{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T09:04:37Z","timestamp":1790845477562,"version":"4.1.0"},"reference-count":21,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Selecting the correct endotracheal tube (ETT) size is critical for safe anesthesia in dogs. Current ETT size recommendations are largely based on body weight (BW), although some breeds, particularly brachycephalic dogs, may receive smaller ETTs than predicted from BW alone. This two-part retrospective study was performed to evaluate the effect of breed on ETT selection. In Part 1, computed tomography (CT)-measured tracheal diameters (TD) were compared among five small dog breeds weighing 4\u20135 kg and having a body condition score of 5\/9. In Part 2, an expanded clinical cohort of 512 dogs from eight breeds was used to compare clinically selected ETT sizes with BW-based predictions. Statistical models assessed whether breed influenced clinically used ETT sizes after accounting for body mass using the cube root of BW. CT measurements revealed that TD differed significantly among breeds within a similar body-weight range. In the Part 2 clinical cohort, clinically selected ETT size was significantly associated with breed, the cube root of BW, and their interaction. Shih Tzus, French Bulldogs, Pekingese, and Boston Terriers had clinically selected ETT sizes smaller than BW-based predicted sizes, with a median discrepancy of approximately 0.5 mm in Shih Tzus and approximately 1.0 mm in French Bulldogs, Pekingese, and Boston Terriers. These findings suggest that the magnitude of discrepancy from BW-based predictions varies among brachycephalic breeds, indicating that breed may warrant consideration when estimating ETT size.<\/jats:p>","DOI":"10.3390\/ani16193089","type":"journal-article","created":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T08:19:08Z","timestamp":1790842748000},"page":"3089","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Influence of Breed on Tracheal Diameter and Endotracheal Tube Size Selection in Dogs: A Retrospective Analysis"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-0390-712X","authenticated-orcid":false,"given":"Jieun","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea"},{"name":"Ian Animal Diagnostic Center, Seoul 06258, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-8079-2332","authenticated-orcid":false,"given":"In","family":"Lee","sequence":"additional","affiliation":[{"name":"Ian Animal Diagnostic Center, Seoul 06258, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5431-3254","authenticated-orcid":false,"given":"Won-gyun","family":"Son","sequence":"additional","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0712-7165","authenticated-orcid":false,"given":"Inhyung","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4962-9830","authenticated-orcid":false,"given":"Hyunseok","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Veterinary Anesthesia and Pain Medicine, College of Veterinary Medicine, Konkuk University, Seoul 05029, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,10,1]]},"reference":[{"key":"ref_1","unstructured":"Creedon, J.M.B., and Davis, H. (2023). Tracheal intubation. Advanced Monitoring and Procedures for Small Animal Emergency and Critical Care, Wiley-Blackwell. [2nd ed.]."},{"key":"ref_2","unstructured":"Thomas, J.A., and Lerche, P. (2017). Canine and feline anesthesia. Anesthesia and Analgesia for Veterinary Technicians, Elsevier. [5th ed.]."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Grimm, K.A., Lamont, L.A., Tranquilli, W.J., Greene, S.A., and Robertson, S.A. (2024). Anesthesia equipment. Lumb & Jones\u2019 Veterinary Anesthesia and Analgesia, Wiley-Blackwell. [6th ed.].","DOI":"10.1002\/9781119830306"},{"key":"ref_4","unstructured":"Thomas, J.A., and Lerche, P. (2011). Canine and feline anesthesia. Anesthesia and Analgesia for Veterinary Technicians, Elsevier. [4th ed.]."},{"key":"ref_5","unstructured":"Muir, W.W., Hubbell, J.A.E., and Bednarski, R.M. (2012). Equipment for tracheal intubation and securing the airway. Handbook of Veterinary Anesthesia, Elsevier. [5th ed.]."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"45357","DOI":"10.1038\/srep45357","article-title":"A canine model of tracheal stenosis induced by cuffed endotracheal intubation","volume":"7","author":"Su","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"236","DOI":"10.5326\/0440236","article-title":"Evaluation of two methods of endotracheal tube selection in dogs","volume":"44","author":"Lish","year":"2008","journal-title":"J. Am. Anim. Hosp. Assoc."