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donawick
11/11/98

he had an experience recently...was 
out in Wyoming, elk hunting (?!)
The organizer of the hunt told them not 
to shoot any grizzly bears b/c he would lose license and person who did 
it would go to jail. he said, bears can't climb trees. So Dr was up on 
this peak and this bear came up to them. He decided to climb a tree. but 
there were few branches. the bear came, looked up, started to shake the 
tree. bear looked up, shook tree, Dr D getting scared. finally bear went 
away. Now, he tried to get away but the bear came back with a cub. now 
both shake the tree. then, the cub climbed up on mom's back, and tried to 
grab Dr D but couldn't reach. finally both went away. so Dr D tries to 
leave again. but now she comes back with 4 black things on her back. they 
were beavers, she made them start chewing the tree.

Truth? You be the 
judge.

we were talking about rupture of the cecum which was very bad, 
and insidious. when they rupture, they get sandpaper feel to serosa of 
abdominal viscera. severe peritonitis ensues; if they don't die right 
away, they die pretty soon. it's tough to manage these cases b/c the only 
tx is to either do surgery and clean stuff out, or if it is very early to 
carefully try IV neostigmine to stimulate cecum and see if it will empty 
out. (that would be for impaction prior to rupture, I guess). Dr Ross did 
a study on neostigmine to treat impaction of the cecum. He had a million 
dollar horse patient. He tried neostigmine on it and the cecum ruptured  
- but that's what happens in medicine, you aren't always right. But the 
fact is the surgical therapy does not have high success anyway.

Diseases 
of the large colon:
impaction
nonstrangulating displacements
dorsal 
displacement and entrapment by the gastrosplenic or suspensory ligament 
of the spleen
ileus?
180 degree volvulus
enteroliths, foreign bodies. 

360 degree volvulus
diaphgragmatic hernia - colon can enter thorax

thromboemobolism of cecal/colic arteries.

Impactions: large colon rarely 
ruptures, compared to cecum. So you can treat large colon impactions over 
time - may take 3-5 days for impaction to subside but that's ok b/c this 
process isn't such an emergency. signs = mild/intermittent abdominal pain 
(colic). on rectal exam, you can feel ingesta filled, firm, distended 
colon.  you would feel the pelvic flexure. you feel it on the left side. 
it's firm, and doughy. some people - and in the literature it talks about 
these being pelvic flexure impactions - but it's the whole thing, you 
just feel the pelvic flexure. that's why some people call it that. you 
get huge quantities of ingesta passing when it breaks down, it's the 
whole thing. 
treatment: water per os by NG tube, and IV as needed. you 
want to turn suff back into a slurry and allow it to pass through. where 
does impaction most often start? no one knows. we do not see that part. 
might start when a horse isn't feeling well b/c a horse that isn't 
feeling well first stops drinking. the object of colon is to suck water 
out of the feces; so the intestine is absorbing water and horse isn't 
taking new water in so the stuff dries out. gets stuck. Dr D does not use 
MgSulfate. some people do - but think aboutit. here is a horse that is 
not drinking on his own. has been absorbing water from the gut to sustain 
fluid volume. if you put Mg Sulfate in there, you suck water from the 
body into gut, but it really is probably better to just add the water in! 
one of the few txs you can get for free from the owner and then charge 
for it. "fill this bucket with lukewarm water please" then pour it in and 
charge $50. ha ha. very funny. how about using mineral oil? well, 
probably won't hurt. give a gallon of mineral oil into two 55 gallon 
drums of ingesta...probably won't do a whole lot. probably just goes into 
the ingesta and doesn't lubricate the mucosa. you can use it. it's not 
wrong to use it.

Non-strangulating displacements of the colon. the colon 
seems to "know" where it belongs b/c it isn't usually displaced. at 
surgery if you don't put the colon back where it belongs, it finds its 
own way back to where it should be. it "tries" to be in the right spot. 
rarely, thought, the colon becomes displaced. the history is: horse is 
alive :) not feeling so good but has lived for many hours to days - so 
this isn't life threatening. on rectal exam, you can't find the colon, or 
it is in the wrong place. now, you can't be sure b/c you do not be the 
colon that it definitely has this problem, but you can suspect it. should 
be on left. if you feel it on the right, that's a big clue. again you 
feel the pelvic flexure. 
tx: surgically reposition. just put it back. 
easy surgery. just go in, grab, move. hope it stays there. 

