Objective—To assess validity and reliability for a visual analogue scale (VAS) used by owners to measure chronic pain in their osteoarthritic dogs.
Sample—68, 61, and 34 owners who completed a questionnaire.
Procedures—Owners answered questionnaires at 5 time points. Criterion validity of the VAS was evaluated for all dogs in the intended-to-treat population by correlating scores for the VAS with scores for the validated Helsinki Chronic Pain Index (HCPI) and a relative quality-of-life scale. Intraclass correlation was used to assess repeatability of the pain VAS at 2 baseline evaluations. To determine sensitivity to change and face validity of the VAS, 2 blinded, randomized control groups (17 dogs receiving carprofen and 17 receiving a placebo) were analyzed over time.
Results—Significant correlations existed between the VAS score and the quality-of-life scale and HCPI scores. Intraclass coefficient (r = 0.72; 95% confidence interval, 0.57 to 0.82) for the VAS indicated good repeatability. In the carprofen and placebo groups, there was poor correlation between the 2 pain evaluation methods (VAS and HCPI items) at the baseline evaluation, but the correlation improved in the carprofen group over time. No correlation was detected for the placebo group over time.
Conclusions and Clinical Relevance—Although valid and reliable, the pain VAS was a poor tool for untrained owners because of poor face validity (ie, owners could not recognize their dogs' behavior as signs of pain). Only after owners had seen pain diminish and then return (after starting and discontinuing NSAID use) did the VAS have face validity.
Objective—To determine whether age, breed, sex,
weight, or distraction index (DI) was associated with
the risk that dogs of 4 common breeds (German
Shepherd Dog, Golden Retriever, Labrador Retriever,
Rottweiler) would have radiographic evidence of
degenerative joint disease (DJD) associated with hip
Design—Cross-sectional prevalence study.
Procedure—Hips of dogs were evaluated radiographically
by use of the ventrodorsal hip-extended view, the compression view, and the distraction view. The ventrodorsal hip-extended view was examined to determine whether dogs had DJD. For each breed, a multiple logistic regression model incorporating age, sex, weight, and DI was created. For each breed, disease-susceptibility curves were produced, using all
dogs, regardless of age, and dogs grouped on the basis of age.
Results—Weight and DI were significant risk factors
for DJD in all breeds. For German Shepherd Dogs, the
risk of having DJD was 4.95 times the risk for dogs of
the other 3 breeds combined. In all breeds, the probability
of having DJD increased with age.
Conclusions and Clinical Relevance—Results indicated
that the probability of having hip DJD increased
with hip joint laxity as measured by use of DI. This
association was breed-specific, indicating that breedspecific
information on disease susceptibility should be
incorporated when making breeding decisions and
when deciding on possible surgical treatment of hip
dysplasia. (J Am Vet Med Assoc 2001;219:1719–1724)
Objective—To determine which imaging modality
best determines the microscopic extent of primary
appendicular osteosarcoma in amputated limbs in
Animals—10 dogs with appendicular osteosarcoma.
Procedure—10 dogs with appendicular osteosarcoma
that did not receive neoadjuvent chemotherapy
were treated by use of limb amputation. Amputated
limbs were imaged by use of radiography, computed
tomography (CT), and magnetic resonance imaging
(MRI) and examined microscopically to determine
longitudinal extent of neoplastic cell involvement and
length of associated intramedullary fibrosis. Changes
detected by use of the various imaging studies were
compared with the actual tumor length determined
microscopically. Data were analyzed to determine
which imaging technique most closely predicted
Results—Measurements obtained by use of craniocaudal
radiographic views were most accurate at predicting
tumor length but underestimated tumor length
substantially in 1 limb and slightly in another limb.
Measurements made by use of CT were most accurate
at predicting tumor length when intramedullary
fibrosis was taken into account but underestimated
tumor length in 1 limb. Measurements made by use of
MRI were least accurate but did not underestimate
tumor length in any of the limbs.
Conclusions and Clinical Relevance—Although
radiography is used in diagnosis of osteosarcoma in
dogs, additional imaging studies to confirm the
extent of neoplasia prior to limb-sparing ostectomy
may be beneficial. Underestimation of tumor length
would be associated with higher incidence of incomplete
excision and local tumor recurrence. (J Am Vet
Med Assoc 2002;220:1171–1176)
Objective—To determine matrix metalloproteinase
(MMP) activity in synovial fluid (SF) obtained from the
joints of dogs with degenerative joint disease (DJD)
secondary to various underlying conditions.
