Your dog may be itching for many reasons that have to do with the state of your dog’s skin and general health, as well as what he may be exposed to.
Contact Dermatitis
This skin irritation occurs from direct contact with an irritant, and can appear right away or over a period of days. Substances your dog may come into contact with that can cause a skin reaction include chemicals such as pyrethrins in flea collars and pesticides from lawns, materials such as wools in bedding, or plants that contain certain irritating substances, such as burdock burs or daisies.
Allergies
Dogs can become allergic to various things, resulting in skin rashes and irritation. Your dog may develop an allergy to various environmental allergens, such as pollens, dust, or mold, and may also exhibit respiratory symptoms. Food allergies and sensitivities can also create skin problems, especially around their anal areas. While fleas are a nuisance for any dog, some can develop a specific allergy to their saliva, which can result in hair loss and red bumps.
Medical Conditions
There are certain physical conditions that can cause your dog’s skin to itch. These include various cancers, autoimmune diseases, hypothyroidism, or even anal glands that have become too full.
Parasitic Infections
Parasites can cause chronic states of itching in our canine companions which cannot resolve until the parasites are removed. Common parasites include fleas and scabies mites, but dogs can also become infected with sarcoptic mange and demodex mites.
Bacterial Infections
Bacterial infections can be a result of your dog scratching the itchiness, but they can also be the cause of the itching. Even infections that are not necessarily in the skin can cause itching, such as an infection in the ear or bladder.
Fungal Infections
Fungal infections can affect the skin and cause irritation. Yeast infections are common, as is the ringworm fungus that can be picked up in the yard.