Radiographic characterization of diaphragmatic excursion in halothane anesthetized ponies: Effect of mode of ventilation and muscle paralysis

A radiographic technique was used to identify and characterize segmental diaphragmatic movement in anesthetized ponies breathing spontaneously and with controlled ventilation with and without muscle relaxant-induced paralysis. Paralyzed mechanically ventilated ponies were also studied at varying peak inspiratory pressures. Controlled ventilation induced a change in pattern of diaphragmatic displacement which was accentuated by paralysis and increased inspiratory pressure. In conclusion, these results indicate that uneven distribution of inspired gases is not corrected by mechanical ventilation. Furthermore, increased tidal volume during mechanical ventilation is largely wasted because this increased volume is distributed principally to the poorly perfused nondependent lung. Thus, while mechanical ventilation can alleviate hypoventilation, i.e., will decrease P_aCO₂, it will be of limited value in relieving arterial hypoxemia due to venous admixture in anesthetized patients.     

A distinct Mendelian autosomal recessive syndrome involving the association of anotia, palate agenesis, bifid tongue, and polydactyly in the dog.

A presumed genetic syndrome is described in a family of St. Bernards. Four identically affected littermates presented the association of palate agenesis, anotia, incomplete bifid tongue, preaxial hind paw polydactyly, and an extra thoracic vertebra and rib. Pedigree analysis is compatible with an autosomal recessive gene.     

A comparison of the clinical field efficacy and safety of florfenicol and tilmicosin for the treatment of undifferentiated bovine respiratory disease of cattle in western Canada.

We compared the field efficacy of a new antibiotic, florfenicol, with tilmicosin in the treatment of naturally occurring undifferentiated bovine respiratory disease. Beef calves with rectal temperatures greater than 40.5 degrees C and signs compatible with undifferentiated bovine respiratory disease were entered into the trial. Calves were randomly assigned to receive either florfenicol (20 mg/kg bodyweight intramuscularly; 2 injections 48 h apart) or tilmicosin (10 mg/kg bodyweight subcutaneously; 1 injection). Clinical measures of efficacy included mortality, rectal temperature, illness index score, assessment of treatment success or failure, and the number of relapses or reinfections. Performance was assessed based on weight gains from day 0 to day 90. Two hundred and twenty calves entered the trial; 112 received florfenicol and 108 received tilmicosin. Seventeen deaths occurred between day 0 and day 90, but only 10 during the 28-day trial period. Seven calves receiving tilmicosin died, compared with 3 receiving florfenicol (P = 0.20). Of the 220 initial treatments, 45 (20%) were categorized as treatment failures; 27 in the tilmicosin group and 18 in the florfenicol group (P = 0.10). The number of calves experiencing a 2nd relapse was significantly different, with 17 of 30 (57%) calves on tilmicosin compared with 7 of 26 (27%) calves on florfenicol relapsing at least twice (P = 0.02). Average daily gains over 90 days were 1.55 kg/day for florfenicol-treated calves and 1.51 kg/day for tilmicosin-treated calves. No significant adverse reactions were noticed with either drug. Results indicate that florfenicol and tilmicosin are comparable in the treatment of undifferentiated bovine respiratory disease in western Canada.     

Management of disc-associated wobbler syndrome with a partial slot fenestration and position screw technique

A previously unpublished surgical technique for the management of disc-associated wobbler syndrome is described. A series of 17 middle-aged dobermanns (mean age 7·4 years) with this condition were managed by a technique of partial slot fenestration and position screw fixation of the affected disc space (C6/7 in all cases). One patient was lost to follow-up and, of the remaining 16 cases, 13 improved following surgery (81 per cent). The three failures were a consequence of incorrect placement of one of the screws. Careful evaluation of immediate postoperative radiographs allows this problem to be identified; the screw can then be correctly repositioned with an immediate return to surgery.