There is a chance that your cat’s problem is related to food. However, there is a greater chance that fleas are causing the problem.
Many different issues can cause cats to develop scabs on their bodies. Allergic reactions, skin infections with bacteria or fungus, skin parasites and immune system diseases may all cause problems such as the ones you describe.
Of the possible causes, allergic reactions are most common. And flea allergy is the most likely culprit. Cats that are allergic to fleas often develop a syndrome called miliary dermatitis. These cats develop small scabs all over their bodies. There may be an especially heavy distribution of scabs near the tail and around the neck.
Therefore, the first step I would recommend is high-quality flea control.
What if your cat doesn’t have fleas? Flea control should still be the first step. A pet does not require a visible flea infestation to suffer from flea allergies. Nor does she need to go outdoors or come into contact with other pets.
I do not recommend applying ointments to the affected areas of skin. I also don’t recommend removing the scabs. Both of these actions may make the problem worse.
Although it may be difficult to orchestrate, a trip to the vet is the best option for your cat. And if flea control doesn’t help with the problem, a veterinary checkup is really your only option.