My 17 year old t.bed, who I've had for ten years, has had an intermitten cough for six months. He's had countless courses of antibiotics, anti-imflammatories from the vet, and 2 tubs of Ventipulmin. I've spent £600 at the vet's and can't claim it back cos' about 5 years ago he had a sore throat and had antibiotics, but that cleared up really quickly. He's got a 24x12 shelter with a deep bed in it, and has ad-lib hay and 2 bucket feeds a day, amount depending of weather and time of year. My problem is - rugging - I just can't get it right I last go out to see to him at 7pm, and it can be really warm and sunny so I just leave him a lightweight rug on, but then I get up to a frost and he's coughing again! At present he's got a lightweight rug on through the day, and because it turns cold at night he has a medium weight with neck cover on top of that for through the night (he's living out, the vet said this would be better for his respiration). His problem is his throat - you can actually feel the swollen glands when the temperatures have dropped suddenly and I've been caught out with his rugs. The weather is so variable - that's the problem. He's very finely built and was bred for short distance flat racing. He needs to be molly coddled really with his rugs, but I know it's bad for him to be sweating underneath. Has anybody any suggestions as to feed or supplements which would build his immune system up please?