Itchy dogs are a common sight in any vet clinic. From the occasional scratch to the all-night nibbling sessions, itchiness can drive dogs (and their owners) a little bit crazy. But did you know that “itch” is not a diagnosis in itself? It’s a symptom — and it can have many different causes.
Understanding why your dog is scratching is the key to helping them feel comfortable again. Let’s look at the five most common causes of itch in dogs — from the obvious to the often-overlooked.
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Parasites
When it comes to itchy dogs, parasites top the list. Fleas are by far the most common culprit. And they’re not just a summer problem — thanks to warm, centrally-heated homes, fleas can thrive all year round. Even if you can’t see fleas, they might still be there. A single flea bite can be enough to set off intense itching in some dogs, especially those with flea allergies. That’s why year-round flea prevention can be so important. But fleas aren’t the only parasites to watch out for. Mites, such as Sarcoptes scabiei or mange mite, can cause intense, relentless itching, along with significant skin damage. Different mite species can affect various areas of your dog’s body, including the ears.
If your dog has started itching and their parasite prevention isn’t up to date, this is always the first place to start.
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Skin infections
Bacterial, fungal, and yeast infections can all cause significant itchiness. They might result in:
- Moist, painful “hot spots”
- Red, inflamed skin with pustules
- Scaling, crusting, or ulcers
- Ear infections (the skin of the ear canal is affected just like the rest of the body)
Often, skin infections are secondary problems — meaning something else (like parasites or allergies) weakened the skin’s defenses first. That’s why treating the infection alone isn’t always enough. If the underlying cause isn’t addressed, the problem may keep coming back.
Occasionally, an infection might be due to a small injury or insect bite gone bad. Either way, your vet will need to diagnose the type of infection causing your dog to scratch and prescribe the most appropriate treatment.
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Anal gland issues
Your dog’s anal glands are two small sacs located either side of their anus. If these glands become impacted (blocked) or overfull, they can cause irritation.
While some dogs will “scoot” across the floor to relieve the discomfort, others lick, chew, or scratch — sometimes making it look like they have general body itchiness.
Signs that anal glands might be the issue include:
- Licking or chewing the base of the tail, inner thighs, or backside
- Scooting along the ground
- Soreness or skin infections around the rear end due to self-trauma
Anal gland impaction can be uncomfortable, and if left unresolved can can result in a nasty abscess that bursts out through the skin.
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General skin condition
Some dogs develop itchiness due to problems within the skin itself. This is a broad category that includes:
- Dry skin or overly greasy skin
- Hormonal imbalances (e.g., thyroid problems) that affect skin health
- Autoimmune diseases where the body’s immune system attacks the skin
- Poor diet lacking essential fatty acids, leading to brittle, itchy skin
Sometimes, these conditions come with other symptoms, such as coat changes or weight gain/loss. In other cases, diagnosis is a process of ruling out other causes, taking blood or skin samples, and trialing treatments.
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Allergies
Allergic skin disease is one of the most common and most frustrating causes of long-term itchiness in dogs.
There are several types of allergies:
- Flea allergy dermatitis — An allergy to flea saliva. Even one flea bite can cause extreme itching and widespread skin irritation.
- Atopy (environmental allergies) — An allergy to environmental substances like pollens, mould spores, or dust mites. It’s similar to hay fever in humans, except instead of sneezing, dogs get itchy skin.
- Food allergies — A reaction to certain ingredients in the diet, often proteins such as beef, chicken, or dairy. Food allergies can cause itchiness all year round and may also lead to ear infections or digestive upset. Diagnosis usually requires a strict elimination diet trial.
Dogs with allergies often scratch year after year. Treatment focuses on controlling symptoms, avoiding triggers where possible, and keeping the skin healthy to prevent secondary infections.
The bottom line
An itchy dog is an uncomfortable dog — and watching them scratch endlessly can be frustrating for any pet owner. But with so many possible causes, from parasites to allergies, the only way to truly help is to find and treat the root cause.
If your dog is scratching, licking, or nibbling more than usual, don’t wait for it to “go away on its own.” The sooner your vet can diagnose the problem, the sooner your dog can get back to living their best, itch-free life.