Excessive Sneezing

Question
Hi Becky!  My 12 year old neutered male cat has been having sneezing fits for about 2 weeks now.  We took him to the vet after a few days, who put him on an antibiotic.  The medicine is now done, and he's still having sneezing fits.  There is no discharge, no fever, his eyes are clear, he's alert, and he's eating, drinking, and playing.  We also have 3 other cats who are not sneezing.  I hate to spend another $75 to bring him back to the vet, but he is a member of our family and we've had him since birth, so I certainly want to do what I can to ensure he lives a long, healthy life.  He's already cost us several thousand dollars in vet bills for urinary blockages, and we would do it all again in a heartbeat if necessary.  
I guess my question is, if he's already had antibiotics, and if none of the other cats are sick, could it simply be allergies?  This isn't the first time we've gone through this with him, although I'm not good at record keeping and couldn't say if it's the same time of year each time.  Are allergies that only cause sneezing common in cats?

Answer
Hi Kim!
Yes, it could very well be allergies.  Animals have allergies just like humans.  I wouldn't take him back to a Vet unless the discharge from the nose is mucousy or an abnormal thickness and/or color.  Since you have been to the Vet already, then I doubt it's anything else.  You can try giving him some Benadryl, but it will make him sleepy.
If you decide to try it, be sure to follow the directions that I will post below.... such as do NOT give liquid Benadryl.  If it were me, I would probably just let it run its course, however, if it is a constant sneezing you may want to try this.  Good luck and God bless!  Becky

Benadryl for Dogs or Cats

Benadryl is a brand name for an anti-histamine (diphenhydramine).  Although it is considered fairly safe for use in dogs and cats,  please be aware that it does have potential adverse side effects.  It may interact with other meds that your pet is taking, so do not use it without first consulting your veterinarian. You should also use extreme caution using Benadryl in dogs that have glaucoma, prostatic disease, cardiovascular disease or hyperthyroidism.  

Benadryl is quite effective when used in proper dosages.  
Stops itching
Controls vomiting
Good for motion sickness
Can be used as a mild tranquilizer
Good for snake bites
Useful for vaccination reactions
Good for bee stings and insect bites

Be sure to use only the plain Benadryl formula. Giving benadryl with other combination of meds could be fatal, so be sure to read the box.

Liquid Benadryl is too high in alcohol content to be safely used for animals.  Please use capsule or pill form.  

Dosage every 8 hours
Dogs under 30 lbs and Cats :  10 mg
Dogs 30-50 lbs:  25 mg
Dogs over 50 lbs: 50 mg