Biomechanical evaluation of four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs

ABSTRACT Purpose: This study compared, through biomechanical evaluation under ventral flexion load, four surgical techniques for ventral stabilization of the atlantoaxial joint in dogs. Methods: In total, 28 identical atlantoaxial joint models were created by digital printing from computed tomography images of a dog, and the specimens were divided into four groups of seven. In each group, a different technique for ventral stabilization of the atlantoaxial joint was performed: transarticular lag screws, polyaxial screws, multiple screws and bone cement (polymethylmethacrylate-PMMA), and atlantoaxial plate. After the stabilization technique, biomechanical evaluation was performed under ventral flexion load, both with a predefined constant load and with a gradually increasing load until stabilization failure. Results: All specimens, regardless of stabilization technique, were able to support the predefined load without failing. However, the PMMA method provided significant more rigidity (p ≤ 0.05) and also best resisted the gradual increase in load, supporting a significantly higher maximum force (p ≤ 0.05). There was no statistical difference in flexural strength between the transarticular lag screws and plate groups. The polyaxial screws method was significantly less resistant to loading (p ≤ 0.05) than the other groups. Conclusions: The PMMA technique had biomechanical advantages in ventral atlantoaxial stabilization over the other evaluated methods.

Bone alignment after minimally invasive plate osteosynthesis of the tibia in dogs / Avaliação do alinhamento ósseo após osteossíntese minimamente invasiva com placa de tíbia em cães

ABSTRACT: This study assessed radiographically changes in tibial alignment in the frontal and sagittal planes in dogs that underwent minimally invasive plate osteosynthesis (MIPO) without the aid of image intensifiers. Radiographs of dogs with complete non-articular tibial fractures submitted to MIPO were included and evaluated, without the aid of a transoperative image intensifier and / or an association of implants. The tibial mechanical angles (mMPTA, mMDTA, mCaPTA and mCrDTA) were measured by three evaluators. The data obtained were compared with results from previously published studies. Twenty-seven animals were included in the study. The mean and standard deviation of the angular changes were as follows: mMPTA, 2.54° ± 3.10 (-1.1º to 8.7º); mMDTA, 0.03º ± 0.16 (-3.44º to 0.79º); mCaPTA, 37º ± 4.29 (-6.23º to 14.87º); and mCrDTA, 8.25° ± 5.53 (-0.2º to 17.28º). There was a negative correlation between "mCaPTA" and "mCrDTA". MIPO of the tibia without using image intensifiers and implant association can potentially cause angular changes, which can lead to clinically relevant deformities after bone healing.

RESUMO: Este estudo teve como objetivo avaliar radiograficamente as alterações no alinhamento da tíbia nos planos frontal e sagital em cães submetidos à osteossíntese minimamente invasiva com placa (MIPO) sem o auxílio de intensificadores de imagem. Foram incluídas e avaliadas radiografias de cães com fraturas completas da tíbia não articulares submetidos a MIPO, sem o auxílio de intensificador de imagem transoperatório e/ou associação de implantes. Os ângulos mecânicos tibiais (mMPTA, mMDTA, mCaPTA e mCrDTA) foram mensurados por três avaliadores. Os dados obtidos pela média de todas as avaliações foram comparados com resultados de estudos previamente publicados. Vinte e sete animais foram incluídos no estudo. A média e desvio padrão das alterações angulares foram os seguintes: mMPTA= 2,54° ± 3,10 (-1,1º a 8,7º); mMDTA= 0,03º ± 0,16 (-3,44º a 0,79º); mCaPTA= 37º ± 4,29 (-6,23º a 14,87º); e mCrDTA= 8,25 ° ± 5,53 (-0,2º a 17,28º). Houve uma correlação negativa entre "mCaPTA" e "mCrDTA". A realização de MIPO em tíbia sem o uso de intensificadores de imagem e associação de implantes pode causar alterações angulares, o que pode levar a deformidades clinicamente relevantes após a cicatrização óssea.

