Bald Spot in Fur and Brown gunk in Ear

Question
1.  I have a 12 month old female Newfie who all of the sudden without any changes to her diet or lifestyle has a bald spot about the size of an egg in her fur on her back near her hind quarters.  It appears to have been shaven and still has some fur on the skin with no rash on the skin in the area.

2.  I have a 12 year old female Lab who for the past month has had ALOT of brown gunk in her left ear only.  I clean it out, put ear cleaner and ear mite stuff in it and it is there again the next day.  She shakes her head frequently.  The right ear is fine.

Answer
For the Newfie pup, I would ask your vet to check for ringworm and mange.  It could also be a traumatic lesion.

For the older lab, your vet needs to look in the ear and test the gunk to see what it is made of (wax, bacteria, yeasts, mites, mucus or pus) and then recommend specific therapy.  If it returns as quickly as you describe, there may be a wax producing tumor in the ear.