Xeno 450 is Ivermectin based and is used to treat mites - does he have mites?
It is safe to use topically on guineas but the dose depends on their weight. You can order it online more cheaply than getting it from the vets. Very small / baby pigs need Xeno 50 which is a lower dose
Sophie
x
It wouldn't hurt to give him a bath, and might sort out his ear as well - if you're able to send a picture of the ear to Chrissie at Gorgoues Guineas she can usually recommend a cream or melt to use on him to soothe his skin
Sophie
x
Aloe Vera Ointment or Coconut Oil are useful products to use on dry skin. Both products are normally found in high street chemists' shops.