Eczema is a term owners use for a range of inflamed, itchy skin conditions in dogs. In veterinary terms the two most common things behind it are allergic skin disease and acute moist dermatitis, better known as a hot spot.

Hot spots

A hot spot appears very quickly, sometimes over a few hours. A red, wet, raw, painful patch, often with the hair matted over it, most commonly on the cheek, neck, hip or tail base.

It is created by the dog itself. Something itches, the dog licks and chews at it, the damaged skin becomes infected, that itches more, and the cycle accelerates.

Thick coated breeds in warm humid weather are the most affected, and the trigger underneath is very often fleas or an ear infection.

Treatment is to clip the hair away so the area can dry, clean it, treat the infection and, most importantly, stop the dog getting at it. A collar is not optional here; without it the treatment cannot work.

And then find the trigger, because a hot spot treated without addressing what started it will come back.

Allergic skin disease

This is what most chronic “eczema” turns out to be. Itching, redness, hair loss and thickened, darkened skin over time, typically at the paws, ears, armpits, belly and face.

The classic combination is a dog that licks its paws and has repeated ear infections. Those two together are an allergy picture until proven otherwise.

The causes, in the order they must be excluded:

Fleas. Treated rigorously for at least eight weeks, every animal in the household, whether or not fleas are seen. This step is skipped constantly and it is why many cases go nowhere.
Food. A strict elimination diet with a novel or hydrolysed protein for eight to twelve weeks, with absolutely nothing else given: no treats, no scraps, no flavoured medication.
Environmental allergy, which is what remains, and which is managed lifelong rather than cured.

Why surface treatment alone fails

Creams, sprays and shampoos help the skin while they are being used. They do nothing about the cause, so the moment they stop, it returns.

Owners often go through several rounds of this before the underlying allergy is worked up properly. Doing the eight to twelve week investigation once is faster than repeating symptomatic treatment for years.

What not to do

Do not apply human creams, particularly steroid creams, without advice. Do not use products containing tea tree oil, which is toxic to dogs. Do not let the dog keep licking the area; licking is what turns irritation into infection.

When to come in

Any raw, wet or rapidly spreading patch. Skin that is red, thickened, darkened or smells. Constant licking or chewing, especially at the paws. Recurrent ear infections. Or a dog that has had repeated courses of treatment without the problem being worked up.