Objective—To determine concentrations of excitatory
and inhibitory amino acids in CSF of a large number
of dogs with idiopathic epilepsy or genetic epilepsy
and to evaluate changes in CSF amino acid concentration
with regard to drug treatment and sex.
Animals—35 Labrador Retrievers with genetic
epilepsy (20 male and 15 female), 94 non-Labrador
Retrievers with idiopathic epilepsy (71 male and 23
female), and 20 control dogs (10 male and 10 female).
Procedure—Collection of CSF was performed > 72
hours after the occurrence of seizures. Cerebrospinal
fluid concentrations of γ-aminobutyric acid (GABA),
glutamate (GLU), aspartate (ASP), serine, and glycine
were determined by use of high performance liquid
chromatography with electrochemical detection.
Results—CSF concentrations of GABA and GLU
were significantly lower in Labrador Retrievers
with genetic epilepsy (LR-group dogs) than in control-group dogs or in non-Labrador Retrievers with
idiopathic epilepsy (non–LR-group dogs). The GLU-to-GABA ratio was significantly higher in LR-group
dogs than in non–LR-group dogs. CSF concentrations
of GLU and ASP were significantly lower
when all dogs with epilepsy (non–LR- and LR-group
dogs combined) were compared with control-group dogs.
Conclusions and Clinical Relevance—A decrease in
CSF concentrations of GABA appears to play a role in
the pathogenesis of genetically determined epilepsy
in Labrador Retrievers. However, this decrease in CSF
concentrations of GABA may also be a consequence
of seizure activity. The GLU-to-GABA ratio may prove
to be a useful indicator of genetic epilepsy in Labrador
Retrievers. (Am J Vet Res 2004;65:1108–1113)
Objective—To compare nociceptive withdrawal
reflexes (NWRs) evoked from the distal aspect of the
left forelimb and hind limb in conscious standing horses
and to investigate NWR recruitment for graded
electrical stimulation intensities.
Animals—20 adult horses.
Procedure—Surface electromyographic (EMG) activity
evoked by transcutaneous electrical stimulation of
the digital palmar (or plantar) nerve was recorded from
the common digital extensor and cranial tibial muscles.
Stimuli consisted of 25-millisecond train-of-5 constant
current pulses. Current intensity was gradually
increased until NWR threshold intensity was reached.
The EMG signal was analyzed for quantification of the
NWR. Behavioral responses accompanying the reflex
were scored (scale, 0 to 5). The NWR recruitment
curves were determined at 0.9, 1.1, 1.2, and 1.3 times
the NWR threshold intensity.
Results—The NWR threshold was significantly higher
for the hind limb (median value, 6.6 mA; range, 3 to
10 mA) than the forelimb (median, 3 mA; range, 1.7 to
5.5 mA). The NWR of the hind limb had a significantly
longer latency (median, 122.8 milliseconds; range,
106 to 172 milliseconds), compared with the forelimb
(median, 98 milliseconds; range, 86 to 137 milliseconds),
and it was associated with significantly
stronger behavioral reactions. Gradual increase of
NWR amplitude was evident at increasing stimulation
intensities and supported by the behavioral observations.
Conclusions and Clinical Relevance—We documented
NWRs evoked from the forelimb and hind
limb and their recruitment with stimuli of increasing
intensity in horses. These results provide a basis for
use of NWRs in studies on nociceptive modulation in
horses. (Am J Vet Res 2003;64:700–707)
Objective—To determine whether lymphocyte apoptosis in intestinal mucosae is more common in healthy dogs than dogs with inflammatory bowel disease (IBD) and whether numbers of apoptotic cells increase after successful treatment of affected dogs.
Animals—8 dogs with IBD (IBD dogs) and 8 healthy control dogs.
Procedures—Biopsy specimens of the duodenum and colon were obtained via endoscopy from dogs with IBD before and after 10 weeks of standard treatment and compared with specimens obtained from control dogs. Expression of activated caspase 3 (Casp3), caspase-cleaved fragment p85 from poly-ADP-ribose polymerase (PARP), and B-cell leukemia/lymphoma 2 (Bcl-2) was measured in the duodenal (villous tip and base) and colonic mucosae.
