Effects of oral propranolol on the resistive and pulsatility indices of major abdominal vasculatures in domestic short-haired cats.

BACKGROUND: No study has been performed regarding the effects of oral administration of propranolol on pulse-wave spectral Doppler indices of major abdominal vessels in healthy adult cats. OBJECTIVE: The objective of this study was to assess the pulse-wave spectral Doppler indices of abdominal aorta, caudal vena cava, and portal vein in clinically normal adult domestic short-haired (DSH) cats, before and after propranolol ingestion. METHODS: Twenty intact adult client-owned DSH cats were evaluated (10 males and 10 females). A duplex Doppler ultrasonography machine with a 10-MHz frequency linear transducer was used. Peak systolic velocity, end-diastolic velocity (EDV), resistive index (RI), pulsatility index (PI), and pressure gradient were measured. All the cats received 1 mg/kg of propranolol tablet, and after 2 h, ultrasonography measurements were repeated. RESULTS: The mean RI of the aorta and caudal vena cava significantly decreased in male cats following oral administration of propranolol after 2 h (p = 0.03, p = 0.02). In the caudal vena cava, the PI decreased from 2.98 ± 0.62 to 1.15 ± 0.19 post-propranolol ingestion (p = 0.01). The mean EDV in the caudal vena cava of males and portal veins of females significantly decreased after propranolol ingestion (p = 0.04, p = 0.02). CONCLUSIONS: This study showed that propranolol decreased the PI of the aorta and PI and RI of the caudal vena cava in healthy normal cats 2 h post-propranolol ingestion at the dosage of 1 mg/kg.

Effect of medetomidine on left ventricular outflow tract velocity in cats: A Doppler echocardiography study.

The purpose of the present study was to evaluate effects of medetomidine on left ventricular outflow tract (LVOT) velocity in domestic short-haired cats. Eighteen healthy adult male domestic short-haired cats were used for this study. All animals were client-owned. Echocardiography machine with 7.50 MHz transducer was used. Specific veterinary two-dimensional and pulse-waved echocardiogram images in apical five chamber right parasternal view were obtained and blood velocity in LVOT was calculated. After baseline echocardiographic recordings, 0.04 mg kg-1 of medetomidine was intramuscularly administered to each animal and LVOT velocity was calculated after 15 (T15), 50 (T30) and 80 (T80) min following drug administration. The LVOT velocity values (mean SEM) of cats in baseline were 1.06 0.04 m sec-1. There were significant differences between baseline and T15 and T30 regarding mean LVOT values. Age and weight had no significant effect on LVOT velocity values. The LVOT velocity values of T15, T50 and T80 were 0.77 0.04, 0.80 0.02 and 0.960.03 m sec-1, respectively. Our findings revealed significant decrease in mean LVOT velocity up to 50 min following medetomidine administration. The present study determined normal LVOT velocity range for a small population of cats before and after intra-muscular medetomidine administration.

Effects of medetomidine on intra-renal arteries resistive and pulsatility indices in clinically normal adult domestic shorthair cats.

The aim of this study was to determine the effects of intramuscular injection of medetomidine on intra-renal arteries resistive and pulsatility indices by duplex Doppler ultrasonography in clinically normal adult domestic shorthair cats. For this purpose, twenty-six neutered adult healthy domestic shorthair cats (13 females and 13 males) were evaluated. B-mode, color Doppler and pulsed wave Doppler ultrasonography of right and left kidneys were performed to record the resistive index (RI) and pulsatility index (PI) of intra-renal arteries. To minimize statistical errors, the mean RI and PI were determined for each kidney by averaging three waveforms from the intra-renal arteries. Twenty-four hr later, the cats were sedated by 0.04 mg kg-1 intramuscular administration of medetomidine. All the Doppler measurements were repeated 15 min after drug administration. Mean ± standard deviation )SD( of PI and RI of the intra-renal arteries before administration of intramuscular medetomidine were 1.03 ± 0.08 and 0.61 ± 0.02, respectively. Fifteen min after medetomidine administration, the mean ± SD of PI and RI values were 1.04 ± 0.08 and 0.61 ± 0.02, respectively. Significant differences were not detected in mean PI and RI values before and 15 min after drug administration. Our findings showed that intramuscular administration of medetomidine does not cause significant hemodynamic changes in the intra-renal arteries after 15 min.