Bad reaction to Benadryl given orally

My 13 year old Bombay, Maddie, rather abruptly started wheezing/coughing spells several times a day or night, both when active or at rest or even waking up from sleep to undergo one. Her vet checked her lungs via stethoscope and found nothing out of the ordinary. He put her on prednisolone, 1 mg twice a day for one week, then 1 mg once daily for one week, then down to 1 mg once every other day until the 30 mg prescrption was used up. Halfway through the last stage of this regimen, she started manifesting labored breathing. She was not panting or gasping for air, but I could feel her lungs working harder than normal when she laid in my lap, (one of her favorite things to do). A small amount of physical stress, like from playing or running, would cause her to breath through her mouth, and a little more physical stress would induce panting. Her vet diagnosed COPD (Chronic Obstructive Pulmonary Disease), which basically means she has trouble breathing due to allergies or asthma or perhaps an upper respiratory infection (i.e., a "kitty cold"), or due to some other form of upper respiratory constriction of her breathing passages or throat. He put her back on 1 mg per day of Prednisolone and recommended I try an antihistamine through this spring season, with a mind to ameliorating any seasonal allergy she may be experiencing. He recommended trying children's liquid Benadryl at a dose of 6 mg up to three times a day and see if that helped any. He cautioned against using a pill because if a pill got lodged in a perhaps already constricted throat along with a blocked-up nosey, she could asphyxiate on the spot - NOT a desired outcome! I was able to purchase 25 mg liquid-filled Benadryl capsules and dissolve them in warm water, then dilute to 6 mg per milliliter in kitty treat chicken broth, which I could inject into her mouth using a 1-mL syringe. 'BAD REACTION! The first drop I injected caused immediate tongue in-and-out oscillation with profuse salivation. Once she calmed down from that, I tried a 2-3 drop squirt. 'WORSE REACTION! More desperate "tongueing," severe drooling and desperate attempts to "run and hide!" ensued. So much for Benadryl for THIS kitty!

Thanks to a post on this site, I tried a few drops of a 5 mg oral dose (in 1 mL of water) of Loratadine ("Claritin"), and there was no immediate bad reaction. I gave her 1/2 mL and am awaiting to see if nothing else bad happens for a few hours. If that goes OK, I will try a full 5 mg oral dose once every 12 hours and see if this form of antihistamine helps alleviate the labored breathing problem. I am hoping that this plus 1 mg of Prednisolone per day will do the trick. I'll report on the results anon.

I also have some Respo-K solution and some AmazaPet solution on order from NativeRemedies.com. I would like to know if anyone else has tried these homeopathic pet products and how successful they were.

It sounds just like my boy cats asthma attacks and I started the Claritin because of his coat problems but it also eliminated his asthma attacks. .5 every 24 hours should be enough unless he's heavier than 13 pounds.

I don't think you need the cortisone but it can't hurt either. But I suggest a shot, not the pill regimen.

DISCLAIMER: I'm definitely not a Vet. But I paid really close attention to this asthma issue and he's now gone years with no serious attacks.