The effect of axial and abaxial release on meniscal displacement in the dog.

The meniscal release (MR) is used to minimize meniscal pathology after Tibial Plateau Leveling Osteotomy (TPLO) surgery. The purposes of this study were: (i) to describe meniscal orientation in a unaltered cadaveric canine stifle, a cruciate deficient stifle, TPLO repaired stifle with and without the MR using magnetic resonance imaging; (ii) to determine if the abaxial release is equivalent to the axial release in its ability to affect caudal pole displacement in a TPLO repaired stifle and (iii) to evaluate with MRI the effect of MR on the femorotibiol articular cartilage contact area in a TPLO repaired stifle. Briefly, cadaver limbs were placed into a jig designed to mimic a weight-bearing stance at 140 degrees and 90 degrees at the stifle. The limbs were sequentially evaluated from the unaltered state; after cranial cruciate ligament transection; after TPLO stabilization; and finally after a meniscal release. No significant difference was found between the intrameniscal area (IMA) of the abaxial and axial meniscal releases although there was an increase in the IMA after the meniscal release compared to the IMA in the normal, cranial cruciate ligament deficient stifle, and TPLO stabilized stifle. In the abaxial release, a meniscal remnant remained in situ and provided a space effect between the femur and the tibial plateau. This is in contrast to the axial meniscal release, where the entire caudal pole of the medial meniscus relocated caudolaterally and consequently permitted more direct femorotibial contact. Overall, however, there was evidence of caudal pole compression of the medial meniscus throughout the MRI series which was ameliorated by either of the MR procedures.

The effect of a combination of medetomidine-butorphanol and medetomidine, butorphanol, atropine on glomerular filtration rate in dogs.

The effects of intramuscularly administered medetomidine and butorphanol (MB), and medetomidine, butorphanol, atropine (MBA) on glomerular filtration rate (GFR) were determined in six dogs as measured by 99m-Tc-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA) nuclear scintigraphy. Direct systolic, diastolic, and mean arterial blood pressures and heart rate were measured at regular time intervals before, during, and after GFR calculations. The mean GFR measurement following MB was significantly greater (4.44 ml/min/kg) than following MBA (3.82 ml/min/kg) or saline treatment (3.41 ml/min/kg). There was no significant difference between the mean GFR measurements following MBA injection and following saline injection. Diastolic and mean arterial pressures following MBA injection were significantly higher than the values recorded after either MB or saline alone. Heart rate following MB administration was significantly lower than that recorded for dogs receiving MBA or saline alone. The results of this study indicate that the administration of medetomidine in combination with butorphanol significantly increases total GFR in healthy dogs, while the administration of the combination of medetomidine, butorphanol, and atropine does not.