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  • Author or Editor: Benjamin J. Ahern x
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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.

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in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate the analgesic properties of transdermally administered fentanyl and IM administered buprenorphine in sheep undergoing unilateral tibial osteotomy.

Animals—20 mature sheep.

Procedures—Fentanyl patches (n = 15 sheep) or placebo patches (5 sheep) were applied 12 hours before sheep underwent general anesthesia and a unilateral tibial osteotomy. Buprenorphine was administered to the placebo group every 6 hours commencing at time of induction. Signs of pain were assessed every 12 hours after surgery by 2 independent observers unaware of treatment groups.

Results—There were no differences in preoperative and intraoperative physiologic data between the 2 groups. Sheep treated with fentanyl required less preoperative administration of diazepam for sedation and had significantly lower postoperative pain scores, compared with those treated with buprenorphine. No complications associated with the antebrachium at the site of patch application were detected.

Conclusions and Clinical Relevance—Under the conditions of this study, transdermally administered fentanyl was a superior option to IM administered buprenorphine for alleviation of postoperative orthopedic pain in sheep. This information can be used to assist clinicians in the development of a rational analgesic regimen for research and clinical patients.

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in American Journal of Veterinary Research

Abstract

Objective—To investigate the pharmacokinetics of fentanyl administered transdermally and IV in sheep.

Animals—21 adult female sheep.

Procedures—Fentanyl was administered IV to 6 healthy sheep. Transdermal fentanyl patches (TFPs) were applied to 15 sheep 12 hours prior to general anesthesia and surgery. Seria blood samples were collected for 18 hours after IV injection and 84 hours after TFP application. Fentanyl concentrations were quantified via liquid chromatography-mass spectrometry, and pharmacokinetic values were estimated.

Results—All sheep completed the study without complications. Following a dose of 2.5g/kg administered IV, the half-life was 3.08 hours (range, 2.20 to 3.36 hours), volume of distribution at steady state was 8.86 L/kg (range, 5.55 to 15.04 L/kg), and systemic clearance was 3.62 L/kg/h (range, 2.51 to 5.39 L/kg/h). The TFPs were applied at a mean dose of 2.05 g/kg/h. Time to maximum plasma concentration and maximal concentration were 12 hours (range, 4 to 24 hours) and 1.30 ng/mL (range, 0.62 to 2.73 ng/mL), respectively. Fentanyl concentrations were maintained at > 0.5 ng/mL for 40 hours after TFP application.

Conclusions and Clinical Relevance—IV administration of fentanyl resulted in a short half-life. Application of a TFP resulted in stable blood fentanyl concentrations in sheep. (Am J Vet Res 2010;71:1127—1132)

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in American Journal of Veterinary Research

Abstract

Objective—To evaluate effects of apheresis on mesenchymal stem cells (MSCs) and compare those MSCs with MSCs obtained from adipose tissue or bone marrow (BM).

Sample Population—Samples obtained from 6 adult horses.

Procedures—Samples of blood from a peripheral vein, adipose tissue, and BM aspirate were obtained from each horse. Samples were processed via apheresis of blood and techniques reported elsewhere for adipose tissue and BM. Cultures were maintained until adherence and subsequently were subjected to differentiation protocols to evaluate adipogenic, osteoblastogenic, and chondrogenic potential.

Results—Apheresis product had a significantly higher mononuclear percentage, higher platelet count, and lower RBC count, compared with values for peripheral blood. No cell adherence to the tissue culture plates was detected for the apheresis product. Adherence was detected for 6 of 6 adipose-derived and 4 of 6 BM-derived samples. Variations in efficiency were detected for differentiation of adipose- and BM-derived cells into adipocytes, chondrocytes, and osteoblasts.

Conclusions and Clinical Relevance—Apheresis was able to concentrate mononuclear cells and reduce RBC contamination. However, the apheresis product was unable to adhere to the tissue culture plates. In matched horses, adipose- and BM-derived MSCs were capable of producing lipids, glycosaminoglycan, and mineral. The BM was vastly superior to adipose tissue as a source of MSCs with osteoblastogenic potential in matched horses. Additional studies will be necessary to optimize apheresis techniques for horses before peripheral blood can be considered a suitable source for multipotential cells for use in cell-based treatments.

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in American Journal of Veterinary Research