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Basic animal anatomy



By: medicinemann
Posted: 29-Mar-10

In humans, we know that the heart lies slightly left of center mass.

While I have taken my fair share of game, whenever I have performed an "autopsy", the animal is laying on its side.

I have been shooting a LOT in preparation for a Spring brown bear hunt. Once I get an arrow in that animal, I will follow-up with ANY shot that I can get....yes, even a head on shot. As I am looking at the bear, I have always assumed that his heart would be slightly right of center as I am looking at him (on HIS left)....just like a human.

I checked THE PERFECT SHOT by Craig Boddington. His illustrations of the whitetail deer and the black bear (pages 39 and 95, respectively) BOTH show the heart to be to the right of the animals centerline (to the left, as I am looking at them). Nowhere does the book make mention of the fact that organ placement is substantiated by a veterinarian, but Boddington is world famous, and I was surprised by the fact.

By chance, is there a veterinarian amongst our ranks?...and if so, what say you?


By: guidermd
Posted: 29-Mar-10

i'm not a vet, but i would say aim for the heart as if it would be in the middle. beyond that i might say we would be splitting hairs


By: medicinemann
Posted: 29-Mar-10

I was thinking the same thing.


By: Geaux Tigers
Posted: 29-Mar-10

No vet again, but I am a biologist. When collecting blood samples straight from the heart immediately after death, animals are placed on their right side and blood is drawn from an incision on the left side. This is due to the heart lying closer to that side and not being blocked as much by lung tissue. So I would assume that when alive the heart is positioned slightly left of center. I would aim slightly off center to avoid hitting the sternum.


By: BB
Posted: 29-Mar-10

Jake I wish you well on your brown bear hunt.

I am not a vet, but through the years I really have tried to pay attention to how animals die and how far they go with the different shots I make.

In my early years I just didn't even think of things like that, but for the past 20 or so I have done a lot of thinking and a lot analyzing and many autopsies on the animals I have taken and those taken by my hunting partners.

What I have come to find out and what I now believe and what I think a veterinarian would collaborate, is the heart shot, although a very deadly shot, is not the fastest killing shot by any means, nor will it allow the critter to go down in the shortest distance.

Many, if not most heart shots allow the animal to live 10 seconds or more and they can travel slightly over 100 yards in many instances. A good double lung shot will often put the animal down in about ½ that time and slightly more than half the distance of a heart shot.

In recent years I try to aim so that my arrow passes over the top of the heart taking out the bundle of arteries and veins and have found most animals hit that way make it less than 40 yards and are stone dead in less than 5 seconds.

Some years ago I was sitting with my son when he was quite young in an antelope blind. A nice buck came in and he said he wanted to shoot it. For years I had advocated to him that same principle of hit just over top of the heart. While he drew his bow and readied for the shot, I videoed him shooting that buck. On the camera was a second timer that told the time and the seconds (in tenths). From the time his arrow hit that buck to the time it fell over stone dead was 2.4 seconds. I don’t think the last buck I shot lived that much longer.

I know antelope are not brown bear, but the principle is basically the same.

The organ that is most susceptible to lack of oxygen and blood deprivation is the brain. Most organs in the body are capable of going quite a long period ((minutes) of time without either blood or oxygen, but the brain is limited to a very few seconds, and therefore the animal will go down almost immediately. The ascending aorta is often hit with that shot and if it is missed, there are enough large vessels, that death is usually achieved faster time wise and the animal makes it a shorter distance, than if hit through its heart.

Just some food for thought.

Have a great bear hunt. BB


By: medicinemann
Posted: 29-Mar-10

Geaux Tigers,

That would be consistent with human anatomy as well....but contrary to Boddington.

If nothing else, it gives me something to consider while I wait for my upcoming Spring hunts.


By: John Haeberle
Posted: 29-Mar-10

Not a vet here, either, though I do some human work.

Humans are flattened antero-posterior, whereas the animals we hunt (except baboons, for people who would whoot them) are flattened from the sides.

The reason that human hearts are off to the side is that AP flattening ... which we don't share with these other mammals.

Here's the deal, though, Jake -- as I see it: Exactly like BB said, the place to aim is really the great vessels, and they are ALWAYS in the midline. The bulk of the heart (like the left ventricle, in humans) may be off-center, but the great vessels (aorta, pulmanary arteries) are midline, and that's what you really want, anyway.


By: medicinemann
Posted: 29-Mar-10

BB/John Haeberle,

We all seem to be thinking along similar lines.

Realistically, IF a head-on, frontal shot is the only follow-up shot that I am going to have, obviously a double lung shot is NOT possible. The greater vessels ARE the best place to aim.

