Allergic skin disease equally affects males and females, regardless of age or breed. Causes of skin allergies can be divided into four main categories – food allergies, contact allergies, insect bite allergies (flea bite hypersensitivity), and allergic inhalant skin disease (pollens, mold spores, and dust mites).
a) Food allergies
Food allergies are very common in dogs, with dietary protein being the culprit for this allergy. This allergen often affects the face, ears, feet, groin and armpit region, however a chronic ear infection can often be the only sign. Food allergies can also affect cats, although much less than dogs, with clinical signs including skin lesions and itching around the face, neck and ears. Typically in order to diagnose and treat suspected food allergies provide a diet that contains proteins to which your pet has not been exposed for a minimum of eight weeks, ensuring that no other foods are given. Individual proteins can be removed, then reintroduced to determine whether or not they are the cause of the allergy. At the Victoria Road Animal Hospital we sell specific veterinary diets that are targeted for food allergic pets, once an allergen has been identified.
b) Contact allergies
Contact allergies are not common in pets, but when they do occur reactions are typically found only at the sites of contact with the allergen, or areas where the hair coat is thin. Possible allergens include plants, plastic food dishes, wool, carpet deodorizers and cleaning products. The diagnosis of a contact allergen is not easily made, but by eliminating potential sources and identifying any reduction in clinical signs, the culprit is usually uncovered.
Insect bites, particularly from fleas, can also cause allergic reactions in pets. Flea allergy dermatitis can occur in dogs and cats that are hypersensitive to the saliva in a flea’s bite. The reaction produces a raised bump or scab and hair loss along the backbone to the base of the tail. Mosquito bites can also leave raised red bumps, like they do in humans. Biting flies will target the tips of ears, and cause thick, dark, scabby lesions that will easily bleed, with pets usually showing a distinctive head shaking motion. There are a number of flea prevention options are available at the Victoria Road Animal Hospital, please enquire, as to which one is best suited for your pet.
d) Allergic inhalant skin disease
This is the most common form of allergy in pets. Inhaled substances cause an allergic reaction by animals that are genetically predisposed to them. This type of allergy is known as atopic dermatitis, or atopy. Atopy affects 10%-15% of the dog population, and usually appears within the first three years of life. The most common allergens include airborne pollens (trees, weeds, grasses), mold spores, and dust mites. While some pets may only experience seasonal itchiness (like pollen allergies in fall), most often more than one allergic trigger exists, and some pets experience discomfort year round. Lesions can appear in many locations of the body, including the face, ears, ventral neck, chest, and abdomen, and lower parts of the limbs (between toes) usually due to self-induced trauma from excessive itching. Pets that suffer from chronic itchiness, may develop a secondary chronic skin and ear infections that required antibiotic treatment. Treatments for atopy may include supplements (e.g. essential fatty acid), antihistamines, prescription drugs (e.g. corticosteroids), and desensitization injections (as long as specific allergens can be determined by skin or blood testing).
There is no cure for allergies, and lifelong avoidance measure and symptom treatment might be necessary to ensure the allergic pet maintains a high quality of life.
- Veterinary Information Network – Airborne Allergies
- Veterinary Information Network – Itching and Allergy in Cats
- Veterinary Information Network – Itching and Allergy in Dogs
Inflammation of the ears can fall into one of three categories: otitis externa – inflammation of the external ear canal, otitis media – inflammation of the middle ear, and otitis interna – inflammation of the inner ear (see diagram of the ear below).
We will only expand on otitis externa here. Otitis externa is usually characterized by pain when the ears are touched, head shaking, scratching at the pinnae, ear exudate (yellow-tan to dark brown) and malodorous ears. The primary cause is usually one or more of the following – parasites, hypersensitivities, foreign bodies, obstructions, or autoimmune disease. Perpetuating factors include secondary bacterial infections due to yeast overgrowth, bacteria, and rarely fungus, and chronic water exposure (from swimming regularly). Otitis externa is best diagnosed from microscopic examination of aural exudate – which is the single most important diagnostic tool after complete examination of the ear canal has been performed. Treatment usually consists of the prescription of a topical therapy and an ear cleaner. If the infection is due to severe amounts of bacteria then oral antibiotics may also be prescribed. For dogs that swim regularly, ensure that their ears are dried well after each dip in the water.
Leptospirosis is a serious infectious disease that can affect both animals and humans. Caused by the Leptospira bacteria, dog are especially susceptible when they come into contact with infected wildlife (through bite wounds or ingestion of infected tissues), or areas where infected wildlife have contaminated the environment (puddles, ditches, or streams). Early stages of leptospirosis can have the same flu symptom appearance, and progress to potentially become fatal. Currently at the Victoria Road Animal Hospital, we offer a Leptospirosis vaccine for dogs (either as part of your dog’s annual vaccines or at any other time) that protects them against the four (4) most common strains of Leptospira that affect dogs.