From your own experience, you know there’s a big different between having a head cold and the flu. It’s the same for cats. Cats can get upper respiratory tract infections (a ‘cold’ in plain English) that are mild and don’t need treatment, but catching cat flu is a whole different story.
What Causes Cat Flu?
Traditionally cat flu is a viral disease, caused by feline Calici virus and feline Herpes virus. But now two bacteria, namely Chlamydia and Bordetella, are acknowledged as causing flu-like symptoms in cats.
Even tiny microbes have individual characteristics and these quirks can make cat flu tricky to pin down.
- Feline Calici Virus: This virus is constantly changing and adapting, which makes it hard for the vaccine manufacturers to keep up. Indeed the latest strain, VSD (or Virulent Systemic Disease) targets lung tissue causing pneumonia and severe fever.
- Feline Herpes Virus: This is more straightforward than Calici virus, as there’s only one strain which is well covered by the cat flu vaccination.
- Bordetella: This is related to the human whopping cough bug, but don’t worry, these bugs rarely (if at all) swap between the species.
- Chlamydia: This is related to bugs that cause ill health in people, but you can relax because this particular variant is ‘species specific’, meaning it only infects cats.
If your cat has the snuffles, your vet is unlikely to bother identifying the specific bug, because this doesn’t influence the treatment.
How Do Cats Catch Flu?
Did your Mum tell you to cover your mouth when you sneezed?
This is because of droplet dispersal, which is how flu bugs spread. The flu bugs love to hitch a ride on the moist droplets ejected in a sneeze, or indeed in saliva or a runny nose.
Most flu bugs happily survive on surfaces for seven days, just waiting for the next cat to come along and sniff or lick and pick up infection. The key point here is that cats don’t need direct contact, with infection acquired from contaminated bowls, grooming tools, or surfaces. Typically, the incubation period from contact to illness is around two weeks.
Is Cat Flu Dangerous?
Yes and no!
An adult cat with a strong immune system will feel rough for a few days, but with TLC (tender loving care) will soon shake off the infection. These cats are often snuffly and sneezy, and perhaps lose interest in food, but with careful nurturing they do just fine.
Those most at risk of serious illness are the very young or adults that are vulnerable because of pre-existing health conditions. Some drugs designed to fight the inflammation associated with IBD or skin allergies, or indeed chemotherapy drugs used against cancer, directly suppress the immune system leaving the cat with its defences down and open to attack.
What are the Symptoms?
Remember what it feels like to have proper flu? Well that’s pretty much how your cat feels.
- Achy joints
- Bunged up nose
- Sore throat
- Sore throat
In addition, specific complications include:
- Ulcers: On the tongue and on the surface of the eye
- Secondary pneumonia
- Loss of appetite
Kittens in particular suffer from a sticky eye discharge which can glue eyelids shut. This, along with ulceration on the corneal surface, can cause severe damage and even blindness.
When cats are ill, they aren’t great at helping themselves. A sick cat soon stops eating and drinking, which leads to a vicious downward spiral as dehydration makes them feel even worse. Hence, the importance of good nursing for a feline with flu.
How is Cat Flu Treated?
There’s no medical cure for cat flu and it’s up to the cat’s immune system to fight off infection. Therapy is aimed at making the cat more comfortable and treating complications such as pneumonia.
- Mucolytics: These are drugs, eg Bisolvin, which break down mucous and make it easier for the cat to breathe.
- Antibiotics: These don’t kill viruses and therefore don’t directly treat cat flu. (The exception is Chlamydia which responds to the tetracycline family of antibiotics). However, they may be needed against secondary infections such as pneumonia.
- Lysine: This is a new treatment which makes it harder for the herpes flu virus to replicate (breed), thus limiting the amount of virus in the cat. Feline herpes virus uses arginine to reproduce, but lysine antagonises and decreases arginine’s availability.
However, lysine has limited benefits against viruses other than herpes virus, and the flu vaccine gives good protection against the latter. So if your cat is vaccinated and catches cat flu, the illness is probably due to a bug other than herpes virus and lysine is unlikely to be helpful.
The Importance of Nursing
Excellent nursing and good old TLC make a real difference. Your sick cat has lost their sense of smell, has a sore throat, and ulcers on their tongue, and in this state they have all the strength of a piece of wet lettuce. But great nursing can pull them around.
Feeding: Hand feeding can tempt their appetite. Offer soft, smelly foods that are slightly warm. Try pilchards, mackerel, or tuna to appeal to those taste buds.
Housekeeping: Keep eyes wiped clean of gunk and that nose free of discharge. Gently groom the cat, to help her feel better, and wash her face with a damp cotton wool ball.
Ensuite facilities: Your cat won’t feel like going downstairs to the litter tray, so place one nearby.
Decongestants: Cats hate having a bunged up nose: It makes it difficult to breathe and stops them smelling food. You can help by sitting with them in a steamy shower room, which will help loosen the mucous (but be careful they don’t scald themselves on hot water.)
Please get your cat vaccinated, before they get sick. Although vaccination is not guaranteed to prevent infection, it does make it significantly less likely and could save your cat from becoming extremely unwell.
Dr Pippa Elliott BVMS MRCVS is a veterinarian with 27-years’ experience in practice and a special interest in feline medicine and behaviour. Pippa is housekeeping staff to four highly individual cats that conspire to keep her busy opening doors on demand.