Correlation of serum acute-phase proteins with bone repair in rabbits (Oryctolagus cuniculus) submitted to partial radio ostectomy / Correlação do proteinograma sérico com a reparação óssea em coelhos (Oryctolagus cuniculus) submetidos à ostectomia parcial do rádio

ABSTRACT: Bone trauma triggers an acute inflammatory response, which can alter the serum concentration of acute-phase proteins (PFA). We aimed to evaluate the effectiveness of PFA measurement as a laboratory biomarker for inflammation related to bone regeneration. A partial ostectomy of the right radius was performed on 22 young male rabbits. The complete blood count, albumin, ceruloplasmin, haptoglobin, C-reactive protein, and transferrin levels were recorded and correlated with the radiographic evolution of bone healing. Statistically the best correlations with the inflammatory process and radiological findings were reported with haptoglobin and transferrin compared to the other measured PFAs. Haptoglobin and transferrin showed a maximum peak 24 and 36 hours after surgery, respectively. Transferrin displayed signs of decrease in the first 6 hours after surgery, in advance of the leukocyte response. The measurement of acute-phase proteins proved to be viable, considering the conditions in which the present study was carried out. Among all variables studied, haptoglobin and transferrin showed best correlation with the inflammatory process of bone healing. Additional studies are needed to determine the sensitivity of acute-phase proteins as predictors of complications in the treatment of fractures.

RESUMO: Os traumas ósseos desencadeiam resposta inflamatória aguda e consequentemente alteram a concentração sérica das proteínas de fase aguda (PFA), podendo essas representarem um parâmetro para avaliação da evolução do processo inflamatório relacionado à cicatrização óssea, assim como complicações. Objetivou-se avaliar a inter-relação da mensuração de PFAs com a repação óssea em coelhos submetidos à ostectomia parcial do rádio. Foram utilizados 22 coelhos, machos, jovens (160 a 180 dias) e peso médio (3,8 ± 0,3). Para acompanhamento da evolução do processo inflamatório foram realizados hemograma completo e mensuração de albumina, ceruloplasmina, haptoglobina, proteína C reativa e transferrina, além do acompanhamento radiológico. Foi observado a melhor correlação da haptoglobina e da transferrina junto ao processo inflamatório e achados radiológicos frente às demais PFAs mensuradas. A haptoglobina apresentou pico máximo 24 horas do pós-operatório e a transferrina após 36 horas, entretanto, essa última já mostrou indícios de diminuição nas primeiras 6 horas do pós-cirúrgico, antecipadamente à resposta leucocitária. Nas condições em que o presente estudo foi realizado, a mensuração das proteínas de fase aguda mostrou-se factível. Das proteínas estudadas, a haptoglobina e transferrina foram as que mostraram maior correlação com o processo inflamatório da cicatrização óssea. Estudos adicionais são necessários para determinar a sensibilidade das proteínas de fase aguda como previsores de complicações do tratamento das fraturas.

Canal flare index evaluation for different dog breeds / Avaliação do canal flare index femoral de diferentes raças de cães

ABSTRACT: This study determined the canal flare index (CFI) of four dog breeds using two distinct femoral regions as a reference. Thirty-five radiographs of the hip joints of Golden Retrievers (GRG), German Shepherds (GSG), Labrador Retrievers (LRG), and Rottweilers (RG) of both sexes were used. Seventy experimental units were submitted to CFI calculation. Objective (CFIob) and subjective (CFIsub) values of the CFI of each experimental unit were determined according to the anatomical reference used for the calculation. A significant difference in the CFIob between the Golden Retriever and German Shepherd breeds (1.68 ± 0.16 and 1.49 ± 0.08), and in the CFIsub between Golden Retriever, German Shepherd, and Rottweiler breeds (2.09 ± 0.31, 1.86 ± 0.11, and 1.84 ± 0.18) was reported. The subjective form of measurement showed higher values than the objective form (GRG: 2.09 ± 0.31; GSG: 1.86 ± 0.11; LRG: 2.07 ± 0.12; RG: 1.84 ± 0.18). The CFI values of each breed were similar, suggesting a certain racial pattern. A significant difference in the interobserver assessment for both CFIsub and CFIob, in all races was observed. The CFI analysis identified morphological patterns of the proximal femur in the different races. Results indicated the need for standardization of the anatomical references used to calculate the CFI because there were statistical differences among the measurements among the observers.

