The study looked at how freezing affects the DNA of canine sperm and if melatonin can help protect it. They collected sperm from ten dogs and froze it with or without melatonin. The DNA fragmentation was similar in fresh and frozen samples. Fresh sperm moved better than frozen sperm, and freezing decreased acrosome integrity. Melatonin didn't improve sperm motility or acrosome integrity after freezing. In conclusion, freezing canine sperm doesn't change DNA integrity, but it does affect motility and acrosome integrity.