I have two Degus, both male, about 2 years old. One of them has developed a bald spot that covers about 1/3 of his hind leg. After doing some research online I thought that he may have ticks... but wouldn't the other one have them as well? If this is indeed what he has, what do I use to treat it? If he doesn't have ticks, is the treatment still safe to use anyway? Thank you so much in advance!!