Itchy skin might be every pet parent’s worst nightmare. What starts with scratching and licking quickly progresses to open wounds and crusty lesions that are further complicated by bacterial infections. In the veterinary world, we refer to this as atopic dermatitis, a chronic condition that accounts for nearly 25% of all veterinary visits(Couceiro, 2021)

Atopic dermatitis affects more than just our pets – pet parents also feel the impact. Research in the journal Veterinary Dermatology reported that pet parents are directly affected by their dog’s itchy skin, noting changes in their mood, family life, leisure activities, and sleep. Not to mention the financial burden with more and more veterinary visits, diet changes, and desperately testing different supplements(Linek & Favrot, 2010). This means your pet's itchy skin is not just scratching and licking; it becomes a part of your life.

If you skip to the end of this article, we’ll show you how nutrition can prevent your dog’s itchy skin. But, if you want to truly understand atopic dermatitis and the different tools veterinarians use to treat this disease, you should keep reading.

In this article, we’ll cover some of the most recent updates on itchy skin in pets and even go one step further to show how you can help as a pet parent (especially regarding nutrition).

What is atopic dermatitis?

Atopic dermatitis is a chronic inflammatory skin condition characterised by intense itching and recurrent skin infections. It’s often triggered by different allergens, but it also has a genetic predisposition.

This condition is extremely common, leaving pet parents wondering how to break the itchy skin cycle. To put it into perspective, back in 1997, it was estimated that atopic dermatitis affects 3-15% of dogs. Fast-forward to 2024, and we’re seeing nearly 5x more cases of itchy skin related to atopic dermatitis(Drechsler et al., 2024).

Most pet parents begin to notice classic signs of itchy skin between six months and three years of age. Regarding the genetic component, particular dog breeds are especially vulnerable. These include:

• Shar-Pei
• Wirehaired Fox Terrier
• Golden Retriever
• Labrador Retriever
• Dalmatian
• Boxer
• Boston Terrier
• Lhasa Apso
• Scottish Terrier
• Shih Tzu
• West Highland White Terrier.

The hallmark symptom of atopic dermatitis is pruritus (intense itching), which can be seasonal, non-seasonal, or non-seasonal with seasonal flare-ups. You’ll notice the itching usually affects areas like the feet, face, ears, armpits, and abdomen.

 

 

Figure 1. Common distribution of clinical lesions and pruritus associated with canine AD and food allergies.

With atopic dermatitis, the itching comes first. We don’t typically see bumps and rashes until after the itching has started. It’s the self-trauma caused by constant scratching, licking, and biting that causes most of the damage. Within a few days, this “harmless” itching becomes complicated by secondary infection. Now, we start to see the classic clinical signs of atopic dermatitis, including hair loss, redness, scaling, scabs, thickened skin, and darkened pigmentation.

It’s usually at this moment when pet parents start making phone calls to their veterinarian.

The Complexity of Canine Atopic Dermatitis

Atopic dermatitis was once thought to be a simple allergy, mainly driven by an exaggerated immune system response that disrupts the skin’s barrier by IgE antibody activation. This was supported by two main theories. The "Outside-In" theory, where damage to the skin barrier leads to immune activation under the skin, and the "Inside-Out" theory, which suggests the opposite.

 

 

Figure 2. Inside-out and outside-in hypotheses of atopic dermatitis

However, recent studies have revealed that atopic dermatitis is much more complex. It's not as simple as having a faulty skin barrier or a problematic immune system. A major challenge for researchers is figuring out whether skin barrier dysfunction, immune system problems, digestive issues, or imbalances in the skin’s microbiome are the primary cause of the disease or if they develop secondary to the root cause. It’s a classic "chicken and egg" dilemma—making treatment difficult unless we understand what triggers itchy skin and atopic dermatitis in the first place.

Disruption in your dog’s skin barrier

The skin is a crucial barrier against external threats like irritants, microbes, and allergens. When this barrier is compromised, harmful substances can penetrate the skin and trigger an immune response that leads to inflammation. This immune reaction further weakens the skin by reducing essential structural proteins, resulting in a constant scratch-itch cycle that causes even more damage(Outerbridge & Jordan, 2021). Here, the skin’s integrity is problematic, not the immune response.

