What is cat flu?
Cat flu, also known as feline viral rhinotracheitis, is an upper respiratory infection caused by viruses like feline herpesvirus and feline calicivirus. It is a highly contagious disease that spreads easily between cats (https://www.bluecross.org.uk/advice/cat/health-and-injuries/cat-flu).
Common symptoms of cat flu include fever, sneezing, discharge from the nose and eyes, loss of appetite, lethargy, and mouth ulcers. The viruses attack a cat’s upper respiratory tract, including the nose, throat, and sinuses, causing inflammation and discomfort. While some cats only experience mild symptoms, others can become very ill.
How do cats get infected?
Cats become infected with cat flu primarily through direct contact with other infected cats. The viruses can be spread through saliva, nasal discharge, or eye secretions from a cat that is currently shedding the virus or is a chronic carrier. Even sharing food bowls, water bowls, litter boxes, or grooming with an infected cat can transfer the virus.
The viruses can also spread through contaminated objects and surfaces. If an infected cat sneezes or rubs its face on a toy, bed, furniture or other objects, the viruses can survive on those surfaces for several days. Another cat coming into contact with the contaminated object can pick up the infection. This is why cat flu often spreads quickly in multi-cat households or shelters.
There is also evidence that cat flu viruses can be spread through the air in droplets, especially in confined spaces like a house or shelter. The viruses can travel short distances through the air when an infected cat sneezes or coughs. A susceptible cat breathing in those virus particles may become infected.
The most common way cat flu spreads is by direct contact with infected cats. But contaminated objects and airborne transmission also facilitate the spread of these highly contagious viruses among cats in close contact.
Is cat flu serious?
Cat flu is usually mild in adult cats who are otherwise healthy, but it can become more severe and lead to potentially fatal secondary infections (Bluecross.org.uk, 2023). The viruses that cause cat flu, such as feline herpesvirus and feline calicivirus, often only result in mild upper respiratory symptoms like sneezing, runny nose and eyes, and loss of appetite. However, in some cases cat flu can progress to more severe pneumonia, mouth ulcers, dehydration, and other secondary bacterial infections.
Kittens and senior cats tend to be at higher risk for developing severe illness from cat flu (Cats.org.uk, 2023). Kittens have an underdeveloped immune system, making it harder for them to fight off infection. Senior cats often have underlying illnesses that make battling a cat flu infection more difficult. For these vulnerable populations, cat flu can become serious and even fatal if left untreated and if secondary infections develop.
While cat flu is mild in the majority of cases, it’s important to monitor all cats for signs of worsening illness and secondary infections, especially high-risk kittens and senior cats. With prompt veterinary care and treatment, even serious cases of cat flu can often be managed, but fatalities can occur in untreated cases.
Can cat flu be fatal?
While the mortality rate of cat flu is relatively low, it can be fatal in some cases. According to the Cats Protection charity, around 5-10% of cats with cat flu will die if they are not treated properly. Death is usually the result of secondary bacterial infections or dehydration.
Cats with weakened immune systems, kittens, and elderly cats are at higher risk of developing life-threatening complications from cat flu. Even when cats recover from the initial infection, they often become chronic carriers of the virus and can experience recurrent bouts of illness throughout their lives. While not directly fatal, chronic infections may lower a cat’s quality of life.
If a cat with flu stops eating and drinking, it can quickly become dehydrated. Vomiting and diarrhea associated with secondary gastrointestinal infections can also contribute to dangerous fluid and electrolyte imbalances. Dehydration left untreated can lead to organ failure and death. That’s why supportive care with fluids, electrolytes, and nutrition are so important in cats with cat flu.
Overall, while most cats recover from cat flu, owners should watch for signs of worsening illness and secondary infections that may become fatal if left untreated. With prompt veterinary care and at-home supportive care, the prognosis for survival is good.
Treatment for cat flu
Cat flu is a viral infection that is usually self-limiting and will resolve within 2-4 weeks with supportive care at home. However, there are some medications your vet may prescribe if symptoms are severe:
Antibiotics like doxycycline may be given for any secondary bacterial infections that occur as a complication of cat flu (https://www.bluecross.org.uk/advice/cat/health-and-injuries/cat-flu). The antibiotics treat pneumonia or other respiratory issues caused by opportunistic bacteria.