RESUMO: Objetivou-se determinar o canal flare index (CFI) de quatro raças específicas de cães, utilizando-se duas regiões femorais distintas como referência. Foram analisadas 35 radiografias de articulações coxofemorais de cães das raças Golden Retriever (GGR), Pastor Alemão (GPA), Labrador Retriever (GLR) e Rottweiler (GR), de ambos os sexos, configurando 70 unidades experimentais submetidas ao cálculo do CFI. Determinaram-se os valores objetivo (CFIob) e subjetivo (CFIsub) do CFI de cada unidade experimental de acordo com a referência anatômica utilizada para o cálculo. Houve diferença significativa do CFIob entre as raças Golden Retriever e Pastor Alemão (1,68 ± 0,16 e 1,49 ± 0,08), e do CFIsub entre as raças Golden Retriever, Pastor Alemão e Rottweiler (2,09 ± 0,31, 1,86 ± 0,11 e 1,84 ± 0,18). A forma subjetiva de mensuração apresentou valores maiores que a forma objetiva (GGR: 2,09 ± 0,31; GPA: 1,86 ± 0,11; GLR: 2,07 ± 0,12; GR: 1,84 ± 0,18). Os valores de CFI de cada raça se apresentaram similares, sugerindo haver determinado padrão racial. Houve diferença significativa na avaliação interobservadores, tanto do CFIsub quanto CFIob, em todas as raças. A análise do CFI identificou padrões morfológicos do fêmur proximal nas diferentes raças. Os resultados indicaram a necessidade de padronização dos referenciais anatômicos utilizados para o cálculo do CFI, uma vez que houve relevância estatística entre as diferentes mensurações entre os observadores.

Capital femoral physeal dysplasia in cats submited to ostectomy of the femoral head and neck / Displasia femoral capital em felinos submetidos a ostectomia da cabeça e colo femoral

ABSTRACT: This report described pathological fracture of the femoral head (physeal dysplasia) in four male cats (three mixed breed and one Bengal), with an average age of 16 months, treated by an ostectomy of the femoral head and neck. Three cats were neutered and one entire. All presented with mild intermittent lameness in the pelvic limbs. Displacement of the femoral epiphysis and resorption of the femoral neck were present and excision of the femoral head and remaining neck was performed in all cases. Hstological examination showed mild foci of compaction and trabecular fibrosis with deposition of fibrous connective tissue, permeated by granulation tissues, consistent with the original diagosis. Limb function improved in all patients from 2 to 4 weeks postoperatively. Diagnosis of physeal dysplasia is challenging and treatment is different from acute traumatic fractures. Femoral head and neck excision was considered a good alternative in these patients.

RESUMO: Este trabalho descreve a fratura patológica da cabeça do femur (displasia fiseal) em quatro machos (três raças mistas e um Bengal), com idade média de 16 meses, que foram tratados com ostectomia da cabeça e colo femorais. Três gatos eram castrados e um inteiro. Todos apresentaram leve claudicação intermitente nos membros pélvicos. O deslocamento da epífise femoral e a reabsorção do colo femoral estavam presentes, a excisão da cabeça e colo femoral foi realizada em todos os casos. O exame histológico mostrou focos de compacteção e fibrose trabecular com deposição de tecido conjuntivo fibroso, permeado por tecidos de granulação, consistentes com o suposto diagnóstico. A função dos membros melhorou em todos os paciente entre dois a quatro semanas pós-operatório. O diagnóstico da displasia fiseal pe desafiador e o tratamento é diferente das fraturas traumáticas agudas. A excisão de cabeça e colo femoral é considerada uma boa alternativa nesses pacientes.

