Heatstroke and brachycephalic dogs – is there an increased risk?



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PICO question

Do dogs that are brachycephalic have an increased risk for developing heat-related illness compared to dogs that are not brachycephalics?


Clinical bottom line

Category of research


Number and type of study designs reviewed

Four studies were critically appraised. Three of these were cohort studies, one was a case-control study.

Strength of evidence


Outcomes reported

Brachycephalic dogs are at increased risk of developing heat-related illness and brachycephalic breeds are over-represented in presentations for heatstroke. Other factors named, such as body weight, also contributed to the risk of developing heat-related illness.


Dogs that are brachycephalic are likely to have an increased risk for developing heat-related illness compared to non-brachycephalic dogs.


How to apply the evidence in practice

The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.

Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.


Brachycephalic Working Group. (2020). Setting a limit for conformational exaggerations in dog breeds to halt the slide towards even more extreme conformations (Full Version). [online]. Available at: http://www.ukbwg.org.uk/wp-content/uploads/2020/12/201030-Full-version-BWG-Position-on-Setting-a-limit-for-conformational-exaggerations-in-dog-breeds-.pdf [Accessed May 2022].

Bruchim, Y., Horowitz, M. & Aroch, I. (2017). Pathophysiology of heatstroke in dogs – revisited. Temperature. 4(4), 356–370. DOI: https://doi.org/10.1080/23328940.2017.1367457

Davis, M., Cummings, S. & Payton, M. (2017). Effect of brachycephaly and body condition score on respiratory thermoregulation of healthy dogs. Journal of the American Veterinary Medical Association. 251(10), 1160–1165. DOI: https://doi.org/10.2460/javma.251.10.1160

Hall, E., Carter, A. & O’Neill, D. (2020). Dogs Don't Die Just in Hot Cars–Exertional Heat-Related Illness (Heatstroke) Is a Greater Threat to UK Dogs. Animals. 10(8), 1324. DOI: https://doi.org/10.3390/ani10081324

Hall, E., Carter, A., Bradbury, J., Barfield, D. & O’Neill, D. (2021). Proposing the VetCompass clinical grading tool for heat-related illness in dogs. Scientific Reports. 11(1), 6828. DOI: https://doi.org/10.1038/s41598-021-86235-w

IPCC. (2022). IPCC Sixth Assessment Report. [online]. Available at: https://www.ipcc.ch/report/ar6/wg2/resources/spm-headline-statements [Accessed: May 2022].

Knowler, S.P., Gillstedt, L., Mitchell, T.J., Jovanovik, J., Volk, H.A. & Rusbridge, C. (2019). Pilot study of head conformation changes over time in the Cavalier King Charles spaniel breed. Veterinary Record. 184(4), 122. DOI: https://doi.org/10.1136/vr.105135

Lilja-Maula, L., Lappalainen, A., Hyytiäinen, H., Kuusela, E., Kaimio, M., Schildt, K., Mölsä, S., Morelius, M. & Rajamäki, M. (2017). Comparison of submaximal exercise test results and severity of brachycephalic obstructive airway syndrome in English bulldogs. The Veterinary Journal. 219, 22–26. DOI: https://doi.org/10.1016/j.tvjl.2016.11.019

O’Neill, D., Baral, L., Church, D., Brodbelt, D. & Packer, R. (2018). Demography and disorders of the French Bulldog population under primary veterinary care in the UK in 2013. Canine Genetics and Epidemiology. 5(3). DOI: https://doi.org/10.1186/s40575-018-0057-9

Packer, R., Hendricks, A., Tivers, M. & Burn, C. (2015). Impact of Facial Conformation on Canine Health: Brachycephalic Obstructive Airway Syndrome. PLoS ONE. 10(10), e0137496. DOI: https://doi.org/10.1371/journal.pone.0137496

Segev, G., Aroch, I., Savoray, M., Kass, P. H. & Bruchim, Y. (2015a). A novel severity scoring system for dogs with heatstroke. Journal of Veterinary Emergency and Critical Care. 25(2), 240–247. DOI: https://doi.org/10.1111/vec.12284

Segev, G., Daminet, S., Meyer, E., Loor, J. de, Cohen, A., Aroch, I. & Bruchim, Y. (2015b). Characterization of kidney damage using several renal biomarkers in dogs with naturally occurring heatstroke. The Veterinary Journal. 206, 231–235. DOI: https://doi.org/10.1016/j.tvjl.2015.07.004

Additional Files

Vol. 7 No. 4 (2022): The fourth issue of 2022

Section: Knowledge Summaries

Categories :  Small Animal  /  Dogs  /  Cats  /  Rabbits  /  Production Animal  /  Cattle  /  Sheep  /  Pig  /  Equine  /  Exotics  /