessive blinking, squinting, and discharges from the eyes and nose that can be clear and watery or thick and purulent (containing yellow/green pus). The virus may also cause keratitis, leading to corneal ulcers and, in chronic or severe cases, corneal scarring or "dry eye." Other possible symptoms include fever, lethargy, anorexia (poor appetite), and enlarged lymph nodes.

While there is no cure for FVR, treatment focuses on managing symptoms and reducing secondary complications. Topical eye medications are used to treat eye infections, and it is crucial to aggressively treat corneal ulcers to prevent permanent eye damage. Antiviral medications, such as oral antiviral drugs or antiviral ophthalmic drops, may also be prescribed. Additionally, antibiotics are often used to control secondary bacterial infections.

To prevent the spread of FVR, vaccination and hygiene practices are essential. The standard FVR vaccine included in core vaccines for cats can significantly reduce the severity of the infection and shorten its duration. However, it is not entirely effective in preventing infection. Maintaining good hygiene, such as washing hands before and after handling cats, is also crucial in reducing the likelihood of disease spread.

Feline distemper

The virus typically enters a cat's body through the nose or mouth and infects rapidly growing and dividing cells, such as those in the bone marrow and intestines. It suppresses the production of white blood cells, which are crucial for fighting off infections, leaving cats vulnerable to further health issues. Feline distemper can be spread through infected cats' feces, urine, saliva, and vomit, as well as contaminated items like food and water bowls, bedding, and litter boxes. It can also be transmitted by fleas from infected cats.

Symptoms of feline distemper can range from mild to severe and include a painful abdomen, a rough or unkempt hair coat, decreased appetite, and, in severe cases, collapse and bruising of the skin or gums. Kittens infected with feline distemper may experience intention tremors, have a wide-based stance, and seem uncoordinated.

Diagnosis of feline distemper is made through a thorough medical history, blood work, and fecal testing. Treatment focuses on supportive care, including intravenous fluid therapy, prescription medications, and antibiotic therapy to control secondary bacterial infections.

To prevent feline distemper, vaccination is key. The distemper vaccine is part of the core vaccine series for cats, with the first dose typically given between 6 to 9 weeks of age, followed by boosters every three to four weeks until the cat reaches 14 to 16 weeks old. This vaccination is then repeated every one to three years, depending on the cat's lifestyle and veterinarian recommendations.

Avian influenza

In cats, avian influenza can cause a range of symptoms, including fever, lethargy, dyspnoea, conjunctivitis, and rapid death. Neurological signs such as circling, ataxia, paralysis, and seizures have also been recorded. In some cases, cats infected with avian influenza may develop severe illness and even die.

If you suspect your cat has been exposed to avian influenza, contact your veterinarian immediately. The veterinary authorities should also be notified, and oropharyngeal, nasal, and/or rectal swabs or faecal samples should be submitted for PCR and/or virus isolation. It is important to keep cats with suspected H5N1 infection in strict isolation and to confine them to a separate room prior to bringing them to the veterinary clinic.

To prevent the spread of avian influenza, it is recommended to limit contact between pets and wild birds, as well as ill livestock and potentially contaminated environments. Practicing good hygiene, such as thoroughly washing hands after touching animals or birds, is also important.

SARS-CoV-2

The first reported case of SARS-CoV-2 in cats was in Wuhan, China. Since then, there have been reported cases of cats infected with SARS-CoV-2 in many countries, including China, Belgium, Italy, the UK, France, Spain, Brazil, the USA, Argentina, Germany, Russia, Japan, Chile, Greece, Canada, Switzerland, and Latvia. In most of these cases, the cats were in close contact with humans who had COVID-19.

Cats infected with SARS-CoV-2 may show mild symptoms such as lethargy, mild respiratory or digestive symptoms (sneezing, coughing, ocular discharge, vomiting, and anorexia). In rare cases, cats may develop severe respiratory problems. In one case, a cat in France developed myocarditis after being infected with the British variant of SARS-CoV-2.

Experimental studies have shown that SARS-CoV-2 can be transmitted between cats, but there is no evidence of cat-to-human transmission. Cats that have recovered from SARS-CoV-2 infection may still be able to transmit the virus to other cats, but the risk of transmission decreases over time. It is recommended that people with COVID-19 isolate themselves from their pets to reduce the risk of infecting them.

Overall, the available research suggests that SARS-CoV-2 infection in cats is usually mild and may even be asymptomatic. However, more studies are needed to fully understand the impact of emerging SARS-CoV-2 variants on the epidemiology of the virus in animals.

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