Why Your Dog's Itchy Skin Might Start in the Gut

If you've ever watched your dog scratch the same spot for the fifth time before breakfast, you already know the feeling. You've tried the shampoos. Maybe a different food. Possibly a supplement or two. And yet, still scratching, still licking, still uncomfortable.

The truth is, most approaches to allergy support focus on what's happening at the surface. But what if the itch isn't just a skin problem?

Emerging research into the gut-immune-skin connection is changing how we think about dog wellness, and it's exactly what led us to take a fresh look at how we approach itch and seasonal allergy support. 

Here's what we learned, what we changed, and why we think it matters for your dog.

The Gut-Immune-Skin Connection

Here's something that might surprise you: roughly 70% of your dog's immune system lives in the gut.[3]

That means the gut isn't just responsible for digestion. It plays a central role in how your dog's body recognizes and responds to the world around them, including seasonal triggers that can show up as skin irritation, itching, and coat changes.

Here's how the connection works: when gut bacteria are in balance, they produce beneficial compounds that travel through the bloodstream and help regulate immune activity throughout the body. When that balance is disrupted, the immune response can become less regulated — and for many dogs, that shows up on the skin.[4,5]

This gut-immune-skin connection has gained significant attention in both human and pet wellness research in recent years. And while every dog is different, the science is consistent enough that it's changing how seasonal allergy and skin support are being approached.

Which brings us to postbiotics, and why we think they're a more targeted way to support that system.

Why Postbiotics

You've probably heard of probiotics. Prebiotics too. But postbiotics are quickly gaining attention in microbiome health, despite being studied for decades. In fact, postbiotics just received a standardized definition in 2021.[2]

Think of probiotics as seeds you plant and hope take root, and prebiotics as the water and nutrients that help them grow. Postbiotics are the harvest, the beneficial compounds already ready to go to work. No viability challenges, no guesswork.

For dogs dealing with seasonal skin and allergy challenges, that directness matters. Rather than hoping live bacteria survive manufacturing, shipping, and digestion, postbiotics get to the point.

The postbiotic in our new Itch & Allergy formula is proprietary, patent pending, and clinically studied in canines, meaning it's not a generic ingredient. It was specifically selected to support balanced immune function and a healthy gut microbiome, with the gut-immune-skin connection squarely in mind.[1]

What's In the New Formula

So what does this actually look like in practice? Here's what's in the updated Itch & Allergy formula and why each ingredient earned its place.

Immune Postbiotics 

The hero of the new formula. Our clinically studied postbiotic was specifically selected to support balanced immune function and gut microbiome diversity in dogs. This is the ingredient that makes the formula different, and it's the reason we felt confident enough to update it.[1]

Colostrum 

A core ingredient we kept for good reason. Colostrum supports immune health and skin wellness, making it a natural complement to the postbiotics' gut-immune focus.*[6]

Wild Alaskan Salmon Oil 

Retained for its role in supporting normal skin moisture and coat shine. While the postbiotic works from the inside out, salmon oil supports what you actually see and feel on the outside.*[7]

Turmeric + Licorice Root 

Both kept for their role in supporting overall skin comfort during seasonal changes. Together, they round out a formula that addresses the gut-immune-skin connection at multiple points.*[8,9]

Every ingredient in this formula is here for a specific reason. No fillers, no trend-chasing. Just a streamlined lineup built around how the science says skin and seasonal allergy support actually works.

FAQs

Why did PupGrade update the Itch & Allergy formula? 

As research into the gut-immune-skin connection continued to grow, we saw an opportunity to take a more targeted approach to seasonal allergy and skin support. The updated formula is built around that science, with a clinically studied, proprietary postbiotic at the center.

What are postbiotics and are they safe for dogs? 

Postbiotics are beneficial compounds produced by gut bacteria. Unlike probiotics, they don't rely on live bacteria surviving digestion, making them more stable and consistent. The postbiotic in our formula is clinically studied in canines and has undergone extensive safety analysis. As always, we recommend consulting with your veterinarian before introducing any new supplement into your dog's routine.

Is the new formula still good for seasonal allergy support? 