Biomechanical evaluation of a new femoral stem design for total hip replacement in a canine model

ABSTRACT Purpose To evaluate the biomechanical properties of a novel total hip replacement femoral stem. Methods Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. Results Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. Conclusions The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.

Comparison of intraoperative nociception and postoperative acute pain after traditional or minimally invasive ovariohysterectomy in dogs

Many variations of ovariohysterectomy techniques have been described, including the traditional one and minimally invasive procedures. Non-laparoscopic Snook hook technique is an alternative for performing minimally invasive ovariohysterectomy. Few studies have been carried out in order to assess pain in animals submitted to minimally invasive surgeries, especially involving one of the most performed surgical procedures in veterinary practice. The aim of this study was to evaluate surgical duration, intraoperative nociception and acute postoperative pain after traditional ovariohysterectomy or minimally invasive non-laparoscopic technique in dogs using Snook hook. The hypothesis is that non-laparoscopic minimally invasive ovariohysterectomy would be faster and less painful than the conventional technique. Thirty dogs were divided into Traditional Group (TG = 15) and Minimally Invasive Group (MIG = 15). Heart rate, respiratory rate, systolic blood pressure, body temperature, oxyhemoglobin saturation, end-tidal carbon dioxide concentration (ETCO2) and end-tidal isoflurane concentration were evaluated before the surgery begins (M0), during incision (M1), clamping of the first ovarian pedicle (M2), second ovarian pedicle (M3), uterine cervix (M4), abdominal suture (M5) and at the end of surgery (M6). The modified Glasgow Pain Scale was used for acute postoperative pain assessment and Visual Analogue Scale (VAS) was used to assess the sensitivity of surgical wound. The level of significance established for all statistical analysis was 5%. Statistical differences were not observed between groups considering total surgical time and postoperative acute pain intensity (P > 0.05), in spite of MIG having shorter duration of surgery. There was no statistical difference between groups considering all intraoperative parameters except respiratory rate (TG < MIG; P < 0.05) and ETCO2 (MIG < TG; P < 0.05) at the moment of traction of the first ovarian pedicle (M2). Pain assessment by VAS showed statistical difference 24h after the end of surgery (TG < MIG) (P < 0.05). Both procedures were similar regarding intraoperative nociception and acute postoperative pain. It is possible that the sensation of pain in both procedures was blocked by the effectiveness of analgesics, once they might cause an inhibition of painful behaviors limiting a possible difference in pain identification. Higher respiratory stress observed in MIG at M2 and higher pain score by VAS noted in MIG 24 h after the end of surgery can be justified by greater traction of ovarian pedicle, due to limited surgical access of minimally invasive technique. Minimally invasive ovariohysterectomy non-laparoscopic seems to be potentially faster, probably due to the smaller size of the abdominal incision, which takes less time to be closed. In the present study, both techniques were performed by an experienced surgeon, providing safe procedures, nevertheless it is important to emphasize that iatrogenic injury can be caused by surgeons non-proficient in the Snook hook technique, considering the limited visualization of anatomical abdominal structures. Data obtained indicate that traditional ovariohysterectomy and non-laparoscopic Snook hook technique promote similar intraoperative nociception and acute postoperative pain, however minimally invasive procedure is potentially faster with less surgical trauma.(AU)

Classification, fixation techniques, complications and outcomes of femur fractures in dogs and cats: 61 cases (2015-2016) / Classificação, métodos de fixação, complicações e desfecho das fraturas de fêmur em cães e gatos: 61 casos (2015-2016)

