Objective—To reexamine (via immunohistochemical techniques) canine tissue samples that had been previously classified as gastrointestinal leiomyosarcomas (GILMSs), identify and differentiate gastrointestinal stromal tumors (GISTs) from GILMSs, and compare the biological behavior and clinical course of GISTs and GILMSs in dogs.
Design—Retrospective case series.
Procedures—Medical records of 42 dogs for which a histologic diagnosis of GILMS was confirmed were reviewed for signalment, clinical signs, physical examination findings, results of initial diagnostic tests, surgical findings, adjunctive treatment, location of the tumor, completeness of resection, and outcome after surgery. Archived tumor tissue specimens from each dog were restained via immunohistochemical techniques to differentiate tumor types. Long-term follow-up information was obtained from the medical record or through telephone interviews with owners and referring veterinarians.
Results—On the basis of immunohistochemical findings, 28 of 42 tumors were reclassified as GISTs and 4 were reclassified as undifferentiated sarcomas; 10 tumors were GILMSs. In dogs, GISTs developed more frequently in the cecum and large intestine and GILMSs developed more frequently in the stomach and small intestine. Median survival times for dogs with GISTs and GILMSs were 11.6 and 7.8 months, respectively; if only dogs surviving the perioperative period were considered, median survival times were 37.4 and 7.8 months, respectively. These differences, however, were not significant.
Conclusions and Clinical Relevance—In dogs, many previously diagnosed GILMSs should be reclassified as GISTs on the basis of results of immunohistochemical staining. The biological behavior of these tumors appears to be different.
Objective—To assess risk factors for recurrence of
clinical signs associated with thoracolumbar intervertebral
disk disease (IVDD) in dogs that had decompressive
laminectomy without attempted prophylactic
treatment of other disk spaces.
Procedure—Medical records of dogs that had
decompressive laminectomy without prophylactic
fenestration for a first episode of IVDD and were available
for follow-up were reviewed. Information on 7
clinical and 8 radiographic potential risk factors were
Results—Clinical signs associated with recurrence of
IVDD developed in 44 (19.2%) dogs. Ninety-six percent
of recurrences developed within 3 years after
surgery. Recurrence developed in 25% of Dachshunds
and 15% of dogs of other breeds combined. Number
of opacified disks was a significant risk factor for recurrence.
Risk increased with number of opacified disks
in an almost linear manner; each opacified disk
increased risk by 1.4 times. Dogs with 5 or 6 opacified
disks at the time of first surgery had a recurrence rate
Conclusions and Clinical Relevance—When all likely
episodes of recurrence are considered and a long
follow-up period is achieved, true rate of recurrence of
IVDD appears to be higher than in many previous
reports. Dogs with multiple opacified disks at the
time of first surgery should be considered a high-risk
subpopulation. (J Am Vet Med Assoc 2004;225: