Couple of questions...
What dosage of pain meds is he on and what kind?
When are you trying to feed as far as timing from the pain meds?
When we first started the meds/feeding with Chilli two years ago, I found that if I did his pain meds and then went back about an hour later he was more receptive to the feeding. Also, while not recommended as a regular thing, I found that rubbing the tip of the syringe on the inside of a raisin piqued his interest in the syringe. By the end of the week, I had Chilli eating happily from the syringe. He just stands there and chews on the end of the syringe while I squeeze. We have been very fortunate that Chilli has been an easy keeper with his teeth problems, trimmings when he starts dropping weight, critical care for a couple of days after and his metacam as needed. However, antibiotics will also impair his appetite. Some people have had success with mixing in things like applesauce and baby bananas and pumpkin. One last thought on the feeding is the size of the syringe. Chilli won't eat from a large syringe, but he likes the tip size on a 20ml one and refill as he eats it.
At the end of the day though, you must ask yourself if you are willing to go through extraordinary measures that may not help your boy at all. It is a very difficult decision, and only you can make it. I hope you are able to get his infection and pain under control. If the meds are working, you should expect to see an improvement in a few days. And keep at the feeding, his poops are small and hard because his input has been so limited. If he will only eat 5 ml at a time, you may have to feed him every half hour to get his intake up. With Chilli, I would feed a few, go back and feed a few more. I could not get the burrito thing down, I did try several times. Even my vet tech couldn't get him the normal way. What did work was taking a towel and wrapping it around his front end, putting him on a pillow and holding him in the crook of my elbow with my left hand holding the towel so he was pinned down and couldn't back up. That left my right hand to operate the syringe. Like I said though, he is now Mr. Cooperative. At his last trimming, the tech was going to wrap him up to give him his pain meds. My husband had taken him that time, took the syringe from her and just held it up for the little guy. He went right to it and the tech just about melted, thought he was super cute holding his syringe and begging for more!
Good luck, and I don't want to give you false hope. Just know you are not alone in your pain. Keep us posted.
