Can Dogs Be Tested for Food Allergies with a Blood Test?
Many dog owners are told their dog is allergic to specific proteins based on blood test results. But science shows these tests are frequently inaccurate and misleading.
Do they work?
Recent studies and clinical reviews emphasize that serological blood tests (IgE-based) and other laboratory tests are unreliable for diagnosing food allergies in dogs. These tests consistently fail to distinguish between dogs with clinical food reactions and healthy dogs, and frequently produce false positives (Lam et al., 2019; Mueller & Olivry, 2017; Vovk et al., 2019).
What does the research say?
A pivotal 2019 study compared serum IgE, salivary IgA/IgM, and elimination diets followed by provocation. The researchers concluded that both blood and saliva-based tests lacked diagnostic accuracy, with poor sensitivity, specificity, and predictive value. None of the tests reliably identified food allergens responsible for clinical symptoms, and many positive results occurred in healthy dogs (Lam et al., 2019). Further evaluations of commercial IgE panels showed poor correlation between test results and clinical signs, reaffirming that elimination diets remain the gold standard for diagnosing adverse food reactions in dogs (Heinze & Freeman, 2020). In a recent epidemiological investigation, Marti et al. (2025) found elevated IgE antibodies against food proteins in dogs without any clinical signs, indicating that IgE sensitization alone is insufficient to confirm clinical food allergy.
Blood tests are convenient - but unreliable
In recent years, many veterinary clinics have begun offering commercial IgE blood tests or "food sensitivity panels" that claim to identify food allergies in dogs. These tests analyze serum for antibodies (commonly IgE or IgG) directed against specific food proteins such as chicken, beef, lamb, or fish. While they are widely marketed as a fast and simple alternative to diet trials, these tests lack scientific validation for diagnosing clinical food allergies in dogs (Vovk et al. 2019). Diagnostic laboratories often promote these tests, capitalizing on pet owners' desire for quick answers and clinicians' time constraints. However, studies show that serological tests frequently produce false positives, identifying antibodies in dogs with no clinical signs, or reacting to proteins the dog actually tolerates (Mueller & Olivry, 2017).
So what does actually work?
A homemade elimination diet is widely recommended as the first-line approach when investigating suspected food allergies in dogs. This method provides complete control over ingredients, eliminates the risk of cross-contamination, and ensures the exclusion of all non-essential additives and hidden allergens (Olivry et al., 2015). In contrast, several studies have shown that commercial limited-ingredient diets —even those labeled as containing only one protein source (singleprotein) —frequently contain undeclared animal proteins. For example, Ricci et al. (2018) detected DNA from undeclared species in commercial dry and wet LID dog foods using microarray analysis, raising concerns about the reliability of ingredient labels. Similarly, studies by Horvath-Ungerboeck et al. (2017) and Koppel et al. (2018) confirmed cross-contamination in both novel protein and hydrolyzed diets, even those marketed for elimination trials. Other investigations using PCR and species-specific DNA detection methods further support these findings (O'Sullivan et al., 2017; Fritz et al., 2018; Premrov Bajuk et al., 2020).
Trust what works
When it comes to diagnosing food allergies in dogs, the science is clear: homemade elimination diets remain the most accurate and effective method available. Unlike commercial diets—many of which have been shown to contain undeclared proteins—a carefully prepared home-cooked diet offers full control and eliminates the guesswork. This approach has successfully identified food allergens and improved quality of life for thousandes of dogs worldwide suffering from chronic itching, digestive issues, or unexplained skin problems.
Need help getting started?
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Refrences
Heinze, C. R., & Freeman, L. M. (2020, March 6). Food allergy testing. Tufts University: Petfoodology. Retrieved from https://sites.tufts.edu/petfoodology/2020/03/06/food-allergy-testing/ Lam, A. T., Johnson, R. A., Heinze, C. R., & Suchodolski, J. S. (2019). Comparison of saliva and serum testing for the diagnosis of adverse food reactions in dogs. Journal of Veterinary Allergy and Clinical Immunology, 27(3), 145–152. https://doi.org/10.1016/j.cvsm.2019.06.001 Marti, E., Dolf, G., Mueller, R. S., & Olivry, T. (2025). Prevalence of food-specific IgE in asymptomatic dogs: Implications for allergy testing. Veterinary Sciences, 12(6), 563. https://doi.org/10.3390/vetsci12060563 Fritz, J., Widmer, C., & Künzi, N. (2018). Determination of mammalian DNA in commercial canine diets with unusual and limited ingredients. Veterinary Medicine and Science, 4(3), 118–126. https://doi.org/10.1002/vms3.125 Horvath-Ungerboeck, C., Widmer, C., & Handl, S. (2017). Detection of DNA from undeclared animal species in limited-antigen wet dog and cat foods. Acta Veterinaria Scandinavica, 59(1), 32. https://doi.org/10.1186/s13028-017-0302-2 Koppel, C., & Baade, S. (2018). Critically appraised topic on adv…