Search Results

Abstract

Objective—To determine racing performance after surgery for colic in Thoroughbreds.

Design—Retrospective cohort study.

Animals—85 racing Thoroughbreds that survived to discharge following colic surgery and 170 race-matched reference horses.

Procedures—Earnings, starts, and earnings per start were compared between horses that underwent surgery and reference horses, the proportions of horses that returned to racing were analyzed, and career longevity was determined.

Results—Among 85 racing Thoroughbreds that underwent colic surgery, 31 (36%) had primarily small intestinal lesions, of which 11 underwent resection; 54 (64%) had large intestinal lesions, of which 2 underwent resection. Fifty-nine of 85 (69%) horses that underwent colic surgery returned to racing after a 6-month recovery period versus 125 of 170 (73%) reference horses (OR, 0.81). In the 36-month postoperative period, reference horses earned a mean of $7,866 more, had a mean of 0.26 more starts, and had mean earnings per start of $29 more than horses that underwent surgery. Horses that underwent surgery did not have different career lengths than reference horses.

Conclusions and Clinical Relevance—Horses that underwent colic surgery did not have a significant reduction in measures of performance or career length, compared with a reference cohort.

Abstract

Objective—To determine the effects of long-term oral administration of levothyroxine sodium (L-T₄) on glucose dynamics in adult euthyroid horses.

Animals—6 healthy adult mares.

Procedures—Horses received L-T₄ (48 mg/d) orally for 48 weeks. Frequently sampled IV glucose tolerance test procedures were performed on 3 occasions (24-hour intervals) before and at 16, 32, and 48 weeks during the treatment period. Data were assessed via minimal model analysis. The repeatability of measurements was evaluated.

Results—During treatment, body weight decreased significantly from the pretreatment value; mean ± SD weight was 49 ± 14 kg, 43 ± 7 kg, and 25 ± 18 kg less than the pretreatment value at weeks 16, 32, and 48, respectively. Compared with pretreatment findings, 1.8-, 2.4-, and 1.9-fold increases in mean insulin sensitivity (SI) were detected at weeks 16, 32, and 48, respectively; SI was negatively correlated with body weight (r = −0.42; P < 0.001). During treatment, glucose effectiveness increased and the acute insulin response to glucose decreased. Overall mean within-horse coefficients of variation were 5% and 29% for plasma glucose and serum insulin concentrations, respectively, and 33%, 26%, and 23% for SI, glucose effectiveness, and the acute insulin response to glucose, respectively.

Conclusions and Clinical Relevance—Long-term administration of L-T₄ was associated with weight loss and increased SI in adult euthyroid horses, although other factors may have confounded results. Levothyroxine sodium may be useful for the treatment of obesity and insulin resistance in horses, but further studies are required.

Abstract

Objective—To evaluate equids with enostosis-like lesions (ELLs) and document the clinical and epidemiological features of this disease.

Design—Retrospective case series.

Animals—79 equids with a scintigraphic diagnosis of at least 1 ELL on ≥ 1 occasion.

Procedures—Medical records of 4,992 equids that underwent bone scintigraphy between March 1997 and March 2009 were reviewed; 78 horses and 1 pony had a scintigraphic diagnosis of an ELL. For those equids, signalment; physical, scintigraphic, radiographic, and lameness examination results; and outcome were reviewed.

Results—Of the 79 equids, 4 (5.1%) had anatomically distinct ELLs on 2 (n = 3) or 4 (1) separate occasions that caused lameness in different limbs. Thus, there were 85 ELL-related admissions to the hospital. Overall, 157 ELLs were detected. Among all equids undergoing scintigraphic examination, Thoroughbreds were more commonly and Standardbreds were less commonly affected. Older animals were more likely to have ELLs. Lameness was directly attributed to scintigraphically evident ELLs in 42 of the 85 (49.4%) admissions. The tibia (62/157 [39.5%]) and the radius (46/157 [29.3%]) were most commonly affected. The ELLs located in the humerus caused more severe lameness than did ELLs in other anatomic locations. Lameness severity was associated with radiopharmaceutical uptake intensity. Among racehorses, those with 1 ELL were more likely to return to racing than were those with multiple ELLs detected in 1 scintigraphic examination; mean interval from diagnosis to first start was 184 days.

Conclusions and Clinical Relevance—Results of this retrospective evaluation of a large group of equids with ELLs have provided a better understanding of this disease process.

Abstract

Objective—To investigate the effects of dexamethasone or levothyroxine sodium on endotoxin-induced alterations in glucose and insulin dynamics.

Animals—24 horses.

Procedures—Horses were randomly allocated to 3 treatment groups and received 48 mg of levothyroxine mixed with 200 g of oats, 20 mg of dexamethasone plus oats, or oats alone (control) for 15 days, followed by IV infusion of lipopolysaccharide (20 ng/kg) while individually housed in stalls. Frequently sampled IV glucose tolerance tests were performed prior to pretreatment, after pretreatment, and 20 hours after lipopolysaccharide administration. Area under the curve for plasma glucose and serum insulin concentrations was calculated, and minimal model analyses were performed.

Results—Significant treatment-by-time effects were detected for insulin sensitivity (SI) and area under the curve for glucose and insulin in the 15-day pretreatment period. Insulin sensitivity significantly decreased over time in all treatment groups, with the largest decrease detected in the dexamethasone group. Administration of lipopolysaccharide further decreased mean SI by 71% and 63% in the dexamethasone and control groups, respectively, but did not affect horses in the levothyroxine group. Mean SI was the lowest in the dexamethasone group, but percentage reduction was the same for dexamethasone and control groups.

