In Part 1, amphotericin B-induced synovitis of the left tarsocrural joint was used to create hindlimb lameness in 11 horses. Caudal epidural catheters were placed and advanced to the lumbosacral region. Baseline heart and respiratory rates were recorded and horses were videotaped at a walk and trot. Treated horses received 0.2 mg/kg morphine sulfate and 30 ug/kg detomidine hydrochloride through the epidural catheter; control horses received an equivalent volume of physiologic saline solution through the catheter. At hourly intervals after epidural injection for a total of 6 hours, heart and respiratory rates were recorded and horses were videotaped walking and trotting. At the end of the observation period, video recordings were scrambled onto a master videotape. Lamenesses were scored by 3 investigators. Lameness grades, heart rates and respiratory rates were compared. There was a significant decrease in lameness grades after treatment with epidural morphine and detomidine. Initially, heart rates significantly increased in control horses and decreased in treated horses. A similar trend occurred for respiratory rates. In Part 2, caudal epidural catheters were used to administer injections to 10 horses every 12 hours for 14 days. Treated horses received 0.2 nlg/kg morphine sulfate and 30 ug/kg detomidine hydrochloride, and control horses received an equivalent volume of physiologic saline solution. Body weights were recorded on days 1 and 14. Rectal temperature, heart rate, respiratory rate and gastrointestinal motility were recorded twice daily, and daily hay and water consumption was measured. Horses were euthanatized day 15. Atlanto-occipital cerebrospinal fluid samples were submitted for bacteriologic culture and determination of white and red blood cell counts and protein and glucose concentrations. Post mortem examinations were performed and representative samples of the spinal cord and surrounding tissues were taken from cervicothoracic, thoracolumbar, lumbosacral, sacral and catheter entry point regions. Spinal tissue segments from these regions were graded for histologic degree of inflammation and fibrosis. Cerebrospinal fluid values and spinal tissue segment inflammation and fibrosis grades were compared between control and treated horses, and between all 10 catheterized study horses and 6 uncatheterized horses. No problems were encountered with epidural catheter maintenance or injection. No significant difference was identified in body weight change, daily variables or hay and water consumption between control and treated horses. All cerebrospinal fluid cultures were negative for growth. No significant difference in cerebrospinal fluid values or spinal tissue inflammation or fibrosis grades for any segment was demonstrated between control and treated horses. However, when compared to uncatheterized horses, cerebrospinal fluid red blood cell counts were marginally higher and protein concentrations were significantly higher in catheterized horses. As well, lumbosacral and sacral spinal tissue segment inflammation grades and sacral segment fibrosis grades were significantly higher in catheterized compared to uncatheterized horses. Results of these studies indicate that an epidural combination of morphine and detomidine provides profound hindlimb analgesia in horses and is not associated with apparent adverse systemic effects. Localized epidural inflammation and fibrosis appear to be catheter-related. / Master of Science

Orientador: Frederico Ozanam Papa / Resumo: RESUMO A indução farmacológica da ejaculação é uma alternativa utilizada para aumentar a função ejaculatória de garanhões incapazes de ejacularem pelos métodos tradicionais de coleta de sêmen. No entanto, os protocolos desenvolvidos até o presente momento apresentam baixas taxas de sucesso na indução da ejaculação, alta variabilidade de doses, vias de administração e efeitos adversos. A ocitocina é um hormônio que participa ativamente no desencadeamento da ejaculação, no entanto, não existem estudos avaliando sua atuação em protocolos de indução farmacológica da ejaculação. Nesse sentido, o presente estudo teve por objetivos: 1) Comparar a eficiência de diferentes protocolos na indução da ejaculação; 2) A IX - Imipramina (3/mg/kg/v.o) + xilazina (0,66/mg/kg/i.v); IXO - Imipramina (3/mg/kg/v.o) + xilazina (0,66/mg/kg/i.v) + ocitocina (20UI/i.v); D- detomidina (0,02/mg/kg/i.v); DO - detomidina (0,02/mg/kg/i.v) + ocitocina (20 UI/i.v); ID-Imipramina (3mg/kg/ v.o) + detomidina (0,02mg/kg/i.v); IDO-Imipramina (3mg/kg/v.o) + detomidina (0,02mg/kg/i.v) + ocitocina (20 UI/i.v); IO- Imipramina (3mg/kg/v.o) + ocitocina (20 UI/i.v). xiv ocitocina quando adicionada aos protocolos; 3) Comparar os parâmetros seminais de ejaculados coletados em vagina artificial e por indução farmacológica da ejaculação. Foram avaliados os protocolos X - Xilazina (0,66/ valiar a eficiência da mg/kg/i.v); XO - xilazina (0,66/mg/kg/i.v) + ocitocina (20UI/i.v); Nenhum... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The pharmacological induction of ejaculation has been an alternative used to increase ejaculatory function of stallions incapable of ejaculating by the traditional methods of semen collection. However, the protocols developed to date are available in high rate of dose variation, routes of administration, adverse effects and ejaculation rates. In general, pharmacological protocols have shown low success rates in inducing ejaculation. Thus, the aims of the study were: 1) Compare the efficiency of different protocols to induce ex copula ejaculation when detomidine and oxytocin was added to the protocols; 2) Compare seminal parameters between in copula and ex copula ejaculates; We evaluated the nine protocols to ex copula ejaculation: X - xylazine (0.66mg/kg/ i.v); XO - xylazine + oxytocin (20UI/i.v); IX - imipramine (3mg/kg/v.o) + xylazine (0.66mg/kg/i.v); IXO - imipramine (3mg/kg/v.o) + xylazine (0.66 mg/kg/i.v) + oxytocin (20UI); D - detomidine (0.02mg/kg/i.v); DO - detomidine (0.02mg/kg/i.v) + oxytocin (20UI/i.v); ID - imipramine (3mg/kg/v.o) + detomidine (0.02mg/kg/i.v); IDO- imipramine (3mg/kg/v.o) + detomidine (0.02mg/kg/i.v) + oxytocin (20 UI/ i.v); IO- imipramine (3mg/kg/v.o) + oxytocin (20 UI/i.v). Four young stallions (2-3 y old) and 12 sexually mature stallions (6 to 26 y old) were each submitted to 2 treatment trials conducted at 3-day intervals. Induced ejaculates were collected into a plastic bag and compared with in copula ejaculates. None of the 4 young stallions... (Complete abstract click electronic access below) / Mestre

Alpha 2 agonists are frequently used in equine medicine. This study focused primarily on α2 agonist-induced changes in PCV and TSP. A secondary aim of this study was to investigate the effects of α2 agonist on selected serum biochemical parameters and splenic size in order to identify potential causes for the changes seen in PCV and TSP. Four healthy adult mares were treated in a blinded, randomized, cross-over design with a single dose of xylazine (0.5 mg/kg), romifidine (0.04 mg/kg) or detomidine (0.01 mg/kg) intravenously, or detomidine (0.02 mg/kg) intramuscularly. A 1-week washout period was allowed between treatments. Haematology, TSP, COP, plasma osmolality, glucose, BUN, serum lactate, electrolytes, venous blood pH, ultrasonographic splenic size and degree of clinical sedation were evaluated at different time points post-injection and compared to baseline values. All treatments induced similar clinical sedation in the mares. A significant change over time in PCV and TSP following each treatment was identified, with overall median (range) maximal reductions compared to baseline of 20.9% (12.9 - 27.3%) and 5.8% (3.0 - 10.3%), respectively. Additionally, changes over time were significant for RBC count, BUN, COP and Ca2+, which decreased; and glucose, plasma osmolality, Na+ and splenic size, which increased, when compared to baseline. There was no significant main effect of treatment on PCV, TSP or any other parameters measured except for glucose. This study concluded that changes in PCV, TSP and other biochemical parameters induced by α2 agonists should be taken into consideration when assessing critically ill horses that received these drugs. There was evidence of splenic RBC sequestration as well as fluid shifts; therefore, the results suggest a multifactorial cause for the changes in PCV and TSP. / Dissertation (MSc)--University of Pretoria, 2011. / Companion Animal Clinical Studies / unrestricted