ABSTRACT: The aim of this study was to retrospectively evaluate the frequency of femur fractures in dogs and cats in the routine of a school hospital, determining their classification, fixation methods, complications, and outcomes. A total of 61 animals, 50 (82.0%) dogs and 11 (18.0%) cats, had femoral fractures that were submitted to osteosynthesis. Sixty-two femoral fractures were evaluated. Single fractures in the distal epiphysis (n=25) were the most frequent (P=0.0001). Intramedullary pins were used in association with cerclage and tension band for osteosynthesis in proximal fractures. In diaphyseal fractures, bone plates and screws, two intramedullary pins (insulated or with cerclage) and Tie-In configuration were used. In distal fractures, modified Rush intramedullary pins, cross pins and Tie-In configuration were used. Comparing complication frequencies at fracture sites that required reintervention after osteosynthesis, a significant difference was observed (P=0.0253) between the diaphyseal (31.25%) and distal (7.14%) fractures independent of the technique used. We concluded that distal epiphyseal fractures were the most frequent in the routine of a school hospital. Distal epiphyseal fractures presented a lower frequency of complications for consolidation when treated with modified Rush intramedullary pins or crossed pins.

RESUMO: O objetivo deste estudo foi avaliar, retrospectivamente, a frequência das fraturas de fêmur em cães e gatos, na rotina de um hospital escola, determinando a classificação, métodos de fixação, complicações e desfecho. No total, 61 animais, 50 (82,0%) cães e 11 (18,0%) gatos, apresentaram fraturas de fêmur submetidas a osteossíntese. Sessenta e duas fraturas de fêmur foram avaliadas neste estudo. As fraturas simples localizadas na epífise distal (n=25) foram as mais frequentes (P=0,0001). Para osteossíntese das fraturas proximais, foram utilizados pinos intramedulares em associação a cerclagem e banda de tensão. Nas fraturas diafisárias, foram utilizadas placas ósseas e parafusos, dois pinos intramedulares (isolados ou com cerclagem) e fixador externo Tie-In e, nas fraturas distais, pinos intramedulares de Rush modificados, pinos cruzados e fixador externo Tie-In. Comparando-se a frequência de complicações que necessitaram reintervenção após osteossíntese, entre as localizações das fraturas, independente da técnica empregada, houve uma diferença significativa (P=0,0253) entre as diafisárias (31,25%) e distais (7,14%). Conclui-se que as fraturas epifisárias distais foram as mais frequentes na rotina de um hospital escola e, quando tratadas com pinos intramedulares de Rush modificados ou pinos cruzados, apresentaram menor frequência de complicações para a consolidação.

Comparison of morphine, ketoprofen and Arnica montana 6x and 30x per oral transmucosal or subcutaneous route for control of postoperative pain in cats subjected to hysterectomy with bilateral salpingo-oophorectomy / Comparação de morfina, cetoprofeno e Arnica montana 6x e 30x por via transmucosa oral ou subcutânea para control e de dor pós-operatória em gatas submetidas à histerectomia e ooforectomia bilateral

ABSTRACT: The postoperative analgesic effect of Arnica montana (Arnica) was compared to morphine and ketoprofen in 50 cats following hysterectomy with bilateral salpingo-oophorectomy (HSO). Cats were randomly allocated to five groups (n=10) and were treated 30 minutes before surgery and over 72 hours with 1ml of Arnica 30x per subcutaneous (SC) route (GA30SC); Arnica 30x per oral transmucosal route (P.O.) (GA30PO); Arnica 6x P.O. (GA6PO); morphine 0.1mg kg-1 SC (GM) SID or ketoprofen 2mg kg-1 SC (GK) before and 1mg kg-1 after surgery. Sedation and postoperative pain were assessed by means of a dynamic and interactive visual analogue scale (DIVAS) and variable count scale (VCS) and hyperalgesia using an esthesiometer. Whenever the VAS and VCS scores attained 33% of the maximum value, rescue analgesia was performed with morphine 0.3mg kg-1 per the intramuscular (IM) route. Other variables assessed were vomiting, defecation, urination, body weight and wound healing. Vomiting only occurred in animals treated with morphine. The groups did not differ in defecation, urination, body weight or wound healing. Hyperalgesia was detected only on the occasions that the criterion for rescue analgesia was met. One animal in GK and one in GM required rescue analgesia, differing from groups GA30SC, GA30PO and GA6PO, in which 4, 4 and 5 animals, respectively, required rescue analgesia. It can be concluded that ketoprofen and morphine were more efficacious than Arnica and that there was no difference among the various potencies and routes of administration of Arnica for postoperative analgesia in cats undergoing HSO.

