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Research article - Peer-reviewed, 2018

Interbreed variation in serum serotonin (5-hydroxytryptamine) concentration in updates healthy dogs

Hoglund, K.; Haggstrom, J.; Hanas, S.; Merveille, A. -C.; Gouni, V.; Wiberg, M.; Willesen, J. Lundgren; Mc Entee, K.; Sorensen, L. Mejer; Tiret, L.; Seppala, E. H.; Lohi, H.; Chetboul, V.; Fredholm, M.; Lequarre, A. -S.; Ljungvall, I.


Introduction: Serotonin (5-hydroxytryptamine [5-HT]) has several biological functions. In different species, excessive 5-HT has been linked to valvular lesions, similar to those seen in dogs with myxomatous mitral valve disease. Previous studies suggest higher 5-HT in healthy Cavalier King Charles Spaniels (CKCSs), a breed highly affected by myxomatous mitral valve disease, compared to other breeds.Objective: To investigate potential interbreed variation in serum 5-HT in healthy dogs.Animals: 483 healthy dogs of nine breeds aged 1-7 years.Methods: Dogs were examined at five European centers. Absence of cardiovascular, organ-related, or systemic diseases was ensured by thorough clinical investigations including echocardiography. Serum was frozen and later analyzed by enzyme-linked immunosorbent assay (ELISA).Results: Median 5-HT concentration was 252.5 (interquartile range = 145.5-390.6) ng/mL. Overall breed difference was found (p<0.0001), and 42% of pairwise breed comparisons were significant. Univariate regression analysis showed association between serum 5-HT concentration and breed, center of examination, storage time, and sex, with higher 5-HT in females. In multiple regression analysis, the final model had an adjusted R-2 of 0.27 with breed (p<0.0001), center (p<0.0001), and storage time (p=0.014) remaining significant. Within centers, overall breed differences were found at 3/5 centers (p <= 0.028), and pairwise comparisons within those centers showed breed differences in 42% of comparisons. Among the included breeds, New-foundlands, Belgian Shepherds and CKCSs had highest 5-HT concentrations.Conclusions: Interbreed variation in serum 5-HT concentration was found in healthy dogs aged 1-7 years. These differences should be taken into account when designing clinical studies. (C) 2018 Elsevier B.V. All rights reserved.


Breed difference; Biomarker; Canine; Heart valve; 5-HT

Published in

Journal of Veterinary Cardiology
2018, volume: 20, number: 4, pages: 244-253

Authors' information

Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry (AFB)
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Evidensia Animal Clinic Västerås
Swedish University of Agricultural Sciences, Department of Clinical Sciences

UKÄ Subject classification

Medical Bioscience

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