180 degree 
volvulus of the colon: bands of the left ventral colon are plapable at 
the dorsal loop of the pelvic flexure. you shouldn't feel ventral colon 
with its bands and sacculations, in the region of the dorsal colon. this 
doesn't affect blood supply, but causes a mechanical obstruction. this is 
another quick and wonderful surgery. go in, flip back down. just 
surgically reposition it.

enteroliths and foreign bodies: history - 
pastured on sand, access to conveyor fencing or discarded tires, other. 
one thing to look at when a horse comes in to NBC is the address of the 
owner so you can see if they come from NJ - if horse lives in sand dunes, 
will eat sand when eating grass. sand filters out into colon and becomes 
a foriegn body. also a major disease in Florida. 
signs: recurrence of 
colic, abrupt cessation of fecal passage, relief regardless of therapy. 
recall blockages usually occur at the transverse colon. 

slide: baler 
twine foreign body
slide: big ugly enterolith - this is associated with a 
great story. Mr W brought in a yearling and they opened it up and found 
this in the large colon - made incision in *right dorsal* colon. this is 
smooth, irregular, about a foot long, 6-8 inches across. it's polyhedral 
but was the only one in there. he broke it open with a hammer. horse is 
doing fine. it looked like a rug inside. carpet, with backing and 
everything. Dr D told Mr W - your horse ate a rug. how did it get a rug? 
Mr W said he put up a new fence and the horses were chewing the 
fenceposts and it pissed him off, so he went to a rug store and got old 
samples, and had the rug samples nailed to the tops of the fenceposts. 
this was, apparently, a bad idea. Dr D told him to go see how many rugs 
were missing. they had to do three surgeries, all had rug enteroliths. 

for sand foreign body: tx mineral oil, or sx - because when colon is full 
of sand this is the one case where the colon can in fact rupture b/c sand 
will act like sandpaper and wear a hole through it. to dx sand, do a 
rectal, grab some feces, mix with water, shake, and see if sand falls to 
bottom. 

360 degree volvulus of colon - loss of vascular supply. horse 
gets very sick. has distended abdomen and large colon on rectal exam b/c 
nothing can get in or out and it distends with gas. slide: typical case - 
colon is dark purplish black with blood on it. horse needs to have a 
large colon - needs at least 50% of it to survive. you can not remove the 
whole thing. if twisted so far back towarrd the root that you can't even 
expose the twist, that's bad. if you untwist it - do you let horse 
survive and wake up and see what happens, or do you euthanize? no good 
answer. it is hard to assess clinically if bowel is alive enough to 
survive. hasn't worked well. fluorescein stains to check circulation, 
assessment of mucosa, just nothign works well. ends up being a clinical 
judgement. a lot of it depends on relationship b/w owner and vet, value 
of horse, expectations of owner. if owner wants to try at all cost fine, 
if they say no, fine. if the horse does survive, it's going to have big 
hospital bills for the first few days. BIG bills. different clinicians 
handle this in different ways. overall, results are poor. slide: this 
colon is black. completely black. no way it will live. the longer this is 
present prior to surgery, the easier your decision is. 
tx: early sugery, 
get it untwisted ASAP.

peritonitis can occur at any time, for any reason 
- the main thing to know is we try to NOT do surgery on horses with 
peritonitis. all you do is spread a local infection (if you're lucky) all 
over the abdomen. usually you don't find anything in there to do anyway. 
tx high systemic levels of penicillin and aminoglycosides. avoid 
exploratory surgery. if you don't know the cause of the peritonitis, you 
can't fix it anyway. 
dx of peritonitis with perforation of bowel - 
peritoneal fluid will contain many gram positive and gram negative 
bacteria. if you find only *one* kind of bacteria - whatever kind it is - 
then it's probably from an abscess. if you find a whole mixed bag, it's 
probably a perforation. unfortunately, you can gather peritoneal fluid 
and not find any bacteria, and then you don't know...we had a horse at 
NBC - TwoPunch (?) the most valuable TB stallion in MD, insured for $6 
million! he was found in the pasture - there is a man who said horse was 
normal at noon and then at 1:30 was standing and wouldn't move, so he 
called vet who came out and saw the left testicle was distended and 
painful on palpation. they coaxed horse into barn. was febrile, obvious 
abdominal pain - referred to NBC. got here, and abdominoparacentesis 
showed 350,000 WBC/cu mm. they did a gram stain - no bacteria. spun some 
down, looked again. no bacteria. next day, gathered fluid from the common 
tunic of the left testicle, and also got some more abdominal fluid. no 
one found bacteria. did cultures. no bacteria found. the horse is very 
sick. insurance company is breathing down his neck, everyone is upset, 
what did he do? well, he assumed it was a bacterial peritonitis, somehow 
due to perforation or something in testicle. put horse on broad spectrum 
antibiotics - amikacin and penicillin and metronidazole for 
anaerobes...and waited. horse got better. they just called local vet this 
week - horse is doing great. now, why was it just one testicle? well, the 
next day, the other testicle was also affected. did dz come from 
testicles and enter peritoneal cavity, or the other way? dunno. horse's 
sperm count is down right now and motility is down, but takes 90-120 days 
to make new ones so you have to wait and see if he's still fertile. when 
you give all those abx, btw - do you damage gut flora? usually not if you 
are using IV antimicrobials (although if you use tetracycline, you might) 
but IV pcn and amikacin do not seem to disturb gut flora when given IV. 
avoid oral route, though.

