Objective—To measure oxytocin concentrations in
blood and CSF following central administration of opioid
agonists in dogs.
Animals—5 male dogs.
Procedure—In a crossover design, CSF and blood
were collected immediately before and 15 and 30
minutes after cisternal administration of D-Ala2,
MePhe4, Gly-ol-enkephalin (DAMGO, a µ-receptor
agonist); D-Pen, pCl-Phe4, D-Pen5-enkephalin (a δ-receptor agonist); U50488H (a κ-receptor agonist);
morphine; and saline (0.9% NaCl) solution.
Results—Plasma oxytocin concentration was significantly
increased 15 minutes after administration of
DAMGO and 30 minutes after administration of
U50488H, compared with concentrations obtained
after administration of saline solution. Concentration
of oxytocin in CSF was significantly decreased 30
minutes after administration of U50488H, compared
with concentration after administration of saline solution.
Conclusion and Clinical Relevance—Results suggest
that in male dogs, activation of centrally located
µ and κ receptors elicits an overall excitatory effect on
neurons that regulate peripheral release of oxytocin,
whereas activation of centrally located κ receptors
elicits an overall inhibitory effect on neurons that regulate
central release. These results are in contrast to
those reported for other species, in which opioids
have a pronounced inhibitory effect on release of oxytocin
from the neurohypophysis. (Am J Vet Res 2001;
OBJECTIVE To sequence exons and splice consensus sites of the dynactin subunit 1 (DCTN1) gene in Leonbergers and Labrador Retrievers with clinical laryngeal paralysis.
ANIMALS 5 unrelated Leonbergers with laryngeal paralysis, 2 clinically normal Leonbergers, 7 unrelated Labrador Retrievers with laryngeal paralysis, and 2 clinically normal Labrador Retrievers.
PROCEDURES Primers were designed for the entire coding regions of the DCTN1 gene, a noncoding exon at the 5´ end of the gene, and a 900-bp single-nucleotide polymorphism (SNP)-rich region located 17 kb upstream of the DCTN1 gene by use of the CanFam3 assembly of the canine genome sequence. Sequences were generated and compared between clinically normal and affected dogs. The SNPs flanking the DCTN1 gene as well as a previously identified nonsynonymous SNP in exon 32 were genotyped in affected and clinically normal Leonbergers and Labrador Retrievers.
RESULTS None of the affected dogs were homozygous for any mutation affecting coding regions or splicing consensus sequences. Of the 16 dogs tested for the missense SNP in exon 32, all were homozygous for the reference allele, except for 2 affected and 1 clinically normal Labrador Retriever and 1 clinically normal Leonberger. The DCTN1 gene sequences (5 dogs) and haplotypes of polymorphic markers surrounding the DCTN1 gene (all dogs) were not consistent with the hypothesis that laryngeal paralysis was associated with inheritance of the same DCTN1 disease-causing allele within all Labrador Retrievers or Leonbergers evaluated.
CONCLUSIONS AND CLINICAL RELEVANCE Mutations in the DCTN1 gene did not appear to cause laryngeal paralysis in Leonbergers or Labrador Retrievers.
OBJECTIVE To evaluate the clinical response, adverse effects, and outcomes associated with palliative radiation therapy (PRT) in dogs with various solid tumor types at various body locations.
DESIGN Retrospective case series.
ANIMALS 103 dogs with solid tumors.
PROCEDURES Medical records for dogs with solid tumors treated with PRT between July 2007 and January 2011 at a veterinary teaching hospital were reviewed. Data collected included signalment, tumor type and location, initial staging results, PRT protocol, other tumor-specific treatments, patient and tumor response, outcome, and acute and chronic adverse effects. Median progression-free survival time, median survival time (MST), and other descriptive statistics were calculated.
RESULTS Types of tumors treated included carcinoma, sarcoma, melanoma, primary bone tumor, mast cell tumor, and ameloblastoma. For all dogs, the overall tumor and clinical response rates to PRT were 75% and 77%, respectively, and the MST was 134 days, but those responses varied substantially among tumor types. Dogs that developed a positive clinical response or maintained stable disease after PRT had a significantly longer MST than did dogs with progressive disease. Tumor location was not significantly associated with median progression-free survival time or MST. Most dogs tolerated the PRT well. Acute and chronic adverse effects were observed in 57 and 8 dogs, respectively, but were generally self-limiting.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that dogs with various types of solid tumors that received PRT had objective beneficial responses and an improvement in quality of life that was positively associated with survival time.
Objective—To describe the clinical characteristics, treatment, complications, and outcome of dogs and cats treated surgically for major abdominal evisceration.
Design—Retrospective case series.
Animals—8 dogs and 4 cats.
