[Amethyst_ice]

If it was a genuine abscess, you are best letting them drain and heal from the inside out. Usually warm compresses but sounds like it has already drained, in which case you are better to leave the scab and not put anything over it that would seal it. However, what concerns me is you mention he also has diarrhea.

Many vets are still doing zoom appointments anyway, it would be worth contacting a vet, explainign the situation and going from there rather than trying to pre-empt things. Problem shared is problem halved and all

Keep us posted