Neck pain but not neurologic disease occurs more frequently in horses with transposition of the ventral lamina from C6 to C7.

OBJECTIVE: To determine reasons for horses to have neck radiographs performed, the incidence of transposition of the ventral lamina of C6 onto C7 (TC67), and the final diagnoses for all horses. Our hypotheses were to find a similar incidence of TC67, as has been previously reported, and an increased incidence of neck pain and dysfunction in horses with TC67. ANIMALS: 135 horses. METHODS: Retrospective observational study. Medical records of 135 horses with cervical vertebral column radiographs between 2020 and 2022 were assessed. Patient signalment, reasons for radiographs, radiographic findings, and diagnoses were analyzed. The Shapiro-Wilk test was used for normality determination. Nonparametric tests were used to analyze data. RESULTS: 20% of horses were diagnosed with TC67. Significantly more horses with TC67 were warmblood horses (63%); TC67 was found in 28% of warmblood horses. There was no significant difference in signalment or whether horses were in work between the groups, although significantly more horses with TC67 performed in English disciplines (71%). No differences in reasons for examination or final diagnoses of neurologic disease, cervical orthopedic disease, or lameness were present between groups. In horses with neck pain, TC67 was significantly more common (31%) than in horses without (18%). CLINICAL RELEVANCE: Our results indicated that TC67 occurs more in warmblood horses. In the small group of horses with neck pain reported, TC67 was more commonly seen than in those without. Given the complexity of this region and the paucity of studies exploring neck pain and neck biomechanics, we suggest the need for standardized prospective studies.

Fibrosarcoma over the tarsal groove of a 14-month-old Quarter horse.

A 14-month-old male Quarter horse was presented for evaluation of a grade 3 out of 5 (grade 0 = sound; grade 5 = non-weight bearing) right rear lameness. A firm, 8 x 16 cm mass was palpable at the caudal medial aspect of the distal tibia and proximal tarsal region of the right hind limb. A percutaneous needle aspirate contained mesenchymal cells that were moderate to large in size with single, oblong nuclei. Differential diagnoses included fibrous hyperplasia, fibroma, or well-differentiated fibrosarcoma. Excisional biopsy for both definitive diagnosis and treatment was offered and selected by the owner. A fibrosarcoma was confirmed by histological examination of the mass. One and a half years after resection signs of lameness or evidence of regrowth of the mass were not evident.

Arthroscopic debridement of subchondral bone cysts in the distal phalanx of 11 horses (1994-2000).

REASONS FOR PERFORMING STUDY: Historically, there has been a consensus that conservative management of subchondral cystic lesions of the distal phalanx carries a poor prognosis. Surgical management has been advocated; however, there are no reports documenting its routine use and successful surgical treatment. OBJECTIVES: To describe arthroscopically-guided curettage of distal phalangeal subchondral cystic lesions (SCLs) and report the qualitative and quantitative results in 11 affected horses age 16-33 months. METHODS: Medical records of horses with previously treated lameness resulting from SCLs of the third phalanx were reviewed. Arthroscopic debridement of the SCLs was described. Follow-up information was obtained from race records and telephone contact with owners and trainers. The sign-rank test was used to compare performance of operated racehorses to that of unoperated siblings. RESULTS: Ten of the 11 horses (91%) in the study returned to athletic soundness after surgical treatment and had performance records similar to their siblings. CONCLUSIONS: Data show that arthroscopic debridement of distal phalangeal SCLs is a viable treatment for affected horses age 16-33 months and can result in a successful return to intended athletic performance. No horses younger than 16 months or older than 33 months were treated and results in horses younger or older than this group may vary in success. POTENTIAL RELEVANCE: The description of treatment and approach used for arthroscopic curettage will increase awareness of this option and increase treatment options for this condition.