Always have Rabies at the Top of Your List

D. E. Larsen, DVM

“We have a cow coming in this morning for Necropsy,” Dr. Norrdin said. “The ambulatory people have been treating this cow all week, and it died this morning.”

“It should be a good time for it, we don’t have anything in the cooler to work on,” I said.

“This cow died with neurological signs,” Dr. Norrdin said. “I want you guys to be thoughtful during this necropsy. Especially you, Larsen, when you remove the brain. Do you have any idea what I might be talking about.”

I had talked with a classmate earlier in the week about this cow. He was working on the ambulatory service this summer. Colorado State University had to scramble to keep students in the clinic during the summer months to keep up with the workload.

This cow had been looked at by two different clinicians and their students on multiple occasions. The cow suffered from a progressive neurological deterioration. People had their hands in the cow’s mouth and into the back of her throat, trying to ensure there was no foreign body causing some swallowing difficulties.

“What kind of a differential diagnosis list should you be working within your mind when treating a neurological case?” Dr. Norrdin asked.

I had been lax during the summer and was not used to coming up with immediate answers. This job was sort of one to do the manual labor of the necropsy room. It obviously provided a tremendous learning experience but from observation, not rote memory from a textbook.

“I guess viral encephalitis would be on the list, along with secondary bacterial meningitis from any of the respiratory viruses,” I said.

“You came close with your first guess,” Dr. Norrdin said. “You should always have rabies on your list. It should be at the top of your list, even though you will not see it often these days. The reason is that if you miss that diagnosis and fail to take care of yourself, you end up dead.”

“That is probably a good point,” I said.

“So be thoughtful, and work with your mouth closed today,” Dr. Norrdin said. “Hopefully, that will not be the diagnosis. If it is, we will have a mess. There have been over a dozen guys with their arms down this cow’s throat in the past week. The clinicians have really dropped the ball on this case.”

When the truck with the dead cow backed up the loading dock, we shackled the cow’s hock and picked her up with the hoist. This allowed us to move her on the track to the middle of the necropsy room floor.

We started the necropsy under the direct supervision of Dr. Norrdin. This was unusual in its self, we seldom had direct supervision at this stage. Dr. Norrdin was very worried about a possible rabies case, and he wanted to make sure everything was carefully documented.

When it came time to remove the head, I moved it to the butcher block in the middle of the room. I had become an expert at removing the brain from all the animals this summer. It was a skill that I would probably seldom use in practice, but I enjoyed being the best at something on the job.

With the skull on the table, I first had to remove the skin and soft tissue on the top half of the head. Then, with a large cleaver, I started shaving the bone from the skull to reveal the braincase. 

Once the braincase was exposed, the accuracy of my strokes with the cleaver became more critical. Finally, I would be able to lift the top of the skull cap and expose the brain covered by the meninges—those layers of tissues that become inflamed in meningitis.

There were several specific snips to be made to free the brain. Once this was done, I could lift the intact brain out of the skull and place it on the dissection table. Most of the time, I would slice the brain in a prescribed manner. In half, separating the right and left side. Then slice each side into quarter-inch slices, looking for any abnormalities. This time, Dr. Norrdin took over at this point. He did all the work on the brain and disappeared into the lab with the pieces.

There are several levels of diagnostic testing to confirm rabies as a diagnosis. The diagnosis of rabies is made in several ways. The one that is fastest and considered the most reliable, if present, is finding Negri bodies in the part of the brain called the hippocampus.

By the next day, rabies was a confirmed diagnosis in the cow. Most of us students had received several doses of rabies vaccine during our freshman year of school. Because of that previous vaccination and a positive titer, I only had to have a single booster vaccine. The students who had carelessly had the hands and arms in the cow’s mouth during the week preceding her death had to go through a complete series of vaccinations. 

That was a lesson well learned. But then, there is just a little more to the story.

A long year later, I was in Enumclaw Washington, ready to do a necropsy on a large dairy cow. Standing in the middle of the field, I sharpened my necropsy knife, the same one used to necropsy the rabid cow. As I stood there, the farmer had a whole list of questions. We stood and talked for some time. The entire time during this conversation, I continued to sharpen my knife on the wet stone.

Don’t allow anyone to tell you that a sharp knife never cuts you. After standing there sharpening my knife for 15 minutes, I lifted the hind leg of the dead cow and started the cut through the skin on her belly. This knife slid through the skin like it was butter. My stroke was so smooth, the knife flew through the prescribed cut, continued out into the air, and buried into the muscle of my lower left leg. Going into my leg a full inch. Ouch!

I stopped and put a wrap on the wound before preceding with the necropsy. By the time I was done, my left boot was sloshing with blood.

I did make a trip to the doctor’s office. We laughed at my careless actions and decided to leave the wound open. Antibiotics and a light wrap should take care of things.

Then I mentioned that I had done a necropsy on a rabid cow with this knife a little over a year ago.

“What do you think?” the doctor asked. “I would think that it would not be a problem at this point in time.”

“Will, the knife has been washed since then, but never autoclaved,” I said. “I would think that any virus on it would be long since dead.”

