Saturday, September 10, 2011

Being a food animal veterinarian, day 3

Day 3. I signed up to ride with Dr. Cripi, just him and me. I was hopeful that I would get to do more hands on stuff when I was not competing with other students for opportunities.

I expected to get right in the truck and head out, but Dr. Cripi said that a cow was being brought to us this morning. Some farms are so far outside the clinic’s usual area that they are only worth visiting if there is some other work in the same region. These farms can be our clients, but have to let us schedule our visits to groups of them on the same day. When they have emergencies, they have to bring their animals to us. This was why the cow was coming to us now.

She got off the truck nicely and we put her in the stocks so that she was restrained and could easily be examined. Dr. Cripi noted that her eyes were sunken, indicating dehydration. Some other students were standing around as well, and we all got to examine her. A large part of examining a cow is trying to identify problems with its complicated GI system. If part of the GI is displaced to somewhere it shouldn’t be (a fairly common problem, especially in cows that are fed too little roughage in their diets, e.g., are not out on pasture or fed mostly hay) then that part of the GI will start filling up with gas. You can “ping” the cow to hear this. You snap a finger hard against her side while listening with your stethoscope. This was the first ping I had ever heard, as I had never before examined a cow with a displacement. It sounded like a basketball bouncing on a metal floor. I referred to the ping as “gorgeous,” which amused the farmer no end.

This cow had an RDA, or right displaced abomasum. This means that the cow’s true stomach, or abomasum, had floated up on the right side of the cow. (Normal location: right side, but a lot more ventral, e.g., closer to the ground). We performed standing surgery on the cow to fix the problem. We did not sedate her, as she was so sick that Dr. Cripi thought sedation would make her lie down, which would make the surgery much more difficult. We did give her a local block in the area where we would be cutting. Then she was shaved and prepped (aseptically scrubbed) over her right side.

First we scrubbed in. This was hilariously different from scrubbing in to surgery in the small animal hospital, which I had done a lot of on my surgery rotation over the previous month. A cow holding area is going to be inherently dirty. We scrubbed our arms off with iodine and put on long surgical gloves (they have to go up to your shoulder, because you’re going to be reaching deep inside a big animal), then normal sterile gloves on top of that.

Then Dr. Cripi made a maybe 5 inch incision in the cow’s side. She didn’t seem to notice; hurray for local anesthetics. He pointed: “See? Her abomasum is right there. That’s huge!” The abomasum was hugely distended with gas and floating right under the surgical incision. Dr. Cripi put a needle into it, attached to a long tube, and let a lot of the gas out. He had all the students smell the gas: a sort of sweet smell, much nicer than rumen smell. (The rumen is the largest and possibly most important part of the cow’s complicated four chamber stomach, the part that feed first falls into to ferment.) The farmer declined to take a sniff, and made a face.

Once the abomasum was somewhat deflated, Dr. Cripi tacked it to the body wall with tacking sutures. Then he closed the incision’s lower layers with the biggest needle I have ever seen in my life. Then he showed me how to close the last layer, the skin. I have done my share of small animal skin closures, and this was really different: that cow’s skin was insanely thick and tough. If you’ve sewn leather, you know what it’s like. I had to really put my back into it to get the needle through.

Then we dosed the cow with a liter of intravenous fluids plus dextrose, and a liter of electrolyte solution. I got to hold the fluids up “as high as you can!” If it is going to make your arm tired, it is the student’s job.

Then the cow walked politely back on her truck and went home.

We got in our truck and headed off to our first farm, with Dr. Cripi angsting about how late we were the whole way. En route, we talked about our lives. Some ambulatory vets use the ride as a teaching opportunity (Dr. Mulain); some ride in silence (Dr. Thery); some just want to chat (Drs. Cole and Cripi). Dr. Cripi had a pretty interesting life, it turned out, spending five years just traveling the world before realizing he wanted to work with food animals as a veterinarian.

Farm number one: a herd check. Checking cows in a herd for pregnancy seems to be the bread and butter of the practice. It was a typical concrete floor, feces-covered barn, but with a particularly open design that I really liked, basically just a roof over the cows, no walls. I asked about their plans for winter (this was a brand new structure). They intend to put up some cover then, but nothing permanent. We worked with a fantastic view of rolling Connecticut hills. It was a lovely scene to look at while putting one’s arm up a cow’s butt.

