Objective—To evaluate the possible association
between facet joint geometry and intervertebral disk
degeneration in German Shepherd Dogs.
Animals—25 German Shepherd Dogs and 11 control
dogs of similar body weight and condition.
Procedure—Facet joint angles in the caudal portion
of the lumbar region of the vertebral column (L5-S1)
were measured by use of computed tomography, and
the intervertebral discs were evaluated microscopically.
The relationship between facet joint geometry
and disk degeneration was evaluated by use of statistical
Results—German Shepherd Dogs had significantly
more facet joint tropism than control dogs, but an
association with disk degeneration was not found.
However, German Shepherd Dogs had a different
facet joint conformation, with more sagittally oriented
facet joints at L5-L6 and L6-L7 and a larger angle difference
between the lumbar and lumbosacral facet
joints, compared with control dogs.
Conclusion and Clinical Relevance—A large difference
between facet joint angles at L6-L7 and L7-S1 in
German Shepherd Dogs may be associated with the
frequent occurrence of lumbosacral disk degeneration
in this breed. (Am J Vet Res 2002;63:86f–90)
Objective—To measure concentrations of nitric oxide
metabolites (nitrite-nitrate [NOt]) in cartilage, synovial
membrane, and cranial cruciate ligament (CCL) in
dogs and evaluate associations with osteoarthritis in
dogs with CCL rupture.
Animals—46 dogs with CCL rupture and 54 control
dogs without joint disease.
Procedure—Tissue specimens for histologic examination
and explant culture were harvested during surgery
in the CCL group or immediately after euthanasia in the
control group; NOt concentrations were measured in
supernatant of explant cultures and compared among
dogs with various degrees of osteoarthritis and
between dogs with and without CCL rupture.
Results—Osteoarthritic cartilage had significantly
higher NOt concentration (1,171.6 nmol/g) than did
healthy cartilage (491.0 nmol/g); NOt concentration
was associated with severity of macroscopic and
microscopic lesions. Synovial membrane NOt concentration
did not differ between dogs with and without
CCL rupture. Ruptured CCL produced less NOt
than did intact ligaments. In control dogs, NOt concentrations
were similar for intact ligaments
(568.1 nmol/g) and articular cartilage (491.0 nmol/g).
Synthesis of NOt was inhibited substantially by coincubation
Conclusions and Clinical Relevance—Results suggest
that NOt in canine joint tissues originates from
the inducible nitric oxide synthase pathway. Nitric
oxide metabolite production in cartilage was greater
in dogs with osteoarthritis than in healthy dogs and
was associated with lesion severity, suggesting that
nitric oxide inhibitors may be considered as a treatment
for osteoarthritis. The CCL produces substantial
concentrations of NOt; the importance of this finding
is unknown. ( Am J Vet Res 2000;61:530–536)
Objective—To investigate whether volumetric
capnography indices could be used to differentiate
between horses without recurrent airway obstruction
(RAO) and horses with RAO that were in clinical
remission or that had clinically apparent RAO.
Animals—70 adult Swiss Warmblood horses (20
used for pleasure riding and 50 used for dressage or
Procedure—Horses were allocated to 4 groups on
the basis of history, clinical signs, results of
endoscopy, and cytologic findings (group 1, 21
healthy horses; group 2, 22 horses with RAO that
were in remission; group 3, 16 horses with mild RAO;
group 4, 11 horses with exacerbated RAO). Expiratory
volume and CO2 curves were recorded by use of a
computerized ultrasonic spirometer. Volumetric
capnograms were plotted, and derived indices were
Results—Dead-space volume (VD) was calculated by
use of the Bohr equation (VDBohr) and for physiologic
VD (VDphys). Ratios for VDBohr to expiratory tidal volume
(VT) and VDphys to VT as well as an index of effective
CO2 elimination were significantly different among
groups of horses. Age and use of the horses also significantly
affected volumetric capnography indices.