“I would think so also,” said the doctor.

“I am sure I still have a positive titer, just for insurance,” I said.

I did live, by the way.

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All the Better to See You With

D. E. Larsen, DVM

RC was a big orange tabby cat. I had first treated RC for a severe fracture of a hind leg when he fell from a tree. Repair of that fracture required a pin and many wires, plus four weeks of cage rest. He was a friendly cat but displayed utter self-confidence when he was in the clinic.

He sat upon the exam table, watching for me to come through the door when I entered the room. 

“My, what an ugly eye,” I said. RC’s right eyeball was swollen and bulging out from under his eyelids.

“I noticed this a little bit yesterday, and then this morning it was like this,” Nancy said. “It is painful if I try to touch it, but he seems to tolerate it well when he is left alone.”

“This is an advanced case of glaucoma,” I said. “It is a little unusual to see this occur with no prior warning.”

“Do we have any treatment options?” Nancy asked.

“We have a couple of options with an eye like this,” I said. “We can go to Corvallis to see the veterinary ophthalmologist, or we can remove the eye.”

“What is the ophthalmologist going to do,” Nancy asked.

“There are a couple of surgeries that can be done to save the eyeball, and maybe its vision,” I said. “However, with an eye that looks like this, the vision is probably already lost. She can also offer evisceration and implantation of a silicone prosthesis instead of removal of the eyeball. Some people think that gives a better cosmetic appearance. A blank, nonfunctional eyeball remains.”

“And what do we have when you remove the eye?” Nancy asked. “He will still have one eye, so I guess it won’t change his vision much.”

“I remove the eye and all the associated structures, including the eyelid margins,” I said. “When things are healed, we have a blank slate. If I do it right, that side of the face is smooth. If there is not enough dense tissue to close over the eye socket, there may be a little caved in appearance over the socket. Most cats get along fine with one eye.”

“I think that we will just have you take the eye out here,” Nancy said.

With that decided, we removed RC’s right eye. Dr. Maxwell had recommended that I submit that eye for a pathologist to look at. She thought it was unusual for such a sudden onset of advanced glaucoma.

I had the results from the pathologist when Nancy returned with RC for suture removal.

“He is absolutely normal,” Nancy said. “He does everything he did with two eyes. He still climbs his tree and everything.”

“I am not sure that he has always climbed that tree too well,” I said with a chuckle. “The pathology report says he had an autoimmune problem in his eye. They say there is a possibility that he may develop the same problem in his left eye.”

“I guess we will cross that bridge when it happens,” Nancy said.

In the following years, RC seemed to have more issues than I would expect to see in a middle-aged cat. But everything was manageable, and he was not bothered by the loss of his right eye.

It was almost 3 years to the day that Nancy rushed RC through the door. His remaining left eye had literally exploded overnight.

“He seemed fine last night,” Nancy said as she caught her breath. “Then I looked at him early this morning, and I could see that his eye was getting big like his other eye. A few hours later, I look, and this is what we have.”

“It looks like we have crossed that bridge you mentioned years ago,” I said. “This eye is going have to come out, there is no saving it now.”

“Oh my! How will he get along, being totally blind?” Nancy asked.

“To be honest with you, I haven’t had too many patients who were totally blind,” I said. “I did have a client with a calf that was born blind. It had no functional eyes. It did just fine. It knew the pastures, knew where the feed rack was and where the water was. It could go in and out of the barn as long as it was with another animal or two. That calf grew up and had several calves, all born with normal vision.”

“RC is so active, it will break his heart if he can’t go out in the yard and climb his tree,” Nancy said.

“I was at a veterinary conference several years ago,” I said. “One of the speakers was a veterinary ophthalmologist. He told the story of his cat, who, it turned out, was totally blind. He said they had dinner guests at the house one night, and the guy noticed that the cat was blind. The doctor had no clue. That cat had lived in the house for several years, and the ophthalmologist had not noticed that it was blind.”

“Okay, let’s get it done,” Nancy said.

The surgery was done, and RC went home with a blank slate for a face. It was a little eerie when he came back for suture removal. Sitting up on the exam table like he always did, he followed my every move with his ‘blank slate.’ Just like he was watching me.

“He is outside playing in the yard, just like he has always done,” Nancy said. “Yesterday, he was even climbing his tree. We are so pleased that we didn’t make the decision to put him to sleep.”

RC lived an almost normal life. As he aged, like many cats, he had his share of problems. Whenever RC was on the exam table, he ‘watched’ every movement I made. When he was in the clinic for hospital treatment, he would sit in his kennel and ‘watch’ everyone in the room.

RC lived to a couple of months short of his 18th birthday and died of chronic kidney disease. Chronic kidney disease is the number one killer of cats over 14 years of age. In those years, a male cat, neutered or not, was most unusual living to the age of 18.

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Fleeing the Flea

D. E. Larsen, DVM

It is another hot August day in Sweet Home, and fleas are eating most of the dogs alive.

Returning from lunch, I could see that Dixie had started the sprinkler on the roof already. That helped keep the clinic cool. The water would run hot, coming off the roof.

