Dogs can get skin conditions that can cause their skin to have red bumps. Many of these skin conditions can be itchy, making your dog miserable. Some of these conditions may be caused by parasites, but others may be allergies and hereditary diseases. Many may require a veterinarian to diagnose and treat the condition.
Dogs who suffer from food allergies often show signs in the skin and coat. Food allergies may appear as red bumps, pustules and rash. The dog may scratch, thus further inflaming the skin and causing an infection.
Diagnosing food allergies can be tricky as it can mimic other conditions such as flea allergy dermatitis (FAD). The dog must be put on a hypoallergenic diet for at least 10 weeks to see if the skin issues resolve themselves. The hypoallergenic diet has a novel protein source, meaning that it is unusual for dogs to eat, such as certain fish, venison or other types of meat. The carbohydrate source is usually something singular such as oats, millet or even potatoes.
Switching to another commercial diet is unlikely to remedy the situation as these diets have more ingredients than prescription diets and often do not have protein and carbohydrate sources necessary to make it novel.
Once the dog shows improvement, the veterinarian may direct you to add one ingredient at a time back into the dog's diet until signs of the allergy appears. Some pet owners opt to stay with the hypoallergenic diet rather than worry about what the allergy actually was.
Flea Allergy Dermatitis (FAD)
Flea allergy dermatitis occurs when the dog becomes allergic to the saliva of fleas. The dog's skin becomes itchy and has red, pimplelike bumps on it. It may last for weeks after the last flea is killed. The only way to get rid of flea allergy dermatitis is to get rid of the fleas permanently. Luckily there are many spot-on topical flea systemics that will help you totally eliminate fleas on your dog.
Puppy Dermatitis (Acne)
Puppies three months of age or older may experience a type of puppy acne in which their skin on the chin and lips can have red pustules. These pustules can drain pus. Occasionally acne is found on the genitals as well. Your veterinarian may prescribe special benzoyl peroxide shampoos for dogs and oral antibiotics to treat the acne.