Doppler evaluation of renal resistivity index in healthy conscious horses and donkeys

Abstract

The renal resistive index (RRI) is used as a measurement of downstream resistance in arteries. The aim of this study was to assess the RRI of the arcuate arteries by pulsed-wave Doppler ultrasonography in healthy conscious horses and donkeys, and to verify any differences related to age, breed, bodyweight (BW) or body condition (BCS). Thirty-three healthy conscious horses and nine donkeys had their systolic and diastolic flow velocities at the level of the arcuate arteries estimated by pulsed-wave Doppler ultrasound, and the RRI was calculated. The relationship of RRI with age, breed (Trotters vs. other breeds), bodyweight (BW), and body condition score (BCS) were evaluated. PW Doppler evaluation of RRI was successfully applied in most of the horses, but to date not in the donkeys. In horses, median RRI values for the right kidney (0.58±0.006) were statistically higher than for the left (0.51 ±0.006). For the donkeys the values were comparable. There was no significant difference in RRI between horses younger or older than 15 years, and between breeds in horses. No correlation with age, BW or BCS was found in either horses or donkeys.

Transabdominal Renal Doppler Ultrasound in Healthy Adult Holstein-Friesian Cows: A Pilot Study

“…Renal RI is influenced by numerous hemodynamic and physiological factors such as vascular compliance, different pressures (pulse, urethra, intra-abdominal) and plasma renin activity [ 16 ]. The RI values obtained in the present study were within the range of reference values reported for healthy adult humans [ 11 ], dogs and cats [ 10 , 12 ], and horses and donkeys [ 24 , 25 ].…”

“…Age, sex and body weight (BW) have been studied as potential factors influencing the RI in humans [ 11 , 19 ], dogs [ 20 ], cats [ 9 , 23 ], horses and donkeys [ 24 , 25 ]. Although sex has not been identified as an influential factor in any species, age [ 11 , 20 ] and BW can alter the RI [ 23 ].…”

“…Although sex has not been identified as an influential factor in any species, age [ 11 , 20 ] and BW can alter the RI [ 23 ]. Differences between right and left kidney RI have also been investigated in humans, dogs, horses, and cats, and although contradictory results have been reported [ 9 , 11 , 12 , 20 , 24 ], some difference can be observed in hypertensive patients or can be considered indicative of urinary obstruction [ 20 ] or a result of anatomical and physiological differences between the right and left kidney [ 25 ]. Other influencing factors such as breed and the effect of training have also been investigated in cats [ 26 ] and horses [ 24 ].…”

Changes in Renal Resistive Index Values in Healthy Puppies during the First Months of Life

“…In contrast, Tipisca et al [4] reported significantly higher RI values in the left than right kidneys in healthy cats. In horses, the RI in the right kidney was statistically higher than in the left kidney [13]. These authors reported that different RI values between both kidneys is difficult to explain.…”

“…These authors reported that different RI values between both kidneys is difficult to explain. Unless there were any microscopical differences in functional subunits which are not known, or technical factors, since ultrasonography is essentially an operator-dependent method [4,13].…”