Musculoskeletal ultrasonography of the elbow joint in dogs: applicability and evaluation protocol / Ultrassonografia musculoesquelética da articulação do cotovelo em cães: aplicabilidade e protocolo de avaliação

The elbow is a complex joint and has great clinical relevance in small animal medicine. Previous research in this area has been performed using radiographic and tomographic methods; however, there are limited studies on ultrasonography. The aims of this study was suggesting an evaluation protocol for elbow scan and describe the ultrasonographic anatomy of the elbow joint in dogs. Ten cross-breed dogs weighing 5-15kg underwent radiography and were selected for this ultrasonographic study. The protocol was established for the ultrasonographic description dividing the articular areas in the proximal, middle, and distal, lateral, cranial, medial, and caudal faces. The approach was performed in the longitudinal, transverse and oblique planes and the musculoskeletal structures were described according to the architecture, echogenicity and echotexture. Computed tomography and magnetic resonance imaging scans were obtained for one animal for comparison. Ultrasonography was effective in visualizing and analyzing muscles, tendons and ligaments. Bone contours and regions that have clinical significance such as the medial coronoid process and anconeus process were identified, but with limited access. Prior knowledge of the normal sonographic anatomy of the elbow joint, as well as its technical advantages and limitations will allow further studies related to the identification of musculoskeletal disorders.(AU)

O cotovelo é uma articulação complexa e tem grande relevância clínica na medicina veterinária de pequenos animais. Pesquisas prévias nesta área foram realizadas utilizando radiografias e tomografia computadorizada, entretanto há limitados estudos com ultrassonografia. O objetivo desse estudo é sugerir um protocolo de avaliação da articulação do cotovelo e descrever sua anatomia ultrassonográfica. Dez cães sem raça definida, pesando 5-15kg foram submetidos à radiografias e foram selecionados para o estudo ultrassonográfico. O protocolo foi estabelecido para a descrição anatômica ultrassonográfica dividindo as articulações em proximal, média e distal, faces lateral, cranial, medial e caudal. A abordagem foi realizada nos planos longitudinal, transverso e oblíquo e as estruturas foram descritas de acordo com a arquitetura, ecogenicidade e ecotextura. Tomografia computadorizada e ressonância magnética foram realizadas em um animal para comparação. A ultrassonografia foi efetiva na visualização e análise de músculos, tendões e ligamentos. Os contornos ósseos e regiões com significado clínico como o processo coronóide medial e o processo ancôneo foram identificados, mas com acesso limitado. Conhecimento prévio da anatomia ultrassonográfica normal da arquitetura do cotovelo, bem como suas vantagens e limitações, irão permitir estudos adicionais relacionados à identificação de desordens musculoesqueléticas.(AU)

Evaluation of sedative and antinociceptive effects of dexmedetomidine, midazolam and dexmedetomidine-midazolam in tegus (Salvator merianae).

OBJECTIVE: To evaluate dexmedetomidine, midazolam and dexmedetomidine-midazolam for sedation and antinociception in tegus. STUDY DESIGN: Prospective, crossover, randomized, blinded study. ANIMALS: Six healthy tegus (Salvator merianae) weighing 1.6±0.3 kg. METHODS: Tegus were administered intramuscularly saline (0.5 mL; CON), dexmedetomidine (0.2 mg kg-1; DX), midazolam (1 mg kg-1; MZ) and dexmedetomidine-midazolam (same doses; DM). Heart rate (HR) and respiratory frequency (fR) were recorded before treatment (baseline) and 15, 30 minutes, 1, 2, 3, 4, 6, 8, 12 and 24 hours after the treatments. Sedation scores were recorded according to resistance to manual restraint, posture and response to noxious stimulus, at baseline and 5, 10, 15, 30 minutes, 1, 2, 3, 4, 6, 8, 12 and 24 hours after the treatments. Antinociception was evaluated by measurement of latency of limb withdrawal reflex (LWR) to thermal stimulus, recorded at baseline and 15 minutes, 1, 2, 4, 8, 12 and 24 hours after the treatments. RESULTS: Lower HR (DX and DM) and fR (MZ, DX and DM) than CON were measured 15 minutes after the treatment and for up to 6 hours. Sedation was mild to moderate in MZ, deep in DM and absent in DX, although animals showed behavioral changes in DX, with increase in aggressiveness. Median (interquartile range) duration of sedation were 170 (50; 235) minutes in MZ and 230 (115; 235) minutes in DM. Recovery period was prolonged in both treatments, surpassing the duration of the experiment. Higher LWR than CON was detected from 15 minutes until 12 hours in DX and DM. CONCLUSIONS AND CLINICAL RELEVANCE: Midazolam provided sedation without antinociception, and dexmedetomidine provided antinociception without sedation. Drug combination increased the duration of sedation but not antinociception. Due to increased duration of sedation, reversal of effects with flumazenil and atipamezole should be considered after conclusion of clinical procedures.

Antinociceptive efficacy of intramuscular administration of morphine sulfate and butorphanol tartrate in tegus (Salvator merianae).

