I was told by my daycare that my 9-month-old unaltered male GSD(working lines DDR/West German) is nibbling large chunks of hair from his playmates. It is not painful and his playmates let him nibble- Their owners are not too happy.
Our trainer asked a few vets on site, who call it "fisking" and they say it's due to anxiety. I have searched the internet and found nothing dog-related for "fisking".
Kato has over-stayed his welcome at daycare as an unaltered male because the staff loves him, but this behavior was the "tipping point" and he can't return until the problem is controlled. The fact that he's lasted this long is a testament to how sweet he is and how much the staff adores him. He probably should have left daycare a month ago.
The part that I don't understand is the "anxiety" thing - he's extremely calm, confident, and still puppyish. My layperson opinion is that this behavior is more sexual than anxiety-related, and may improve after he's altered.
Please let me know your thoughts - Thank you.