Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.
Do you mean he has been cut or wounded?
Is it gaping or bleeding?
Can you take a photo of this? If you can and post them, it will let me see what you are seeing. To post them online, you can use the paper clip icon above your text box. Or if you cannot see that on your phone/computer, just post them on any site (ie Flickr, Photobucket, Imgr etc) and paste the web link here for me follow.