David E. Larsen, DVM

It was the best afternoon we had seen in some time. Colorado’s weather had taken a little getting used to, and the sunshine and warm temperatures this afternoon were a welcome relief.

Dr. Bass was shuffling papers at the podium in the auditorium as the class took our seats. Seats were not assigned, but as we started the spring quarter of our freshman year, everyone sat in the same seat that we started with in the fall.

“Today, we are going to dispense with any lecture, and you guys are going to go down to the Student Health Center and get your rabies vaccines. Veterinarians are high on the list of people exposed to the rabies virus in this country. This new vaccine, grown on duck eggs, provides excellent preexposure protection. It is given in three doses, three weeks apart. So, you can expect some escape from the classroom a couple more times this spring. There is no cost; they are using you guys as guinea pigs. But it is wise to take advantage of the opportunity.”

So we all marched down to the clinic in a formation that would make a drill sergeant shudder. There were eighty-four of us, so the line took a bit. 

***

The summer following my sophomore year of Veterinary school, I landed a job working in CSU Veterinary Hospital’s necropsy room. I spent the entire summer immersed in pathology. The work provided much-needed income but also provided me with the best learning experience I could have hoped to have.

I became somewhat of an expert at removing brains. I used a cleaver and could take a brain out of any animal in record time.

It was nearly mid-summer when Dr. Norriden came out on the necropsy floor. I pulled us all together for a little lecture. This was unusual for him.

“They are in the process of bringing cow around from the clinic shortly,” Dr. Norriden said. “This cow was treated by our ambulatory service about ten days ago. She was not diagnosed on the farm. On their initial exam, the cow had difficulty eating. They treated her several times, and things only got worse. They hospitalized her three days ago. In the hospital, they diagnosed a neurological disease, probably encephalitis.”

“Now, based on what I have just told you, are there any red flags here?” Dr. Norriden asked.

Bob, the pathology resident, looked around, waiting for one of us technicians to say something.

“Maybe rabies,” I said with little confidence in my choice.

“That’s the big thing,” Dr. Norriden said. “Anytime you deal with an undiagnosed neurological case, you should have rabies at the top of your list. You won’t see it often in your career, rabies is almost rare in our pet population due to the vaccination requirements. But this case is a good example. We will have a real mess if this cow is positive for rabies. The ambulatory crew and the hospital failed to have it on their list of possibilities. We have students who had their arms down this cow’s throat. When you take this brain out, Larsen, you work with your mouth closed. That is probably a good idea for everybody.”

It was not long before the cow was delivered to the necropsy room. Bob quickly examined the head and removed the tongue along with the esophagus and larynx. Then he severed the head and brought it over to the large chopping block for me to remove the brain.

I skinned the upper part of the head and then started removing the bone surrounding the brain. It was not long before I had the brain case exposed. Then, with careful strokes of the cleaver, I shaved the bone away from the underlying brain. A little work with scissors and I had the dura opened, and the brain was carefully lifted out of the brain case.

Dr. Norrdin was beside me as I lifted the brain. He took it from my gloved hands and disappeared into his lab/office.

The rest of the necropsy was unremarkable. The problem was in the central nervous system. Getting a good fixed slide under the microscope would take a day or two of processing. Then, if this was rabies, Dr. Norrdin could make the diagnosis by finding Negri Bodies in pyramidal cells of the hippocampus. Negri bodies are round or oval, sharply demarcated, eosinophilic inclusions within the cytoplasm of the infected neurons. They are considered the hallmark of rabies.

The following afternoon, Dr. Norrdin had the diagnosis. The cow was positive for rabies.

“The good thing is all of you guys have had your rabies vaccines, so you only need one booster,” Dr. Norrdin said. “Put this case in your memory bank. It will be unusual to see another one like this, but keep it in mind.”

***

“What do you think is going on, Doc?” Larry asked as we stood over a dead cow in his pasture.

“I don’t know,” I said. “But we will open her up and take a look.”

I had only been out of school for a few months, but my summer in the necropsy room gave me total confidence in doing a necropsy in the pasture.

