Why is my dog still scratching?

Last Updated MON 7 OCT 2019

This article is written by Pet Circle Veterinarian, Dr Carla Paszkowski BVSc.

Does your dog suffer from itchy skin that just won't seem to resolve? Are you kept awake night after night by your dog's incessant scratching, biting, and licking?

Pinpointing the origin of your dog's sensitive or itchy skin can be an exhausting endeavour. And worse still, you might feel that you've finally found a cure for your dog's scratching, only to discover a new flare up for no obvious reason.

Scratch, scratch, lick, lick, bite, bite... why won't it stop?!

Most of the time these symptoms arise from an allergy, and unfortunately, every case is unique and won't always follow the same course.

Blood and intradermal tests can be performed by a vet to pinpoint the causal allergen, however due to the relatively high cost of these tests, a diagnosis is often reached by trying to exclude each cause. This can be done in the following steps:

1. Rule out fleas

2. Rule out food allergies

3. Consider Atopy

4. Strengthen the skin barrier

1. Rule out fleas

This is the first place you must start, even if you don't think your dog has fleas. Not only is flea allergy one of the most common causes of itchy skin, but it is also the easiest to rule out.

This is done quite simply by putting your dog on a reliable and effective flea preventative treatment like Bravecto, Nexgard or Comfortis. We generally recommend staying away from flea powders, flea shampoo, and some older generation topicals, as they aren't considered quite as effective nowadays. (Not sure whether your flea prevention is considered reliable? Read our vet's article on which is the most effective treatments in Australia.

Most pet owners with a flea problem in the house will never actually see fleas. What you may find, however, is flea dirt. This is a black 'dirt'-like granular residue found in your dog's fur. Flea dirt is actually flea faeces. You can determine the difference between 'regular' dirt and flea dirt by getting a piece of white paper or a paper towel and placing some of the dirt onto it. Add a small amount of water to the dirt - if it turns a reddish colour, this is flea faeces. The red colour is caused by the high blood content from feeding female fleas.

Dogs with flea allergy dermatitis may not show signs of fleas or flea dirt in their coat, because just one bite of a flea can be enough to set off an allergic reaction. For this reason it is important to ensure that your dog is covered for fleas before proceeding further. Read more about how to get rid of fleas here.

Our top recommended flea treatments

See the table below for our top vet-recommended flea treatments, what they cover, and the cost of each. All costs are based on pack size for a 20kg dog.

Product Name Frequency Parasite Coverage Pack Size Cost Per Pack Cost Per Month

Bravecto

Every 3 months* Fleas and ticks 1 chew

$46.14

$15.38

Comfortis

Every month Fleas 6 tablets

$79.15

$13.19

Nexgard

Every month Fleas and ticks 6 chews

$75.19

$12.53

Seresto

Every 4 months** Fleas and ticks 1 collar

$42.30

$10.58

Simparica

Every month Fleas and ticks 6 chews

$60.60

$10.10

*For ticks alone, Bravecto only needs to be given every 4 months. **For flea coverage alone, Seresto has 8 months coverage. For fleas and ticks combined, coverage is for 4 months.

Note: The prices above were accurate at time of publication, and may fluctuate; please consult links above to see current prices.

The above products are standalone flea-and-tick products. For products that cover worms too, we recommend Nexgard Spectra, Advocate + Seresto Combo, or The Big 5.

2. Rule out food allergies

If your dog's itchiness still persists despite adequate flea prevention, the next step is to rule out the possibility of a food allergy.

A lot of the time, symptoms of food intolerance will manifest in the skin and coat rather than via the digestive tract. The most common sources of food allergies in dogs are proteins, particularly beef, wheat, dairy, chicken, egg and soy. When the protein crosses the gut wall into the blood stream, the dog's immune system mounts an abnormal response causing them to become sensitised to the protein, resulting in an allergic reaction.

To find out what your dog is allergic to, an elimination diet is usually recommended by your vet. This can be done in one of two ways; either by feeding a veterinary diet containing a hydrolysed protein source, or by feeding a diet containing a novel protein. Whichever diet you choose, it needs to be fed exclusively (no extras) for at least 6 to 8 weeks. At the end of that time if the dog's skin has settled, a diagnosis of a food allergy can be made. If not, a food allergy is much less likely.

Hydrolysed protein is a protein source that has been been broken up into smaller pieces that cannot bind allergy receptors on your dog's immune cells.

A novel protein is one that your dog has never been exposed to before, like venison, duck or fish. Browse food with novel proteins here or read more about hypoallergenic diets and how they work.


Top Hydrolysed Diets for Allergies

Royal Canin Anallergenic

Using a hydrolysed feather protein source, this diet is currently the gold standard for diagnosing and managing food allergies.

Royal Canin Hypoallergenic

Great for diagnosing and managing food allergies, this diet may more cost-effective for large breed dogs who tolerate a soy-based diet.

Hill's Prescription Diet Z/D

This completely hydrolysed diet is perfect for elimination trials. It includes essential fatty acids and clinically proven antioxidants.

Royal Canin Sensitivity Control

Combining a hydrolysed protein with a novel protein (duck) and carbohydrate (tapioca), this diet is great for sensitive skin or stomach.



Top Novel Protein Diets for Sensitive Skin

Billy and Margot Salmon and Superfood Blend

This range is Australian-made, and one of the few diets on the market that includes either raw or fresh meat as the number one ingredient.

