My senior bulldog has had this issue since 2013. He is is 12 years old is on prescription eye drops, supplements and antifungal wipes for his paws. No other current medications and is about 40 lbs.
We have tried every store brand & holistic brand dry and wet food. We've seen a dermatologist, allergist, injections, and allergy medication such as apoquel over several years. All of which has help but the side effects/cost did not work out for us. These three things have been the major game changers for my dog's quality of life:
1. Dental check up revealed infected teeth that were inflaming his sinuses and severely exacerbating his allergies. The Extraction and regular dental cleanings have changed his life. This year we have decided not to undergo sedated dental cleaning unless it is absolutely necessary due to his age so we've upped his home cleanings (try using a waterpik!)
2. Diet Change/Allergy management. This one took years and years. We found a good dry kibble in 2015 (grain/corn free etc, but i noticed his allergies/GI/stool were still causing issues and he was gaining weight/elevated protein levels. He wasn't excited about food and would often starve himself to the point of vomiting. I also noticed certain store bran dog treats/jerky would trigger severe gagging episodes. Beef and Pork seemed to make it worse, we had to try a lot of different brands and combinations. I switched him to fresh food on 02/17/22 and i noticed instant results. He has lost over 5 pounds and his allergies/GI/stool/appetite/energy have improved trifold. His dry eye has also improved by over 75% (no more crazy boogers!) Its unfortunate i only discovered this 2 months ago. Fresh food is very pricey but it has helped in my vet costs and i do want to give him the best last years of his life and he is now obsessed with his new food.
3. Find good quality supplements. We use Prudence Hip and Joint High Potency Soft chews and Vet's Best Allergy chews which contains sea kelp. No slouchy hips here! Ask your local holistic dog feed store team they helped me with references on food brand and local vets that specialize in certain breeds.
I have also gotten him an elevated angled feeding bowl and have spread his feedings out to 3 to 4 times a day to avoid low blood sugar (another trigger) / bloating / aspiration.