Malignant Catarrhal Fever

 D. E. Larsen, DVM

I stepped back from the chute to get a wider view of the cow. This was a sick cow. She was probably going to die. But what is going on with her?

“Bill, has this cow been anywhere other than here?” I asked. 

“No, she was born right here,” Bill said. “She hasn’t stepped off the place in her whole life.”

“I have only seen two cows that looked like this, and both were in school,” I said. “One had bluetongue, and the other had malignant catarrhal fever. Bluetongue is usually seen in sheep, but it can occur in cattle. I am not sure that it is seen in Oregon.”

“I haven’t heard of either of those, but they don’t sound good,” Bill said.

“I think it is more likely that she has a bad case of bovine virus diarrhea,” I said. “That is much more common, and I see a lot of it around here. But I haven’t seen a case of BVD that looked this bad.”

“What does all of that mean for the cow?” Bill asked.

“I think it means this cow is going to die,” I said. “Some cows will recover from BVD, and a few will recover from bluetongue, but the cows with MCF all die. My guess is this cow is going to die. Her eyes are both infected, making her blind. The mucus membranes in her mouth have many blisters and ulcers. It looks like the skin on her tongue is going to slough off. She has swollen lymph nodes and is draining mucus from her nose. She has a lot of trouble breathing, but I think most of that is upper airway issues.”

“Maybe we should just shoot the poor girl,” Bill said.

“That might be an option. There is really no effective treatment for any of this, especially MCF,” I said. “But the state will want a say in this case.”

“That doesn’t sound very good,” Bill said. “They will want me to spend a lot of money finding out what is wrong with my dead cow.”

“I think they are going to want to know what is wrong with her,” I said. “But, the testing they do will be at their expense. They won’t be asking you to pay for any of it.”

“What about my other cows?” Bill asked.

“We have talked about BVD before, and we did some vaccines last fall,” I said. “That distracts from that diagnosis, but some individuals will still contract the disease, even if they are vaccinated. Bluetongue is spread by biting flies and is considered to have no direct transmission. MCF is

spread from carrier animals, usually sheep, and infected cattle are not considered a source of infection to herd mates.”

“So is the state going show up with a bunch of vets, or what?” Bill asked.

“I don’t think that is going to happen,” I said. “I will collect some blood and some tissue from her mouth, which might be all they need. I will give you a call after I talk with them.”

After I collected the samples, I returned to the office and called Doctor White at the state veterinarian’s office. He was an assistant state veterinarian but much easier to work with than the other veterinarian in the office.

“Doc, I am pretty sure I looked at a cow with MCF today,” I said. “I collected some tissue off her tongue, some serum, and a purple top tube of blood that I can send to your lab. Are you going to want to look at this cow?”

“The only thing we worry about with MCF is making sure we are not dealing with a wildebeest strain,” Doctor White said. “What is the status of the cow?”

“She is pretty sick,” I said. “I think she will die in a day or two, maybe sooner. I didn’t treat her with anything. In school, I was always told it was a waste of time and money.”

“If she dies, just have the rendering company drop her off at OSU’s diagnostic lab for a necropsy,” Doctor White said. “I will call them so the rancher isn’t charged for anything.”

“So, this guy thinks that shooting her might be a good option,” I said. “I guess there is no problem with diagnosis if we do that.”

“Well, one disease they like to rule out is rabies,” Doctor White said. “Shooting her in the head might disrupt the tissues for that diagnosis.”

“That’s just great,” I said. “I never even considered rabies as a differential diagnosis. I was involved with a necropsy of a rabid cow when I was in school. We had a group of students and professors who had their hands and arms in the mouth of that cow. And I ended up getting some vaccines after that event. I think we will just wait for her to die. I doubt he will want to pay for a bottle of euthanasia solution.”

“Well, send me your samples, and send the cow to the diagnostic lab when she dies,” Doctor White said. “I will let you know about the diagnosis as soon as I have it.”

“The book says that there is no risk to the rest of the herd from this cow. Is that correct in your experience?” I asked.

“That’s correct,” Doctor White said. “This virus is probably carried by a sheep, and the sheep aren’t bothered. Transmission is somewhat of a mystery. It happens with direct contact but also from airborne transmission up to a few miles away. Don’t ask me how.”

“I don’t think there is a place in the valley where you can be over two miles from a sheep,” I said.

“Probably not, but the good thing is this a rare disease. If you see more than a couple of cases in your lifetime, that would be unusual.”

As soon as I finished my conversation with Doctor White, I called Bill to let him know the plan.

“She is going to make things easy for those state boys,” Bill said. “That cow fell over dead, not more than a half hour after you left.”

