Evaluation of a modification of the McKinnon technique to correct urine pooling in mares.

The research article explains an experiment on a modified McKinnon technique for the correction of urine pooling in mares. The method was tested on 30 mares and involved splitting the urethral fold and creating an extension, then using parts of this fold to prevent defect formation.

Methodology and Experimentation

• The researchers worked with 30 mares and implemented a modification of the McKinnon technique on them. The technique included splitting the urethral fold of the mares transversely into dorsal and ventral shelves.
• The ventral shelf was then used to create a urethral extension. Meanwhile, the dorsal shelf was stretched in a caudal direction and sutured to the roof of the extension. The configuration was such that at least the cranial half of the extension was covered by the dorsal shelf.
• For 20 out of the 30 mares, the researchers made a relaxing incision on the vagina to enable them to retract the dorsal shelf more caudally. This incision was made on the part cranial to the external urethral orifice.

Results

• Post the surgery, a third of the mares (precisely, 10 out of 30) developed a complication in the form of a defect. Importantly, none of these defects formed in the part that was covered by the dorsal shelf of the urethral fold.
• Out of the total, two mares (6.7%) had developed a defect so small that special detection methods had to be used. The researchers inserted dye into the tunnel under pressure to detect these small defects.
• Eight out of the total 30 mares developed only a grossly visible and palpable defect. The creation of the relief incision seemed to have had some effect, as four out of the 10 who did not receive the relief incision and six out of the 20 who did receive it, developed a defect in the extension.

Conclusion

• The results of the research suggested that the modification of the McKinnon technique by splitting the urethral fold transversely helped to prevent defect formation in the cranial portion of the extension. Also, retracting the dorsal shelf further caudally was made possible by creating a relief incision on the floor of the vagina.
• The study provided valuable insights into treating urine pooling in mares and furthering the understanding of the McKinnon technique and its potential modifications.