So...
I have a lovely 3 year old boar who has seemingly been on and off ill over the past couple of weeks with 2/3 vet trips. The first time he looked listless, was eating the bare minimum, poo's were normal size but weren't many of them so off we went to the vets. He had a look and said there's a slightly rasp to his breathing and one of his lymph nodes in his neck was slightly enlarged. He sent me away with a course of Baytril and by the next day he seemed back on his feet.
I will add Spike has a lump under his armpit that has been tested with a fine needle aspiration and has come back and benign. He was attacked 18 months ago by his old cage buddy and the lump appeared at the scar site. The vet said to leave it alone unless it starts to irritate him. In the last 18 months the lump hasn't grown any bigger.
Around 2/3 days ago Spike stopped eating/drinking/pooing so I immediately took him to the vets who took his temp, said he couldn't find a temp to suspect an infection, no swollen glands, checked his teeth and said they were fine, had a listen and feel of his tummy and said no bloat/swelling etc. He did have a raspy breath, however the vet said his chest way clear from infection no rattling/fluid sounds etc.
So I took him home and immediately began syringe feeding him Critical Care and water. I also decided to start him on the Baytril with Pre/probiotics as I was almost sure he had a URI with raspby breathing, sunken eyes, lack of appetite, ruffled fur etc etc. He has slowly (very slowly) began to pick up in himself, he has a slight more energy and pays an interest to veg and grass. However, he won't actually eat them. He bites the pepper and spits in back out. This afternoon I slid some grass into the side of his mouth as he was biting at it and he began to very very slowly chew and grind loudly. However, he didn't go to eat anymore of it

Over these past few days his poos have come on from tiny solid little thin tubes to almost normal shaped but very very small and he seems to struggle getting them out as I don't think he is taking enough water in.
I have no idea what is wrong with him, I am now wondering if he has dental issues even though my vet told me they looked fine? Could he have teeth growing into his gum? Abscess?
I am feeding/watering around the clock, his last feed is 11pm and then again between 2:30am/3:30am and then again between 7 and 8am. Throughout the day I am alternating between water and a Critical Care mix which I have to make fairly watery otherwise he spits it out as he has always hated the taste.
He is also having Avipro Plus to try and soothe his little tummy/bowels.
If anybody has any advice/experience of what could be wrong with this little fella.
Also, how much should I be syringing into him and how often?