Antiviral medications such as feline recombinant interferon omega may be used in very severe cases of cat flu where the cat’s immune system needs help fighting the virus (https://www.trudellanimalhealth.com/learn/further-reading/cat-flu-signs-symptoms-treatments). However, these are not always necessary.
Supportive care is the mainstay of treatment. This includes encouraging eating, fluids to prevent dehydration, keeping nasal passages clear of discharge, and monitoring for secondary issues. Your vet will tailor a treatment plan to your cat’s specific needs.
Preventing cat flu
There are several ways cat owners can help prevent the spread of cat flu, including:
Vaccination – According to the RSPCA, “All kittens and cats should be vaccinated against the viruses that cause cat flu. Vaccination can prevent disease or reduce the severity of clinical signs.” [1] Kittens should receive an initial vaccination course starting at 6-8 weeks old, followed by annual boosters. Vaccines help prevent infection but are not 100% protective.
Limit exposure to infected cats – Since cat flu is highly contagious, limiting interactions with unknown or infected cats can reduce transmission opportunities. This includes keeping cats indoors and avoiding multi-cat households.
Proper hygiene and disinfection – Thoroughly cleaning litter boxes, food bowls, bedding, and toys can help remove contaminants. Using disinfectants registered to kill feline viruses is also recommended. Isolating sick cats and having dedicated items for them aids control.
Recovery and long-term effects
With proper treatment, most cats make a full recovery from cat flu. However, complete recovery can take several weeks or even a couple months.
Some cats may become chronic carriers of the virus after recovering. This means they continue to harbor the virus but show no symptoms. These cats can infect other cats even though they appear healthy.
In more severe cases, cat flu can cause permanent damage. Corneal scarring is one of the most common long-term effects. This impairs vision and increases the risk of recurring eye infections.
According to Purina, “The majority of felines that contract cat flu will recover without any long-term impact on their health. The most common problem following a bout of illness is the potential for recurrence or flare-ups in times of stress.”
Blue Cross notes that “Depending on which virus has caused the cat flu and your cat’s general level of health, there is a risk of long-term damage to the eyes. Eye ulcers and corneal scarring are relatively common.”
Quality of life concerns
Cat flu can significantly impact a cat’s quality of life, especially if symptoms become chronic. Appetite loss is a major concern, as cats not eating properly can quickly become malnourished. Difficulty breathing is another worry if nasal passages become blocked from discharge. Lingering symptoms like sneezing, coughing, eye/nose discharge, fever, and lethargy can take a major toll over weeks or months.
Veterinarians emphasize looking at the whole picture – is the cat able to eat, breathe, and function reasonably well day-to-day? Or has their quality of life become so diminished that euthanasia may be the most humane option? This is a very personal decision for owners based on their cat’s symptoms, temperament, and prospects for improvement. Consulting with a vet can help determine if the cat still has a decent quality of life or if their suffering warrants euthanasia.
When to euthanize
Unfortunately, in some cases cat flu can lead to suffering and severely impact a cat’s quality of life, despite treatment efforts. Euthanasia may need to be considered if1:
- The cat is suffering and has a poor quality of life despite medical treatment
- The cat is not responding to medications and their condition continues to deteriorate
- Severe organ damage from the infection is present
It’s a very difficult decision, but euthanasia may be the most humane option if the cat flu has advanced and is not responsive to treatment. Quality of life is key – if the cat is struggling with severe symptoms, pain, and deteriorating health despite the best efforts of the owner and veterinarian, then euthanasia may need to be considered to prevent further suffering. Discussing all options with your veterinarian, and focusing on your cat’s comfort, can help guide this decision.2
Takeaways
Although cat flu is usually mild and will resolve on its own, it can sometimes take a serious or even fatal turn. Therefore, prevention through vaccination and precautions like limiting exposure to infected cats is important. For cats that do develop symptoms of cat flu, prompt veterinary care can help manage the illness, prevent secondary infections, provide supportive care, and increase the chances of recovery. If a cat becomes severely ill from cat flu complications, euthanasia may need to be considered to spare suffering. Key takeaways for cat owners include remaining vigilant about vaccination, seeking veterinary care at the first signs of illness, and being prepared that cat flu can sometimes have serious consequences including death.