If your cat has itchy, scabby spots under his fur, he may be suffering from one of several skin ailments–some of which can be serious if left untreated. Treating the symptoms may make him more attractive and comfortable for a time, but unless you understand what is causing the scabs on his skin, the malady may return shortly after your initial treatment.
Examine your cat's skin for signs of demodectic or sarcoptic mange. Look for somewhat inflamed, bald patches of skin or pustules with a bloody discharge and strong odour. These are signs of demodectic mange, which needs to be treated by your veterinarian. Other symptoms of demodectic mange are shedding, bare spots around the eyes and a bloody discharge. Your cat may also exhibit lesions on his head, elbows or toes. Look for bald spots, persistent itching and thick, scabby skin spots if your cat has sarcoptic mange. Your veterinarian will examine a skin scraping from your cat under a microscope for a definitive diagnosis of demodectic or sarcoptic mange. Either diagnosis will require medicinal skin creams and anti-parasitic medication.
Look for evidence of ringworm, a highly contagious fungal disease affecting the skin of animals or humans. Look for round or oval lesions on the skin of your cat's head, belly or other hairless areas of your cat's body. The lesions may have scabbed over, and your cat may be missing hair around the lesions due to scratching. Wear rubber gloves when performing a ringworm search on your cat, as the disease is transmissible to humans. If you find ringworms on your cat, call your vet, and she'll likely prescribe an oral medication and tincture of iodine or an iodine ointment. Remove the hair around each lesion and thoroughly cleanse the scabs before applying the ointment or liquid medication.
Look for honeycombed crusty areas on your cat's face, head, ears or paws. These may be caused by Favus–a fungal parasite that grows inside the hair follicles. Call your veterinarian if you find these types of lesions, and wear gloves when handling your cat, as the disease is contagious to humans. Ask your vet for a tincture of iodine or iodine cream to treat your cat.
Though eczema is not contagious or particularly dangerous, its symptoms mimic those of other more serious skin conditions, so your vet will need to perform a microscopic evaluation of your cat's skin cells to rule out parasites. Once the diagnosis of eczema has been made, you may apply a soothing calamine lotion after cleansing the scabs with mild soap and water. Your vet may also suggest that you alter your cat's diet, as many ingredients in commercial cat food can contribute to skin irritation in cats.
Examine your cat's undercoat and skin for evidence of dandruff–flaky, dry patches of greyish or translucent skin that are easily removed with brushing or petting. Scabs from dandruff can occur when your cat scratches relentlessly in one itchy spot. Groom your cat daily with a medium-bristled cat brush and feed him a diet rich in Omega 3 fatty acids to help alleviate dry skin and dandruff.
Look for evidence of red, pus-filled blotches or bumps on your cat's skin. These may be caused by a highly contagious skin disease called Impetigo. Wear gloves when performing an examination on a cat with pustules, as they may break and spread the disease through contact. If you find evidence of Impetigo, take your cat to the veterinarian to get a prescription for an antiseptic powder, then apply the powder to the pustules after thoroughly cleansing each one first.
Suspect generalised dermatitis if your cat has itchy, scaly skin and is losing his hair in places, but there are no open pustules or oozing scabs on his body. Try altering his diet to include Omega 3 fatty acids and less processed foods. Wipe your cat down with a warm, damp cloth several times a day, and call your veterinarian if his symptoms do not improve after a week.
Take your cat to the vet if you have concerns that she may be allergic to something in her environment. Allergies can cause many of the same symptoms seen in cats with fungal, bacterial or viral illnesses, so you should have your cat tested if you suspect allergies or disease.
Brush your cat's coat several times a day with a wire cat brush to remove excess shedding fur and stimulate the natural oils in his skin. If your cat will not stop biting or scratching her scabs, ask your vet for an Elizabethan collar, and keep it on your cat until the sores heal.