Meals for Mutts Salmon and Sardine

With fish and a completely grain-free recipe, this novel protein diet is great for adult dogs of all sizes.

Ziwi Peak Venison Wet Food

Using venison as the novel protein source, this grain-free diet is high in quality meat and contains Green Lipped Mussel for extra joint care.

Instinctive Bite Kangaroo

With nutritious lean kangaroo meat and grain-free recipe, this novel protein diet is perfect for dogs with food allergies.

3. Consider Atopy

Once flea allergy dermatitis and food allergies are excluded, quite often atopic dermatitis is suspected.

What is atopy? Atopy, or atopic dermatitis, is a generalised allergy to things in the environment like pollen, dustmites, grasses, etc. Some dogs with atopy might only be allergic to one or two things, but others might be allergic to literally dozens of allergens. This is similar to humans - ever noticed how some people who are allergic to cats are often also allergic to dust and pollen too?

Like hayfever in humans, dogs can experience symptoms in the spring time as grass, plants, and pollens start to proliferate. For some unfortunate dogs, however, symptoms can last all year round (particularly if your dog is allergic to dust).

Symptoms commonly manifest as seasonal itching, biting or licking of the paws, itchy ears, and watery or goopy eyes (conjunctivitis).

Unfortunately, unlike changing your pet's diet or keeping flea control up to date, avoiding pollen and grass is not a feasible task. Unless your pooch is kept in a quarantine zone, pollen and dust exposure is inevitable. If your dog is experiencing environmental allergies, you will need to visit a veterinarian for advice on oral or injectable medications.

Dogs with atopic dermatitis can have intradermal skin testing with a veterinary dermatologist to identify the cause of their allergies. This is usually followed by a course of immunisations to desensitise the dog against the cause of the allergy, helping to control symptoms. Although not always effective, this approach is the best way to avoid long term use of steroids.

If intradermal testing and desensitisation are not effective or available, other medications and methods can be used to try and minimise the side effects, or strengthen the skin barrier. Which brings us to our next step...

4. Strengthen the skin barrier at home

This step, although listed here as number 4, can really be implemented from the beginning of the diagnostic process. A stronger skin barrier means that your dog has a stronger physical barrier to the causative allergen, and also reduces the inflammatory response as the skin is thicker, healthier, and stronger.

Thankfully it is easy to help strengthen the skin barrier at home, with some affordable over-the-counter products, and some easy at-home changes.

1. Provide beneficial oils into the diet, to help nourish the skin from the inside out. You can either swap over to a skin care diet or a fish-based dog food, or you can buy omega 3+6 fatty acids in a pump bottle, which can be added onto the food directly. Natural Animal Solutions Omega Oil is a great product for this.

Many people find that a change in food is the easiest way to increase their dog's intake of omega fatty acids, as it doesn't require a change in their daily routine. Royal Canin Dermacomfort is enriched with an exclusive nutrient complex that helps to support the skins barrier role, as well as omega 3 and 6 fatty acids. It is also highly palatable for fussy dogs.

Royal Canin Maxi Dermacomfort

This highly palatable diet is enriched with an exclusive nutrient complex that helps support the skins barrier role, including oomega 3 and 6 fatty acids.

Billy and Margot Salmon and Superfood Blend

This salmon diet from Billy and Margot is one of the few diets on the market that includes either raw or fresh fish as the number one ingredient.

Savourlife Salmon

This salmon-based grain-free formula is not only great for the skin, but 50% of profits go to help rescue dogs.

Natural Animal Solutions Omega Pump Bottle

This handy pump bottle allows you to add pure omega oil directly onto the food, making it perfect for dogs who require another specific diet.

2. Provide beneficial oils topically - it might seem strange, but you can actually get omega oils and pop them straight onto the skin. PAW Essential 6 pipettes allow you to put oils directly onto your dog topically like a flea treatment.

3. A nice soothing lotion - not only can moisturising conditioners provide a physical barrier, but they can help nourish the skin cells so they are stronger.

See our top conditioners below:

A note about shampoo: does it help or harm?

For some dogs, the source of sensitive skin may be related to a more local issue like a strongly perfumed shampoo. When using products on your pooch's skin or coat, never use human products. Only ever use those that are approved for canine use.

However, not all shampoos are bad. Some shampoos can provide relief from inflammation or help with infection. Shampoo is not a replacement for treatment though and most pets will still require an oral or injectable medication from a vet.

Yeast or fungal infections will also cause symptoms which manifest through the skin and coat, such as itchy skin or inflammation. Malaseb medicated shampoo is an antifungal, antibacterial and antipruritic solution to not only alleviate discomfort but also help treat yeast and fungal infections.

The take away

Finding the cause of itchy or sensitive skin can be a time consuming endeavour but it's worth it to see that tail wagging again. Keep your dog treated for fleas, consider a diet change, and remember to strengthen the skin barrier. If your dog has ongoing itchiness despite your best efforts, we recommend further workup with your vet.

Further Reading

Want to read more? Check out our other articles:

What is the Best Dog Food for Skin Allergies?

Which Flea or Worming Product Do I Need?

How To Get Rid of Fleas in Dogs

How to Get Rid of Fleas in Cats

Complete Guide to Cat Parasite Products in Australia