This farm’s staff included a scrawny kid just out of his teenage years who noticed that a female had arrived and immediately took off his shirt. This became even more hilarious when I was told that it was my job to castrate a  bull calf and that the kid would help restrain. I later asked Dr. Cripi if the kid took off his shirt every time a female vet student appeared. Dr. Cripi rolled his eyes and said yes.

How to castrate a bull calf: the vet will draw a diagram for you on a paper towel, hand you a scalpel, and send you on your way. I asked if we used lidocaine for analgesia; he said I could if I wanted to. I said yes please. (The debate in use of lidocaine for a local block in castration is that arguably it is more unpleasant to have a needle shoved into multiple spots in your scrotum and have something that burns injected than just to have the stuff ripped off real quick. Personally I think pain meds are mandatory, but even more so if the job is being done by someone who’s never done it before.) I gave the calf lidocaine injections at various locations around his scrotum and waited five minutes for it to take effect.

My experience in castrating dogs and cats was helpful. I cut off the tip of the scrotum, squeezed the testicles out. They are slippery and don’t like to come out, but I had done this before on a smaller scale and knew how to squeeze. Then I grabbed them and pulled until they came off. (The hardest part was getting a grip. In small animal medicine one uses little four by four pads to hold on to them, not your hands.) The kid asked why we didn’t just cut them off. I said that Dr. Cripi hadn’t said, but my guess was that the bleeding would be worse if you cut; ripping provides some hemostasis.

Farm number two. En route, the sun came out. My spirits immediately lifted. It is amazing what a difference some blue sky makes. At this farm we had a sick cow who was two weeks fresh. This means she gave birth two weeks ago and has been being milked for two weeks. The stress of parturition means that many of these fresh cows are at risk for a variety of diseases, like a displaced abomasum such as we’d seen earlier that morning. In this case, she seemed to have some nerve injury from when the baby passed over the obturator nerve along the pelvis. We prescribed rest, TLC, and anti-inflammatories (banamine is what you give to cows).

Farm number three. Another hobby farm, but a somewhat bigger one. This farmer had quit her previous job to just be a cow farmer, and her husband’s income was presumably supporting the operation. The cows were out on grass in a truly lovely setting (we drove over a little covered bridge across what I have to describe as a sparkling brook on the way in). The cows were spotlessly clean. Normally you sort of hesitate to pet them because of all the manure all over them (at least until you have manure on your hands, which inevitably happens). These cows were so clean that I actually sniffed one and discovered that natural (manure free) cow smell is a lot like horse smell. The farmer had put the sick cow into a holding area, which had a concrete floor which was also spotlessly clean. No huge masses of spider webs! No dead birds in the rafters! Crazy! The farmer actually hovered with a bucket to catch the urine when the cows peed, which is farther than I would go in her place, but I really did appreciate the cleanliness. As Dr. Cripi pointed out, these cows were basically pets.

This cow had a left displaced abomasum (same problem as the first patient of the day, different side). LDAs are actually a lot more common than RDAs, which is too bad, as you still have to cut on the right side of the cow (the rumen covers everything on the left side) and as you then have to reach across the inside of the cow to get to the abomasum on the other side, it becomes quite a process. This cow was dry (no longer being milked) and due to freshen (give birth) in a few weeks. Dr. Cripi was amazed that she had an LDA. Dry cows almost never get displaced abomasums; it is a disease of fresh cows. Cows out on grass also almost never get this disease. This particular cow also turned out to have pneumonia, so maybe the stress of that had caused the displacement. Weird.

So, same surgery, except that Dr. Cripi had to reach through the cow this time instead of having the abomasum pop right up under his incision. I did not get to close, as I had inadvertently contaminated myself on the cow’s side while trying to prevent the drape from falling off of her.

Last farm of the day: again, a horse owner. Her horse needed his yearly vaccines. He was 31 years old! He was a super nice horse. Dr. Cripi sat down and handed me the vaccine bottles. I drew them up and injected them into the horse’s neck. He never flinched. Old patients can be the easiest ones to handle.

End of day 3: less wet, more confident, starting to have fun.

No comments:

Post a Comment