diaphragmatic hernia - usually history of 
injury or foaling. on PE - muffled heart and lung sounds, labored 
respirations, abnormal thoracic percussion - dull thudding when you 
percuss. with u/s, now we can do a u/s of diaphragm and thorax and see if 
colon is up there. on rectal exam - colon not palpable. rads:   bowel 
within thorax. can you fix this? usually not. why not? well, they blow 
out near the vena cava and esophagus, so they are deep into the abdomen, 
and the tear begins around the site where the vessels or esophagus 
perforate diaphragm, and you can't sew it up b/c stuff is in the way. if 
hernia is down near the sternum, you can sew it up. also, when bowel goes 
in there it takes the liver with it, and adhesions form. now guts are 
stuck to lungs and pericardial sac, and you can't get them back. so it's 
difficult. if it's a small hole, maybe. 

this is fun. detective work. 
can be rewarding, or desperately disappointing. 
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Bovine 
diseases...

slide: cow distended like an apple - that means gas. fluid 
makes a pear shape, remember. so she has bloat. the rumen is on the left. 
rum - left. rumen- left. one day, I will remember this. 

signs of rumen 
disease: pain, bloat, rumen atony or decreased ruminations. should hear 
1-2 rumen contractions per minute. abdominal distension, interference 
with food bolus regurgitation, change in rumen pH, anorexia, decreased 
milk production. normal rumen pH is 6.8 - slightly acid. 

traumatic 
reticulitis:
seen after calving due to straining (maybe)
also called 
hardware disease
signs: anorexia, decreased milk production, decreased 
rumenation, splashy rumen, low grade fever, increased respiratory rate, 
increased HR > 100, leukocytosis, positive grunt test (if you put 
pressure on her sternum she will grunt in pain), arched back stance.

now 
that grain must pass a magnet prior to being fed, there is a lower 
incidence of this disease. also, cows are given their own magnets as 
yearlings. magnet stays in reticulum, trapping any wires/nails there. 


normal high temp of a cow: 102.5 F
he said to write that down.
so a low 
grade fever is like 103 or 103.5
it's a low grade fever b/c it is a 
localized peritonitis. they have an increased respiratory rate b/c they 
are trying to breathe shallowly b/c it hurts to breathe. cow will have an 
increased WBC count. cow normally has 8-10,000. btw, there are a million 
microliters in a liter. 

classic case  - will stand with elbows akimbo, 
back arched, and walking on tippytoes - dr d is doing a cow imitation 
right now, most amusing. 

dx: exloratory celiotomy, exploratory 
rumenotomy, rads, physical exam.

slide: cow with traumatic reticulitis - 
her tongue is sticking out. she's grunting in pain. 

why do cows get 
this? b/c cow prehends with her tongue - has much less sensitivity about 
what she's grabbing - sheep/goats prehend with lips, and they feel 
everything, and they do not eat wires and stuff. they spit those things 
back out. 

slide: rad - wire in cow where it should not be. you need a 
strong xray machine to take a picture like this, though. 

tx: magnet per 
os, removal of foreign body, systemic antibiotics. first need to know if 
she has a magnet. how do you know? use a compass. put it near her 
reticulum/rumen, see where it points :). if you determine that magnet is 
back in the rumen, give her another but if you give two in the same spot 
it doesn't work as well. 

now, wire is poking through reticulum and 
stuff is dripping out. what you want to do is get wire back inside so 
hole can seal up. well, really, you want to get the wire all the way out 
surgically if possible...but usually just try to move it magnetically. 


