Bob's Blog: It was a strange deer hunt

It was quite a gun deer season opener for me last weekend.
I have hunted Wisconsin's woods, fields and swamps for more than six decades and this season is certainly one for the books... not for the deer I shot, but how it acted.
Here's the scene:
Our youngest son, Evan, and I were hunting from our usual stands in a steep valley in northern La Crosse County. I never saw a deer on opening day, but Ev missed the buck of his lifetime. I felt sorry for Ev, but assured him it wouldn't be the last deer he misses with his 30-06 rifle, handed down to him from his late grandpa.
Sunday was a different story. One nice-sized buck sneaked past me about 7:30 a.m., before I could get a clear shot.
Shortly after 8 o'clock, I heard a loud bark from Ev's rifle. "Kaa-whop!"
Instantly, I knew Evan hit something this time. Longtime hunters have learned there is a distinct difference in sound from a hit or a miss. A missed shot sounds more like a "twang," while a good hit sounds like a "kaa-whop." This was definitely a "kaa-whop, followed several seconds later by another "kaa-whop."
"Got a buck down Dad," Evan radioed on his walkie-talkie.
I climbed down the steps from my "condo stand" that the late Friendly Farmer's kids built for me several years ago, and trudged up the old logging road to meet Ev.
He told me it was a large buck, but only had a half-rack. Ev said it dropped in its tracks, struggled to get back up, before he finished it off. Ev pointed to the massive deer sandwiched between logs about 40 yards uphill and across a deep ravine.
As we made our way down a deer trail to the bottom of the ravine and were within about 15 yards from Ev's dead buck, I turned and glanced down the ravine. There, no more than 20 yards away, was a deer staring at us. I whispered to Ev that I thought I could see one small spike.
"Shoot it," I whispered.
"You shoot it," he whispered back. I've got my buck."
The deer didn't move, not a muscle, and continued staring at us.
"Go ahead and shoot it," I said as my whisper grew louder.
"No, you shoot it. Besides, it doesn't look right," Ev replied.
The deer continued to look straight at us, almost frozen in its tracks.
"OK. It certainly looks healthy, but I don't want to leave a sick deer in the woods. There's definitely something wrong with it. I'll put it out of its misery," I countered.
Setting down my walking stick quietly and shouldering my .223 rifle, I pulled down on the front of the deer and shot. It fell in a heap.
The mercy killing was finished. We approached the spike buck and noticed frozen pus below both eyelids. The antler base, or pedicle, where one spike was missing, also showed some pus. We agreed. This deer had to be shot. We also agreed it wasn't emaciated. The body appeared fully grown and healthy.
We left it to field-dress Ev's buck before returning to field-dress the smaller buck. We also called the Friendly Farmer's kids to come and help us.
The deer I shot looked fine except for the head which was infected. It skinned out fine and the venison looked just like the one from Ev's large buck.
Our venison processor cut off the head and neck from the young buck. I drove to Neshonoc Sports in West Salem. Anna Jahns, a DNR wildlife technician, aged the deer and removed lymph nodes for CWD testing. After I described what happened, Jahns said she believed the deer had cranial abscessation syndrome (CAS). That was the same thing Gerald Sheperd, from Shep's Taxidermy, told me several years ago when I described to him that I shot a half-rack 6-point buck with a very wobbly remaining antler which rattled the skull when I wiggled it. The only difference was that deer acted normal like any other deer.  
After recalling what Shep said and what Jahns just told me, I went home, looked up cranial abscessation syndrome and found this DNR story reported from Bill Ishmael.
Ishmael, a DNR wildlife biologist in Spring Green, responded promptly when he received reports that a deer in northwestern Sauk County was walking in circles, acting disoriented and lacking any fear of people.
When Ishmael arrived on the scene, the deer was standing with its head down and did not react to him. As he got closer, Ishmael noticed the buck's antlers had broken off. Pus was exuding from the base of the antlers and the animal's eye sockets.
"It seemed as if it were blind," Ishmael noted.
All of these symptoms are characteristic of cranial abscessation syndrome, a disorder regularly found in Wisconsin's wild deer. The bacterium that causes CAS, Arcanobacterium pyogenes, is found naturally in the mouths of healthy Wisconsin deer, but can cause infections through broken antlers, abrasions in antler velvet, or through any open wound on a deer's head. After entering through the skin, the bacterium can "eat" through the deer's skull, causing abscesses in the brain.
CAS occurs most commonly between October and April and may account for up to six percent of the natural mortality in bucks.
"This disease affects adult antlered deer almost exclusively," says Kerry Beheler, DNR wildlife health specialist.
The annual cycle of shedding antlers, getting nicks when new antlers are in velvet, and rutting battles provide plenty of opportunity for head wounds through which CAS bacteria can enter.
"We know that CAS can cause loose or deformed antlers, or kill trophy bucks," Beheler said, "but we don't have enough data to gauge the impact on the whole buck population."
In theory, meat from a deer infected with CAS isn't unhealthy and can be eaten if cooked thoroughly until the juices run clear. In practice, it's not advisable to eat such meat because the bacterial infection can make the meat tough and unpalatable.
I picked up our deer from the meat processor on Tuesday and Dan assured me the meat from my deer looked as good as Evan's buck.
Personally, I plan to eat the venison from this young buck just like I did with the similar tender buck I shot several years ago.