Allergies

My cat "Harley" just turned 14 yrs old. Summertime is hard on him because he has some kind of allergy towards certain weeds. Our Vet stated he could give him Steroids. We opted out last summer. Now-in this past week, he started the "dry" hacking allergy cough but stopped eating and drinking, lost some weight. His brother passed away 1 yr ago of renal failure and I'm scared that maybe this is what he has. I want to take him to the Vet but not real positive they can help him. Pondering-should I take him in to see his Vet or keep him indoors and try to get him to eat?

Have you tried an OTC antihistamine?  We give our kitty a daily dose of generic Claritin, just 1/4 - 1/2 pill daily.