The outer skin layer (stratum corneum) normally consists of mature skin cells surrounded by lipids, including cholesterol, fatty acids, and ceramides. In dogs with atopic dermatitis, these lipid layers are often abnormal, disorganised, and fewer in number compared to healthy dogs. This can result from nutrient deficiencies that make it difficult for the skin to maintain its barrier function, or it can be attributed to mutations in a protein called Filaggrin, a crucial component of a functional skin barrier. Studies have shown that filaggrin, total lipid, and ceramide concentrations are significantly lower in atopic dogs(Drechsler et al., 2024). Nonetheless, diet modifications and supplementation with specific fatty acids can help restore the natural skin barrier.

This skin barrier breakdown associated with atopic dermatitis is now well-documented in human and veterinary medicine. However, it’s uncertain whether this is a primary cause of the disease or a consequence.

Immune system dysregulation and itchy skin

If the problem isn’t originating from the skin, it could be the immune system. Inflammation can become dysregulated and disproportionate, where a minor irritation triggers a severe immune response in dogs with atopic dermatitis.

This dysregulation is associated with a Th2 immune response that recruits more (and more) inflammatory cells. It’s characterised by elevated levels of interleukins (IL-4, IL-5, and IL-13) in the blood and skin. These interleukins promote allergen-specific IgE antibody production and attract inflammatory cells, amplifying the itching and skin damage(Outerbridge & Jordan, 2021).

Recently, IL-31 has been identified as a critical mediator of this “itching” sensation. Produced by Th2 cells and other immune cells, IL-31 activates itch-sensing nerves and perpetuates this vicious itch-scratch cycle of inflammation. Fortunately, developing a monoclonal antibody that targets and neutralises IL-31, known as lokivetmab (Cytopoint), has been significant for temporarily relieving immune-mediated itching in atopic dermatitis.

Dysbiosis of the skin microbiome

Sometimes the problem isn’t what’s going on under the skin, but what’s living above it. The skin hosts a complex community of microorganisms known as the “skin microbiome,” which includes a variety of bacteria and fungi. Dogs with atopic dermatitis often suffer from recurring skin infections because the diversity and proportions of microorganisms on the skin have become imbalanced.

The most common overgrowths that lead to skin infections are caused by Staphylococcus pseudointermedius and Malassezia pachydermatis, worsening the condition and complicating treatment options for dogs. This overgrowth can be treated with topical antibiotics and antifungal medications, but this will also remove any beneficial bacteria on the skin. Imbalances in any of the body’s microbiomes cannot be restored without proper nutrition(Drechsler et al., 2024).

Problems with the gut-skin axis

Just as the skin has its own microbiome, so does the gut. When harmful bacteria begin to replicate in the digestive system, we have an overgrowth that disrupts the balance in the gut microbiome. This is referred to as gut dysbiosis and often develops when harmful bacteria take advantage of stress, antibiotic use, and poor nutrition to thrive. As these pathogenic bacteria replicate, they outcompete and use up resources that beneficial bacteria (probiotics) rely on to survive in the digestive tract. This disruption changes the entire microenvironment.

With the intestinal barrier compromised, the digestive system becomes inefficient and leaky—a syndrome referred to as "leaky gut”. Microscopic connections that maintain the integrity of the intestinal lining begin to weaken, allowing toxins to leak out of the digestive system. Not only are harmful substances leaking and spreading to the rest of the body, but this dysregulation simultaneously makes it difficult for your pet to absorb essential nutrients. It’s a slippery slope once your pet loses the integrity of their digestive system(Kim & Kim, 2019).

What does this have to do with your dog’s itchy skin? Eventually, these toxins spread to the skin and cause direct damage that triggers an inflammatory response. Clinically, this can present as atopic dermatitis.

With more research published, it’s clear that atopic dermatitis doesn’t follow any specific set of rules. It can have various triggers that all have the same outcome—severe itching that leads to severe inflammation.