“Yes, that makes things easier,” I said. “We will call the rendering truck for you. They drop her off at the diagnostic lab in Corvallis. It might take a few days, but we should have a confirmed diagnosis.”

“What I don’t understand, Doc, is how the hell did she get this MCF stuff?” Bill asked. “I mean, she hasn’t left this place, and no new animals have come into the place in years.

“This virus is carried by sheep,” I said. “It doesn’t make the sheep sick. The book says it is transmitted by direct contact or through the air. They don’t know how it gets through the air, but it can travel a couple of miles.”

“Well, hell, there isn’t a place in this valley two miles away from some damn sheep,” Bill said. “What am I supposed to do about that.”

“It is rare, Bill,” I said. “Don’t lose any sleep over it. I will probably never see another case in my lifetime.”

***

The cow’s diagnosis was malignant catarrhal fever, and it was the usual sheep strain. I was relieved that the rabies virus was not involved.

Oddly enough, I did see another cow with MCF a couple of months later, about two miles down the road from Bill’s place. And there was a flock of sheep between the two places.

So I saw the cow in school and the two cases in Sweet Home. There was never another case. Three cases in a lifetime, all coming within a few years of each other.

Photo by Kris Rae Orlowski on Unsplash.

https://www.merckvetmanual.com/generalized-conditions/malignant-catarrhal-fever/malignant-catarrhal-fever-in-animals#v3275876

The Land is Cheap There

 D. E. Larsen, DVM

When I pulled into the driveway, I could see Don waiting in the doorway of the little barn behind their house. He had one old Jersey cow when I called on him at his little place over on North River Drive. He had said he wanted his cows checked for pregnancy, so I figured he had more than one cow in this new place.

“This is a nice little place you have out here, Don,” I said as I got ready to check his cows.

“Yes, we enjoy it out here,” Don said. “But little is the keyword in your sentence. I only have four cows. I could probably run six if I bought more hay. But my pasture is pretty limited.”

“What do you do with your milk?” I asked.

“I suppose I should be careful telling you, but I jug it,” Don said. “Raw milk is pretty popular around here. I have people lined up at the milk house every evening.”

“I don’t know all the rules, I think there is a small farm exception, but raw milk sales on the retail level are illegal in Oregon,” I said. “When I was in Washington, I cared for a large raw milk dairy. There were a lot of rules and a lot of testing for them to keep their milk on shelves.”

“I don’t know why that is. Raw milk is probably better for you than the stuff you buy in the store,” Don said.

“That’s a discussion we won’t find common ground on, Don,” I said. “There are some arguments in favor of raw milk, but there is a whole list of diseases that can be transmitted by the stuff. Some of those are probably considered rare in a small, closed herd like you have here. But if they start selling raw milk in a big way, there will be problems. I say that even though I grew up on the stuff. The immune status of a farm kid is probably far stronger than in the little girl in town who seldom gets out of the house.”

“Well, let’s get these cows checked,” Don said. “I am selling them next week. We are going to sell this place and go to Iowa and buy a farm.”

“I will be sorry to see you go,” I said. “But what made you choose Iowa. It gets pretty darn cold there in the winter.”

“My wife is from Iowa,” Don said. “Land is a lot cheaper there.”

“I used to tell people that when I was in school in Colorado, we used to go up in the mountains so we could watch the riverboats on the Mississippi River,” I said as seriously as I could. “We could do that because there was nothing in-between. All the land is flat.”

Don was quiet for a few minutes. Deep in thought as he processed my statement.

“That must be a joke,” Don finally said. “I don’t think you could see that far.”

“It’s a joke, Don,” I said. “It is meant to illustrate that there is a lot of flat land between the Rocky Mountains and the Mississippi River.”

“It might be flat, but it’s good land,” Don said. “And it is cheap. I can sell this little place and go back there and buy a hundred-and-sixty-acre farm. And I will probably have money left over to buy cows. That is what I am going to do. I am going to buy a little dairy instead of playing around with three or four cows.”

We went in the barn to check the cows.

“How far along are these cows?” I asked.

“I only had a bull for a month, so if they are pregnant, they will be about five months along,” Don said. “I really don’t need a close timing. The guy who is buying them just wants to make sure they are pregnant. I haven’t seen any of them in heat, so they have to be pregnant. He just wants your opinion on a piece of paper.”

“At five months, I can’t give you much more than an approximate month,” I said. “Before ninety days, I can get that down to plus or minus five days.”

I pulled on a plastic OB sleeve and checked the first cow. The fetus is often out of reach in the cow at three and four months of pregnancy, but I can usually feel the calf at five months. Size is pretty variable, however.