},{"key":"ref_8","unstructured":"Duke-Novakovski, T., de Vries, M., and Seymour, C. (2016). Breathing systems and ancillary equipment. BSAVA Manual of Canine and Feline Anaesthesia and Analgesia, BSAVA. [3rd ed.]."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.vaa.2017.10.002","article-title":"Selection of appropriate endotracheal tube size using thoracic radiography in Beagle dogs","volume":"45","author":"Shin","year":"2018","journal-title":"Vet. Anaesth. Analg."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1136\/vr.105065","article-title":"Development of a clinical tool to aid endotracheal tube size selection in dogs","volume":"186","author":"Haider","year":"2020","journal-title":"Vet. Rec."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"100635","DOI":"10.1016\/j.tcam.2022.100635","article-title":"Laryngeal paralysis following endotracheal intubation in a dog: A case report","volume":"48","author":"Camargo","year":"2022","journal-title":"Top. Companion Anim. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1177\/194336548202700406","article-title":"Complications of endotracheal intubation, tracheostomy, and artificial airways","volume":"27","author":"Stauffer","year":"1982","journal-title":"Respir. Care"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"114","DOI":"10.1111\/j.1532-950X.2014.12227.x","article-title":"Comparison of radiography and computed tomography for determining tracheal diameter and length in dogs","volume":"44","author":"Montgomery","year":"2015","journal-title":"Vet. Surg."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1111\/vru.12344","article-title":"Comparison of fluoroscopy and computed tomography for tracheal lumen diameter measurement and determination of intraluminal stent size in healthy dogs","volume":"57","author":"Williams","year":"2016","journal-title":"Vet. Radiol. Ultrasound"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/0034-5687(77)90091-3","article-title":"Postnatal growth of the dog\u2019s bronchial tree","volume":"29","author":"Horsfield","year":"1977","journal-title":"Respir. Physiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/0034-5687(78)90070-1","article-title":"Diameter, length and branching angles of the upper airways in the dog lung","volume":"33","author":"Woldehiwot","year":"1978","journal-title":"Respir. Physiol."},{"key":"ref_17","first-page":"848","article-title":"Investigating novel anatomical predictors for endotracheal tube selection in dogs","volume":"60","author":"Tong","year":"2019","journal-title":"Can. Vet. J."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"634","DOI":"10.1111\/vru.12526","article-title":"Assessment of computed tomography-derived cricoid cartilage and tracheal dimensions to evaluate the degree of cricoid narrowing in brachycephalic dogs","volume":"58","author":"Rutherford","year":"2017","journal-title":"Vet. Radiol. Ultrasound"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Mostafa, A.A., McCutcheon, K., and Berry, C.R. (2024). Comparison of tracheal diameter in non-brachycephalic versus brachycephalic dogs using manubrium and thoracic inlet tracheal indexes. Front. Vet. Sci., 11.","DOI":"10.3389\/fvets.2024.1454930"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"5683","DOI":"10.21897\/rmvz.928","article-title":"Effectiveness of predictive factors of canine intubation","volume":"22","author":"Molina","year":"2017","journal-title":"Rev. MVZ C\u00f3rdoba"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1292\/jvms.20-0446","article-title":"Unrecognized difficult airway management during anesthesia in two brachycephalic dogs with narrow cricoid cartilage","volume":"83","author":"Tamura","year":"2021","journal-title":"J. Vet. Med. Sci."}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/19\/3089\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T08:44:59Z","timestamp":1790844299000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/19\/3089"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,1]]},"references-count":21,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["ani16193089"],"URL":"https:\/\/doi.org\/10.3390\/ani16193089","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,1]]}}}