Introduction
Many pet owners are eager to boost their dog’s health and appearance, often turning to home remedies and dietary supplements for that extra shine in their pup’s coat or relief from itchy skin. One popular trend is adding vegetable oils—like olive oil or sunflower oil—to dog food, based on the widespread belief that these oils can improve skin and coat health. But could this well-meaning habit actually be making things worse for some dogs?
A new study published in BMC Veterinary Research raises important questions about the safety of oil supplements in canine diets, especially for dogs with sensitive skin or food allergies. The research uncovers a possible link between the use of certain vegetable oils and an increased risk of food allergies in dogs, offering fresh insight into a topic that matters to many pet owners.
Research Background
Until now, the common narrative has been that vegetable oils, thanks to their essential fatty acids, are beneficial for dogs. Pet forums and even some commercial advice often recommend adding a splash of olive or seed oil to kibble for skin and coat benefits. However, scientific data supporting these claims—especially concerning the long-term impact on allergies or inflammation—has been thin.
This new research stands out because it is the first to systematically examine whether supplementing a dog’s diet with omega-6-rich vegetable oils might unintentionally contribute to food allergies. While omega-6 fatty acids are essential in small amounts, excessive intake can disrupt the delicate balance between inflammatory and anti-inflammatory pathways in the body. The lack of clear, evidence-based recommendations on the optimal balance of fatty acids in canine diets makes this study especially timely for both veterinarians and pet owners.
Study Details
This investigation by Maina et al. employed a cross-sectional analysis to explore the relationship between dietary oil supplements and food allergies in dogs.
Key aspects of the study:
- Design: Cross-sectional analysis of dermatology clinic cases
- Location: Multiple veterinary dermatology clinics across Italy
- Participants:
- 459 dogs presenting with various skin conditions
- Dogs diagnosed with either food allergies (adverse food reactions) or other dermatological issues
- Study Period: January 2022 – December 2023
- Method: Review of medical records and owner-reported dietary supplementation, focusing on the use of vegetable oils (primarily olive oil)
By comparing the diets of dogs with food allergies to those with other skin diseases, researchers aimed to clarify whether oil supplementation might be linked to allergy development.
Key Findings
Primary Results
The study revealed a striking pattern: dogs diagnosed with food allergies were much more likely to have been given oil supplements than those with other skin conditions. Specifically, 29.3% of dogs with food allergies were receiving some type of oil supplement, compared to only 10.1% of dogs with other dermatological problems. This difference suggests a significant association between vegetable oil supplementation—especially with olive oil—and an increased risk of adverse food reactions in dogs.
Olive oil was the most commonly used supplement among all the oils reported, making up the majority of cases. The researchers hypothesize that the high omega-6 content of these oils may play a role in triggering or worsening allergic reactions in susceptible dogs.
Secondary Findings
While the study primarily focused on the connection between oil supplementation and food allergies, it also highlighted broader concerns about the lack of regulation and evidence-based guidance for at-home dietary modifications. The findings suggest that well-intentioned efforts to improve a dog’s coat or skin with oil supplements could inadvertently disrupt the balance of essential fatty acids, increasing inflammation and the risk for allergic skin disease.
Notably, the research did not find a similar association between oil supplementation and other non-allergic skin conditions, strengthening the argument that the effect may be specific to food-related allergies.
Implications for Pet Owners
What This Means for You
If you have been adding olive oil or other vegetable oils to your dog’s meals in hopes of improving their skin or coat, this study suggests it may be time to reconsider—especially if your dog has a history of food sensitivities or allergies. While fatty acids are essential for your dog’s health, achieving the right balance is critical, and excess omega-6 can potentially do more harm than good.
Instead of making dietary changes on your own, consider discussing your dog’s nutritional needs with your veterinarian, especially if your pet is prone to skin issues or allergies. If your vet recommends omega-3 supplementation, consider high-quality fish oil supplements specifically designed for dogs rather than adding vegetable oils. Simple, well-intentioned additions to your dog’s diet may have unintended consequences.
When to Consult Your Veterinarian
If your dog is experiencing symptoms like persistent itching, red or inflamed skin, recurrent ear infections, or digestive upset, it’s important to consult with your veterinarian before adjusting their diet. These could be signs of an underlying food allergy or another health issue that requires professional diagnosis and treatment.
Veterinarians can help you assess your dog’s overall nutrition, guide you on safe supplement choices, and determine whether additional testing or dietary adjustments are necessary. They can also help you interpret study findings like these in the context of your individual pet’s health needs.
Study Limitations
Like all scientific research, this study has its limitations. As a cross-sectional analysis, it can identify associations but cannot prove that oil supplementation directly causes food allergies. Other factors—such as breed, genetics, underlying health conditions, or the use of multiple supplements—might also influence the results. Additionally, the study relied on owner-reported data, which can be subject to recall bias. Future research, including controlled trials, will be necessary to confirm these findings and clarify the mechanisms involved.
Bottom Line
This new research highlights a potential downside to a popular home remedy: supplementing your dog’s diet with olive oil or other vegetable oils may increase the risk of food allergies, particularly in dogs already prone to skin problems. Nearly one in three dogs with food allergies in the study had been given oil supplements, compared to just one in ten dogs with other skin issues.
The safest course is to avoid self-prescribing dietary supplements for your dog—especially oils rich in omega-6—without first consulting your veterinarian. While the idea of improving your dog’s coat or easing itching with a natural remedy is appealing, this study suggests that such interventions may not be as harmless as they seem.
Recommended Products
Based on the research findings discussed in this article, we’ve carefully selected these top-rated products to help you support dogs with food sensitivities and allergies. These products are chosen for their quality, customer satisfaction, and alignment with the scientific evidence presented—offering safer alternatives to problematic omega-6 rich oil supplements.
Hill's Science Diet Sensitive Stomach & Skin Dog Food
Purina Pro Plan Sensitive Skin and Stomach Dog Food
Fish Oil for Dogs - Healthy Skin & Coat Support
Native Pet Omega 3 Fish Oil for Dogs & Cats
Disclosure: We only recommend research-based products that support your pet’s health. As an Amazon Associate, we earn from qualifying purchases at no additional cost to you—helping us fund our mission to provide cutting-edge research to all pet lovers.
Disclaimer
This article summarizes peer-reviewed research for educational purposes. Always consult with your veterinarian for personalized advice about your pet’s health and behavior.