I planned on aiming for the bundle of arteries at the top of the heart....but I needed to know where the heart was, in order to do that. Those creatures are SO big, that IF the heart was slightly offset, I thought that the vessels may be slightly offset as well. I was tempted to favor the bear's left side (right side as I am looking at him). Based on these types of input, I don't know if I will......

My other BIG question is whether the sternum covers the ascending aorta and the remaining greater vessels? Any thoughts about this? I am guessing that the sternum is centered and the greater vessels are behind it for this very fact. Like Geaux Tigers mentioned, I'd like to sever the greater vessels WITHOUT hitting the sternum. I just wonder if it is possible.

Then again, I might be able to sever the greater vessels regardless of their position WRT the sternum.....but it might be a function of bow poundage more so than arrow placement.


By: Beendare
Posted: 29-Mar-10

That would be my thoughts. If you aim too low on a big animal, you have possibly too much heavy brisket to shoot through. The area just under and around the collar is a softer spot for better penetration to lung area. Lower on the brisket is iffy.


By: medicinemann
Posted: 29-Mar-10

Beendare,

I shot my desert bighorn at 17 yards, head-on. My arrow hit him in the VERY middle of the thickest part of his sternum. I only got 17 inches of penetration on a 200 pound animal....despite using a fairly high poundage bow.

I don't even want to think about how much LESS penetration I would get on a 800-1,000 pound heavy boned carnivore.....if I were to hit him in the brisket.

You can bet that I'd be aiming at the "collar" as you called it....I'm wondering how much that would be above the top of the heart, on an animal that size? I guessing 4-6 inches.....my grizzly bear was about 8'4", but it was mounted in a 3/4 upright stance, so it is somewhat difficult to tell for sure. It will also depend on the elevation "angle" of the bear....as he is facing me.


By: DPS
Posted: 29-Mar-10

Since I am having a slow night at the veterinary emergency hospital, I thought I would give the veterinary view. The heart lies pretty much directly in center between the sternum and the spine with just a smaller amount on the animal's LEFT side (which is your right hand as you look at it face on) The AORTA will come off the top of the heart, slightly LEFT of the midline. So if I was going to take a frontal shot, shoot just to YOUR RIGHT of midline (the animals left) and you will have the best chance of taking out the Aorta. Geaux Tiger's info is right on. Most dogs (wolves/foxes/coyotes) and cats have their hearts slightly more caudal (toward the rear) than do deer/antelope/elk. When I went bear hunting, I aimed a couple inches further back than I aim at deer/antelope and took out the top of the heart. 20 yard recovery. Remember that the hair of the bear will hang down (3 to 4 inches plus)past the chest wall so it gives the appearnces you will be shooting higher on the chest wall than you really are.


By: medicinemann
Posted: 29-Mar-10

Doug,

While ALL of the info on here seems to have considerable merit, your info has given me even more to consider.

Thank you.

Jake


By: 300 Win Mag
Posted: 29-Mar-10

Always so much to learn here!


By: stubbleduck
Posted: 29-Mar-10

Clip the aorta leaving the heart and blood pressure drops rather rapidly to essentially zero. As noted above the central nervous system is very sensitive to loss of oxygen and zero blood pressure means no oxygen to the CNS.


By: Bowfreak
Posted: 29-Mar-10

Jake,

Do a search and look at the pictures of the black bear Woody Sanford did pics of. If you have not seen it....it is awesome.


By: bumpinblaze4x4
Posted: 29-Mar-10

How about an "almost veterinarian"? I'll be recieving my veterinary degree in about 6 weeks so hopefully i know this stuff by now. I haven't performed any necropsies (autopsy in relation to human anatomy) on bears but in deer, elk, pigs, cattle, horses, cats, and dogs the heart is located slightly to the left of midline (like humans). The best way to listen to an animals heart is to use a stethoscope on the left side of the animal; although it can be heard on the right side too. The significance is minimal whether it lies sligthly to the left or right but in my experience it is usually a few inches to the animals left side. Hope this helps!


By: DPS
Posted: 29-Mar-10

DPS's embedded Photo

Here is Woody's picture from a previous post here on Bowsite.


By: Woody Sanford
Posted: 29-Mar-10

Woody Sanford's embedded Photo

All the anatomy work I have done for pictures is on animals in the standing position and as soon after death as possible. Its something that has to be gone after before rigor comes into play or it will twist them out of alignment with the camera. Doing them on their side gives a different view due to gravity, varying with the amount of blood in the heart and the condition of the remaning lung.

