Male Baldness Info

I just adopted two older Ferrets. The male is 6-7 yrs old and the female is 5 yrs old. The male ferret has a large tumor on the right side of his neck under his chin. It is an open sore and bleeds if he brushes it against anything. It doesn’t seem to hurt him, but it bothers me that it is like this. The lady I got the ferrets from said she took him to the vet and they said it is not uncommon for ferrets to get tumors like this and he is fine and that nothing could be done. The female ferret is almost completely bald. Again the lady said the vet said that it is from eating food that is not ferret food and it’s common. Yet, when I picked them up they were both eating cat food. I have changed them to ferret food and am making sure that they are sleeping in a warm, dry place so their problems will not get worse. Also, the male ferret has fleas and is starting to lose hair on his tail. The female has flea bites as well, but no hair for them to hide in. Is there anything that I can use on them for the fleas, and is there anything I can do for her baldness and his tumor? They are both very sweet ferrets and they just don’t deserve to be like this. I am wondering if any of their problems could be caused by age. I am going to make them an appointment with our vet, but I am wondering if there is anything I can do to start to help them. Thank you

I adopted a 3yo chi/italian greyhound mix from the animal shelter about 1.5 mo.’s ago. They were worried no one would want her because her hair is very sparce (not bald, but you can see her scalp though it) above her eyes to her ears on both sides. The vet said it wasn’t anything to be worried about simply a genetic fault. Also when I adopted her her eyes were really goopy.
We welcomed her into my home and her eye goop went away without issue, but the baldness remains, and I think she’s losing some hair in the middle of her head now (male pattern baldness). Not bald, but thinning.
Is this a breed thing? She eats Artemis kibble with salmon oil squirted on it (to keep her skin from being flakey). She’s fully vaccinated, microchipped and spayed.
Lastly.. it seems as though lately she’s developed this baldness around her eyes? She’s a black chi and now seems to have brown rings around her eyes but no goop – what could this be?