Thanks for some great advice, I now realise that I've been listening to the wrong people so from tomorrow I'll feed him sugar beet (no bran) morning and night and give him a lot more hay (can only find the yellow type but will keep looking for alternatives). I'll order a different wormer for next time and show the photos of how his hooves should look to my gypsy farrier to see what he has to say for himself! The henneke body condition scoring was really informative and I now have a better idea of what I'm looking for. I'll post some more photos in a couple of weeks time and hopefully you will all be able to see a difference.
Sounds like you'll be moving on the right track with him. Good job. When you order your dewormer, see if where you order from can sell you a good rotation pack so that you don't keep repeating the type dewormer you're using. Also, in this case, switch up to every month until he's no longer looking "potty" in his belly and his coat is shiny and not long. It should only take 3 or 4 months and then go to 2 months. Unless he is the only horse on the island, I'd stay at 2 months. IF you can get it done, it would be lovely to have a fecal egg count done on your horse's manure. If that's not possible, and IF he still looks dull and wormy in 3 months or so, we have a product called a PowerPak that is a double dose of Fenbendazole, and it's given by weight of the horse, over the course of 5 days. Since it's pretty expensive, all horse stuff is, I'd save it until I was pretty sure I needed it.
I'm not sure what types of dewormer you have available, so I'll give you a fairly typical American rotation list and you can see what you can find that will come close.
When To Dose Product (Chemical Name)
January 1: Broad Spectrum de-wormer such as fenbendazole (Panacur, Safe-Guard); oxibendazole (Anthelcide EQ)
March 1: Ivermectin 1.87% (Equell, Equimectrin, Eqvalen, Ivercare, Zimectrin), for general de-worming.
April 15: Moxidectin plus praziquantel (Quest Plus or Combo Care), to treat encysted strongyles and tapeworms.
June 15: Either double dose pyrantel pamoate (Strongid, Strongyle Care) OR single dose praziquantel combination product with either ivermectin or moxidectin (Equimax, ComboCare, Quest Plus, Zimectrin Gold), to treat tapeworms.
August 15: Ivermectin 1.87% (Equell, Equimectrin, Eqvalen, Ivercare, Zimectrin) for bots; first dose.
October 15: Ivermectin 1.87% (Equell, Equimectrin, Eqvalen, Ivercare, Zimectrin) for bots; second dose.
November 25: Broad Spectrum de-wormer such as fenbendazole (Panacur, Safe-Guard); oxibendazole (Anthelcide EQ)
I was going to mention too, it looks like your fly mask is rubbing on this guy's nose, maybe it's too tight? If it keeps rubbing you could end up with a sore.
Regarding your climate, I remember from living in Italy that it never really got cold in winter, but we did get the occasional hard frost or killing frost. Do you ever get that cold?