Larry had a lot of questions. This was a big investment lying dead in front of us. We stood and talked as I sharpened my knife with a whetstone. By the time we were done talking, my knife was sharper than ever.

I leaned over the cow and inserted the knife under her skin in front of her udder. The knife slid through her skin with no resistance as I ran it forward. My stoke was firm and fast. The knife was so sharp it flew through the skin, and as my arm completed the stroke, it flew out of the skin and buried in the muscle of my lower leg.

“That was smart,” I said.

I took a moment and wrapped the wound on my leg. It was bleeding profusely. Then, I returned to my work on the cow. Once I had her belly and chest opened, the diagnosis was easy. A wire poked out of her reticulum, through her diaphragm, and into her heart.

“Hardware disease,” I said as I pulled the wire out to show Larry. 

We had a brief discussion, but I cut it short as I could hear the blood slouching in my boot.

“You can come to the office tomorrow, and I will review everything with you,” I said. “We will need to get some magnets for you for the rest of your cows. But, right now, I think I need to get my leg to the Doctor.”

The nurse at the Doctor’s office got me right into the treatment room when she heard the blood sloshing in my boot with every step.

The Doctor was quick to get the wound taken care of, and he chuckled at my story about how my knife came to be buried in my leg.

“There is one thing that worries me a little, Doc,” I said. “A little over a year ago, I used this knife to do a necropsy on a cow with rabies. This knife has been washed, but it has not been through an autoclave.”

“I don’t know,” the Doctor said. “You wouldn’t think the virus would survive that long, would you?”

We decided probably not, and besides, I had been vaccinated.

And I lived.

***

In Oregon, the reservoir for the rabies virus is in the bat population. Of the bats that are tested for rabies in Oregon, about ten percent are positive for rabies.

That does not reflect the incidence of the virus in the bat population because the only bats tested are those submitted by people of veterinarians.

In the early 1970s, rabies was significantly increased across the state, with several cases in pet dogs. This led the state to require rabies vaccination of dogs and to recommend vaccination for cats.

We held rabies clinics in public buildings for a few years. Rabies vaccines were given at near cost. I donated any profits to the humane society for providing labor in writing certificates. They were grueling events. I finally changed to doing the rabies vaccines in the clinic for a week at a reduced cost. That spread the numbers out, so it was such a pain.

Those vaccines solved the problem in the dog population and helped with the cat, but obviously, they did nothing for the bats.

As time passed, public health officials became strict about how they handled exposures or possible exposures.

Because a bat bite could be difficult to see or even feel in some cases, the rule evolved that a bat in a house with sleeping children was considered to have exposed those children to rabies unless the bat was captured and tested negative. The same went for pets in a house with a bat for any period of time. 

At first, it was recommended that unvaccinated pets in a house with a bat be euthanized. The other option was to quarantine the pet for six. Vaccinated pets could be given a booster vaccine for rabies, and they were considered okay.

It was about this time that I developed the philosophy that the rabies vaccine probably protected the pet from the system more than the disease.

In my years in Sweet Home, I had several rabid bats. One was found flopping around in the bathtub. Several were caught outside by cats, and a couple were captured flying around in the house.

In the 1970s and most of the 1980s, little attention was given to the finding of a rabid bat. But then there was a change in the state public health veterinarian. I don’t know if it was just that we were going follow the rules now or if it was a cover-your-butt type of thing, but the came about strict enforcement of the rules.

Sleeping children found in a house with a bat were considered exposed to rabies if the bat tested positive for the virus or if the bat escaped and was not tested. Pets were in the same boat.

Vaccinated pets were required to get a booster vaccination. Unvaccinated pets were scheduled for euthanasia. Their only other option was a six-month quarantine with vaccination at the end of the quarantine period. We were not allowed to vaccinate before the end of the quarantine period because the could influence the incubation period, which with rabies was known to be as long as six months.

Euthanasia was strongly recommended the the quarantine rules were arduous enough to make many people to go along with that recommendation. 

The reason for the increase in case follow-up was that the consequences for allowing an exposed pet to slip through the cracks would be the exposure of the owner and the public to a rabid animal and a possible human death from rabies.