Procedures—Medical records from January 1998 through March 2008 were reviewed to identify animals that underwent surgery for major abdominal evisceration. Data regarding cause of evisceration, signalment, physiologic variables, and hematologic variables were collected. Details of treatment, duration of hospitalization, and outcome were recorded. Linear regression analysis was performed to evaluate the association of signalment, physiologic variables, and hematologic variables on the number of days of hospitalization.
Results—Major abdominal evisceration was secondary to a traumatic event in 4 animals and to postsurgical dehiscence in 8 animals. All animals had evisceration of the intestines and gross contamination with dirt, leaves, or litter. Two animals eviscerated the spleen, and 1 animal had a perforated colon and was leaking feces into the peritoneal cavity. All animals underwent exploratory abdominal surgery. Surgical procedures performed included resection of compromised intestine, body wall repair, diaphragmatic hernia repair, nephrectomy, splenectomy, and primary colonic repair. All animals survived to discharge from the hospital. Median duration of hospitalization was 4 days (range, 1 to 7 days). Factors associated with an increase in duration of hospitalization included evisceration secondary to trauma, high lactate concentration at time of admission, and small body size.
Conclusions and Clinical Relevance—Despite the dramatic appearance of major abdominal evisceration in cats and dogs, prompt and aggressive medical and surgical intervention can provide a favorable outcome.
Animals—151 dogs treated surgically for GDV and 302 control dogs with no history of GDV.
Procedures—Computerized records of dogs evaluated via exploratory laparotomy or abdominal ultrasonography were searched, and dogs with GDV and dogs without GDV (control dogs) were identified. Two control dogs were matched with respect to age, body weight, sex, neuter status, and breed to each dog with GDV. Data were collected on the presence or absence of the spleen for both dogs with GDV and control dogs. Conditional logistic regression analysis was used to investigate the association of previous splenectomy with GDV.
Results—6 (4%) dogs in the GDV group and 3 (1%) dogs in the control group had a history of previous splenectomy. The odds of GDV in dogs with a history of previous splenectomy in this population of dogs were 5.3 times those of dogs without a history of previous splenectomy (95% confidence interval, 1.1 to 26.8).
Conclusions and Clinical Relevance—For the patients in the present study, there was an increased odds of GDV in dogs with a history of splenectomy. Prophylactic gastropexy may be considered in dogs undergoing a splenectomy, particularly if other risk factors for GDV are present.
Objective—To determine whether an activity monitor (AM) could be used to detect changes in activity in dogs with osteoarthritis treated with carprofen or a placebo.
Design—Randomized controlled trial.
Animals—70 dogs with no clinically important abnormalities other than osteoarthritis for which they were not currently being treated.
Procedures—Dogs wore an AM continuously for 21 days. On days 8 through 21, the dogs were treated with carprofen (n = 35) or a placebo (35). Total activity counts for days 1 through 7 (baseline) were compared with total activity counts for days 15 through 21 (endpoint). The change in total activity count from baseline to endpoint was assessed within each treatment group as well as between groups. Linear regression analysis was performed to test for an association between treatment and percentage change in activity counts while controlling for other variables.
Results—For placebo-treated dogs, median baseline total activity count was not significantly different from median endpoint total activity count (1,378,408 vs 1,310,112, respectively). For dogs receiving carprofen, there was a significant increase in median activity count from baseline to endpoint (1,276,427 vs 1,374,133). When age and baseline activity counts were controlled for, dogs in the carpofen-treated group had a 20% increase in activity counts, compared with placebo-treated dogs (95% confidence interval, 10% to 26%).
Conclusions and Clinical Relevance—Results suggested that the AM used in the present study may be a valid outcome assessment tool for documenting improved activity associated with treatment in dogs with osteoarthritis.
Objective—To define the learning curve and evaluate the outcome for a board-certified veterinary surgeon performing laparoendoscopic single-site (LESS) ovariectomy in dogs.
Design—Retrospective case review and learning curve evaluation with a skill acquisition model.
Animals—27 client-owned dogs.
Procedures—Between April 2011 and December 2012, 27 dogs underwent elective LESS ovariectomy performed by a single experienced board-certified laparoscopic surgeon by means of the same technique. Medical records for these patients were reviewed to determine whether a learning curve could be detected. A commercially available multitrocar port was inserted through a 15- to 20-mm incision at the umbilicus, and LESS ovariectomy was performed with articulating graspers, a bipolar vessel-sealing device, and a 30° telescope. Surgical performance of the surgeon was quantified with an exponential skill acquisition model, and how skill was gained with repetition of the same novel surgical procedure was examined.