Adding another layer of complexity, dogs with food allergies often show symptoms that are very similar to those of atopic dermatitis. Although food allergies and atopic dermatitis were once thought to be distinct conditions, it’s now clear that certain foods can trigger flare-ups of atopic dermatitis(Outerbridge & Jordan, 2021).

How do veterinarians diagnose atopic dermatitis in dogs?

Effective management of atopic dermatitis requires a tailored, multimodal approach that combines different forms of therapy. The first step is to treat any secondary infections before addressing the root of the itching. Once we have this under control, your veterinarian will diagnose the cause of the itchy skin using a systematic approach.

The diagnosis is based on observing specific clinical signs, reviewing the dog’s medical history, and ruling out other causes of itching. This process is outlined by the Merck Veterinary Manual and guided by “Favrot’s Criteria”, a set of key indicators to diagnose atopic dermatitis. These criteria include:

1. Affected ear lobes
2. Affected front paws
3. Itching that started before the age of three
4. Frequent yeast infections
5. Itching that improves with corticosteroid treatment
6. Dogs that mostly live indoors
7. The back area is unaffected
8. Itchiness that starts before skin lesions become noticeable

To reach a diagnosis, at least five of these criteria must be met, and other causes (like diet sensitivities and parasites) must be ruled out.

Once we have a diagnosis, it's essential to educate pet parents about long-term management. Since atopic dermatitis is a chronic condition, it’s important to understand what a multimodal approach to therapy really means.

The multimodal approach to treating your dog’s itchy skin

A “silver bullet” to cure your dog’s itchy skin doesn’t exist. Even if your veterinarian used a pill or injection at the last visit which seemed to help stop the itching, the relief is only temporary. Atopic dermatitis is a chronic condition that absolutely requires a long-term solution.

This is why we need a multimodal approach unique to your dog. While veterinarians have a list of treatment options, we can’t just throw everything at the itchy skin to see what works. We have to start broad and think practically.

Step #1 – Treat the current episode of itching

This is where medications, shampoos, creams, and ointments are most helpful. It’s important to remember that these medications come with risks and are not a long-term solution. They can be used to control a flare-up, but that’s about all.

Step #2 – Identify flare-ups

If your dog suddenly experiences a flare-up after being stable, it’s important to figure out what triggered the itching this time around. Did you take your pet for a walk in a new park? Have you noticed that the itching is seasonal? What about diet? Has there been any changes to what your pet is eating?

Environmental and food allergens are the most common cause of flare-ups!

Step #3 – Avoid allergens

Avoiding allergens that trigger your dog’s itchy skin is easier said than done. There can be several allergies simultaneously, or allergens that are impossible to avoid. This makes it difficult to identify the root problem without adjusting diet and allergy testing. Your veterinarian can help you create a plan to rule out which specific allergens are problematic for your pet.

Step #4 – Supplementing nutrition

So, what other options do we have if it’s impossible to avoid all allergens? We must go back to basics and support your pet’s sensitive skin through diet. This doesn’t mean that you have to make a drastic diet change; instead, key ingredients can be added to your dog’s diet to support their skin and immune system. We’ll talk more about this in a second.

Step #5 – Anti-inflammatory medications

Veterinarians use anti-inflammatory medications as a mainstay to stop active flare-ups as quickly as possible, but they aren’t intended to be used long-term. Since these medications have potential side effects, the goal is to gradually reduce the dosing and eventually manage your pet’s atopic dermatitis without needing anti-inflammatories.

For example, corticosteroids offer rapid relief but must be used cautiously since they affect hormone function and suppress the immune system. Overuse can put your pet at risk of developing more severe infections. Alternatives like cyclosporine, oclacitinib (Apoquel), and lokivetmab (Cytopoint) are immunosuppressive drugs that help control symptoms by reducing the immune response—without affecting hormone levels.