***

“How long was the bat in the house?” I asked Lynn.

“We are not sure, but at least three days,” Lynn replied. “We saw it on Friday and then couldn’t find it. It finally came out on Monday. That is when Mike was able to swat it out of the air.”

“Are you sure you want to send this in?” I asked. “If it is positive for rabies, the public health folks will get involved. Boo’s rabies vaccine is not current. They will want to put him to sleep.”

“That doesn’t sound good, but I think we need to know,” Lynn said.

“Was there any human exposure?” I asked. “Did you or Mike handle this after it was swatted out of the air?”

“No, I just scooped it into this jar, and here we are,” Lynn said.

So, I boxed up the dead bat and sent it to the diagnostic lab at the vet school in Corvallis via our courier service.

Results came quickly, the next day in fact. The bat was positive for rabies. Within a few hours, I had a call from the state public health veterinarian.

“I have a report here that you submitted a bat for rabies testing, and the test was positive,” Dr. Van said.

“Yes, I got those results a little earlier today,” I said.

“Were any people exposed and kids in the house?” Dr. Van asked.

“No kids, the adults didn’t handle the bat,” I replied.

“What about pets?” Dr. Van asked. “And how long was the bat in the house?”

“There is one cat in the house, and the bat was in the house for at least three days,” I replied. “The cat’s rabies vaccine is a couple years out of date. I was hoping that a booster at this time would be adequate.”

“I’m sorry, but if the bat was in the house for three days, the chance of exposure for the cat is very high,” Dr. Van said. “A booster vaccine at this time would not be approved. Our recommendation is euthanasia for the cat.”

“I am pretty sure that this owner is not going to want to go that route,” I replied. “Is there an alternative for quarantine?”

“Yes, if they can do a six-month quarantine where the cat doesn’t leave the house, the rules allow that,” Dr. Van said. “Enforcement falls on your shoulders, Dr. Larsen. At the end of quarantine, you need to vaccinate the cat for rabies and send me a report. Any failure will result in forced euthanasia.”

“I think that is doable,” I said. “I will let the owner know.

So Lynn and Boo said through the quarantine, and I submitted the report along with a copy of the rabies certificate to Dr. Van.

***

Fast forward to the present day. 

Last year, my aortic heart valve went gunny bag. We had been watching it for the last six years, but it went from bad to worse in an acute episode. The Doctor thought I had had a heart attack, but it was just the heart valve.

During the two months that I was waiting for the replacement procedure, I had a conference with the main heart surgeon. He was explaining the procedure to me and the discussion involved the making of the new valve.

“This new valve is made from the pericardium of a cow,” the Doctor said. 

“So, what cat you tell me about the cow?” I asked. 

“What do you mean?” the Doctor asked.

“What about the history of the cow?” I asked. “I mean, I have known cows that wouldn’t their parts in my body.”

“I don’t understand your concern,” the Doctor said.

“If you look at my record, I’m a retired veterinarian, I worry about things like the rabies virus, among others,” I said. “A number of years ago, maybe twenty, a lady in Idaho died of rabies following a corneal transplant. When they investigated, they found the donor was a forest ranger who had died from an undiagnosed neurological disease.”

“I see,” the Doctor said. “All I can tell you is the tissue is treated in a manner that kills all the viruses and bacteria.”

“That sounds a little reassuring, but one day, you are going to have to worry about mad cow disease and those nasty prions that you can’t destroy, even with cremation,” I said.

“Thankfully, that is not a problem yet,” the Doctor said.

Photo Credit – John Torcasio on Pexels

David E. Larsen, DVM

It was a warm afternoon as we crowded into the Large Animal Surgery class. In early fall, Colorado could still see some warm days. 

I was in my final year of Veterinary School, and this class was one of my most enjoyable. Of course, the fact that Dr. Annes was the instructor helped. He had become one of my favorite professors.

“Today, we are going to amputate a digit on a steer,” Dr Annes said. “This is an excellent salvage procedure for a steer with a fractured digit or severe disease in a single hoof claw. It will allow the steer to function well and continue to gain weight for several months, maybe up to a year or so, This is not a procedure to use on a cow or bull that has plans for a lifetime of production. The foot will not hold up for years following this procedure.”