Conclusions and Clinical Relevance—Insulin sensitivity decreased during the pretreatment period in all 3 groups, indicating that hospitalization affected glucose and insulin dynamics. Dexamethasone significantly lowered SI, and endotoxemia further exacerbated insulin resistance. In contrast, there was no additional effect of endotoxemia on SI in horses pretreated with levothyroxine, suggesting that this treatment prevented endotoxemia-induced insulin resistance.

Abstract

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.

Abstract

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.

Abstract

Objective—To determine whether the Canine Brief Pain Inventory (CBPI) can detect changes in dogs with osteoarthritis treated with an NSAID or a placebo.

Design—Double-blind, randomized, placebo-controlled clinical trial.

Animals—70 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.

Abstract

Objective—To evaluate the in vitro susceptibility of various field isolates of Mycobacterium avium subsp paratuberculosis (MAP) to gallium nitrate.

Sample—10 isolates of MAP, including 4 isolated from cattle, 2 isolated from bison, 1 isolated from an alpaca, and 3 isolated from humans.

Procedures—The in vitro susceptibility to gallium nitrate was tested by use of broth culture with detection of MAP growth by means of a nonradiometric automated detection method. For each MAP isolate, a series of 7 dilutions of gallium nitrate (concentrations ranging from 200 to 1,000μM) were tested. Gallium nitrate was considered to have caused 90% and 99% inhibition of the MAP growth when the time to detection for culture of the MAP stock solution and a specific concentration of gallium nitrate was delayed and was similar to that obtained for culture of the MAP stock solution (without the addition of gallium nitrate) diluted 1:10 and 1:100, respectively.

Results—Gallium nitrate inhibited MAP growth in all 10 isolates. The susceptibility to gallium nitrate was variable among isolates, and all isolates of MAP were inhibited in a dose-dependent manner. Overall, the concentration that resulted in 90% inhibition ranged from < 200μM for the most susceptible isolates to 743μM for the least susceptible isolates.

Conclusions and Clinical Relevance—Gallium nitrate had activity against all 10 isolates of MAP tested in vitro and could potentially be used as a prophylactic agent to aid in the control of MAP infections during the neonatal period.

Abstract

Objective—To determine application rate and effectiveness of sodium bisulfate to decrease the fly population in a horse barn environment.

Sample Population—12 privately owned farms in southeastern Pennsylvania.

Procedure—Application rates of sodium bisulfate were approximately 2.3 kg/stall, 1.1 kg/stall, and 0.5 kg/stall. Two or 3 stalls were treated, and 1 or 2 stalls were not treated (control stalls) at each farm. Farm personnel applied sodium bisulfate in treated stalls daily for 7 days. Fly tapes were hung from the same site in treated and control stalls. After 24 hours, the fly tape was removed, flies adhering to the sticky surface were counted and recorded, and a new fly tape was hung. This procedure was repeated daily during each of the testing periods.

Results—Following the application of 2.3 kg of sodium bisulfate/stall, the numbers of flies collected on the fly tape were significantly decreased in treated stalls, compared with control stalls during the same time periods on 9 of the 12 farms evaluated. Following the application of 1.1 kg of sodium bisulfate/ stall, fly numbers were significantly decreased in treated stalls on 6 of the 9 farms evaluated. Following the application of 0.5 kg of sodium bisulfate/stall, fly numbers were significantly decreased in the treated stalls on 3 of the 4 farms evaluated.

Conclusions and Clinical Relevance—Our findings suggest that sodium bisulfate would be effective for fly control in horse barns. (Am J Vet Res 2000; 61:910–913)

Abstract

Objective—To investigate the effects of insulin-like growth factor-II (IGF-II) on DNA and glycosaminoglycan (GAG) synthesis and the expression of matrix-related genes in equine articular cartilage explants and chondrocytes, respectively, with and without interleukin 1-β (IL1-β).

Sample Population—Articular cartilage from 12 adult horses.

Procedure—Articular cartilage was incubated in standard media with and without equine IL1-β (10 ng/mL) containing various concentrations of IGF-II for 72 hours. Synthesis of DNA and GAG was determined by incorporation of thymidine labeled with radioactive hydrogen (³H) and sulfate labeled with radioactive sulfur (³⁵S), respectively. Total GAG content of the explants and spent media was determined by use of the 1,9-dimethylmethylene blue assay. Northern blots of RNA from cultured equine articular cartilage chondrocytes were hybridized with cDNA of major matrix molecules.

Results—Insulin-like growth factor-II stimulated DNA and GAG synthesis at concentrations of 25 and 50 ng/mL, respectively. In cartilage explants conditioned with IL1-β, IGF-II stimulated DNA and GAG synthesis at concentrations of 500 and 50 ng/mL, respectively. Insulin-like growth factor-II had no effect on total GAG content as determined by the 1,9-dimethylmethylene blue assay. No specific effects on steady-state levels of messenger RNAs were observed.

Conclusions and Clinical Relevance—Insulin-like growth factor-II stimulated DNA and GAG synthesis in equine adult cartilage and may have potential application in vivo. (Am J Vet Res 2004;65:238–244)