Results—Median patient body weight was 20 kg (44 lb; range, 3.5 to 41 kg [7.7 to 90.2 lb]). Median surgical time was 35 minutes (range, 20 to 80 minutes). Median patient age was 314 days (range, 176 to 2,913 days). The skill acquisition model revealed that a comparable surgeon could reach 90% of optimal surgery performance after approximately 8 procedures (8.6, 95% confidence interval, 0.5 to 16.6 procedures). According to the model, with each surgery, surgical time would be expected to decrease by 27% (95% confidence interval, 2% to 52%). Complications were limited to minor hemorrhage due to a splenic laceration and a postoperative incisional infection. Follow-up information was available for all 27 cases. All owners were satisfied and indicated that they would pursue LESS ovariectomy again.
Conclusions and Clinical Relevance—The learning curve for LESS ovariectomy was short and definable. Short-term outcome was excellent. Results of this study suggested that an experienced laparoscopic surgeon may anticipate achieving proficiency with this technique after performing approximately 8 procedures.
Objective—To evaluate the outcome following urethral stent placement for the palliative treatment of obstructive carcinoma of the urethra in dogs.
Design—Retrospective case series.
Animals—42 dogs with obstructive carcinoma of the urethra.
Procedures—Medical records for dogs in which a self-expanding metallic stent (SEMS) was used for the treatment of obstructive carcinoma of the urethra were reviewed. Signalment, diagnostic findings, clinical signs before and after SEMS placement, and patient outcome were analyzed. Fluoroscopic images were evaluated to determine the effects of stent size, obstruction length, tumor length, and urethral length and width on the incidence of incontinence or stranguria.
Results—Resolution of urinary tract obstruction was achieved in 41 of 42 (97.6%) dogs. After SEMS placement, 6 of 23 male and 5 of 19 female dogs developed severe incontinence, and 1 of 23 male and 1 of 17 female dogs developed stranguria. Stent length, diameter, and location were not associated with incidence of incontinence or stranguria. Median survival time after SEMS placement was 78 days (range, 7 to 536 days). Treatment with NSAIDs before and chemotherapeutics after SEMS placement increased median survival time to 251 days (range, 8 to 536 days).
Conclusions and Clinical Relevance—Urethral SEMS placement was an effective palliative treatment for dogs with obstructive carcinoma of the urethra; however, severe incontinence subsequently developed in 11 of 42 (26%) treated dogs. Adjunctive treatment of affected dogs with NSAIDs and chemotherapeutics significantly increased the median survival time.
Objective—To develop and psychometrically test an owner self-administered questionnaire designed to assess severity and impact of chronic pain in dogs with osteoarthritis.
Sample Population—70 owners of dogs with osteoarthritis and 50 owners of clinically normal dogs.
Procedures—Standard methods for the stepwise development and testing of instruments designed to assess subjective states were used. Items were generated through focus groups and an expert panel. Items were tested for readability and ambiguity, and poorly performing items were removed. The reduced set of items was subjected to factor analysis, reliability testing, and validity testing.
Results—Severity of pain and interference with function were 2 factors identified and named on the basis of the items contained in them. Cronbach's α was 0.93 and 0.89, respectively, suggesting that the items in each factor could be assessed as a group to compute factor scores (ie, severity score and interference score). The test-retest analysis revealed κ values of 0.75 for the severity score and 0.81 for the interference score. Scores correlated moderately well (r = 0.51 and 0.50, respectively) with the overall quality-of-life (QOL) question, such that as severity and interference scores increased, QOL decreased. Clinically normal dogs had significantly lower severity and interference scores than dogs with osteoarthritis.
Conclusions and Clinical Relevance—A psychometrically sound instrument was developed. Responsiveness testing must be conducted to determine whether the questionnaire will be useful in reliably obtaining quantifiable assessments from owners regarding the severity and impact of chronic pain and its treatment on dogs with osteoarthritis.
Procedures—Owners completed the CBPI on day 0. Dogs received carprofen or a placebo on days 1 through 14. Owners completed the CBPI again on day 14. Pain severity and pain interference scores from the CBPI were calculated, and the change from day 0 to day 14 was assessed within each group and between groups.
Results—No significant differences were detected in median scores for pain severity (3.50 and 3.25 on days 0 and 14, respectively) and pain interference (3.92 and 3.25 on days 0 and 14, respectively) in dogs receiving the placebo. Dogs receiving carprofen had significant changes in median scores for pain severity (4.25 to 2.25 on days 0 and 14, respectively) and pain interference (4.33 to 2.67 on days 0 and 14, respectively). There was a significantly greater improvement in pain severity and pain interference scores in dogs treated with carprofen, compared with improvement in scores for dogs receiving the placebo.
Conclusions and Clinical Relevance—The CBPI was able to detect improvements in pain scores in dogs with osteoarthritis treated with an NSAID or a placebo. These results, in combination with previous reliability and validity testing, support the use of the CBPI to obtain quantifiable assessments from owners regarding the severity and impact of chronic pain and treatment for dogs with osteoarthritis.