Evaluation of the cardiopulmonary and antinociceptive effects of bupivacaine administered epidurally at the first lumbar vertebra in awake dogs

ABSTRACT The aim of this study was to evaluate the effect of epidural bupivacaine administration at the first lumbar vertebra on cardiopulmonary variables, arterial blood gases and anti-nociception. Sixteen healthy female dogs were randomly assigned into two groups based on bupivacaine dose: G1 group, 1mg kg-1 or G2 group, 2mg kg-1, diluted in the same final volume (1mL4kg-1). Cardiopulmonary variables were measured and arterial blood gas was collected (T0), it was repeated 10 minutes after intravenous administration of butorphanol 0.4mg kg -1 (T1). Anesthesia was induced with intravenous etomidate at 2mg kg-1 and the epidural catheter was introduced and placed at the first lumbar vertebra. Thirty minutes later, bupivacaine was administered epidurally. Cardiopulmonary measurements and arterial blood gas analysis were recorded at 10 minute intervals (T2 to T6). Evaluation of pre surgical anti-nociception was performed at 5 minute intervals for 30 minutes by clamping the hind limbs, anus, vulva, and tail with the dogs awake. Subsequently, ovariohysterectomy was performed and adequacy of surgical anti-nociception was evaluated at 5 time points. Parametric data were analyzed using the F test with a <0.05 significance. After bupivacaine administration, there were differences between groups just for bicarbonate means (HCO3 -) on T6 (P=0.0198), with 18.7±1.3 and 20.4±0.8 for G1 and G2, respectively. After T1, before bupivacaine administration, both groups presented a slightly lower pH, base excess (BE), the end-tidal carbon dioxide tension (PECO2), and partial pressure of carbon dioxide (PaCO2), suggesting mild metabolic acidosis. G2 showed better antinociceptive effect both before and during surgery. It was possible to perform ovariohysterectomy in 87.5% of the G2 bitches and 25% of the G1 bitches. The two doses of bupivacaine evaluated do not cause important alterations in the studied parameters and the dose of 2mg kg-1 results in a better antinociceptive effect

Acoustic radiation force impulse (ARFI) elastography of testicular disorders in dogs: preliminary results

The aim of this study was to describe the use of acoustic radiation force impulse (ARFI) elastography in the evaluation of testicular disorders in dogs. Eighteen dogs with testicular disorders (thirty-six testicles) were assessed. Echotexture, size, contours and margins of testes were analysed by ultrasonography. Deformities and tissue stiffness (greyscale and homogenous or heterogeneous) were evaluated by qualitative elastography and shear velocity was determined quantitatively. Subsequent to orchiectomy, testicular samples were collected for histopathology analysis and thirty-six disorders were identified. Qualitative elastography revealed that normal healthy testicular tissues were homogenous and not pliable while the affected testicles had alterations in tissue stiffness and homogeneity. The values obtained for quantitative elastography of the testicular tissues were: normal/healthy - 1.30±0.12 m/s; degenerated - 0.97±0.08 m/s; atrophied - 2.00±0.35 m/s; hypoplastic - 0.82±0.2 m/s; cystic - 1.32±0.18 m/s; orchitis - 2.68±0.42 m/s; interstitial cell tumours - 3.32±0.65 m/s; sertolioma - 2.99±0.07 m/s and leydigoma - 2.73±0.37. ARFI elastography of abnormal testes proved to be an applicable and complementary technique in the diagnosis of testicular disease in dogs

B-mode and Doppler ultrasonography of adrenal glands of healthy dogs

ABSTRACT The aim of this study was to determine the vascular indices of adrenal blood flow in healthy dogs (systolic velocity - SV; diastolic velocity - DV; resistance index - RI). Eighteen dogs (thirty six adrenal) were studied. Physical examination, biochemical profile and dexamethasone suppression test were performed to determine general health status. Echotexture, size, contours and margins, and overall shape of the adrenal gland (right and left) were assessed via ultrasound. By spectral Doppler of the phrenic-abdominal artery, the SV, DV, and RI were acquired. Animals did not show alterations in clinical and laboratory examination and suppression of cortisol. Normal homogeneous and echotexture, regular contours and margins and normal shape and size were verified via B mode. Spectral Doppler of the phrenic-abdominal artery showed monophasic-patterned waves and low vascular resistance and systolic peak evident with means values: left adrenal - SV = 31.34cm/s, DV = 9.54cm/s and RI = 0.69; and right adrenal - SV = 27.83cm/s, DV = 7.71cm/s and RI = 0.68. Doppler evaluation of adrenal was easily implemented and may provide base line data in the study, allowing for the use of this technique as a diagnostic tool for diseases of the dog's adrenal

Spleen evaluation using contrast enhanced ultrasonography and Doppler in dogs with subclinical ehrlichiosis

The aim of this study was to evaluate the splenic parenchyma of dogs with subclinical ehrlichiosis using Doppler and contrast-enhanced ultrasonography and provide reference values for this organ in affected animals. Seventeen dogs naturally infected with E. canis were selected for this study. Splenic parenchyma echotexture and echogenicity, size and borders were determined by ultrasound scan. The vascular indices of the splenic artery were determined by Doppler. SonoVue, at 0.1mL per animal, was used in microbubble contrast-enhanced ultrasonography to determine wash in, wash out and peak enhancement time in the splenic tissue. B-mode ultrasonography revealed splenomegaly with rounded borders, heterogeneous echotexture and mixed echogenicity. The vascular indices of the splenic artery were: systolic velocity of 22.59±8.07cm/s, diastolic velocity of 5.25±4.66cm/s and resistance index of 0.71±0.14; values not yet reported in Veterinary Medicine. Contrast-enhanced ultrasonography recorded wash in time of 5.31±0.7s, peak enhancement time of 18.56±2.90s and wash out time of 94.56±35.21s. The combination of conventional ultrasonography of the spleen and hemodynamic evaluation by Doppler and contrast-enhanced ultrasonography is important for the diagnosis of canine ehrlichiosis and could help monitor the clinical evolution of subclinical cases

Acoustic radiation force impulse (ARFI) elastography of adrenal glands in healthy adult dogs

ABSTRACT To describe the ARFI elastography in the evaluation of the adrenal glands in adult dogs, to evaluate the stiffness of adrenal parenchyma and to determine the qualitative and quantitative standards of the ARFI technique, which have not yet been described in veterinary medicine. Sixty adrenal glands from thirty healthy adult dogs were evaluated by B-mode and qualitative and quantitative ARFI elastography to assess the stiffness of healthy parenchyma and to determine the quality and quantity (shear velocity) standards of ARFI technique in body, cranial and caudal adrenal poles. Findings of ultrasonography evaluations were normal. Qualitative elastography showed that adrenal glands were not deformable and presented homogeneous middle-gray areas. The results of shear wave velocity were similar statically (P = 0.3087): 1) left adrenal - 1.42 m/s for cranial polar, 1.31 m/s for body region, and 1.71 m/s for caudal polar; 2) right adrenal - 1.42 m/s for cranial polar, 1.74 m/s for body region and 1.63 m/s for caudal pole. Quantitative and qualitative ARFI elastography of dogs' adrenal glands is feasible, well tolerated, easily implemented and may provide baseline data in the study of this structure to allow the use of ARFI