Step #6 – Incorporate immunotherapy

For those allergies that are impossible to avoid, allergen-specific immunotherapy (ASIT) immunotherapy should be considered. This involves desensitising the dog's immune system to specific allergens through regular injections or oral drops. The treatment works by exposing your pet to an extremely low level of an allergen that they’re already sensitive to. Over time, this can reduce the severity of allergic reactions by “training” the immune system to avoid launching an exaggerated response. This takes time and must be combined with medications and diet changes until we start to see improvements, emphasising the importance of multimodal therapy.

Since every dog's triggers for atopic dermatitis is unique, combining these different treatment options is needed to keep the itching at bay. Multimodal therapy requires communication and honesty between you and your veterinarian, so ask questions and don’t be shy!

What should you feed a dog with itchy skin?

As promised, let’s revisit Step #4.

Nutrition is the only element that every pet owner has control over.

It’s more than asking yourself, “Is my dog eating enough protein?”. Your pet’s diet must be complete and balanced, with enough macronutrients and micronutrients to meet daily requirements. We’ve gone in-depth about this in our article, showing you how to create a complete and balanced diet for your pets. That being said, a balanced diet isn’t always enough, leaving dogs with sensitive skin needing extra support. And this doesn’t necessarily mean applying creams and conditioning their fur, no. To support your pet’s skin we must consider the connection between gut and skin health.

What you feed your dog directly influences its health, especially regarding the skin. You may have tried different diets and finally found one that works well for your pet, so we’re not here to tell you to change your pet’s diet completely. If you’ve found something that works, let's stick with it and supplement it.

So, let’s cover some key nutraceuticals that studies suggest can be added to your pet’s current diet to help reduce itchy skin and manage atopic dermatitis in dogs.

Omega-3 rich in DHA

Omega-3 fatty acids, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are among the most commonly recommended nutraceuticals in veterinary medicine. Of the two, DHA is different in that it can be converted to EPA in the body, not vice versa, making high DHA content our focus.

These two polyunsaturated fatty acids (PUFAs) are derived from alpha-linolenic acid (ALA); however, dogs have a limited ability to convert ALA into EPA and DHA. This makes it crucial to provide these fatty acids directly through their diet. The most concentrated sources of EPA and DHA are found in fish oil products, but also in algae—suitable for pets with allergies to fish (or vegan pet parents).

The therapeutic value of these fatty acids stems from their ability to modulate the immune system and reduce inflammation. EPA and DHA lower inflammation by competing with arachidonic acid, a precursor of pro-inflammatory molecules like prostaglandins and leukotrienes. They also serve as precursors to potent anti-inflammatory mediators, making them essential in controlling chronic conditions like atopic dermatitis and stopping itching(Magalhães et al., 2021).

After consulting veterinarians and animal nutritionists, we’ve added 314mg of DHA-rich microalgae to our Thera-Chews to help reduce our pets' itching. Adverse effects of omega-3 fatty acids depend on the dosage, so it's essential to know the right amount to supplement or include in the diet. Giving too much of a good thing is certainly possible, so it's best to dose it properly.

Lactobacillus probiotics

Lactic acid-producing bacteria, like Lactobacillus, convert dietary sugars into lactic acid and other byproducts that aid gut fermentation, produce antimicrobial compounds, and support immune function. Recent studies have identified several Lactobacillus species in the healthy canine gut, particularly L. rhamnosus and L. paracasei, which play critical roles in maintaining skin health and preventing atopic dermatitis.

• Lactobacillus rhamnosus:

Known as the "gold standard" probiotic, L. rhamnosus GG can survive stomach acid and adhere to intestinal cells, forming a biofilm that protects the gut and enhances its integrity. This strain also supports immune function and skin health, reducing atopic dermatitis symptoms in dogs and showing lasting benefits even after discontinuation(Jang et al., 2021).

• Lactobacillus paracasei:

Similarily, L. paracasei promotes gut cell longevity and offers a steroid-sparing effect for dogs with atopic dermatitis. In studies, 12-week supplementation reduced dermatitis severity and the need for glucocorticoids, significantly improving dogs' quality of life. While the mechanism is still under investigation, it may involve immune modulation through Th1 cells and related cytokines(Ohshima-Terada et al., 2015).

