Hello and welcome BabyDerm-given that you found them as strays wouldn't like to guess at what it could be(also wouldn't want to frighten you) taking them to the vets for a general check is the best thing to do for them-as hopefully it will be something and nothing-will keep everything crossed for them and you
Do please let us know what happens and know it sounds horrid but if you can maybe take a sample so it can be examined and maybe a bit easier to show the vet if your not to clever with speaking spanish-i can just about speak some sort of English,so i know what you mean