Joseph was waiting with a worried look on his face. He was holding a limp Domino.

Domino was a little five-pound chihuahua. He was black as a young dog but was half gray now.

Dixie herded Joe and Domino into the exam room as soon as I put on my smock. 

“He is not doing so good this morning, Doc,” Joe said. Joe was in his early seventies and had lost his wife several years ago. Domino was about all he had left in the world.

We place Domino on the exam table on a fleece. I pulled up his lip, his membranes were white. I looked at his lower back and ventral abdomen, and he was literally covered with fleas.

“Joe, Domino is being eaten alive with fleas,” I said. “I am going to run a quick CBC on him. I can see that he is anemic, we just need to know how bad.”

After we drew a small tube of blood, I discussed the flea situation with Joe as I waited for results. The in-house blood machine would only take a few minutes.

“I don’t know why he would have so many fleas,” Joe said. “He has had a flea collar on since the first of the month.”

“It is a little complex, Joe,” I said. “You have probably had fleas laying eggs in the house all winter and spring. That flea collar might work a little around his head and neck, but for the most part, that little cloud of protection is about three feet behind him. When the weather gets hot, all the fleas come alive, and for a little guy like this, they suck the blood right out of him.”

The CBC showed a packed cell volume of less than 6% and a hemoglobin of 1.6 gm/dl. I don’t think I have seen levels this low in a living dog.

“Joe, Domino is very critical,” I said. “I need to get some blood into him right now. Any undue stress and he could drop dead in an instant. We will need him for a couple of hours, and I will talk about what we need to do when you pick him up.”

Luck was on Domino’s side, we had Riley in the clinic today. Riley was a large mixed-breed dog weighing over 100 pounds. I got ready to collect blood while Sandy called Riley’s owner.

“We have an emergency with a little chihuahua. We need to give him a blood transfusion,” Sandy said into the phone. “We only need about 35 ccs of blood and would like to collect that from Riley, if that is okay. That is a small enough volume that Riley won’t miss it.”

They consented, of course, and I drew the blood into a heparinized syringe. Then we turned around and administered to Domino via a jugular catheter. The risk of a transfusion reaction on an initial transfusion was low, and Domino’s blood values dictated immediate blood.

The result was almost instantaneous. Domino came alive again. His membranes pinked up, and he sat up and looked around as if to ask, “Where am I?”

I gave Domino a Capstar tablet. This was a new pill that provided close to a total flea kill in 30 to 60 minutes. I also gave him some oral Prednisone to reduce the inflammation in the skin.

When Joe returned, we had him fixed up with some topical Advantage for flea control, and I spent some time discussing year-round flea control. In the old days, we would have needed to use a flea bomb in the house, but those were almost impossible to find. The newer products did a good enough job that we did not have to treat the home.

“The important thing to remember is to maintain flea control all the time, year-round,” I said. “In August, when it turns hot, I probably spend 90% of my time treating dogs and cats with skin issues. And most of those issues are caused by fleas.”

“Okay, Doc, I don’t want to lose this guy,” Joe said. “I would have never thought that fleas could do that to a dog.”

“It all depends on the dog,” I said. “Domino is not much of a dog compared to Riley, his donor. Riley weighs over 100 pounds, and fleas could not do that to him. But Domino should be okay now, you just bring him by next week, and I will recheck that blood, just to make sure he is doing okay.”

Joe left with Domino in the crook of his elbow. Domino standing on his front feet, trying to lick Joe’s face. One happy ending.

Dixie had the next patient ready in the exam room. An older lady, who I had not seen before. Doris had a poodle, Daisy, who was scratching on her tail head, that area on the low back above the tail. This was the textbook appearance for Flea Allergy Dermatitis. 

“Daisy has been scratching herself raw,” Doris said.

I looked Daisy over from head to tail. Everything looked fine except for the skin. Daisy had a ribbon in her hair on both ears, she had probably just come from the groomer. I ran my hand over the sparse hair on her low back—fleas scattered in all directions.

“Doris, this pattern of hair loss is what we see with Flea Allergy Dermatitis,” I said. “We need to use some medication along with some flea control, and this will clear right up.”

“I overheard your conversation with the gentleman who just left,” Doris said. “I want you to know, Doctor, Daisy does not have fleas, and there are no fleas in my house. The groomer thinks this is a food allergy.”

I promptly parted the hair on Daisy’s back again and quickly captured a flea. I placed the flea on the exam table and squished it with my thumbnail. I didn’t say a word.

“We had to wait out there in your waiting room for almost ten minutes,” Doris said.

“We just happen to have a new veterinary dermatologist that has started practice in Eugene,” I said. “She would be the one who you should see to handle Daisy’s possible food allergies. I will send your records down to her and send you home with her telephone number. I think that she will be able to get you right in to look at Daisy since she has just started practice.”

Doris and Daisy left with the information. 

“That was quick,” Dixie said.

“I am too tired to spend my time talking to a brick wall,” I said. “The Dermatologist can tell her it is a flea problem after she does $500.00 worth of skin testing. I am sure she will believe her then.”

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