You didn't mention how old this cockerel is, and that makes all the difference when it comes to doing the procedure.
Years ago I had a pet broiler hen. She had heart disease, and was cared for by the avian specialists at the vet school at the University of Georgia. She was a frequent patient, so all the staff knew me quite well. One day I received a phone call from her veterinarian out of the blue. A good samaritan had seen a broiler chicken get out of one of the transport cages while being driven to slaughter. It had then fallen from nearly the top of the transport truck and was hit by a car on its way down. The good samaritan picked up the nearly dead bird off the side of the road and brought it to the Veterinary Medical Teaching Hospital for care. It was very severely injured, and 3 of the 4 doctors in the department recommended that it be euthanized. The fourth doctor, however, decided that it was worth saving, and that her students would benefit from learning how to treat this level of trauma, so she used her "teaching funds" to finance its care. Things went better than expected, and after a month of hospitalization it was decided that this sweet and now very tame bird needed to go to a good home. The conversation went something like this: "Esmeralda is a special needs bird, and everyone loves her. So many people have volunteered to adopt her, that we had to take a vote. Even though your name wasn't on the list, more than half the staff wrote your name on the ballot. We knew everyone on the list would give her a good home, but you were the person we all knew would make her a member of the family. She looks just like Sydney. Do you think Sydney would like another friend?"
Oh, I'm a sucker! So I had two questions. One, are you sure this is a hen? She answered that she looked just like Sydney, and she didn't look at all like a rooster (this is an avian specialist who treats complicated medical problems in all species of birds, not a poultry specialist). My second question was about any possible disease transmission. It was decided that she would have blood tests by one of the university poultry pathologist that I knew. I called the pathologist, and she agreed to go to the teaching hospital for me and draw the blood. But when the day came to do it, the pathologist was in a hurry, and she called the avian specialist and asked that the blood be drawn for her so she could just pick it up quickly. So the poultry specialist never got to see the bird. All the tests come out fine, and I drove to the university later in the week to pick up Esmeralda.
"Special needs" was putting it mildly. This poor baby was a wreck. She had spent 6 weeks in a broiler grow out barn and 5 weeks in a hospital cage. She had never touched grass, had never walked more than 20 steps in one direction, and had more scars than I'd ever seen on one animal. But she was sweet and in need of lots of TLC and other special care, and I happily took her home. She only weighed 6 pounds at 11 weeks old, so she hadn't gained any weight during the time she was in the hospital, but at least she hadn't lost much. She had grown taller, and thinner, but wasn't emaciated. Over the next 2 weeks I called the poultry pathologist a few times with some questions, and at one point I casually mentioned that different lines of broiler chickens sure do look different as they mature. The new feathers that were starting to come in (poor Esmeralda was nearly naked to start) and the leg structure looked a little different than Sydney at that age. The pathologist asked if I was sure this was a pullet. Of course I was sure -- the doctor I trusted to know everything told me she was!! As my brain was panicking, I asked how I could tell the difference at this age (I was a new poultry keeper at that time, and had never owned a rooster). She went over specific details, and as soon as we hung up the phone I raced to the pen to examine Esmeralda.
OMG, I had just adopted a cockerel!! I lived in the suburbs with lots of neighbors. I had no idea what the local laws were. No one cared about my 3 pet hens, but a crowing rooster was another story. I had a pet hen that I loved more than any animal I had ever snuggled with, a hen with heart disease, a hen that should never be subjected to the attentions of a young rooster. I called the poultry pathologist back in a panic. What was I going to do now? I was already so attached to her, uh, him. The pathologist suggested that I call the avian specialist to see if he could be caponized. That should stop the crowing and the unwanted mating behavior when he grew up. I left a message for the specialist to call me back when she got back from her medical conference.
Two weeks later the specialist was back in town and called me. At this point, the recently renamed Emerald was 15 weeks old, and the sweetest boy imaginable. I explained that she was a he, and asked about caponizing. The specialist asked how I knew for sure, as the bird really didn't look like a rooster. I explained that because of the rapid growth rate of broilers, they seem to be adult sized even though they are still just little chicks, and that gender differences aren't obvious until they're older (I had learned a lot in those few weeks). I was in the process of going over the specific details when Emerald started making the strangest noises just outside the window. First an odd squeak, then a garbled shout, then a full force deep-throated barnyard crow! We both stopped talking for a moment, then she asked if that noise was from him. She then said that, yes, she could do the caponization, and she would do it at no charge, since she had gotten me into this, and she could use him as a teaching case for her students. I asked if she had ever done it before, and she said that she had caponized many 3 week old broilers as part of her surgical training, and that she had caponized numerous aggressive male cockatoos and macaws in her medical practice. She had never done the procedure on a bird this big (he was now 9 pounds, still lean, and rapidly growing), but the surgical procedure should be the same. I dropped him off at the hospital the next week, went home and waited for the phone call.
An hour later than expected, she finally called. He was still under anesthesia and doing well. They had a full surgical team present as only a teaching hospital can, and all the specialized equipment out, including their vascular microsurgery equipment. They had called in the small animal cardiologist (who specialized in vascular surgery, and knew Sydney and myself quite well) to take a look. It was going to be an impossible procedure. At 16 weeks old, his testicles were in full blown hormonal overload, and were almost the size of her fist!! She explained that some birds, such as parakeets, normally enlarge their testicles temporarily to enormous size at the beginning of breeding season, then they shrink down to normal size as breeding season progresses. She didn't think that chickens did this, but apparently he did. She said that the anatomy of the testicle is such that it has a very short artery coming off the aorta (the main artery that runs from the heart to the the back of the bird). Normally, there is just enough distance between the aorta and the testicle to put a clamp on the testicular artery and tie a single ligature to prevent the bird from bleeding to death when the testicle is removed. In his case, his testicles had enlarged so much that they had essentially enveloped the testicular artery, and it was impossible to access it safely. She said that I had 3 options. I could ask them to proceed with the surgery, with a 95% chance that he would bleed to death, even with an experienced vascular surgeon helping (the cardiologist found the whole situation fascinating, and volunteered to help). Or they could close him back up and I could keep him as an intact rooster. Or I could surrender him back to the university, and they would find him a good home as an intact rooster. I chose to keep him as an intact rooster, and divided the yard so that he wouldn't harass the hens. My neighbors loved him, so no one complained, and we moved to a farm a year later.
Bottom line, castrating a cockerel entering breeding age is not the same as caponizing a 2-3 week old bird. Obviously, not all cockerels will have huge testicles, as my slaughtered cockerels typically have testicles that are about 3/4" wide and 1 - 1.5 inches long. But even if the boy has normal sized testicles, this is a much more complex procedure than spaying a dog, since the testicles are intimately connected to the aorta, with almost no room to work in that small space and no stretch that can be applied to the artery. I'm really surprised that you found a vet willing to do if for only $320. Has the vet done it on a cockerel that age before? What is their success rate?