RESUMO: Comparou-se o efeito analgésico de Arnica em relação à morfina ou cetoprofeno, no período pós-operatório, de 50 gatas submetidas à ovariossalpingohisterectomia (OSH). As gatas foram divididas em cinco grupos (n=10) e tratadas aleatoriamente 30 minutos antes da cirurgia por 72 horas com 1ml de Arnica 30D por via subcutânea (SC) (GA30SC); Arnica 30D por via oral (VO) (GA30VO); Arnica 6D VO (GA6VO); 0,1mg kg-1 de morfina SC (GM) TID ou 2mg kg-1 de cetoprofeno SC (GC) antes e 1mg kg-1 após a cirurgia SID. Foram avaliadas a sedação e a dor pós-operatória, por meio de escala analógica visual (EAV), escala de contagem variável (ECV) e hiperalgesia, esta última pelo estesiômetro. Quando os escores da ECV e EAV atingiram 33% do valor máximo, realizou-se resgate analgésico com 0,3mg kg-1 de morfina por via intramuscular (IM). Observou-se ocorrência de vômito, defecação, micção, alteração de peso e a cicatrização. Exceto nos animais tratados com morfina, não houve vômito. Não houve diferença entre os grupos para defecação, micção, peso e cicatrização. A hiperalgesia foi observada apenas nos momentos do resgate analgésico. Um animal de GC e um de GM receberam resgate analgésico, o que diferiu dos grupos GA30SC, GA30VO e GA6VO, onde, respectivamente, 4, 4 e 5 animais necessitaram resgate analgésico. Conclui-se que o cetoprofeno e a morfina foram mais eficazes que a Arnica e que, quanto à Arnica, não houve diferença nem entre as dinamizações e entre as vias SC e oral para analgesia de gatas submetidas à OSH.

Hemodynamics and bispectral index (BIS) of dogs anesthetized with midazolam and ketamine associated with medetomidine or dexmedetomidine and submitted to ovariohysterectomy / Avaliação hemodinâmica e do índice bispectral (BIS) de cadelas anestesiadas com midazolam e cetamina associados à medetomidina ou dexmedetomidina e submetidas a ovário-salpingo-histerectomia

Purpose: To evaluate hemodynamics and bispectral index (BIS) in bitches anesthetized with ketamine and midazolam in combination with dexmedetomidine or medetomidine and submitted to ovariohysterectomy. Methods: Twenty bitches pretreated with levomedetomidine and buprenorphine were anesthetized with 5 mg.kg-1 ketamine and 0.2 mg.kg-1 midazolam i.v. Continuous infusion of 0.4 mg.kg-1.h-1 midazolam and 20 mg.kg-1.h-1 ketamine was initiated in combination with DEX (n=10): 20 µg.kg-1.h-1 dexmedetomidine or MED (n=10): 30 µg.kg-1.h-1 medetomidine over 30 minutes. A pharmacokinetic study provided dexmedetomidine plasma concentration, set to be 3.0 ng.mL-1. Results: BIS decreased in both groups (P<0.05), but it was lower in DEX (P<0.05) as compared to MED. No differences were found in hemodynamic parameters (heart rate, systolic, diastolic and mean arterial pressure) between groups (P>0.05), but heart rate decreased in both groups, as compared to control values (P<0.05). Respiratory rate decreased (P<0.05) and expired end tidal CO2 increased progressively (P<0.05) and similarly in both groups. Anesthetic recovery period was similar between groups (P<0.05) with no adverse effects. Conclusion: Continuous administration of dexmedetomidine with calculated plasma concentration equal to 3 ng.mL-1 in combination with midazolam and ketamine provides suitable anesthesia for spay surgery in bitches, hemodynamic stability and calm awakening with no adverse effects.