Results—Expression of Casp3 was greater in the duodenal villous tips of control dogs, compared with expression in similar tissues from dogs with IBD before or after treatment. Despite clinical improvement of dogs with IBD, expression of Casp3 did not increase after treatment. Expression of PARP did not differ between groups at any time point. Expression of Bcl-2 was greater at all 3 tissue sites in control dogs, compared with expression at the same sites in dogs with IBD. Furthermore, Bcl-2 expression in duodenal villous tips was higher in dogs with IBD after treatment but was not higher elsewhere. In control dogs, expression patterns for all 3 markers were similar between sites (villous tip > villous base > colon).
Conclusions and Clinical Relevance—Expression of Casp3 in lymphocytes in duodenal villous tips was significantly reduced in dogs with IBD, compared with expression in healthy dogs, but no increase was detected following successful treatment of IBD. Increased expression of Bcl-2 may be a potential marker of the success of treatment.
Objective—To evaluate pulsed-wave Doppler spectral parameters as a method for distinguishing between neoplastic and inflammatory peripheral lymphadenopathy in dogs.
Sample Population—40 superficial lymph nodes from 33 dogs with peripheral lymphadenopathy.
Procedures—3 Doppler spectral tracings were recorded from each node. Spectral Doppler analysis including assessment of the resistive index, peak systolic velocity-to-end diastolic velocity (S:D) ratio, diastolic notch velocity-to-peak systolic velocity (N:S) ratio, and end diastolic velocity-to-diastolic notch velocity ratio was performed for each tracing. Several calculation methods were used to determine the Doppler indices for each lymph node. After the ultrasonographic examination, fine needle aspirates or excisional biopsy specimens of the examined lymph nodes were obtained, and lymphadenopathy was classified as either inflammatory or neoplastic (lymphomatous or metastatic) via cytologic or histologic examination. Results of Doppler analysis were compared with cytologic or histopathologic findings.
Results—The Doppler index with the highest diagnostic accuracy was the S:D ratio calculated from the first recorded tracing; a cutoff value of 3.22 yielded sensitivity of 91%, specificity of 100%, and negative predictive value of 89% for detection of neoplasia. Overall diagnostic accuracy was 95%. At a sensitivity of 100%, the most accurate index was the N:S ratio calculated from the first recorded tracing; a cutoff value of 0.45 yielded specificity of 67%, positive predictive value of 81%, and overall diagnostic accuracy of 86.5%.
Conclusions and Clinical Relevance—Results suggested that noninvasive Doppler spectral analysis may be useful in the diagnosis of neoplastic versus inflammatory peripheral lymphadenopathy in dogs.
Objective—To describe the presence and amount of apoptotic ligamentous cells in different areas of partially ruptured canine cranial cruciate ligaments (prCCLs) and to compare these findings with apoptosis of ligamentous cells in totally ruptured cranial cruciate ligaments (trCCLs).
Animals—20 dogs with prCCLs and 14 dogs with trCCLs.
Procedures—Dogs with prCCLs or trCCLs were admitted to the veterinary hospital for stifle joint treatment. Biopsy specimens of the intact area of prCCLs (group A) and the ruptured area of prCCLs (group B) as well as specimens from trCCLs (group C) were harvested during arthroscopy. Caspase-3 and poly (ADP-ribose) polymerase (PARP) detection were used to detect apoptotic ligamentous cells by immunohistochemistry.
Results—No difference was found in the degree of synovitis or osteophytosis between prCCLs and trCCLs. No difference was found in degenerative changes in ligaments between groups A and B. A substantial amount of apoptotic cells could be found in > 90% of all stained slides. A correlation (rs = 0.71) was found between the number of caspase-3-and PARP-positive cells. No significant difference was found in the amount of apoptotic cells among the 3 groups. No significant correlation could be detected between the degree of synovitis and apoptotic cells or osteophyte production and apoptotic cells.