Algal extracts

We’ve combined a blend of two biologically active marine algal extracts. These extracts are sources of marine sulphated polysaccharides, which participate in various immune system functions to help limit inflammation and control immune reactions. What’s more, they can also stimulate a compromised immune system(Bhuyan et al., 2023).

A recent study published in Frontiers of Veterinary Science found that adding 1.5% microalgae to a dog’s diet can support more than just skin health; it can also support the gut microbiome (which then supports skin health). This is supported by protein digestibility and diversity of the gut microbiome found increased in dogs fed microalgae(Cabrita et al., 2023).

Using red and green algae also strengthens innate and adaptive immune responses and enhances the barrier function of the intestinal mucosa. Our Thera-Chews include 190mg of to help support the gut-skin barrier and reduce atopic flare-ups.

Olive fruit extract

Olive fruit extract is packed with polyphenols like oleuropein and hydroxytyrosol, known for their strong antimicrobial properties. These compounds are key to the health benefits seen in olive oil byproducts. For example, oleuropein helps increase nitric oxide production in immune cells, protecting against harmful bacteria. The combined action of multiple phenolic compounds makes olive extracts more effective than using single components, offering a natural and powerful antimicrobial option for pet health(Ferlisi et al., 2023).

In addition to fighting microbes, olive polyphenols are beneficial for gut health. They help maintain the integrity of the intestinal barrier, reduce oxidative stress, and support a balanced immune response. This is especially important when it comes to the gut-skin axis and atopic dermatitis. By encouraging the growth of beneficial bacteria such as Lactobacillus, olive extracts help keep the gut healthy and reduce the risk of digestive issues. A balanced gut microbiome supports your pet’s current health and also strengthens the immune system over time, potentially reducing the need for antibiotics in the future(Ferlisi et al., 2023).

Chinese herb blend

Chinese herbal medicine provides several remedies to help reduce itching and inflammation associated with atopic dermatitis in dogs. White Peony (Paeonia lactiflora) is particularly effective in alleviating scratching behaviour and soothing skin inflammation(Marchegiani et al., 2020). This herb is known for its ability to address these symptoms of itchy skin, making it a valuable component of holistic treatments.

Chinese Liquorice (Glycyrrhiza uralensis) contains a key ingredient, glycyrrhizin, that has been shown to lower levels of interleukin (IL)‐4 and help correct the imbalance between T helper (TH1/TH2) cells in allergy studies. It also reduces the production of allergen-specific immunoglobulins (Ig)E and IgG1 by B-cells and stabilises mast cells(Han et al., 2017). Royal Canin even tested it in a veterinary prescription diet to reduce the medication score and pruritus of dogs with atopic dermatitis during a nine‐month controlled study(Watson et al., 2022).

Chinese Foxglove (Rehmannia glutinosa) is also used to manage skin conditions, including those with psoriatic-like symptoms(Liu et al., 2021). This herb helps to relieve inflammation and scaling, contributing to overall skin health.

We’ve incorporated 90mg of these Chinese herbs into our Thera-Chews to help us enhance the management of atopic dermatitis, offering a complementary approach to conventional therapies.

Conclusion

Navigating your dog's itchy skin can be challenging, but a well-rounded approach offers hope and relief. Understanding atopic dermatitis and using a multimodal approach to therapy is essential. Effective management involves more than quick fixes; it’s about a balanced combination of treatments, including nutrition, medication, and potentially immunotherapy.

Diet is the key element that only you can directly control. While diet alone might not solve your dog’s itchy skin, it is crucial in supporting your dog's skin health and overall well-being. Speak with your veterinarian and create a plan integrating dietary adjustments with other therapies. Remember, effective management of atopic dermatitis is a marathon, not a sprint. It requires patience, persistence, and a partnership with your veterinarian.

If you have any questions, you can always contact us!

Writer: Ash Sadri

Ash is a Canadian final year veterinary student studying in Croatia. Before deciding to become a vet, Ash completed his Masters degree at the University Of Western Ontario where he specialised in cancer stem cells research. Since then, he’s been working as a veterinary technician and has special interests in animal nutrition and surgical procedures!

Works Cited

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