OBJECTIVE To evaluate the antinociceptive efficacy of IM morphine sulfate or butorphanol tartrate administration in tegus (Salvator merianae). ANIMALS 6 healthy juvenile (12- to 24-month-old) tegus (mean ± SD body weight, 1,484 ± 473 g). PROCEDURES In a crossover study design, tegus were randomly assigned to treatment order, with a minimum washout period of 15 days between treatments. Each of 5 treatments was administered IM in a forelimb: saline (0.9% NaCl) solution (0.5 mL), morphine sulfate (5 or 10 mg/kg), or butorphanol tartrate (5 or 10 mg/kg). A withdrawal latency test was used to evaluate antinociception, with a noxious thermal stimulus applied to the plantar surface of the hind limb before (0 hours; baseline) and 0.5, 1, 2, 3, 4, 6, 12, and 24 hours after each treatment. Observers were unaware of treatment received. RESULTS With saline solution, mean hind limb withdrawal latencies (interval to limb withdrawal from the thermal stimulus) remained constant, except at 12 hours. Tegus had higher than baseline mean withdrawal latencies between 0.5 and 1 hour and at 12 hours with morphine at 5 mg/kg and between 1 and 12 hours with morphine at 10 mg/kg. With butorphanol at 5 and 10 mg/kg, tegus maintained withdrawal responses similar to baseline at all assessment points. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that morphine, but not butorphanol, provided antinociception at 5 and 10 mg/kg in tegus as measured by thermal noxious stimulus testing. These data supported the hypothesis that µ-opioid (but not κ-opioid) receptor agonists provide antinociception in reptiles.

MOLECULAR DETECTION OF INFECTIOUS PATHOGENS OF THE UPPER RESPIRATORY TRACT IN CAPTIVE NONDOMESTIC FELIDS.

Upper respiratory tract disease is a complex infectious disease process with multiple pathogens involved. Identification of infectious agents in wild animals is of great importance for wildlife conservation. The aim of this study was to evaluate the molecular detection of feline herpesvirus type 1, feline calicivirus (FCV), Bordetella bronchiseptica , Chlamydophila felis , and Mycoplasma felis using ocular and nasal swabs in three species of captive nondomestic felids. Mycoplasma felis was detected in two ocular samples of Puma concolor and in one nasal sample of one Panthera onca . FCV was detected in association with M. felis in one P. concolor . The other pathogens tested were not detected. To the authors' knowledge, this is the first report of M. felis in nondomestic felids from Brazil.

Hyaluronidase administered with xylazine-tiletamine-zolazepam into adipose tissue shortens recovery from anesthesia in pigs.

OBJECTIVE: To evaluate the effect of hyaluronidase on uptake, duration and speed of elimination of xylazine-tiletamine-zolazepam administered in the subcutaneous fat over the dorsal lumbar region of swine. STUDY DESIGN: Blinded, randomized, crossover study. ANIMALS: Six healthy Landrace/Large White pigs weighing 132±24 kg (mean±standard deviation). METHODS: Animals were administered xylazine (1 mg kg-1) and tiletamine-zolazepam (8 mg kg-1) (control treatment, CON), or xylazine-tiletamine-zolazepam at the same doses with hyaluronidase (400 IU) (treatment HYA). The treatments were administered into the dorsal lumbar adipose tissue, 2.5-3.0 cm laterally from the spinous process of the second lumbar vertebra. The latency, anesthesia and recovery periods were measured. Heart rate, noninvasive systolic, diastolic, and mean arterial pressures, respiratory rate, hemoglobin oxygen saturation and rectal temperature were recorded every 10 minutes for up to 50 minutes. RESULTS: One animal in CON and one animal in HYA were responsive to stimulation and did not allow safe handling. No significant difference was found between treatments for latency (CON 11.3±5.9 minutes, HYA 7.4±5.1 minutes) and anesthesia (CON 53±53 minutes, HYA 49±38 minutes) periods. Recovery period was shorter in HYA (9±6 minutes) than in CON (32±16 minutes) (p < 0.05). Physiological variables were not significantly changed over time and were within accepted normal clinical limits for the species in both treatments. CONCLUSION AND CLINICAL RELEVANCE: Hyaluronidase (400 IU) administered into adipose tissue in pigs did not reduce the latency and duration of dissociative anesthesia, but was associated with faster recovery.

Inconsistency of allometric scaling for dissociative anesthesia of wild felids.

OBJECTIVE: To evaluate allometric scaling for ketamine-xylazine (KX) anesthesia in wild felids using domestic cats for reference. STUDY DESIGN: Prospective single-phase non-blinded study. ANIMALS: Six domestic cats and 13 wild felids (five Leopardus pardalis, five Puma concolor, one Panthera onca and two Panthera leo). METHODS: Six domestic cats (4.1 ± 0.8 kg, REF1) were anesthetized by intramuscular administration of ketamine (15 mg kg(-1) ) and xylazine (1 mg kg(-1) ). Wild cats were divided into three groups based on body weight: 12.9 ± 2.4 kg (G1; n = 7), 43.0 ± 15.7 kg (G2; n = 4) and 126.0 ± 7.8 kg (G3; n = 2). Ketamine and xylazine doses were calculated based on allometric scaling of the basal metabolic rate (BMR = 70 × body mass(0.75) ). Afterwards, the six domestic cats were administered mean KX doses calculated for G1 and G2 (REF2). The heart rate, systolic arterial pressure, respiratory frequency, pH, the venous partial pressure of carbon dioxide, bicarbonate and lactate concentrations were recorded for up to 60 minutes. RESULTS: Additional doses were required in 12 out of the 13 wild cats. Anesthesia was not achieved in G3. Latency periods in wild felids were longer than REF1 and REF2. Anesthesia duration in REF1 was longer than that in the other groups. Recovery from anesthesia in REF1 and REF2 was longer than G1 and G2. Physiological variables remained within the range limits for the species. G1 baseline lactate concentration was higher than in the other groups. CONCLUSION AND CLINICAL RELEVANCE: KX anesthesia established by allometric scaling of BMR from doses administered to domestic cats did not predict reliable anesthetic doses for wild cats. Dose rates calculated with this method must not be applied to these species.