Why is my dog constantly itching, scratching and biting?

Fleas: The most common culprit

One of the top reasons your dog might be having a scratch is down to fleas. These tiny parasites feed on your dog’s blood and can cause intense discomfort.

Even worse, fleas multiply quickly. A single flea can lay dozens of flea eggs, which can spread throughout your home and live in your carpets, bedding, and furniture.

Click here to find out where to look for fleas in your house!

Signs your dog has fleas:

• Persistent scratching and biting, especially near the tail or belly

• Red or irritated skin

• Tiny black specks (flea dirt) in the fur. Watch our TikTok video for a simple trick to find out if the black specks are definitely fleas!

• Visible fleas or flea eggs

How to get rid of fleas:

1. Use vet-approved flea treatments (topical, oral, or collars)

2. Wash your dog’s bedding regularly

3. Vacuum carpets and furniture thoroughly

4. Treat your home as well as your pet

To truly get rid of fleas, you must break their life cycle which means killing both adult fleas and their eggs. See the flea life cycle here and how to get rid of fleas for good!

Allergies (environmental or food)

Just like humans, dogs can develop allergies that lead to constant itching and discomfort. If you suspect it’s allergies then your vet may recommend an elimination diet or allergy testing.

Common allergy triggers:

• Pollen, dust mites, or mold
• Certain foods (like chicken, beef, or grains)
• Household cleaning products

Symptoms include:

• Constant scratching or biting
• Red, inflamed skin
• Ear infections or licking paws

Skin infections

Bacterial or yeast infections often develop when a dog’s skin is already irritated. These infections can make itching and scratching much worse. Treatment is typically medicated shampoos or prescription medication.

Warning signs:

• Strong or unusual odour
• Greasy or flaky skin
• Hair loss or scabs
• Persistent biting at certain spots

Dry skin

Dry skin can also lead to frequent scratching. This is especially common in colder months or in homes with central heating.

Causes of dry skin:

• Poor diet
• Over-bathing
• Low humidity

What helps?

Adding omega-3 supplements to your dog’s diet. This is easy with the Itch Skin & Coat dog treats which include omega-3 and lots of other vitamins to support your pet’s health. You can also try using moisturising dog shampoos but please avoid excessive bathing as this can make their skin worse.

Parasites other than fleas

While fleas are the most common, other parasites like mange (caused by mites) and lice can also cause severe itching.

These conditions often lead to intense scratching, hair loss, and skin irritation. Unlike fleas, they may not be visible to the naked eye, so a vet diagnosis is essential.

If you suspect it could be lice, find out what kills lice here!

Anxiety

Sometimes, constant biting or scratching isn’t physical, it’s behavioural. Dogs may chew, lick, or scratch excessively if they are bored, stressed or suffering from separation anxiety. You can help your pet do this less by increasing their exercise and mental stimulation.

Signs it may be behavioural:

• Focused biting on one area (like paws)
• Occurs mainly when left alone
• No visible skin issues

For more information, check out Dogs Trusts’ guide to pet anxiety

When should you see a vet?

Occasional itching is normal but constant discomfort is not.

Chat to your vet if:

1. Your dog is scratching nonstop and they are already on flea preventative treatment

2. You notice wounds, bleeding, or hair loss

3. Symptoms persist after using flea treatment

4. You suspect allergies or infection

So there are lots of reasons your dog might have their leg constantly behind their ear, try to rule each one of these possible causes (treat it like a checklist) and you might find out what’s wrong with your pet quicker than you realise. Always check serious issues with a vet, but if you need some vet advice quickly and free of charge, you can contact our professionally trained team who can help with fleas, ticks, and lice concerns. Get in touch here!