Peer-reviewed veterinary case report
Atlas and axis bone differences in Maltese dogs with neck instability
By Kim, Dongwook et al.·Published in In vivo (Athens, Greece)·2022·Veterinary Teaching Hospital, South Korea·View original on PubMed →
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Original publication title: Radiographic Evaluation of Atlas and Axis Anomalies in Toy Breed Dogs With and Without Atlantoaxial Subluxation.
- Species:
- dog
Plain-English summary
A group of Maltese dogs with atlantoaxial subluxation (AAS), a condition where the first two neck vertebrae are misaligned, showed a higher rate of bone abnormalities compared to those without AAS. In this study, 45 Maltese dogs were examined using CT scans, revealing that 56% of those with AAS had incomplete ossification (a lack of proper bone formation) of the atlas, while only 19% of the healthy dogs had this issue. Additionally, 78% of the dogs with AAS had dens anomalies, which are irregularities in the second vertebra. Understanding these bone issues is crucial for veterinarians when planning surgery for dogs with AAS to ensure better outcomes.
People also search for: Maltese dog neck problems · atlantoaxial subluxation treatment · dog bone abnormalities · toy breed dog spine issues · dog surgery for AAS
Abstract
BACKGROUND/AIM: Atlantoaxial subluxation (AAS) is generally a congenital condition that mainly affects toy breed dogs. Previous studies in several toy breed dogs revealed that dogs with AAS had a relatively high proportion of incomplete ossification (IO) of the atlas and dens anomalies compared to dogs without AAS. These anatomical characteristics may be important in surgical decision-making. Thus, the present study evaluated morphological differences in the atlas and axis between Maltese dogs with and without AAS. MATERIALS AND METHODS: The medical records of Maltese dogs with and without AAS from 2015 to 2020 were analyzed. Abnormalities of the atlas and axis were evaluated using computed tomography (CT). RESULTS: A total of 45 dogs were reviewed. Maltese dogs with AAS revealed a higher ratio of IO of the atlas (56%) than non-affected dogs (19%). Dens anomalies were identified in 78% of the dogs with AAS and in 26% of non-affected dogs. The shape of the atlas has been identified as thin, solid compact bone in Maltese dogs. Dogs that revealed IO of the dorsal arch of the atlas showed significantly lower CT values (in Hounsfield units) than dogs without IO. The CT values of the midline of the dorsal arch were significantly lower than those of the outer surrounding region. Dens hypoplasia was defined by measuring the dens-to-axis length ratio according to a previous study. A significantly lower ratio was identified in dogs with AAS than in non-affected dogs. CONCLUSION: The incidence ratio of abnormalities of the atlas and axis in Maltese dogs with AAS was similar to that of previous studies. The dorsal arch of the atlas is composed of thin cortical bone with a vulnerable midline region. As dogs with AAS are more likely to be afflicted with abnormalities in the atlas and axis, considering these morphological features is important when planning the surgical stabilization of AAS.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/36309373/