Conclusions and Clinical Relevance—The lack of difference between the 3 groups indicates that apoptosis could be a factor in the internal disease process leading to CCL rupture and is not primarily a consequence of the acute rupture of the ligament.
Objective—To compare oral administration of lomustine and prednisolone with oral administration of prednisolone alone as treatment for granulomatous meningoencephalomyelitis (GME) or necrotizing encephalitis (NE) in dogs.
Design—Retrospective cohort study.
Animals—25 dogs with GME and 18 dogs with NE (diagnosis confirmed in 8 and 5 dogs, respectively).
Procedures—Records of dogs with GME or NE were reviewed for results of initial neurologic assessments and clinicopathologic findings, treatment, follow-up clinicopathologic findings (for lomustine-treated dogs), and survival time. Dogs with GME or NE treated with lomustine and prednisolone were assigned to groups 1 (n = 14) and 3 (10), respectively; those treated with prednisolone alone were assigned to groups 2(11) and 4 (8), respectively.
Results—Prednisolone was administered orally every 12 hours to all dogs. In groups 1 and 3, mean lomustine dosage was 60.3 mg/m2, PO, every 6 weeks. Median survival times in groups 1 through 4 were 457, 329, 323, and 91 days, respectively (no significant difference between groups 1 and 2 or between groups 3 and 4). Within the initial 12 months of treatment, median prednisolone dosage was reduced in all groups; dosage reduction in group 1 was significantly larger than that in group 2 at 6, 9, and 12 months. Combination treatment most frequently caused leukopenia, but had no significant effect on liver enzyme activities.
Conclusions and Clinical Relevance—In dogs with GME and NE, oral administration of lomustine and prednisolone or prednisolone alone had similar efficacy. Inclusion of lomustine in the treatment regimen was generally tolerated well.
Objective—To compare severity of postoperative pain in dogs undergoing hemilaminectomy because of acute thoracolumbar intervertebral disk disease treated with a combination of conventional analgesics and electroacupuncture (EAP) or with conventional analgesics alone.
Design—Controlled clinical trial.
Animals—15 dogs undergoing surgery because of acute thoracolumbar disk disease.
Procedures—Dogs were alternately assigned to treatment (conventional analgesics and adjunct EAP) and control (conventional analgesics alone) groups. Analgesic treatment was adjusted as necessary by the attending clinician, who was not aware of group assignment. Pain scores were assigned 1, 3, and 12 hours after surgery and every 12 hours thereafter for 72 hours by the same individual who performed acupuncture treatments.
Results—Total dose of fentanyl administered during the first 12 hours after surgery was significantly lower in the treatment group than in the control group, but dosages of analgesics administered from 12 through 72 hours after surgery did not differ between groups. Pain score was significantly lower in the treatment group than in the control group 36 hours after surgery, but did not differ significantly between groups at any other time.
Conclusions and Clinical Relevance—Results provided equivocal evidence that adjunct EAP might provide some mild benefit in regard to severity of postoperative pain in dogs undergoing hemilaminectomy because of acute thoracolumbar intervertebral disk disease.
Objective—To investigate whether facilitation of the
nociceptive withdrawal reflex (NWR) can be evoked
and quantified as a measure of temporal summation
from the distal aspect of the left forelimb and hind
limb in standing nonsedated horses via repeated
stimulations of various subthreshold intensities and
Animals—10 adult horses.
Procedure—Surface electromyographic activity
evoked by stimulation of the digital palmar and plantar
nerves was recorded from the common digital
extensor and cranial tibial muscles. For each horse,
the NWR threshold intensity to a single stimulus was
determined for the forelimb and hind limb. Repeated
stimulations were performed at subthreshold intensities
and at frequencies of 2, 5, and 10 Hz. The reflex
amplitude was quantified, and the behavioral responses
accompanying the stimulations were scored.
Results—Repeated stimulations at subthreshold
intensities were able to summate and facilitate the
NWR in conscious horses. The reflex facilitation was
significantly related to the intensity of the repeated
stimuli, whereas no effect of stimulation frequency
was found. Reaction scores increased significantly for
increasing stimulation intensities.