“This cow is pregnant, and five months is a good estimate. I can feel the head,” I said as I changed sleeves.

I worked through all the cows, changing sleeves between each cow. That was not something I usually didn’t do, but the numbers were small, and with Don selling raw milk, it was probably a better practice.

“Everybody is pregnant,” I said. “I think they are closely grouped. That bull must have had a busy few days.”

“He was a little Hereford bull,” Don said. “I like using a Hereford bull on these jerseys. They spit those calves out like nothing is happening.”

“I grew up on a Jersey dairy,” I said. “I never saw a calf pulled until I got to vet school. The shape of the Jersey pelvis makes them the easiest calving cow of them all.”

“Thanks for services over the years, Doc,” Don said as he shook my hand. “I might not see you again. These cows go next week, and the realtor says this place won’t take long to sell. I will probably buy cows in Iowa by next month.”

“Good luck, Don,” I said. “You probably want to buy some long johns and insulated coveralls, along with those cows.”

***

It was months later, in the middle of November, when I came in from a farm call, and Sandy handed me a note with a telephone number.

“Don called from Iowa,” Sandy said. “He sounded a little upset and wanted you to give him a call if you could.”

“Hello, Don,” I said as soon as Don answered the phone. “How are things going, and what can I do for you?”

“I guess I will never be smart enough to know how you can be so smart,” Don said. “I finally broke down and bought a pair of the insulated coveralls you told me about. It is so damn cold here. I don’t understand why anybody settled in this country in the first place.”

“They didn’t know to fix their wagon wheel when it broke,” I said. “So they were stuck and decided to make the best of it.”

“You might be right, Doc,” Don said. “The other morning, a cow pissed on the floor and plastered it everywhere. The damn stuff froze in no time, and I slipped on it and fell. I spilled a bucket of milk and thought I broke a hip at the same time. My hip is okay, but I am still crying over that bucket of spilled milk.”

“You be careful, Don,” I said. “You are starting to talk like me. You didn’t call to tell me stories. How can I help you?”

“Doc, I need help finding a veterinarian,” Don said. “The guy I had out here this week seems like a quack to me.”

“Don, I don’t know any veterinarians in Iowa,” I said. “You might call the vet school at Iowa State and ask them for a list of veterinarians in your area they could recommend. In fact, it might be better to try to talk with one of the large animal professors and ask him. He probably will remember all the ones he thought should be washed out of school.”

“This guy came out to pregnancy check a bunch of cows for me, and he didn’t even change sleeves between cows,” Don said.

“Don, in a large group of cows, that is common practice,” I said. “It is different with I checked your cows here. You only had a few cows.”

“Okay, maybe I was too rough on him,” Don said.

“If it is important to you, just ask him to do it,” I said. “I would guess he would not be bothered by the request. He might make you pay for the extra sleeves, but that is only fair.”

“Okay, I will do that,” Don said. “And I wish you had told me to come back here for a winter before I bought into this place.”

“Just wait, Don, it’s only November,” I said. “You have a long way to go before spring.”

Photo by Get Lost Mike on Pexels.

Where is the Volar Pouch, from the Archives

D. E. Larsen, DVM  

Dr. Adams was a massive man, both in his physique and in his professional reputation. He was not tall, less than six feet, but very muscular. His rugged facial features made him appear to have a scowl on his face in the best of times. In those moments, when he was mad at a horse or a student, some would say he was fearsome.

There was a story while we were in school about Dr. Adams attending a meeting of equine veterinarians. The first presenter was doing a ground-up portrait of the perfect equine veterinarian to lighten the audience. 

He started with the feet, then the legs, on up to the chest and arms. The picture was that of a cartoon gorilla. In actuality, it portrayed Dr. Adams pretty close. Dr. Adams was in the front row and was becoming red in the face because it seemed everyone except the presenter recognized the similarity to Adams. I have no idea if the story was true, but it was told a lot in those years.

However, he was a great teacher. When I was assigned to him for my senior rotation in large animal surgery, I was thrilled. That thrill did not last long.

On the first Monday morning of my two-week rotation, the Junior student and I waited in front of the large animal surgery room. Finally, Dr. Adams arrives at 8:00 AM sharp.

“Good morning, Guys,” Dr. Adams says. “You two are lucky. We have a busy couple of weeks coming up. I want to get off to a running start here.”

He throws up an x-ray of the lower leg of a horse on the viewer.

“Where is the Volar Pouch, Larsen?” Dr. Adams asked. 

“Um,” I stammer.