Sample Population—35 samples of SF obtained
from 18 clinically normal (control) dogs and 34 samples
of SF obtained from 17 dogs with DJD; dogs
with DJD were from 2 populations (client-owned
dogs and research dogs that had DJD secondary to
the lysosomal storage disease mucopolysaccharidosis
Procedure—MMP activity in samples of SF was
semiquantitatively examined by use of gelatin or
casein zymography. Western blot analysis was performed
by use of antibodies for MMP-2 and MMP-9.
In addition, in situ MMP activity was observed in sections
of synovial membrane obtained from healthy
and osteoarthritic joints.
Results—Samples of SF from osteoarthritic joints
had higher MMP-2 activity and dramatically increased
MMP-9 activity, compared with values for healthy
joints. Substrate-overlay analyses indicated minimal
gelatin-degrading activity in synoviocytes obtained
from control dogs, whereas greater activity was seen
in osteoarthritic synoviocytes, with additional activity
in the underlying tissue.
Conclusions and Clinical Relevance—Higher
MMP-2 activity and dramatic increases in MMP-9
activity were associated with the osteoarthritic
state, even though MMP-2 activity was detected
in healthy joints. This study expands information
on MMP production in SF of osteoarthritic joints in
other species and documents the similarity of
MMP activity patterns regardless of the cause of
DJD. (Am J Vet Res 2003;64:1225–1233)
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:
Objective—To determine whether use of electrostimuluated acupuncture (ESA) would result in significant improvements in ground reaction forces and lameness scores in dogs with chronic elbow joint osteoarthritis secondary to elbow joint dysplasia.
Animals—9 dogs with chronic forelimb lameness and radiographic evidence of elbow joint osteoarthritis.
Procedures—All dogs had a 3-week control acclimation period during which gait analysis was performed weekly. Dogs then received ESA once weekly for 3 weeks followed by a sham treatment once weekly for 3 weeks or received the sham treatment followed by ESA. Gait analysis was repeated prior to each treatment, and owners were asked to provide pain scores by use of a visual analog scale method.
Results—Treatment (control, acupuncture, or sham) did not have a significant effect on ground reaction forces for any limb. Owners of 8 of the 9 dogs were able to correctly guess the time period when ESA was delivered.
Conclusions and Clinical Relevance—Results suggested that ESA did not have any significant effects on severity of lameness, as determined by measurement of ground reaction forces, or severity of pain, as determined by visual analog scale pain scores, in dogs with chronic elbow joint osteoarthritis secondary to elbow joint dysplasia.
Objective—To determine prevalence of the contralateral radiographic infrapatellar fat pad sign and contralateral radiographic degenerative sign (degenerative changes) and evaluate both signs as risk factors for subsequent contralateral cranial cruciate ligament (CrCL) rupture in dogs with unilateral CrCL rupture.
Design—Retrospective cohort study.
Animals—96 dogs with unilateral CrCL rupture and 22 dogs with bilateral CrCL rupture.
Procedures—Dogs with unilateral CrCL rupture were classified as having normal (n = 84) or abnormal (12) contralateral stifle joints on the basis of joint palpation. Associations between potential predictive variables and rates of subsequent contralateral CrCL rupture were evaluated.
Results—Of the 84 dogs with unilateral CrCL rupture in which the contralateral stifle joint was palpably normal, 29 (34.5%) had a contralateral fat pad sign and 31 (36.9%) had a degenerative sign. All dogs with unilateral CrCL rupture in which the contralateral stifle joint was palpably abnormal had a contralateral fat pad sign and degenerative sign. The contralateral fat pad sign was the most important risk factor for subsequent rupture of the contralateral CrCL. For dogs with unilateral CrCL rupture and palpably normal contralateral stifle joint with and without a contralateral fat pad sign, median time to subsequent rupture was 421 and 1,688 days, respectively, and the 3-year probability of subsequent rupture was 85.3% and 24.9%, respectively.
Conclusions and Clinical Relevance—Bilateral stifle joint radiography should be performed for all dogs with CrCL rupture. Bilateral stifle joint arthroscopy should be considered for dogs with a contralateral fat pad sign.
OBJECTIVE To describe the torsional and axial compressive properties of tibiotarsal bones of red-tailed hawks (Buteo jamaicensis).