Conclusions and Clinical Relevance—Ratios of
VDBohr to VT and VDphys to VT as well as an index of
effective CO2 elimination were sufficiently sensitive
measures to distinguish between healthy horses and
horses with RAO in remission. To optimize the ability
of volumetric capnography indices to differentiate
among horses in heterogeneous populations, it is
important to account for effects of age and specific
use of the horses. (Am J Vet Res 2003;64:338–345)
Objective—To estimate genetic population variables
for 6 radiographic criteria of canine hip dysplasia
Animals—664 full- and half-siblings from a colony of
Procedure—Heritability estimates and genetic correlations
were calculated for 6 radiographic criteria of
CHD. Two evaluation protocols were compared: the
grade of the most severely affected hip joint and the
sum of the scores for both hip joints. The predictive
performance of estimated breeding values was also
Results—The overall prevalence of CHD (Fédération
Cynologique Internationale grades C, D, and E) was
29.6%. Median age at radiographic examination was
377 days. Heritability for the total CHD grade,
Norberg angle (NA), coverage of the femoral head
(COV), craniodorsal acetabular rim (ACR), subchondral
bone sclerosis (SUBCH), shape of the femoral head
and neck (FHN), and osteoarthritic changes at the
insertion site of the joint capsule (JC) was estimated
as follows: 0.44, 0.43, 0.46, 0.37, 0.32, 0.21, and
0.05, respectively. Heritability estimates were slightly
higher for the sum of the scores for both hip joints. If
NA and COV were included as fixed effects in the
model for the dependent variables ACR, SUBCH,
FHN, and JC , then heritability of these traits significantly
decreased (0.08 to 0.15). High scores of NA
and COV lead to a significant increase of the scores
of the remaining criteria.
Conclusions and Clinical Relevance—Canine hip
dysplasia is heritable to a moderate degree. Signs of
subluxation revealed the highest heritability estimates.
The criteria ACR, SUBCH, FHN, and JC were
strongly influenced by NA and COV. (Am J Vet Res
Objective—To characterize the mucosal IgE network
in dogs affected with inflammatory bowel disease
(IBD) and compare it with that for healthy dogs.
Animals—9 healthy dogs and 20 dogs with IBD.
Procedure—In situ hybridization of mRNA specific
for IgE and interleukin 4 (IL-4) and immunohistochemical
analysis for IgE protein and 2 markers of
mast cells (ie, tryptase and chymase) were performed
on tissue sections obtained from the gastrointestinal
(GI) tract and lymph nodes of dogs.
Results—Dogs with IBD had significantly more cells
positive for IgE protein and more mast cells in the GI
mucosa than healthy dogs. Despite this significant
increase in number of cells positive for IgE, cells positive
for IgE mRNA were rarely detected in the GI
mucosa; most cells positive for IgE mRNA were
found in mesenteric lymph nodes. Signal pattern of
IL-4 mRNA was similar to that of IgE mRNA.
Conclusions and Clinical Relevance—The increased
numbers of cells positive for IgE and mast cells in
dogs with IBD suggest hypersensitivity such as
hypersensitivity to bacterial or dietary-derived antigens
in the intestinal lumen. Future studies need to
elucidate whether this represents a cause of inflammation
or is a result of the inflammatory process of
IBD. (Am J Vet Res 2001;62:211–216)
Objective—To evaluate the 3-dimensional motion
pattern including main and coupled motions of the
caudal lumbar and lumbosacral portions of the vertebral
column of dogs.
Animals—Vertebral columns of 9 German Shepherd
Dogs (GSDs) and 16 dogs of other breeds with similar
body weights and body conditions .
Procedure—Main and coupled motions of the caudal
lumbar and lumbosacral portions of the vertebral column
(L4 to S1) were determined by use of a testing
apparatus that permitted precise application of known
pure moments to the vertebral column. Motion was
compared between GSDs and dogs of other breeds.
Results—All specimens had a similar motion pattern
consisting of main motion and a certain amount of
coupled motion including translation. Vertebral
columns of GSDs had significantly less main motion
in all directions than that of dogs of other breeds.
Translation was similar in GSDs and dogs of other
breeds and was smallest at the lumbosacral motion
Conclusions and Clinical Relevance—Results indicated
that motion in the caudal lumbar and lumbosacral
portions of the vertebral column of dogs is
complex and provided a basis for further studies evaluating
abnormal vertebral columns. ( Am J Vet Res 2004;65:544–552)
Objective—To determine the association between the 3-dimensional (3-D) motion pattern of the caudal lumbar and lumbosacral portions of the canine vertebral column and the morphology of vertebrae, facet joints, and intervertebral disks.
Sample Population—Vertebral columns of 9 German Shepherd Dogs and 16 dogs of other breeds with similar body weights and body conditions.
Procedure—Different morphometric parameters of the vertebral column were assessed by computed tomography (CT) and magnetic resonance imaging. Anatomic conformation and the 3-D motion pattern were compared, and correlation coefficients were calculated.
Results—Total range of motion for flexion and extension was mainly associated with the facet joint angle, the facet joint angle difference between levels of the vertebral column in the transverse plane on CT images, disk height, and lever arm length.
Conclusions and Clinical Relevance—Motion is a complex process that is influenced by the entire 3-D conformation of the lumbar portion of the vertebral column. In vivo dynamic measurements of the 3-D motion pattern of the lumbar and lumbosacral portions of the vertebral column will be necessary to further assess biomechanics that could lead to disk degeneration in dogs.