[he is telling us that story he told us before about the snowplows 
leading the way for him just south of Buffalo. also the story of the 
dystocia call he brought his wife to on xmas when the barn collapsed.]


point of that - when roof fell in, the nails all fell out of the roof 
into the hay. but he had to use that hay b/c he couldn't afford new hay. 
so, these cows didn't have magnets, either - and he was doing 
rumenotomies all the time. he'd remove handfuls of nails. then he'd put 
magnets in. but the magnets couldn't hold all those nails, so you'd have 
to go in and clean off those magnets. 

treatment - rumenotomy and 
removal; rumen transfaunation.
we operate on the left side, in the 
paralumbar fossa - dorsal limit is transverse processes, cranial limit is 
the last rib (13th), and caudal limit is the tuber coxae. you can do a 
line block of the incision site, or you can do an inverted L block. 
the 
nerves innervating the area can be blocked by injecting at T13 - L3 and 
along the caudal border of the 13th rib. the paravertebral block involves 
injecting near the roots of the spinal nerves exiting T13-L3. you want to 
get them just before they divide and you do that by knowing anatomically 
where they are. they come out just behind the transverse process - so you 
go just behind the processes, and the nerve is right there. you go 2 
inches off the midline, just behind the process, just above and just 
below, and you will get both dorsal and ventral branches. when you do 
that, you want to be sure that cow is desensitized. one way is to touch 
the skin with a needle along proposed incision site. theoretically, cow 
shouldn't feel that. the next thing to do is walk behind the cow, and 
look toward her and see if the lumbar area is deformed - instead of 
straight, if it is twisted, the block has worked. the block causes her to 
be convex on the side that you blocked. this is due to relaxation of the 
muscles when the deep branches of the nerves are blocked. 

when you cut, 
you go through skin, subcu tissue, external abdominal oblique, internal 
abdominal oblique, transversus, and peritoneum. the orientation of those 
muscles is how you tell where you are. ext oblique runs caudal-ventral, 
internal oblique runs cranioventral. transversus go around the cow. 

slide: nerves. 
you make the incision, then go in and feel near the 
reticulum - should feel fibrin, inflammation. this is to confirm dx. 
then, open the rumen. use rumen to shield the wound. feel forward and 
find the nail or wire or whatever. try to find one that is perforating 
through. 

an extension of this disease can occur - wire perforates 
diaphragm into pericardial sac and heart. this is traumatic 
reticulopericarditis. it's only 3/4 inch from reticulum to heart in adult 
cow. that's not that far. now, you have a pericarditis, too. an abscess 
around the heart. that's no good. there is a pathognomonic sign 
characteristic of a cow with early stages of traumatic 
reticulopericarditis, and that is the washing machine murmur. it sounds 
like the agitator in a washing machine - splash-splash-splash. b/c 
pericardial sac is distended with some fluid and some space above it. so 
when heart beats, it splashes. if the disease progresses, sac fills up 
and you do not hear that anymore, it's just a muffled heart. if it 
becomes fibrin, you really don't hear the heart and then the cow has 
distended jugular and mammary veins due to impaired venous return. 


slide: picture of cow with large bore cannula through left 5th 
intercostal space, with polyethylene tube through cannula to drain pus 
out of pericarial sac. so you have to do rumenotomy, get wire out, treat 
infection in pericardium. also need to drain it. 

here is a cow who has 
this disease - she was treated more radically - they've drained the 
pericardial sac - she has an incision behind her elbow - they removed the 
distal 4-5 inches of her left 5th rib. then they made an incision through 
deep periosteum, through pleura, through pericardial sac which is now 
adherent to pleura, and drained fluid out. the cow doesn't get 
pneumothorax b/c the pericardial sac is adhered to left thoracic wall due 
to inflammation. 

cow can get better. this is what is done with valuable 
cows. 

most of you have seen cows at NBC who are donors for ingesta - 
the fistulated cows. the idea is if you want a permanent fistula into 
rumen, you cut a circle out and suture rumen to skin. 

rumenotomy in 
other spp is really only done if they've eaten a poisonous plant or 
something.

abomasum:  displaced abomasum is most common abdominal 
surgical disease in cows. normally should be just to the right of 
midline. when it moves to one side it causes a partial obstruction.


signs: left displaced abomasum (LDA): usually freshened recently, 
anorexic, decreased milk production, normal TPR, ketosis, high pitched 
resonance (ping) heard on auscultation/percussion of left flank area, 
loose feces b/c water passes by obstruction but food does not. 

the 
abomasum is fixed at the beginning where it originates off the omasum, 
and at the end where it goes to duodenum. with LDA it is trapped b/w left 
body wall and rumen. pinched sites are where it goes under the rumen. 


same signs for RDA but ping is on right. sounds like empty beer can being 
thrown down an alley. 

when there is an irregular bottom line to the 
area of the "pinging" when you percuss, it is the abomasum. if it is the 
rumen, the bottom line will be flat, horizontal. to be irregular at the 
bottom like this means it is abomasum.  
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