SAMPLE 16 cadaveric tibiotarsal bones from 8 red-tailed hawks.
PROCEDURES 1 tibiotarsal bone from each bird was randomly assigned to be tested in torsion, and the contralateral bone was tested in axial compression. Intact bones were monotonically loaded in either torsion (n = 8) or axial compression (8) to failure. Mechanical variables were derived from load-deformation curves. Fracture configurations were described. Effects of sex, limb side, and bone dimensions on mechanical properties were assessed with a mixed-model ANOVA. Correlations between equivalent torsional and compressive properties were determined.
RESULTS Limb side and bone dimensions were not associated with any mechanical property. During compression tests, mean ultimate cumulative energy and postyield energy for female bones were significantly greater than those for male bones. All 8 bones developed a spiral diaphyseal fracture and a metaphyseal fissure or fracture during torsional tests. During compression tests, all bones developed a crushed metaphysis and a fissure or comminuted fracture of the diaphysis. Positive correlations were apparent between most yield and ultimate torsional and compressive properties.
CONCLUSIONS AND CLINICAL RELEVANCE The torsional and axial compressive properties of tibiotarsal bones described in this study can be used as a reference for investigations into fixation methods for tibiotarsal fractures in red-tailed hawks. Although the comminuted and spiral diaphyseal fractures induced in this study were consistent with those observed in clinical practice, the metaphyseal disruption observed was not and warrants further research.
To compare the torsional mechanical properties of 2 external skeletal fixators (ESFs) placed with 2 intramedullary pin (IP) and transfixation pin (TP) size combinations in a model of raptor tibiotarsal bone fracture.
24 ESF-synthetic tibiotarsal bone model (polyoxymethylene) constructs.
Synthetic bone models were fabricated with an 8-mm (simulated fracture) gap. Four types of ESF-synthetic bone model constructs (6/group) were tested: a FESSA with a 1.6-mm IP and 1.6-mm TPs, a FESSA with a 2.0-mm IP and 1.1-mm TPs, an acrylic connecting bar with a 1.6-mm IP and 1.6-mm TPs, and an acrylic connecting bar with a 2.0-mm IP and 1.1-mm TPs. Models were rotated in torsion (5°/s) to failure or the machine angle limit (80°). Mechanical variables at yield and at failure were determined from load deformation curves. Effects of overall construct type, connecting bar type, and IP and TP size combination on mechanical properties were assessed with mixed-model ANOVAs.
Both FESSA constructs had significantly greater median stiffness and median torque at yield than both acrylic bar constructs; FESSA constructs with a 1.6-mm IP and 1.6-mm TPs had greatest stiffness of all tested constructs and lowest gap strain at yield. No FESSA constructs failed during testing; 7 of 12 acrylic bar constructs failed by fracture of the connecting bar at the interface with a TP.
CONCLUSIONS AND CLINICAL RELEVANCE
Although acrylic bar ESFs have been successfully used in avian patients, the FESSA constructs in this study were mechanically superior to acrylic bar constructs, with greatest benefit resulting from use with the larger TP configuration.
Objective—To evaluate hip joint laxity in 10 breeds of
dogs via 2 radiographic techniques.
Animals—500 clinically normal dogs.
Procedure—Radiographs obtained via routine hip
joint evaluations performed in sedated dogs of 10
popular breeds were randomly selected from a database.
Measurements of distraction index (DI) and hipextended
index (HEI) on 1 hip joint radiograph randomly
chosen from each dog were made.
Results—Mean age of dogs was 20.7 months.
Mean HEI was 0.17 (range, 0.0 to 0.72) and mean
DI was 0.44 (range, 0.07 to 0.96). Borzois had uniformly
tight hip joints as judged by use of both
methods and were considered the gold standard by
which hip joint laxity was judged (all Borzois had DI
≤ 0.32). Overall, DI was significantly greater than
HEI. Within each breed, mean DI was always
greater than mean HEI. Significant differences were
detected among breeds for HEI; however, compared
with DI, the magnitude of differences among
breeds was less.
Conclusions and Clinical Relevance—Distraction
radiography detected the greatest range and magnitude
of passive hip laxity in the 10 breeds of dogs. The
difference in values between breeds known to have
high prevalence of canine hip dysplasia and those in
Borzois was greater for DI than for HEI. Breeds must
be evaluated individually because of inherent differences
in hip joint laxity. ( J Am Vet Med Assoc 2004;