There is a membrane as close to center as you can imagine called the "Mediastinal Plate". The esophagus is to the left and the aorta to the left of that. As far as I can tell its is more than the "10%" most think it is and more in ungulates than carnivores but to say it is "X" amount, well I don't think you could nail it like that.

I've been scoping it with long needles to try and secure it for a 3D model I'm working on but I'm not getting the exact result every time. Since I've moved to the lower 48 I've been doing them against a green screen in the lab and with all the info I have so far, all I can say is "Yep" its to the left.

You could say something about the "Cardiac Notch" in the left lung but how would you measure that in the lungs of a dead animal to understand the significance of it?

The reason I always take animals apart from the left is everything is right there when I remove the lung. I've taken a few griz apart this way and again all I can say is, it is to the left but in the grand scheme of things I don't see that being a big part of shot selection like avoiding large bone.


By: BB
Posted: 29-Mar-10

BB's embedded Photo

Jake, the very first bear I ever shot was standing on all fours facing almost staright on and it was as brown bear. (Ha Ha) Well it was a brown BLACK bear, but hopefully these photos might help a bit.

When I saw the bear it was above me at less than 20 yards looking right at me. (I was on a fairly steep hillside, but below bear). I nocked an arrow while it stood there and watched me. In the photo above I've drawn a red circle around the hole in the hide on this old mount. That is where my arrow hit.

I will add a couple more photos and explain a few things. But this might give you an idea of a frontal shot.


By: BB
Posted: 29-Mar-10

BB's embedded Photo

I stuck a screw driver in the mount at about the angle my arrow entered the bear so you can see where my arrow hit in relation to its front. I was off to the left of center (from my point of view. Really I was off center to the bears right side a bit.) I really should have been over a couple inches to be centered.


By: Ziek
Posted: 30-Mar-10

"THE PERFECT SHOT by Craig Boddington." Isn't that the book that shows a muskox with a long tail? lol

I always thought that the heart was slightly left but just as important, the liver is more to the right. Something to consider on quartering shots especially if you hit a bit too far back.


By: BB
Posted: 30-Mar-10

BB's embedded Photo

I took this next photo off the side a bit so you can kind of see the angle my arrow entered the bear.

Once hit he ran up hill about 20 yards and started turning in a circle. I drew another arrow and hit him again as he was turning. He then ran into the trees and I found him within yards of when he went out of sight. He might have made it 60 yards.

I think I was perfect height but would suggest to me more towards the center than I was.

Perhaps someone with a bit of skill could mark the approximate height of the sternum for Jake.

Bears have much shorter necks than do deer or elk, so one needs to be over the sternum but under the chin. That distance is not a large area on a black bear.

I will never forget the feeling I had shooting that bear. It by far was my most exciting bear kill, and I have taken quite a few bears.

You might want to talk with Blacktail Bob. I know he has taken at least one brown with the frontal shot and perhaps two. He would be a great reference help.

Have a great bowhunt. BB


By: medicinemann
Posted: 30-Mar-10

Ziek,

I didn't know if you were joking or not, so I checked the book....and you were right!! They show the muskox having a very long tail.....and they show the deer and bear having their heart on the right side of the body, instead of the left.....

Wouldn't you think that they would have had a veterinarian check this stuff before it went to print?

BB,

PLEASE tell me that you didn't stick a screwdriver into your bear mount to JUST show me the shot angle!! LOL!!

On a serious note, heaven forbid that I even have to consider such a shot.....but if I do, I am aiming for the thoracic inlet....slightly to the right of the bear's centerline (as I am looking at him)....putting the arrow into him on his left side....above the sternum, and below his chin.

Jake


By: BB
Posted: 30-Mar-10

Jake, I did stick that screw driver in that mount just of you! But don't feel too bad, as its a very old mount and just sits in my garage with all the other stuff I once had mounted and collects dust.

I mounted my last aninmal many years ago and have pretty much got rid of everything I had with the exception of a couple mule deer that have a special meaning to me. So no worries and broadhead hole had broken open years ago.

I understand that would not be the shot you wait for, but its a great shot if you know what your doing and you are close. Be sure to talk with Bob. I know he took a big boar with a shot similar to that on my black bear and the bear didn't make it far.

Another guy you might want to speak with would be Muskox. He really knows his bears too.

Have a great bowhunt. BB


By: medicinemann
Posted: 30-Mar-10

Muskox or Muskeg?


By: BB
Posted: 30-Mar-10

Sorry I meant Muskeg.


By: Bake
Posted: 30-Mar-10

Did anyone see Fred Eichler's (I think it was him) grizzly hunt where he stuck at least two arrows from his recurve into a bear's chest as the bear was standing?