Objetivo: Verificar o comportamento hemodinâmico e o índice bispectral de cadelas anestesiadas com cetamina e midazolam associados à dexmedetomidina ou medetomidina. Métodos: Vinte cadelas receberam pré-tratamento com levomepromazina e buprenorfina e foram anestesiadas com cetamina, 5 mg.kg-1 i.v., e midazolam, 0,2 mg.kg-1 i.v., seguidos da administração contínua de midazolam, 0,4 mg.kg-1.h-1, e cetamina, 20 mg.kg-1.h-1, associados, conforme o grupo, à: DEX (n=10): dexmedetomidina 20 µg.kg-1.h-1 ou MED (n=10): medetomidina 30 µg.kg-1.h-1, mantidos por 30 minutos. A dose de dexmedetomidina foi obtida por meio de estudo farmacocinético planejando-se concentração plasmática de 3,0 ng.mL-1. Resultados: Os valores do BIS diminuíram em ambos os grupos (P<0,05), mas foram menores no grupo DEX (P<0,05), em comparação com o grupo MED. Não houve diferença significativa nos atributos hemodinâmicos (frequência cardíaca, pressão arterial sistólica, diastólica e média) entre os grupos, mas a frequência cardíaca diminuiu em ambos os grupos em relação ao momento controle (P<0,05). A frequência respiratória diminuiu (P<0,05) e o CO2 expirado aumentou progressivamente em ambos os grupos (P<0,05). O tempo de recuperação anestésica foi semelhante entre os grupos (P>0,05), sem a presença de efeitos adversos. Conclusão: A administração contínua de dexmedetomidina em concentração plasmática calculada de 3 ng.mL-1, em combinação com midazolam e cetamina, resulta em plano anestésico adequado para castração de cadelas, estabilidade hemodinâmica e despertar tranquilo, sem efeitos adversos.

Artroplastia total coxofemoral em cães: estudo experimental com prótese nacional / Total hip arthroplasty in dogs: experimental study using a prosthesis made in Brazil

A prótese total da articulação coxofemoral representa uma das técnicas mais aceitas, nos Estados Unidos e na Europa, para o tratamento cirúrgico da displasia coxofemoral severa em cães. Entretanto, ainda é pouco difundida e estudada no Brasil. No presente trabalho, foi utilizada prótese confeccionada no Brasil, com o objetivo de avaliar a sua aplicação, evolução pós-operatória e complicações associadas. Foram utilizados dez cães, sadios e adultos. Todos foram submetidos ao procedimento de prótese total cimentada da articulação esquerda utilizando-se um componente femoral de cromo-cobalto, cabeça fixa, e uma cúpula acetabular de polietileno de alta densidade. As avaliações clínicas e radiográficas foram realizadas no pré-operatório e aos 30, 60, 90, 120 e 150 dias após a intervenção cirúrgica. A prótese total utilizada proporcionou um bom resultado funcional ao membro operado, em 80 por cento dos animais. As principais complicações relacionadas foram a luxação protética e a soltura do componente acetabular.

Total hip prosthesis is one of the most accepted methods used in the United States and Europe for the treatment of severe hip dysplasia in dogs. However, there are few studies with the technique and the procedure is still not well established in Brazil. A prosthesis made in Brazil was used. The purpose of this study was to evaluate its application and determine the postoperative finds and complications. Ten mature healthy dogs were used. A fixed-head cemented total hip prosthesis was applied on the left leg of the dogs. A chrome-cobalt femoral stem and high density polyetylene acetabular cup was used. Clinical and radiographic evaluations were performed before surgery and again at 30, 60, 90, 120 e 150 days post operation. Proper weight bearing was noticed on the operated limb in the majority of the dogs. The main complications were the dislocation and loosening of the acetabular cup.