Conclusions and Clinical Relevance—Temporal summation
obtained by repeated stimulations of subthreshold
intensity appears to represent a new tool for
investigating nociceptive pathophysiologic processes
in horses; this experimental model may be useful to
examine the mode of action and efficacy of analgesic
and anesthetic interventions and possibly to assess
sensory dysfunction in clinical settings. (Am J Vet Res 2004;65:901–908)
Objective—To evaluate the use of immunofluorescence
asssays for perinuclear antineutrophilic cytoplasmic
antibodies (pANCAs) and antibodies to
Saccharomyces cerevisiae (ASCAs) in dogs with
inflammatory bowel disease (IBD) and assess the
clinical value of these serologic markers of the disease.
Animals—39 dogs with IBD, 18 dogs with acute diarrhea,
19 dogs with chronic non–IBD-associated diarrhea,
26 healthy dogs of various breeds and age, and
22 healthy young working dogs.
Procedure—Sera obtained from the dogs in each
group were added to canine granulocyte- and
Saccharomyces cerevisiae-mounted slides for detection
of pANCAs and ASCAs via immunofluorescence
techniques. Sensitivity and specificity (with 95% confidence
intervals [CIs]) were calculated for the group
of dogs with IBD versus each of the 2 groups of
healthy dogs, the group of dogs with acute diarrhea,
and the group of dogs with chronic non–IBD-associated
Results—Among the 39 dogs with IBD, 20 yielded
positive results via the pANCA assay (sensitivity, 0.51
[95% CI, 0.35 to 0.67]) and 17 yielded positive results
via the ASCA assay (sensitivity, 0.44 [95% CI, 0.22 to
0.69]). The specificity of the pANCA assay in the 4
groups of non–IBD-affected dogs ranged from 0.83
(95% CI, 0.85 to 0.96) to 0.95 (95% CI, 0.72 to 1.00).
Conclusions and Clinical Relevance—Immunofluorescence
assays for pANCA and ASCA appear to
be useful for the detection of IBD in dogs. The
pANCA immunofluorescence assay had high specificity
for canine IBD, and pANCAs appear to be accurate
markers of intestinal inflammation. (Am J Vet Res 2004;65:1279–1283)
Objective—To compare the cardiopulmonary effects
of anesthesia maintained by continuous infusion of
ketamine and propofol with anesthesia maintained by
inhalation of sevoflurane in goats undergoing magnetic
Animals—8 Saanen goats.
Procedures—Goats were anesthetized twice (1-month
interval) following sedation with midazolam
(0.4 mg/kg, IV). Anesthesia was induced via IV administration
of ketamine (3 mg/kg) and propofol (1 mg/kg)
and maintained with an IV infusion of ketamine (0.03
mg/kg/min) and propofol (0.3 mg/kg/min) and 100%
inspired oxygen (K-P treatment) or induced via IV
administration of propofol (4 mg/kg) and maintained
via inhalation of sevoflurane in oxygen (end-expired
concentration, 2.3%; 1X minimum alveolar concentration;
SEVO treatment). Cardiopulmonary and blood
gas variables were assessed at intervals after induction
Results—Mean ± SD end-expired sevoflurane was
2.24 ± 0.2%; ketamine and propofol were infused at
rates of 0.03 ± 0.002 mg/kg/min and 0.29 ± 0.02
mg/kg/min, respectively. Overall, administration of
ketamine and propofol for total IV anesthesia was
associated with a degree of immobility and effects on
cardiopulmonary parameters that were comparable to
those associated with anesthesia maintained by
inhalation of sevoflurane. Compared with the K-P
treatment group, mean and diastolic blood pressure
values in the SEVO treatment group were significantly
lower at most or all time points after induction of
anesthesia. After both treatments, recovery from
anesthesia was good or excellent.
Conclusions and Clinical Relevance—Results suggest
that ketamine-propofol total IV anesthesia in
goats breathing 100% oxygen is practical and safe for
performance of magnetic resonance imaging procedures.
(Am J Vet Res 2005;66:2135–2141)