Q. My cat has had hairballs and is licking/gnawing/scratching and is losing large patches of fur, and has red bumps on his skin and scabs on the skin
A. Sounds like you need to take the cat to a veterinarian. There are many reasons a cat would loose fur and have red bumps. The best way to find out what's going on is to see a veterinarian as soon as you can. I'm not sure if all those symptoms are related or if they are all different issues. Talk to the vet about all your concerns and see what they recommend. Try visiting an AAHA accredited veterinary hospital, they run their hospitals to the highest standards.