my cat has licked off almost all of its fur on its lower body. it has even caused an open sore. the skin has revealed small red bumps that resemble insect bites but I am 100% positive there are no fleas. This cat was going to but down by its last owner and I took her in to prevent that. I do not have the extra resources to pay vet expenses and I would like some advice. there have been no change in eating, sleepin, or behavior at all. What can I do?