Is there some OTC remedy for a cat with a cold?

Not a cold, your cat has a URI (upper respiratory infection) which needs treated by a vet or it will become much worse. This is pretty common amongst cats and usually easily treated and not all that expensive. Dont try home remedies you get from strangers here, they aren't trained and could give you bad or even dangerous advice. And there are plenty of trolls here that would gladly give you bad advice just for a laugh. Dont take short cuts with your cats health. Either take proper care of it or surrender it.

Your cat doesn't have a cold, it has an upper respiratory infection that can turn into something WAY more nasty if you do not get it the right treatments. These are very common, treatments will usually run you about $20, plus cost of vet visit. Don't be a cheapskate; it could mean shelling out more in the long run because you let this go.

Who says it's a cold? More often cats get Upper Respiratory Infections which require antibiotics. Get the poor cat to a VET.

No. Any kind of sneezing or runny eyes/nose is an upper respiratory infection and needs treatment by a vet. There is nothing over the counter you can give your cat.

I have a one eyed cat, because the previous owner would not treat for an upper respiratory disease, and the infection spread to his eyes. Having an eye removed surgically is thousands of dollars, get some medicine from your vet.

You can try giving it L Lysine about 250 mg worth a day. I bought a bottle at Walmart for $5 and contains 250 500mg tables. Break one in half and crush it between two spoons and mix it in with wet food. If it doesn't clear up in 4 days you need the vet.

https://www.walmart.com/ip/Spring-Valley-L-Lysine-...

Since cats don't GET colds, no. They do, however, get respiratory problems and those need vet help.