{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T20:25:06Z","timestamp":1789590306345,"version":"build-2803163510"},"reference-count":19,"publisher":"American Veterinary Medical Association (AVMA)","issue":"12","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["ajvr"],"published-print":{"date-parts":[[2017,12]]},"abstract":"<jats:title>Abstract<\/jats:title>\n<jats:p><jats:bold>OBJECTIVE<\/jats:bold> To evaluate and compare morphological characteristics of the dens in atlantoaxial instability (AAI)-predisposed toy-breed dogs (TBDs) with and without AAI and non\u2013AAI-predisposed healthy Beagles.<\/jats:p>\n<jats:p><jats:bold>ANIMALS<\/jats:bold> 80 AAI-affected and 40 nonaffected TBDs and 40 Beagles.<\/jats:p>\n<jats:p><jats:bold>PROCEDURES<\/jats:bold> Each dog underwent CT examination of the cervical vertebral column. On median 3-D multiplanar reconstruction images, the dens angle (DA) was measured as were the lengths of the dens and the body of the axis; the dens-to-axis length ratio (ratio of the dens length to the axis body length [DALR]) was calculated. Data were compared among dog groups.<\/jats:p>\n<jats:p><jats:bold>RESULTS<\/jats:bold> The DALR in nonaffected TBDs and Beagles did not differ significantly. The mean DALR for AAI-affected TBDs was significantly lower than that for nonaffected TBDs. The mean DA of AAI-affected TBDs was significantly greater than that of Beagles and nonaffected TBDs.<\/jats:p>\n<jats:p><jats:bold>CONCLUSIONS AND CLINICAL RELEVANCE<\/jats:bold> Results indicated that a low DALR might be associated with a high probability of dens abnormalities in TBDs. Additionally, dens length in AAI-affected TBDs appeared to be smaller than that in non\u2013AAI-affected TBDs, given the low DALR in AAI-affected TBDs. Further investigations to determine reference ranges of the DA and DALR and the potential usefulness of those variables as diagnostic markers for AAI in TBDs are warranted.<\/jats:p>","DOI":"10.2460\/ajvr.78.12.1400","type":"journal-article","created":{"date-parts":[[2017,11,28]],"date-time":"2017-11-28T14:29:50Z","timestamp":1511879390000},"page":"1400-1405","source":"Crossref","is-referenced-by-count":12,"title":["Evaluation of the dens-to-axis length ratio and dens angle in toy-breed dogs with and without atlantoaxial instability and in healthy Beagles"],"prefix":"10.2460","volume":"78","author":[{"given":"Fumitaka","family":"Takahashi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takaharu","family":"Hakozaki","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobuo","family":"Kanno","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasuji","family":"Harada","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shinya","family":"Yamaguchi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yasushi","family":"Hara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1272","reference":[{"key":"ref1","series-title":"J Small Anim Pract","first-page":"37","article-title":"Atlanto-axial subluxation in the dog: a review of 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syndrome: association with clinical signs and syringomyelia in mature Cavalier King Charles Spaniels","volume":"29","author":"Cerda-Gonzalez","year":"2015"},{"key":"ref17","series-title":"Am J Roentgenol Radium Ther Nucl Med","first-page":"23","article-title":"Occipitalization of the atlas","volume":"70","author":"McRae","year":"1953"},{"key":"ref18","series-title":"Vet Radiol Ultrasound","doi-asserted-by":"publisher","first-page":"596","DOI":"10.1111\/j.1740-8261.2010.01711.x","article-title":"Computed tomography variations in morphology of the canine atlas in dogs with and without atlantoaxial subluxation","volume":"51","author":"Parry","year":"2010"},{"key":"ref19","series-title":"J Am Anim Hosp Assoc","first-page":"663","article-title":"Odontoidectomy in a dog","volume":"11","author":"Swaim","year":"1975"}],"container-title":["American Journal of Veterinary 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