Your cat's coat is a reflection of his internal health.
Regular grooming not only makes your cat look clean and healthy, it also gives you an opportunity to examine his skin and fur closely for potential issues. There are many diseases that express themselves externally, perhaps in the form of skin lesions or a dull coat. As always, if you have a health concern about your cat, consult your veterinarian immediately.
Bare patches of fur can have many causes including ringworm, fleas, allergies, and immune disorders such as eczema. If the problem is ringworm, this must be addressed by a vet, rather than an over-the-counter ointment. Ringworm is actually a fungus, but because the lesions tend to be circular, it was once thought to be caused by a worm curling up in the top layer of tissue.
Ringworm can be transmitted from pet to pet, human to pet, environment to pet, and pet to human. There are several treatment methods for treating ringworm. The method your vet chooses will depend on is the severity of your cat's infection, whether other pets are infected and how easy it will be for you to disinfect your cat's environment. Medication and care are needed to control the condition.
The causes of scratching can include fleas, lice, eczema, allergies, or stud tail (a sebaceous gland condition). If your cat is just scratching his ears, then the culprit is most likely earmites. Your vet will treat earmites with special eardrops. While these mites only live in ears, they can be passed from cat to cat. If you observe a discharge from your cat's ears, this could be from a fungal or bacterial infection. Consult your vet immediately.
Feline acne is best described as small black spots that usually appear on the chin, and can be cause by allergies or poor cleaning. To prevent acne, always keep items that your cat comes in contact with free of bacteria. The most common bacteria sources are food and water bowls, both of which should be washed daily. If your cat develops acne, do not pick at the spots nor treat it with human acne solutions. Your vet will prescribe a specially formulated treatment and if you follow their instructions, the acne should clear up in a week or two.
Do not put off addressing mats. Parasites and other pests that can cause skin diseases love to breed in these soft, warm mats. Remember: do not try to cut the mat off, as you may injure your cat. Rather, work at combing the mat out. Regular grooming should prevent their development.
Being diligent and attentive about grooming your cat will help to address health issues before they become serious.