Dont panic, there is very little research or proper advice on giving piggies Tramadol as like most medicines it is "off label" for piggies ie nobody ever researched it properly. Piggies have a fast metabolism and cope quite well with most veterinary drugs for dogs and cats. Probably your vet advised you based on their own "off label" experience which might be more than the rest of us know. But please keep an eye on his breathing, high doses of Tramadol can in some cases breathing difficulties. This is known in cats and humans but not common in dogs and not documented for other animals. Please dont stress unduly as your vet probably based the dosage on their own knowledge. Just keep an eye on him. If he's alert enough for a syringe feed, this will probably slow the rate at which he absorbs the drug x