A couple of bandages or dressings with bandages attached. Useful if a) you cut their feet a little too much, and it bleeds a fair bit or b) they get an infected cut or wound.
Antibiotic wound powder for any cuts or scrapes, or for a wound that is bleeding a lot, cornflour (as you would buy in the supermarket for thickening).
We use Kaolin and Morphine for scouring (available from the chemists).
We keep a bottle of antibiotics, calcium and syringes and needles, but you may not need those.
Vaccine (Heptavac or Lambivac).
Treacle (for adding to warm water for them to drink, like the electrolyte replacer).
Can't think of anything else at the moment- will update!
Beth