What is Flu?
Cat Flu is used to describe the cold or flu-like symptoms that accompany an infection of the upper respiratory tract in cats. Cats with flu will show signs that include fever, frequent sneezing, discharge from the nose and eyes, loss of appetite, and depression. It is most common in young kittens, elderly cats, animals kept in crowded conditions such as a shelter, and stressed or immunocompromised cats.
If your cat has recently been in contact with sick cats and is showing some of the above symptoms, contact your veterinarian for an exam and workup. Treatment options may vary but will mainly be supportive.
Symptoms of Flu in Cats
As the term "Cat Flu" suggests, the symptoms of the infection resemble a cold or flu and include:
- Fever
- Coughing
- Frequent sneezing
- Nasal discharge
- Eye discharge
- Salivation
- Mouth ulcers
- Corneal(eye) ulcers
- Loss of appetite
- Temporary lameness
- Dehydration
- Depression
Symptoms may have some variation based on the causative agent.
Causes of Flu in Cats
There are several possible infectious causes of cat flu, but the two most common causes are feline calicivirus (FCV) or feline herpesvirus (FHV). With each of the causative agents, there are some common, more generalized symptoms:
- Fever
- Sneezing
- Eye and/or nasal discharge
- Loss of appetite
- Dehydration
- Depression
FHV
- General symptoms listed above
- More severe eye discharge
- Corneal ulceration
- Coughing
FCV
- General symptoms listed above
- Ulcers in mouth
- Transient lameness
Bordetella bronchiseptica
- Fever
- Sneezing
- Nasal discharge
- Cough
Chlamydia felis or Mycoplasma felis
- Fever
- Eye discharge/infection
Diagnosis of Flu in Cats
If your cat or colony of cats is showing signs of flu, contact your veterinarian. Your doctor will conduct a physical examination and collect a history. He or she will want to know if your cat has recently been in contact with other cats or if it was adopted from a shelter. Examination will include checking the mouth, nose, and eyes for signs of inflammation and ulcers. To check for eye ulcers, your veterinarian may use fluorescein dye. A presumptive diagnosis can be made based on the presenting signs. Most treatments will be based on the observed symptoms.
Although treatment can be started based on the presumptive diagnosis, your doctor may collect samples such as swabs around the eye or throat; a cell scraping from the lining around the eye, nose, or inside the mouth; or samples of the discharge from the nose or eyes. The cell scrapings and swabs can be used to help identify or culture for Bordetella, Mycoplasma, or Chlamydia, and the discharge samples could be used to test for the presence of antibodies to FHV or FCV. If your cat seems to have rapid or difficult breathing, your veterinarian may want to take x-rays to check for evidence of pneumonia.
Treatment of Flu in Cats
General Supportive Care
Much of the treatment for cat flu will be directed at the symptoms and designed to provide supportive care. The goal is to keep your kitty comfortable and relieve troubling symptoms so that your cat is better able to fight the infection. Keep the eyes and nose clear of discharge by cleaning away excess secretions, using decongestants, and providing a vaporizer to help ease breathing. It is very important to get your cat to eat and drink. Provide food that has a pleasing aroma and taste. You may want to get some gourmet food. In some cases of severe depression and anorexia, force feeding and administration of fluids may be required. Treatment should continue until symptoms are gone, usually about 7-10 days.
FHV
If testing identifies FHV as the cause of cat flu, your doctor may choose to treat with an antiviral drug such as acyclovir in addition to providing general supportive care.
FCV
If your cat has oral ulcers due to FCV, soft food is recommended. In the case of corneal ulcers, your doctor may prescribe medication to keep the pupils dilated. Antibiotic ointment may also be used to prevent a secondary bacterial infection. Some cats with FCV show signs of lameness, which can be treated with corticosteroids or other anti-inflammatories.
Bacterial causes: Bordetella, Chlamydia, or Mycoplasma
Antibiotics can be prescribed to treat bacterial causes of cat flu. Veterinarians usually choose broad-spectrum antibiotics, such as tetracyclines, fluoroquinolones, or amoxicillin with clavulanic acid, to kill the bacteria and also prevent secondary infections from other bacteria. Antibiotics should be given for at least 2-3 days after the end of observable symptoms.
Recovery of Flu in Cats
Generally treatment will last about 7-10 days until symptoms have resolved. If your cat contracts flu and symptoms do not resolve with treatment within a few weeks, your veterinarian may want to test for Feline leukemia.
Cats may continue to shed the virus or bacteria for as many as 18 months. During this time, your cat could become reinfected, usually showing milder symptoms. In the case of FHV, some of the virus will remain dormant in the nerve cells throughout your cat's life. Most cats will not shed the virus, but during periods of stress, they may start to shed the virus.
The best way to manage or help prevent cat flu is by having your cat or cats vaccinated for FHV and FCV. If your cat is or was recently infected, be sure to isolate them from other cats to prevent spread of the disease.
