He got excited. Just because you fix them doesn't mean they can't be horny anymore. Blunt is blunt :p Not to worry, it's just part of his penis. It's called the Bulbus Gland. It's a long link, but the best I found to help you understand what it is: http://images.google.com/imgres?imgurl=http://www.dog-breeds-and-dog-health.com/images/dog-penis2.jpg&imgrefurl=http://www.dog-breeds-and-dog-health.com/mating-dogs.html&usg=__HfcAhnMsAXe3aN-CHvubawij-aI=&h=290&w=306&sz=25&hl=en&start=8&um=1&tbnid=BhRNDNS6KYK3IM:&tbnh=111&tbnw=117&prev=/images%3Fq%3Ddog%2Bbulbus%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DN%26um%3D1 This link shows a diagram of the male dog's reproductive system: http://www.pfizerah.com/PAHimages/common/dog_tract2.jpg You shouldn't be squeezing him...you could really damage him (emotionally and physically). It'll go back to it's normal state in a few minutes or in longer cases, an hour or so. It shouldn't last a day. Then there is a serious problem. But don't squeeze please!!! :( There's a bone in there!!! You break that bone you put your dog through hell and make yourself cough up a lot of money to fix it...IF it can be fixed. You break that bone and your dog can't pee. So stop that squeezing!