Oh no, I think its PTS time for my best friend, opinions please...

What a handsome boy! I know you say you have had his teeth checked, but when my old girl was chewing things to a complete pulp and then dropping them when she could perfectly easily have swallowed them down, I suspected her back teeth - and was proved right when her big last bottom molar fell out one day (she left it in her feed bucket, bless her). Once it was out she went back to eating just fine. The wobbling as the food passed over it must have been putting her off.
 
Hi just a little update on my boy...
Vet has been out twice to see him and although he is a lot happier in himself his eating is still not right. We changed his food to the one mentioned previously but still dribbles about of 3rd of every mouthful. Is in the field all day and is happy trying to eat the grass and will munch on about half of his hay over night. Vet had him on antibiotics and Danillion (two instead of the usual one) but he's now back on one per day and seems his usual self, just still dropping food!
Anyway yesterday, he went into the clinic for an xray of his head and a scope of his throat but nothing was found. He trotted up well but vet agreed that although he was now a happy horse we havent cured the problem (when you give him a carrot he will take a good 5 minutes to eat it, drop about half of it and really struggle to chew it). So we're now off the thr Royal Vetinary College next week for a CT scan and further tests... I have everything crossed its something simple, but I have a horrible gut feeling about it :(
 
Top