Constant scratching is easy to normalise. The dog has always been a bit itchy, so the itch becomes part of the dog. Then one day the skin is raw, there is a smell, and the problem is no longer just an itch.
Skin complaints are among the most common reasons dogs are brought to a veterinarian, and among the most commonly self-treated with things that make them worse.
Start with fleas, even if you cannot see any
In this climate fleas persist all year, and in a flea-allergic dog the reaction is out of all proportion to the number of fleas. A single bite can produce weeks of itching, so the absence of visible fleas does not clear them as a cause.
Look for flea dirt rather than fleas: part the fur over the lower back and tail base and look for dark specks that turn rust-red on a damp tissue. That colour is digested blood.
The other usual causes
- Other parasites, including mange mites, which cause intense itching and often hair loss
- Bacterial or yeast infection of the skin, frequently secondary to scratching
- Environmental allergy to dust mites, pollens or moulds, often seasonal at first
- Food sensitivity, less common than assumed and diagnosed by a proper elimination trial
- Dry skin, over-bathing, or harsh shampoos that strip the coat
- Ear disease, where a dog scratches at its head and shakes constantly
Much of the damage on an itchy dog is not caused by the original problem. It is caused by the dog, in response to it.
Why it escalates
An itch leads to scratching, scratching breaks the skin, broken skin becomes infected, and infection itches more. The cycle keeps running after the original trigger has gone, which is why treating only the trigger often fails.
This is also why hot, humid weather makes everything worse: moisture trapped against the skin in skin folds and under a thick coat is exactly what bacteria and yeast need.
What not to do
- Do not use human steroid or anti-itch creams: dogs lick them off, and some are harmful
- Do not give human medicines including painkillers, which can be toxic
- Do not bathe repeatedly with strong shampoos, which strips the skin further
- Do not change foods repeatedly, since it destroys the diagnostic picture
- Do not clip or shave affected areas before the vet sees them, unless told to
What actually helps in the meantime
- Keep parasite prevention up to date and dosed by current weight
- Keep the coat dry, particularly in skin folds and after a wash
- Stop the self-trauma if you can, with a collar if the vet advises one
- Photograph the skin, since it changes between the appointment and the flare
- Note the pattern: which areas, what time of year, and whether anything changed at home
When it needs a veterinarian
- Broken, weeping, thickened or foul-smelling skin
- Hair loss, scabs, or spreading patches
- A dog that cannot settle or sleep for scratching
- Itching that has persisted for more than a week or two
- Head shaking and ear scratching, which usually means ear disease
Skin is one of the areas where a photograph and a conversation get you a long way, because the pattern and distribution tell a veterinarian a great deal. An online consultation is a reasonable first step, and it will tell you whether swabs, skin scrapes or an examination are the necessary next one.
Common questions
What is the most common cause of itching in dogs?
Fleas, by a wide margin, especially in a climate like ours where they persist year-round. In a flea-allergic dog a single bite can trigger weeks of itching, so seeing no fleas does not rule them out.
Can I give my dog an antihistamine?
Not without veterinary direction. Doses differ from human ones, some human preparations contain ingredients that are toxic to dogs, and antihistamines help far less with canine itching than most owners expect.
Why does my dog itch more at night?
Fewer distractions makes the itch more noticeable to you and to the dog. Some parasites are also more active at night, and a warm bed can aggravate inflamed skin.
Is it food allergy?
Sometimes, but it is less common than owners assume and it is diagnosed by a properly conducted elimination trial, not by switching foods repeatedly. Random food changes make the picture harder to read.
When should I stop treating it at home?
If the itching has continued for more than a week or two, if the skin is broken, smelly, weeping or thickened, or if your dog cannot rest for scratching. At that point it needs a diagnosis rather than another product.