Glossary

Definitions of terms you may encounter when managing your dog's itch and skin health.

A

Allergen — A substance that triggers an allergic reaction (e.g. pollen, dust mites, certain proteins in food).

Atopic dermatitis (AD) — A chronic, itchy skin disease caused by allergies, usually to environmental triggers (pollen, dust mites, mould) or sometimes food. Often starts between 6 months and 4 years of age.

Atopy — Allergy to environmental allergens (as opposed to food allergy).

C

CADESI — Canine Atopic Dermatitis Extent and Severity Index. A scoring system vets use to measure how widespread and severe skin lesions are.

Cytology — Examination of cells under a microscope. Skin or ear cytology helps identify bacteria or yeast infections.

D

Demodex — A type of mite that can cause demodectic mange (localised or generalised hair loss and skin changes). Diagnosed via skin scraping.

E

Elimination diet — A strict 8–12 week trial using only a veterinary prescription diet (novel or hydrolyzed protein) to confirm or rule out food allergy.

Excoriations — Scratches or sores caused by the dog scratching or biting itself.

F

Flare — A sudden worsening of itch or skin lesions.

Food allergy — Allergy to one or more ingredients in food. Diagnosed by elimination diet and re-challenge; there is no reliable blood test.

H

Hydrolyzed diet — A prescription diet where proteins are broken into very small pieces so the immune system is less likely to react. Used in elimination diet trials.

I

Immunotherapy — Long-term treatment (shots or drops) that gradually desensitises the dog to specific allergens. The only disease-modifying therapy for environmental allergy.

Itch score (pruritus score) — A 0–10 scale used to rate how itchy a dog is each day. Helps track trends and measure treatment success.

L

Lichenification — Thickened, leathery skin that develops after chronic scratching or rubbing.

M

Malassezia — A type of yeast that can overgrow on skin and in ears, causing itch, odour, and discharge.

MDB (Minimum Dermatologic Database) — Basic tests vets perform: skin cytology, skin scrapings, and sometimes cultures. Used to rule out infection or parasites before diagnosing allergy.

Mite — Tiny parasites (e.g. Sarcoptes, Demodex, ear mites) that can cause intense itch. Treated with prescription products (e.g. isoxazolines, selamectin).

N

Novel protein diet — A prescription diet using a protein source the dog has not eaten before. Used in elimination diet trials.

P

Pruritus — Medical term for itch.

Pyoderma — Bacterial skin infection. Often secondary to allergy or parasites. Treated with antibiotics for 3–4 weeks.

S

Sarcoptes — The mite that causes scabies. Causes intense itch, especially around ears, elbows, and belly. Treated with prescription mite products.

Skin scraping — A test where the vet gently scrapes the skin surface to look for mites (Demodex, Sarcoptes) under the microscope.

T

Topical — Applied to the skin (e.g. shampoos, spot-ons, creams) rather than given by mouth or injection.