Neutered dog has penis bumps with black lines. What are they?

Unfortunately it is hard to tell when we cannot see exactly where on the penis this purple spot is. If it is a round swollen area, then that would be the bulbus which swells during copulation and locks the penis in the vagina of the female. If people separate the two dogs rather than wait until they part themselves, this bulbus can get injured and the female can also get injured. It is not a good idea to let this male mate with the three females in heat as he will introduce bacteria into their vagina and possibly uterus and so could cause a uterine infection (pyometra). If you could take some good photos of your dog's penis, we could better assess the situation and give you a more specific answer.

I'm wondering if your dog was neutered recently - it almost looks like there could be a scrotal incision and discharge in the center of the photo. Either way, the raised area looks like it could be a growth, tumor or abscess/infection and if he was not neutered recently the discharge is concerning. I would definitely recommend having your vet take a look.

I'm wondering if what you are describing are your dog's bulbourethral glands. These are glands on either side of the penis that can swell, and in a dog the size of Ollie they would appear about walnut-sized. This can happen even if a dog is neutered. If this is what you're seeing, the enlargement will fluctuate in size and at times will nearly disappear. If what you're seeing is more growth-like (and particularly if it's asymmetrical, rapidly growing, etc) then I would be more concerned about it being a possible mass, and would advise having it looked at by a vet. Hope that helps!

There is no picture attached to your post, so I can't say if his penis looks normal or not. There should be two bumps on the side of the shaft of the penis. They are called the bulbourethral glands, and they become enlarged when the dog is excited or aroused.

I am afraid without at least a photo or description of where these lumps and blackheads are, what size and how long they have been present, I cannot determine the cause, possibly identify them nor how to treat them or suggest whether they need to be examined by a vet or not. This could be anything from cancer, allergic reaction, comedones caused by hyperadrenocorticism to ectoparasite bites or insect stings or bites. I suggest you take a few good photos and upload them here and describe them and I am sure we can give you an idea about what they are and what to do about them or whether you need to worry at all.

Hello and thank you for contacting Petco Pet Education Center, formerly Petcoach. Unfortunately, the picture did not go through, so we cannot advise how serious this problem may be. Please, re-send your questions with some pictures attached and we will try and help as much as possible.

This may be blood blister, a tumor, or a small benign growth. The only way to know what it is and if it is a cancer is to have your vet remove it or biopsy it. At his age, cancer such as a mast cell tumor or hemangiosarcomas are possibilities and the smaller they are when removed, the better the chance it can be completely removed.