Yes. Seasonal allergy support remains the core focus of Itch & Allergy. The updated formula approaches it through the gut-immune-skin connection, which we believe is a more targeted and effective way to support dogs during seasonal changes. The ingredients your dog benefited from before, including colostrum, turmeric, and wild Alaskan salmon oil, are all still part of the formula.

How long does it take to see results? 

Every dog is different, but in a post-launch consumer survey, 93% of dog parents reported seeing an improvement in just 4 weeks.** As with any supplement, consistency is key. We recommend giving Itch & Allergy daily and allowing at least 4 weeks before evaluating results.

We didn't update this formula because we had to. We updated it because the science pointed somewhere worth following, and we believe your dog deserves a supplement that keeps up with what research is actually showing.

That's what PupGrade is built around — not trend-chasing, not a longer ingredient list, but a genuine commitment to formulating with intention. The gut-immune-skin connection isn't a marketing angle. It's the reason every ingredient in the new Itch & Allergy formula is there.

If your dog has been struggling with seasonal skin and allergy challenges, we hope this gives you a clearer picture of what we built and why.

And if you're ready to try out our new Itch & Allergy soft chews for yourself, we're here to help you get started.

Use code BLOG10 for 10% off your first order. Your dog will thank you.

This content is for informational purposes only and is not intended to replace professional veterinary advice. Always consult your veterinarian before introducing new supplements or changes to your dog's routine.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

**Based on a post-launch consumer survey of PupGrade Itch & Allergy customers.

Resources:

1. Data on file.

2. Salminen, S., Collado, M. C., Endo, A., Hill, C., Lebeer, S., Quigley, E. M. M., Sanders, M. E., Shamir, R., Swann, J. R., Szajewska, H., & Vinderola, G. (2021). The International Scientific Association of Probiotics and Prebiotics (ISAPP) consensus statement on the definition and scope of postbiotics. Nature Reviews Gastroenterology & Hepatology, 18(9), 649–667. https://doi.org/10.1038/s41575-021-00440-6

3. Paddock, Z. D., Pilla, R., Suchodolski, J. S., & Wadell, J. S. (2019). The role of the canine gut microbiome and metabolome in health and gastrointestinal disease. Frontiers in Veterinary Science, 6, 498. https://doi.org/10.3389/fvets.2019.00498

4. Trompette, A., Gollwitzer, E. S., Pattaroni, C., Lopez-Mejia, I. C., Riva, E., Pernot, J., Ubags, N., Fajas, L., Nicod, L. P., & Marsland, B. J. (2022). Gut-derived short-chain fatty acids modulate skin barrier integrity by promoting keratinocyte metabolism and differentiation. Mucosal Immunology, 15, 908–926. https://doi.org/10.1038/s41385-022-00524-9

5. Xu, Z., Huang, Z., Shen, Y., Rao, X., & Li, Q. (2022). The role of short-chain fatty acids in inflammatory skin diseases. Frontiers in Microbiology, 13, 1083432. https://doi.org/10.3389/fmicb.2022.1083432 

6. Yu, P., & Satyaraj, E. (2025). Effect of bovine colostrum on canine immune health. Animals, 15(2), 185. https://doi.org/10.3390/ani15020185 

7. Minamoto, Y., Otoni, C. C., Steelman, S. M., Büyükleblebici, O., Steiner, J. M., Jergens, A. E., & Suchodolski, J. S. (2021). Randomized, double-blind, placebo-controlled clinical trial measuring the effect of a dietetic food on dermatologic scoring and pruritus in dogs with atopic dermatitis. Veterinary Dermatology, 32(5), 481–e130. https://doi.org/10.1111/vde.12999 

8. Dąbrowski, G., & Grabska-Liberek, I. (2023). Turmeric and curcumin — health-promoting properties in humans versus dogs. International Journal of Molecular Sciences, 24(19), 14561. https://doi.org/10.3390/ijms241914561 

9. Fiore, C., Eisenhut, M., Krausse, R., Ragazzi, E., Pellati, D., Armanini, D., & Bielenberg, J. (2008). Antiviral effects of Glycyrrhiza species. Phytotherapy Research, 22(2), 141–148. https://doi.org/10.1002/ptr.2295