Differences in second-intention wound healing between horses and ponies: macroscopic aspects.

The study investigates the differences in healing of deep wounds in horses and ponies. The findings indicate a notably faster second-intention wound repair process in ponies than in horses, largely due to a more significant and quicker wound contraction in ponies.

Research Methodology

• The study followed the second-intention healing of deep wounds in 5 horses and 5 ponies.
• Standardized wounds were created on both animals’ distal limbs and hindquarters. Wounds on the metatarsi extended to the metatarsal bone and the depth of the wounds in the femoral biceps muscle was around 18 mm.
• The wounds’ boundaries were identified with tattoos, and photographs were taken at weekly intervals to monitor the wound area.
• The amount that contraction and epithelialization contributed to wound closure was quantified using the tattoos.

Key Findings

• Wound healing occurred significantly faster in ponies than in horses, and the muscle wounds healed quicker than the metatarsal wounds.
• This difference was largely due to the higher contribution of contraction to the wound healing process.
• Ponies’ wounds also showed signs of demarcation earlier than horses’ wounds and a healthier granulation bed developed faster in ponies.
• On the other hand, in horses, the granulation tissue remained irregular and purulent for a longer time.
• Specially, the metatarsal wounds in horses differed greatly from all other wounds as they increased to nearly double their original size in the first two weeks. Also, these wounds exhibited persistent exuberant granulation tissue, delayed start of epithelialization and less significant role of contraction in wound closure.
• Additionally, swelling in the limbs was found to be higher in the horses than in the ponies.
• Periosteal new bone formation was more extensive and active in the metatarsal bones of the horses, in comparison to the ponies.

Conclusion

• The study concludes that second-intention wound healing happens faster in ponies than in horses due to a more pronounced and quicker wound contraction in ponies.
• This finding provides a valuable insight for the veterinary practice suggesting that stimulating wound contraction could potentially improve the effectiveness of second-intention wound healing treatments.