I've just been so very busy these past couple of weeks, I've barely had time to sleep much less anything else. Bella and the kittens I am fostering came down with upper respiratory infections two weeks ago. It started with runny eyes and a couple of sneezes from the mom, Bella. I separated out the kittens right away hoping they wouldn't get a full blown case of it. Bella's infection wasn't too bad in that she did keep eating but she was very sneezy and she had some conjunctivitis. Only one of the kittens seemed to get a passing infection. He spiked a temp one night and was a bit under the weather but was good by the next day. I did call my vet and get them all on some antibiotics as a precautionary measure.
Upper respiratory infections in cats (the cat flu) is usually caused by a virus. The most common viruses are the herpes virus, the calici virus and the chlamydia virus. Most cats are vaccinated against these viruses when they are kittens along with the feline distemper virus. However even cats that are vaccinated may get the infection though it is a much milder infection. The virus is spread through nasal and eye discharge. It can be spread by direct contact, contact with food dishes, litter boxes or other inanimate objects that are contaminated and aerosol exposure from the infected cat sneezing. It can also be spread by the owner when handling the sick cat and then handling other cats without proper hand washing. More simply put it spreads much like a cold in a daycare spreads.
The symptoms of URI are many and include watery reddened eyes, sneezing, sometimes coughing, a runny or stuffy nose and mouth ulcers. The mouth ulcers are usually indicative of calici while the herpes causes more eye problems. The eye discharge may start out watery then progress to thicker with pus in it. The nasal discharge also starts out runny and then gets thicker and more purulent. Some cats even get thick dried discharge around their eyes and nose. Cats may even be forced to breathe through their mouths when they get this stuffy.
Much of the treatment is symptomatic. Your vet may prescribe antibiotics, mostly to prevent or treat any superimposed bacterial infection. One of the most important things is to keep kitty eating. A cat with a stuffy nose cannot smell its food and as a result will usually not eat. Try feeding really smelly fishy wet food and you can warm it up a bit to make it smell more. Try coaxing your cat to eat with jarred all meat baby foods (make sure it is all meat and has no onions in it). With the baby food you can add a full fat unflavored yogurt 50/50. This helps the bowels when taking antibiotics and also has a lot of fat for the kitty who may not be getting lots of calories at this time. Keep the area around the eyes and nose clean and free of discharge. Your vet may prescribe an eye ointment if your cat has conjunctivitis. You can use saline nose drops to keep nasal secretions thinner, you can also ask your vet about using infant nose drops if kitty's nose is extremely stuffy. I do steam treatments by placing the cat either in the bathroom when the shower is running or if you do have a separate room to isolate kitty you can use a vaporizer. If kitty has mouth ulcers that makes it painful to eat, make a soft mush of the food and add water in it to make it even more soupy. Some cats become so sick that they have to be force fed. This is something that can be done at home, ask your vet to show you what to do.
Most cats recover well but this disease can be very serious especially among the very young and the very old. It is also dangerous if your cat is already compromised because of some other health condition. If you have any doubts or concerns about your cats condition, I feel it is always best to err on the side of caution and get them in to see the vet.
The kittens recovered very quickly, only one ever had any outward symptoms. Bella is recovering a bit slower, still has an occasional sneeze but is doing much better.
Disclaimer: I am not a veterinarian; I am sharing my thoughts and experiences from my years of having pets. Information from me should never replace the advice of your pet's veterinarian.