Fleas bite, and their saliva is very allergenic to susceptible animals. This causes skin redness, itching, biting, scratching, chewing, crusts in the skin, and even a greasy feel and malodor for some pets. In non-allergic pets, fleas don't bother the animal in these classic ways.
Fleas love humidity and warmth. They are a year-round problem in many climates, virtually nonexistent in other climates (arid, cold). Click here to learn more about fleas and how to keep them off of your pet.
If not fleas, what could it be? Your veterinarian is the only one that can answer these questions for your pet, but here are a few of the things that vets look for when a pet is itchy:
- Other allergies not related to fleas -- inhalant (grasses, pollens, etc.), contact (allergic to a shampoo, food dish) or systemic (food allergy).
- Other parasites -- mites.
- Fungal -- not usually an itchy condition, but can cause secondary hair loss and possibly make your pet more prone to secondary bacterial infections.
- Skin infections -- moist skin infections secondary to licking, scratching, even swimming. Skin infections (i.e. hot spots) are also very itchy and bothersome on their own and are often secondary to problems with allergies and parasites.
Note of caution: make sure that your pet does indeed have a flea-induced skin problem prior to using any type of flea shampoo or treatment. Flea killers can be dangerous if used improperly, and items such as shampoos can be very drying to the skin, exacerbating an itchy skin problem.
Photo: Scratching dog © blmurch on Flickr