We worked in teams of two, each with a lower leg gathered from the slaughterhouse in the last day or two. The procedure was easy, with the leg lying on the table. It would be more difficult with a live animal.

We did nerve blocks on the digital nerves, reflected the skin from the hoof to the pastern joint, and severed the digital bone using an OB wire saw at a sharp angle to make a smooth appearance on closure. After suturing the skin back over the exposed bone, it made a pretty good-looking foot with just one claw.

At the end of the class, Dr. Annes again cautioned us that this was a salvage procedure.

In Colorado, we were in the middle of cattle country. Feedlots were everywhere. It would be a valuable procedure in those feedlots. I put it in my memory but doubted I would ever need it.

***

After several years in Sweet Home, the practice was getting busy. It was a warm afternoon that was drawing to a close, and I was thinking about taking the kids swimming when Sandy came back and said that Ginger was on the phone.

“What does she have going on?” I asked.

“She has an old ewe with a sore foot,” Sandy said. “It has been a problem for some time, but now the ewe is not using the foot. She wants you to look at today.”

“Okay, it is probably just a foot rot,” I said. “I can run out there now, and we can still have time to take the kids to Foster Lake for a quick swim. Just make sure you get a good address and directions.”

Leaving Dixie to finish cleaning up the clinic from the busy afternoon, I grabbed the file from Sandy and headed to the truck. I got the truck turned around and ready to pull out onto the street. I opened the file to check the address. 

Forty-ninth Street, this is in the middle of town. It can’t be much of a sheep flock. Sweet Home had just completed the annexation of Foster and Midway. Keeping livestock in those areas was grandfathered in, with limitations based on adequate lot size.

Ginger stepped out of the small yellow house as I pulled into the driveway. I could see a lone ewe in the small lot behind the house. The ewe was holding up her right front foot.

“I am so glad you could come today,” Ginger said. “Dottie has been holding up her foot for the last week. She must be in terrible pain.”

“Is this something that just happened?” I asked.

“Oh no, she has been limping for months,” Ginger said. “It has just been part of her. I never gave it much thought. She is getting pretty old, you know.”

“No, I didn’t know,” I said. “How old is Dottie now?”

“I am not exactly sure,” Ginger said. “We got her as a young ewe when our daughter was in 4-H. That was almost twelve years ago. So she must be twelve or thirteen.”

“That’s pretty old for a sheep,” I said.

“I know she is old, but she is such a pet. We want to take care of her as long as we can,” Ginger said.

“Well, let’s get a look at her,” I said. “Are we going to be able to catch her?”

“She is so arthritic, she doesn’t move much,” Ginger said. “And now, with this foot problem, she hardly moves. But I will grab a little can of grain to make sure she stays in place.”

Dottie didn’t move when we approached her in her little pasture. I put a rope on her just in case we needed it when I looked at her foot. Ginger dumped the grain on the ground in front of Dottie, and she started lapping it up.

I did a quick exam while Dottie was eating the grain. Her wool was thick and soiled; she hadn’t been sheared in a few years. Her wool was full of keds (a wingless fly that parasitizes sheep). Palpating her chest wall, hiding under her thick wool, revealed prominent ribs. Dottie was quite thin, likely due to a heavy intestinal parasite load along with the keds.

I turned my attention to Dottie’s sore right front foot. I leaned into her to provide a little support as I pulled up her foot with my left hand. The hoof on her lateral claw was a mess. With my hoof knife, I cleaned away the debris and rot from the hoof. Once I removed the material, I was looking at the coffin bone. There was no saving this hoof.

I set the foot down and allowed Dottie to return to cleaning up her grain.

“Ginger, I’m not sure there is much I can do for Dottie,” I said. “When you feel her ribs under all this wool, she is skin and bones. Her wool is full of keds. Keds are wingless flies that spend their entire life in the wool, sucking blood from the sheep. I would guess she is also loaded with intestinal parasites unless you have been deworming her on a regular schedule.”