I'm sure there's more bone and gristle to shoot through when the bear is facing on all fours, but if he can shoot an arrow from a trad bow through that ribcage, I think your high poundage would help you out Jake

For that matter, what about Pat's grizzly hunt? That arrow he stuck into the bear as it came towards him got what?. . . . 20 inches of penetration? Also from a trad bow. All I remember seeing in the video was the fletching sticking out.

That was a big bear too. Maybe not quite as big as a big brown, but dang big enough

Bake


By: medicinemann
Posted: 30-Mar-10

Bake,

I have both of those videos. I'm going to rewatch both of them. If I remember correctly, neither video shows arrows hitting the sternum, so perhaps the arrows slide in through the ribs.

There is a Mossback video with Jimmy and Angie Ryan, Angie Ryan is bowhunting for Brown Bear. She is shooting a 60 pound bow and she takes a 25 yard shot at a 9'3" to 9'6" boar while he is standing. While the shot actually hits the bear a little low (she got one lung and liver), the bear went 150 yards and died. She actually puts a second arrow in it, but Tom Kirstein said that it was more for the video footage than out of necessity. Nonetheless, if you want to see the type of terrain that we'll be hunting in, that video was really neat to watch.


By: cazador
Posted: 30-Mar-10

If memory serves, BlackTail Bob shot a huge Brown Bear head on and it was over quick. I want to say that bear squared over 10 feet.


By: medicinemann
Posted: 30-Mar-10

Did Blacktail Bob put the story of that hunt on Bowsite?


By: Bake
Posted: 30-Mar-10

The shots probably didn't hit the sternum.

What poundage are you shooting? Like 90 some pounds?

I don't know nothin' 'bout nothin', but Pat's Mozambique CSI feature was really cool showing what a bow and heavy arrow, and strongly constructed broadhead can do. (as your Rosie elk demonstrated too)

Bake


By: medicinemann
Posted: 30-Mar-10

I searched Blacktail Bob's threads and found photos of his three grizzly/brown bear bowkills. TWO of them were taken at less than 20 yards with frontal shots. I'm hoping that he'll post the story of either (of both) bowhunts.

Now you'll have to excuse me....I'm going outside to take a 20 yard frontal shot at my archery bear target!!


By: Blacktail Bob
Posted: 30-Mar-10

Blacktail Bob's embedded Photo

Jake,

Although I agree with those who have concern about the frontal shot and would favor a nice broadside, lung shot over any other, BB is also correct in my opinion. I have taken almost the exact shot, with almost the exact shot placement as he has opined and shown in his photos of the black bear.

I have taken this shot twice and been successful on both. Both were very close shots with the bears slowly walking toward me in a non-aggressive manner. The first was a really big Kodiak Brown bear I shot at 18 yards. That bear turned and ran 26 yards before dropping stone dead in a matter a few seconds at best.

The second was this past fall on an interior grizzly bear. Same situation, the bear was walking directly at me at 12 yards, this time uphill. Shot was about the same but did not penetrate the full length of the bear like the brownie that was pretty much on the level. The grizzly also turned and ran, stumbled after less than ten yards and rolled another 15 or 20 yards down the mountainside. Both were dead in 2 or 3 seconds. Both arrows were heavy aluminum (2219 & 2317) and both broadheads were a two blade Phantom.

I don’t have any knowledge of anatomy, but I agree that death comes more quickly with a shot that cuts the arteries at the top of the heart rather directly through the heart. Didn't know why that was, but the explanation about no blood getting to the brain makes sense to me. That was what happed on both of my bears.

If you have time in Anchorage on either end of you hunt, please give me a call, especially if you have photos of a bear top show off!!!!


By: Blacktail Bob
Posted: 30-Mar-10

Blacktail Bob's embedded Photo

Grizzly from this past fall.


By: medicinemann
Posted: 30-Mar-10

Blacktail Bob,

Send me a PM with your phone number....I have a five hour layover before I fly into Kodiak, and I have an allnight layover on my way back out. I would REALLY like to get together, especially before the hunt, if that would work for you. Just understand that I will inundate you with questions......

I'll make you a deal....I'll treat you and your wife to dinner, if you would be willing to get me at the airport, and then drop me off at the airport after dinner.

Jake


By: Tim Hoeck
Posted: 30-Mar-10

Jake I will talk to some of the vets I work with about placement. With what I do I could look at some of my customers to see what they look like.


By: medicinemann
Posted: 30-Mar-10

Tim,

Like I said, I may be calling you soon!!


End of Topic
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