“Jon, same question?” Dr. Adams says to the junior student.

“I guess I don’t know,” Jon replies.

“Okay, let’s get started on the day,” Adams says. “But, you two have an anatomy test in my office at 1:00 PM on Wednesday. If you fail that test, you fail the rotation.”

And if the rumors of Adams’ power were correct, we will play hell graduating if we fail the rotation. This was not only intimidating, but it was also damn scary.

When the casework was done for the day, Jon and I were in a rush to get home. I had managed to get through the first 3 years of Vet School with little studying outside of the classroom and clinic. Now, I had a couple of nights to review the anatomy of the horse in exquisite detail. 

Dr. Adams was the author of Lameness in Horses and enjoyed the reputation as the leading authority on the horse’s legs. That gave us a clue. Make sure you know every detail of the anatomy of the horse’s legs.

For the next two nights, I reviewed my anatomy notes from my freshman year. I committed the equine section of Sisson’s book, The Anatomy of Domestic Animals, to memory. My memory is pretty much photographic. I can save pictures in my mind, but not text. On occasion, I can save captions to the photos for a brief time.

Finally, Wednesday came. We had surgery scheduled for the morning. Dr. Adams was a skilled surgeon. In this jumper, there was a chip fracture of a carpal bone. A significant amount of the time involved getting the horse under anesthesia and positioned on the surgery table. The surgery was brief in Dr. Adams’  hands. The chip was removed, and Dr. Adams left the closure to his intern and senior student, me.

“Don’t forget the test in my office at 1:00,” Adams said as he pulled off his surgery gloves.

“We’re looking forward to it,” I replied with an unseen smile, but I am sure it reflected in my eyes.

Adams smiled and departed the surgery room. 

When the horse was recovered, and back in the stall, Jon and I had a full hour and a half for a final review.

“I am going to take Sisson and go grab a coffee and a sandwich over at the MU,” I said.

“That might be good,” Jon said. “I will join you, but I think I have had my quota of coffee for the week.”

There was no real conversation at the table. We ate a quick sandwich, and both did a final review of Sisson. My pages turned much quicker than Jon’s. When the time came, we got up and walked back to the hospital. 

Dr. Adams’ office was on the second floor of the hospital. When we turned the corner to his office, we ran into a crowd of classmates. Word of our test had spread through the classes, and everyone wanted to watch. It must be like a crowd viewing a hanging. We worked our way through the crowd and took our seats in the office.

These professors all tried to present themselves as intimidating as possible. I found it almost laughable. In my last year in the Army, it was common for me to make presentations at general staff meetings, for generals with 2 or 3 stars on their collars. They were much more formidable than any professor. So in this situation, I was pretty relaxed. Jon was not so much.

Dr. Adams wasted no time. He started firing questions, some oral, some with x-rays on the viewer, and some with pictures from slides projected on to the wall. Like all tests, they are easy if you are prepared. I think the fact that both of us didn’t miss a question was getting to Dr. Adams. 

“You haven’t asked about the volar pouch,” Jon said.

“I figured that would be the question you studied first,” Dr. Adams said. “But since you mention it, why don’t you tell where it is located and what it is, and why it is important on that x-ray I had Monday morning.”

“The volar pouch is an extension of the joint capsule and is located between the cannon bone and the suspensory ligament, just above the sesamoids of the fetlock. If it is distended, it indicates inflammation in the joint.”

“That’s a good answer, Jon,” Dr. Adams said. “You should not overlook that on an x-ray.”

“If you did an adequate clinical exam, you should know it is distended before the x-ray is ever taken,” I said.

“That’s a good point, but in this business here, I am often looking at x-rays of horses that I didn’t examine,” Dr. Adams said.

Finally, he puts a picture on the wall. This was a picture of the two planter nerves on the lower front legs of a horse. There is a nerve that communicates between these two nerves. It crosses the leg at an angle. . You could tell which leg you were looking at by the directing that this nerve was running between the two primary nerves. This was a picture right out of Sisson.

“Larsen, what leg is this?” Dr. Adams asked.

“The left leg,” I said. “The left front leg,” I added.

“How do you know that?” Dr. Adams asked.

“That is the picture out of Sisson,” I said. And then, looking at a blank wall, I used my finger to trace the words in the caption of that picture as I read the caption.

The hallway audience erupted in laughter.

Adams shook his head and smiled. “That’s all I have, I can’t top that.”

That could have been the only time I ever saw the man smile. There was never a mention of the test in the remaining time days of the rotation. We learned a lot, and even though I was not fond of horses, I learned everything I could from the man.

Photo by Laila Klinsmann from Pexels