Objective—To identify risk factors for successful surgical
management of dogs with atlantoaxial subluxation
Animals—46 dogs managed surgically for AAS.
Procedure—Age at onset of clinical abnormalities,
duration of clinical abnormalities prior to surgery,
radiographic appearance of the dens, type (dorsal or
ventral procedure) and number (1 or 2) of surgeries
performed, grade of postoperative atlantoaxial joint
reduction, and neurologic status prior to surgery (preoperative),
when dogs were discharged from the hospital
(postoperative), and during a follow-up evaluation
(final) were obtained from the dogs' medical records.
Risk factors for surgical success and degree of neurologic
improvement were identified and analyzed for
Results—Age at onset of clinical abnormalities ≤ 24
months was significantly associated with greater
odds of a successful first surgery and final outcome
and a lower postoperative neurologic grade. Duration
of clinical abnormalities ≤ 10 months was significantly
associated with greater odds of a successful final
outcome and a lower final neurologic grade. A preoperative
neurologic grade of 1 or 2 was significantly
associated with a lower final neurologic grade.
Potential risk factors that did not affect odds of a successful
outcome included type of surgery performed,
grade of atlantoaxial joint reduction, radiographic
appearance of the dens, or need for a second surgery.
Conclusions and Clinical Relevance—Age at onset
of clinical abnormalities, duration of clinical abnormalities
prior to surgery, and preoperative neurologic status
are risk factors for success of surgical management
of AAS in dogs. (J Am Vet Med Assoc 2000;
Objective—To determine whether hyperbaric oxygen
treatment (HBOT) would affect incorporation of an
autogenous cancellous bone graft in diaphyseal ulnar
defects in cats.
Animals—12 mature cats.
Procedure—Bilateral nonunion diaphyseal ulnar
defects were created in each cat. An autogenous
cancellous bone graft was implanted in 1 ulnar
defect in each cat, with the contralateral ulnar
defect serving as a nongrafted specimen. Six cats
were treated by use of hyperbaric oxygen at 2
atmospheres absolute for 90 minutes once daily for
14 days, and 6 cats were not treated (control
group). Bone labeling was performed, using fluorochrome
markers. Cats were euthanatized 5
weeks after implanting, and barium sulfate was
infused to evaluate vascularization of grafts. Ulnas
were evaluated by use of radiography, microangiography,
histologic examination, and histomorphometric
Results—Radiographic scores did not differ
between treatment groups. Microangiographic
appearance of grafted defects was similar between
groups, with all having adequate vascularization.
Differences were not observed between treated
and nontreated groups in the overall histologic
appearance of decalcified samples of tissue in grafted
defects. Mean distance between fluorescent
labels was significantly greater in cats given HBOT
than in nontreated cats. Median percentage of bone
formation in grafted defects was significantly
greater in cats given HBOT.
Conclusions—Hyperbaric oxygen treatment
increased the distance between fluorescent labels
and percentage of bone formation when incorporating
autogenous cancellous bone grafts in induced
nonunion diaphyseal ulnar defects in cats, but HBOT
did not affect revascularization, radiographic appearance,
or qualitative histologic appearance of the
grafts. (Am J Vet Res 2000;61:691–698)
OBJECTIVE To determine effects of prosthetic laryngoplasty on return to racing, performance index, and career longevity in racing Quarter Horses with recurrent laryngeal neuropathy (RLN) and to evaluate performance variables for horses with RLN undergoing prosthetic laryngoplasty, compared with a control horse population.
DESIGN Multicenter, retrospective cohort study.
ANIMALS 162 racing Quarter Horses with RLN treated with prosthetic laryngoplasty (case horses) and 324 racing Quarter Horse without RLN (control horses).
PROCEDURES Medical and race records of case and control horses examined at 5 referral centers between January 2000 and December 2015 were reviewed retrospectively. Two control horses were matched with each case horse. Return to racing, earnings, number of racing starts, performance index, and career longevity were evaluated.
RESULTS The odds of returning to racing did not differ significantly between case and control horses but decreased with increasing age. Neither racing starts nor career longevity were affected by prosthetic laryngoplasty or by RLN grade. In fact, horses undergoing laryngoplasty for treatment of RLN and horses with the lowest RLN grade before surgery had higher performance indices after the surgery, compared with indices for control horses.
CONCLUSIONS AND CLINICAL RELEVANCE The faster speeds and shorter distances raced with Quarter Horses could alter how RLN impacts respiratory variables and performance in Quarter Horses, compared with other racehorse breeds. Further study is needed to understand the impacts of RLN and surgical treatments for RLN in racing Quarter Horses.