Let’s explore how nutrition plays a preventative role in canine skin disease - moving beyond a reactive approach to influencing disease risk from the start.

And what about the dog with atopic dermatitis? Once we’ve done an elimination trial, how can we continue to support and strengthen skin health through diet?

1. Can diet prevent skin disease?

Two studies published by DogRisk - an independent, university-based research group - identified early diet exposure as a significant variable for the development of otitis¹ and canine atopic dermatitis².

The level of processing of the diet was a significant risk factor.

🔬 STUDY 1

Early life programming by diet can play a role in risk reduction of otitis in dogs (Hemida et al., 2023)¹

Method

• Cross-sectional study of 3,064 dogs using owner-reported data.

• Examined 26 early-life exposures, including diet, at four key early life stages: prenatal, neonatal, postnatal, and puppyhood.

Results

• Puppies eating >75% dry, carbohydrate-based foods, had a significantly increased risk of otitis later in life.

• Puppies fed a fresh, meat-based diet showed a lower risk of developing otitis when diet included >25%

Conclusion

The degree of processing of the diet fed in early life appears to be a risk factor for developing otitis later in life.

• Fresh food appears protective, while dry, carbohydrate-based diets may increase risk.

🔬 STUDY 2

Identification of modifiable pre- and postnatal dietary and environmental exposures associated with owner-reported canine atopic dermatitis in Finland using a web-based questionnaire (Hemida et al., 2020)²

Method

• Cross-sectional study of 2236 dogs using owner-reported data.

• Examined genetic, dietary and environmental factors from pre- to post-natal stages.

Results

• Dry, carbohydrate-based foods were linked with increased CAD risk.

• Fresh meat-based diets fed during pregnancy and early puppyhood were associated with lower canine atopic dermatitis (CAD) risk.

• Among other genetic and environmental factors.

Conclusion

The degree of processing of the diet fed in early life appears to be a risk factor for developing CAD later in life.

• Fresh food appears protective, while dry, carbohydrate-based diets may increase risk.

While this evidence suggests early diet plays a role in the later development of CAD and otitis, the studies were based on owner-reported data. Prospective trials are needed to confirm the causal effects of diet.

2. Initial approach to the pruritic dog

Given the implications of chronic skin disease, prevention is clearly ideal. However, we know this isn’t the reality for many patients.

So what about dog who is already itchy?

After ruling out infectious or parasitic causes of pruritus, we should look to diet as a next step in the diagnostic and therapeutic approach.

A dietary elimination trial with a novel or hydrolysed protein is a logical next step. The aim is to rule out a cutaneous adverse food reaction (CAFR)³. The concept of food-induced atopic dermatitis (FIAD) is also increasingly recognised, where dogs can have both dietary and environmental hypersensitivities⁴.

• This trial is conducted strictly, over 8-12 weeks.

• Infections should be managed prior to, and during the trial. This helps assess the full response of the diet change.

• Objective scoring systems, like the CADESI-4 system⁵ at the start, mid-point and end of the trial may assist with monitoring response.

Elimination diets can be frustrating for the pet, owner and clinician. However, they are generally advised to achieve a complete diagnosis, and to avoid unnecessary investigation and treatment.

Dietary hypersensitivities are thought to occur in only 10-20% of allergic skin disease cases⁶. So, how can we help manage the remaining dogs through diet?

3. Dietary management of skin disease

Regardless of the outcome of an elimination trial, diet must not be forgotten. Diet should be considered a cornerstone of multi-modal treatment in patients with chronic skin disease.

Research shows that diet can influence gene expression⁷ and modulate immune function⁸, affecting their skin health. Though, its full effects are yet to be appreciated.

With many options available, deciding on an appropriate diet for optimal skin support can be challenging.

Do minimally processed diets really work?

Fresh, whole food diets have been shown to improve immune function in dogs⁸. In this study, dogs fed the whole food diet had significantly lower TNF-α-to-IL-10 ratios (decreases in this ratio are associated with a decrease in inflammation) and higher production of IL-8 (which plays a role in wound healing and infection control).

While further research is required to understand the mechanism behind this, fresh food diets are often high in bioavailable nutrients that benefit skin function.

One example is protein, a “nutrient of concern” for skin disease. Fresh food typically contains higher levels of protein and offers greater protein digestibility compared to extruded (dry) food⁹.

🔎 Understanding nutrients of concern

In this context, "nutrients of concern" are key nutrients that influence specific body systems.

They are prioritised in therapeutic diets and are a useful place to start when critically evaluating diets for any health condition.

For skin disease, key nutrients of concern include:

1. Protein

• The skin and coat are demanding of protein, with up to 30% of daily protein intake utilised for hair growth¹⁰.

• Sulphur-containing amino acids, like cysteine¹¹and methionine, are vital for skin function. These amino acids are higher in animal proteins compared to plant proteins.

• Deficiencies in protein can lead to alopecia and poor wound healing.

🔬 Clinical tip: analyse the source, quantity and digestibility of protein in the diet.

2. Vitamin E

• Exerts antioxidant effects¹², particularly relevant for chronic inflammatory skin disorders.

• Fat metabolism is a source of free radicals, meaning vitamin E requirements are directly linked to intake of polyunsaturated fatty acids¹³ (often higher in therapeutic diets for skin).

• One randomised, placebo-controlled trial showed improvements of atopic dermatitis scores (CADESI-3) and decreased oxidative stress markers in dogs supplemented with vitamin E for eight weeks¹⁴.

