Distinguishing Between Canine Skin Allergies and Parasites

Canine skin allergies can result in dermatitis, a condition with symptoms including intense pruritis (itching), redness, pimples, hives, crusting, bleeding or oozing lesions or hair loss. You may observe your dog scratching, licking or biting affected areas to find relief. Two main types of allergic reactions of the skin are environmental dermatitis and parasitic dermatitis. You and your vet will work together to find the cause of your dog's particular skin allergy to determine the best way to treat it.

Characteristics of Dermatitis Due to Environmental Causes

Otherwise healthy dogs that come into contact with allergens in their environment may develop skin rashes. Your vet will take your dog's history to determine if any of these triggers of dermatitis may be responsible for an allergic reaction of the skin:

Exposure to outdoor foliage like grass and thistles, which irritate the skin. Remnants may be found on your dog's coat or skin during an exam, making a diagnosis of environmental dermatitis more conclusive.

Exposure to various allergens in the environment, including food, carpeting, blankets, pollen, plastic, upholstery and house plants, which may cause itching and hives. Individual dogs may react to most anything found in the environment.

Exposure to rain and water in swimming places, like pools, ponds, ditches, lakes and streams, which can lead to development of hot spots, also known as moist eczema. Especially if long and matted, your dog's coat, along with shedding hair, provides a medium where bacteria can grow and cause serious infection. Your dog can develop an allergic reaction to the bacteria, too.

Characteristics of Dermatitis Due to Parasitic Infestation

From microscopic to visible, parasites attack your dog's skin and cause severe canine skin allergies. Here are the major sources of skin allergies from parasite bites and the various symptoms they cause:

  • Fleas, whose bite cause itching, scabs, bald spots and secondary infections, if your dog is allergic to flea saliva
  • Ticks, whose bites cause slow-healing skin ulcers but little itching
  • Cheyletiella mites, whose bites cause "walking dandruff" that itches and leads to hair loss
  • Sarcoptic mites, also known as scabies, whose bites cause red mange, with symptoms like intense itching, hair loss, inflammation and scabs, a skin condition so intense some veterinarians insist on ruling
  • it out before considering other causes of canine skin allergy
  • Demodex mites, whose bites cause a different type of mange, with symptoms like patchy hair loss but little or no itching

Remember: Never ignore any symptom of canine skin allergies, no matter how minute. Allergic skin reactions both cause your dog to feel ill, as well signal underlying conditions that can be extremely uncomfortable and have serious complications. In hard-to-treat cases, your vet may refer you to a veterinary dermatologist for further examination.