“We had no idea she had any problems,” Ginger said. “She always looked fine. But I guess we never handled her like you just did. I hope you are not suggesting we put her to sleep.”

Now, what am I going to do? Here I have an old ewe, skin, and bones, heavily parasitized, probably missing some teeth, and with a foot beyond repair. She has probably been out in this pasture for years and hardly looked at in that time, but now we will have to save her.

I thought for a moment before I spoke. My mind drifted back to Dr. Annes and his large animal surgery class. Could I buy Dottie a year or two using the salvage procedure Dr. Annes recommended for saving market steers?

“So, this is what will have to happen to give Dottie a chance at living another year or two,” I said. “First, we must get her sheared and treated for intestinal parasites and keds.”

I pulled Dottie’s head up and looked in her mouth. She was missing three incisor teeth. I turned her head so Ginger could see the missing teeth.

“We are not going to be able to replace those teeth,” I said. “So that will mean more grain and maybe some pelleted feed, like small alfalfa pellets or calf manna. And then we need to take care of Dottie’s feet.”

“The lateral hoof on her right front foot is beyond saving,” I said. “There is a salvage procedure to amputate that toe to remove the pain. Dottie will be light enough that it might work for her for a year or two. If she lives beyond that time, that foot will be a problem. Now, you have to know that this surgery is meant to be used to get injured market through a few months before they go to slaughter. It is not meant for use on animals that will live a long time. But it might just work for Dottie.”

“If that is what it takes to save Dottie, let’s do it,” Ginger said.

“This is going to cost more than you would pay to buy three or four pregnant young ewes,” I said.

“I don’t want a bunch of young ewes and lambs,” Ginger said. “I want to give Dottie a chance at another few years of life.”

“Just so you know the score,” I said. “And I said another year or two, not a few more years.”

“What do we have to do to get started?” Ginger asked.

“I am going to give her some injections today: a long-acting antibiotic, a deworming injection, and a Bo-Se injection,” I said. “You can call the office, and they will give you the name of someone who will shear Dottie for you. After you have her sheared, I will leave you some powder for the keds. Then, stop at the feed store and pick up some small alfalfa pellets. After that is all completed, I will come out and take care of Dottie’s feet.”

***

A couple of weeks later, I returned to take care of Dottie’s feet. After getting three years of wool removed, she was a different-looking animal. The pelleted feed was making a difference. Her ribs were visible but only slightly. She tried to move away from me as we approached, although she was still not using her right front foot.

I placed a rope on her just for insurance, and leaning over her from the left side, I grabbed her right flank and right armpit, lifted a bit, and dropped her on her left side.

I checked all her feet while I had her down. Surprisingly, there was little foot rot on her other feet. I cleaned them up some with my hoof knife and foot trimmer. Then, I concentrated on her right front foot.

There was very little change from my first exam. Dottie’s only chance was to amputate this diseased digit. I just hoped it would buy her some time.

I clipped the lower leg and foot with battery clippers and scrubbed the lower leg with Betadine Surgical Scrub. Then, I used three ccs of lidocaine to block each digital nerve. I scrubbed the entire lower leg and foot again while waiting to make sure the nerve block was working.

The remainder of the procedure was brief. I incised around the top of the lateral hoof and up both sides of the digit, then reflected the skin away from the bone. With a short piece of OB wire, I severed the pastern bone and closed the skin over the wound using interrupted nylon sutures.

I rinsed the scrub from the leg and helped Dottie to her feet. She stood on all four feet, and after I removed the rope, she walked away, using the right front foot normally.

***

The following week, Ginger was in the clinic to pay the bill and reported that Dottie was doing well and using her right foot. Ginger was well pleased.

 I checked Dottie two weeks after surgery. The incisions were well healed, and, just as Ginger had said, Dottie was walking normally. I observed Dottie in her pasture occasionally when I would drive by, and she continued to have no problems.

Unfortunately, Ginger and Dottie moved about a year later, and I lost track of them, so I have no idea how long Dottie survived with her salvaged foot. At least she had one good year. 

Photo Credit: Giovanna Kamimura on Pexels