3. Phytonutrients

• Found in fruits, vegetables and botanicals and often not considered in traditional diets.

• Exhibit anti-inflammatory properties and improve the skin barrier¹⁵.

• Spirulina, a dense supply of phytonutrients (e.g. flavonoids), may be protective against food sensitivities¹⁶.

Phytonutrients are sensitive to thermal processing¹⁷. Their quantity and bioavailability may therefore be reduced in extruded (dry) or highly processed diets.

4. Vitamin A

• Vitamin A supports epidermal integrity and promotes normal turnover of keratinocytes, helping to prevent hyperkeratosis, flaking, and follicular plugging.

5. Zinc

• Supports keratinocyte proliferation, vitamin A metabolism and epithelialisation¹⁰.

• Deficiencies may be more commonly seen in Northern breeds (e.g. Siberian Huskies).

6. Omega 3 fatty acids

• Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) support skin barrier function, and can reduce trans epidermal water loss (TEWL)¹⁸.

🔬 Clinical tip: Analyse the omega-6 to omega-3 ratio of the diet:

• High omega-6:3 ratios (>5:1) tend to promote pro-inflammatory eicosanoids.

• Lower ratios (ideally <5:1) shift the balance toward anti-inflammatory mediators¹⁹.

Note: Omega-6 fatty acids also play an important role in skin health and integrity. However, the balance between omega-3 and omega-6 fatty acids must be carefully considered.

4. Functional Nutrition for Skin Health

All Lyka meals support skin health through nutrient-dense whole foods.

Lyka’s Hypoallergenic Pro is a single, novel protein diet, providing targeted clinical nutrition to support dogs with skin and gut sensitivities.

Hypoallergenic Pro (Goat)

A therapeutic diet formulated by Board-Certified Veterinary Nutritionists, and is suitable for dogs of all life stages including large and giant breed puppies.

Hypoallergenic Pro (Goat) can be implemented for elimination trials or as a long-term diet in dogs with:

• Suspected adverse food reactions

• Skin sensitivities

• Chronic otitis externa

• Gastrointestinal problems

1. A fresh option

   One of the few therapeutic novel protein diets in Australia made with minimally processed, fresh ingredients.

2. Highly palatable

   Supports dogs requiring a restricted, long-term diet where compliance is a concern.

3. Targeted nutrition through functional ingredients

Carefully curated ingredients deliver key nutrients of concern for skin disease. Including:

• Goat as a single, novel, highly digestible source of protein.

• Algae oil, providing a non-fish source of omega 3 fatty acids to help modulate the immune response.

• Purple sweet potato, high in anthocyanins, a flavonoid phytonutrient that acts as an antioxidant.

• Key vitamins and minerals - such as zinc and vitamin E - included at clinically relevant levels.

Beyond nutritional adequacy

Nutritional adequacy is the bare minimum. Hypoallergenic Pro safely exceeds minimum nutritional standards to provide targeted nutrition for skin support.

References

1. Hemida MBM, Vuori KA, Borgström NC, Moore R, Rosendahl S, Anturaniemi J, Estrela-Lima A, Hielm-Björkman A. Early life programming by diet can play a role in risk reduction of otitis in dogs. Front Vet Sci. 2023 Nov 6;10:1186131. doi: 10.3389/fvets.2023.1186131. PMID: 38026629; PMCID: PMC10657834.

2. Hemida M, Vuori KA, Salin S, Moore R, Anturaniemi J, Hielm-Björkman A. Identification of modifiable pre- and postnatal dietary and environmental exposures associated with owner-reported canine atopic dermatitis in Finland using a web-based questionnaire. PLoS One. 2020 May 29;15(5):e0225675. doi: 10.1371/journal.pone.0225675. PMID: 32469869; PMCID: PMC7259748.

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5. Olivry T, Saridomichelakis M, Nuttall T, Bensignor E, Griffin CE, Hill PB; International Committe on Allergic Diseases of Animals (ICADA). Validation of the Canine Atopic Dermatitis Extent and Severity Index (CADESI)-4, a simplified severity scale for assessing skin lesions of atopic dermatitis in dogs. Vet Dermatol. 2014 Apr;25(2):77-85, e25. doi: 10.1111/vde.12107. Epub 2014 Jan 25. PMID: 24461108.

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11. Shimomura Y, Aoki N, Rogers MA, Langbein L, Schweizer J, Ito M. Characterization of human keratin-associated protein 1 family members. J Investig Dermatol Symp Proc. 2003 Jun;8(1):96-9. doi: 10.1046/j.1523-1747.2003.12180.x. PMID: 12895003.

12. Jewell DE, Motsinger LA, Paetau-Robinson I. Effect of dietary antioxidants on free radical damage in dogs and cats. J Anim Sci. 2024 Jan 3;102:skae153. doi: 10.1093/jas/skae153. PMID: 38828917; PMCID: PMC11185959.

13. Raederstorff D, Wyss A, Calder PC, Weber P, Eggersdorfer M. Vitamin E function and requirements in relation to PUFA. British Journal of Nutrition. 2015;114(8):1113-1122. doi:10.1017/S000711451500272X

14. Plevnik Kapun A, Salobir J, Levart A, Tavčar Kalcher G, Nemec Svete A, Kotnik T. Vitamin E supplementation in canine atopic dermatitis: improvement of clinical signs and effects on oxidative stress markers. Vet Rec. 2014 Dec 6;175(22):560. doi: 10.1136/vr.102547. Epub 2014 Sep 9. PMID: 25205675.

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