"Well, Didja Skin'Em?"

 Some of the lab's clients are rather ... colorful. My favorites are the guys that run small beef cow/calf operations. I learned years ago how to schmooze with just about anybody, and some of these crusty old guys can get downright chatty with the right schmoozing. I never fail to learn something new and useful. Maybe I learn a new word, or get more detail about a management procedure. It's always a lot of fun. In fact, I see the time I spend talking to them on the phone or in person as part of my job, not an interruption.

There are two important reasons for this. Firstly, I can always get a more detailed history from them directly than they will ever write down on the submission form. I get them to tell me all kinds fascinating details about how they are managing, or in some cases, mismanaging their herd. And secondly, I'm building their trust in the lab. Building their trust in me and my team's ability to help them solve their problem. 

We recently had a guy bring in a couple of young pigs, about 5 or 6 months old. Yeah, I know, pigs aren't beef calves. But this guy was cut from the same cloth. It wasn't my day in necropsy but I always get called when producers show up because everyone in the lab knows that I like to chat with them. I was standing on the dock, looking down into the bed of his truck at two dead pigs. Body condition looked good. They were clean, well kept. But certainly dead. And he was telling me and my colleague that the entire pen of nine pigs was sick. I let him talk on until he mentioned staggering. Ah ha! I asked him, were any of them dog sitting (that means sitting back on their haunches like a dog) or head pressing (that means pressing their head into a corner)? Yes, he said, all of them. Head tremors or seizures? I asked. Yes, that too. Turns out he had some nice videos of these exact behaviors, which he showed me on his phone. How about the water supply? Hoses and spigots still working? Tanks full? Oh, well, yeah, it seems that he did have a bit of trouble with the water supply in that pen when we had a freezing spell a few days earlier. Only that pen affected? Yes, only that one. 

They literally teach you about this in vet school: water deprivation leading to sodium toxicity and death in pigs. The videos were magnificent--I had him send them to my work cell right away. The water deprivation leads to an electrolyte imbalance that affects the brain. The neurological signs I asked him about are considered textbook signs of the sodium toxicity.

I was so excited to get this case for us to work up that I never let him feel bad about killing his pigs. I gave him some advice about how to save the remaining pigs, and thanked him for bringing the case. He called me two days later and reported that he had followed my advice and saved the remaining pigs in the pen. With some ingenious sample collection, my colleague and I were able to make a convincing argument that it was indeed sodium toxicity that was the problem. We considered other differentials such as pseudorabies (also called Aujesky's disease) and rabies that could cause the same neurological signs, but we tested for and eliminated the first and rejected the second as reasonable (unlikely to affect an entire pen at the same time). In the end, it was a solved case and a happy client!

At the other end of the spectrum is the old guy that called up a few weeks ago wanting to bring in a calf that had died overnight. He had lost five or six calves in a 24-hour period. My brain was spinning out a list of possible differentials when he said, I think they were shot. Oh, okay, I said, we can take a look and see if that is the case. Odd differential, as I was thinking about things like lightening strike or infectious agents that can kill several animals at the same time. But sure, getting shot is possible too. 

So I did the necropsy on this calf and didn't really find much of anything except that it had a lot of intestinal worms. Those absolutely can kill a calf if the parasite burden is high enough, but the calf was in good flesh and it wasn't a definitive finding. I found nothing else that was particularly helpful or diagnostic as to the cause of death. And as is my usual procedure, I called the producer to let him know this. He started yelling at me, saying, I brought that calf in so you could prove it was shot! I told him that there was no evidence that it had been shot. He replied, well, didja skin'em? I paused, trying not to laugh, and said, sir, I did a complete, thorough necropsy and there was no evidence of any projectile trauma in this calf (no, we don't skin animals for most necropsies). 

By this point, I have unfortunately seen quite a few animals with gunshot wounds and I am confident in my ability to identify that. Definitely no gunshot in this case. But this old crank managed to get the county sheriff's office involved and they contacted the lab director for more information last week. We sent them the final report and I thought that was the end of it. 

But no, no, my year will not end so quietly. This cranky old guy is bringing us another calf today. One of seven more that died last night. He still thinks they are being shot! I'll try again to find a cause of death. I hope this calf tells us a better story, although I suspect that he won't be satisfied with anything less than being presented with the bullet that killed the calf.

'Tis the Season...For Bovine Abortions

 Winter is the season for bovine abortions. Two-thirds of bovine abortion cases are closed with no cause determined. That's an average that holds true in veterinary diagnostic labs across the country. As a side note, miscarriage is not used in vet medicine. Vets use the word abortion to cover the loss of a fetus in animals.

Despite the statistics, I recently had a bovine abortion case for which I was able to get a diagnosis. The fetus looked like all aborted bovine fetuses, that is, not very diagnostic. But this time the vet sent us some placenta, a very rare sample indeed. Bovine placentas are membranes studded with these raised, thick, slightly cup-shaped structures. There are two parts to these structures, a dam side and a fetal side. They supply nutrients and blood and waste removal for the placenta.

At first glance, this sample was fairly typical for placentas (even unicorns have "typical"). It had been picked up off the ground so it had bits of leaves and grass and dirt stuck to it. It was torn so had probably been partially eaten by the dam, foxes, or the farm dogs. But some of those cup-shaped structures looked off to me. Wrong color, wrong texture. I made sure we trimmed those in for histopathology. Turns out they had fungus growing deep inside of them! There was a strong immune response to the fungus, causing disruption of placental function, early fetal death, and the subsequent abortion.

They teach us about all the causes of abortion in vet school. Even so, my histopathologist said it was the first case of fungal placentitis that he'd ever seen in his decades-long career. It will probably be the only one I ever see too. So for once I had a rare successful bovine abortion case. 

On the other end of the scale is a bovine fetus I unwrapped a couple of weeks ago. I always do a physical examination of animal remains before starting a necropsy. As I was looking this one over, I noticed that it was missing both ears, the right eye (crows, most likely), the last couple of centimeters of its lower jaw, and then...whoops! I turned it over and found that it was missing all of its abdominal organs. All of them, including the skin of the abdomen and the umbilicus. Neatly removed along with all of the ligaments that hold them in there. The abdominal cavity of that fetus was smooth and clean as a whistle. Farm dogs are efficient. Amazingly, the diaphragm was intact so I sampled what I could--lungs, heart, thymus. Not much hope of getting a diagnosis from this one. I called the vet and asked her why she sent me the case. Turns out she had received a call from the producer about the abortion, and she told him to box the fetus up and get it to the lab. She didn't know it was in such bad shape. I gave her a pass as this does happen now and then. 

Production animal necropsies come with unique challenges. In order to get diagnoses for the cause of death, we have to be flexible and creative with the samples that we get. 

Except for maggots. I don't do maggots.

Bird-Shaped Bags of Maggots

 We get a lot of backyard chickens submitted to the lab for necropsy. The State Vet has a grant that pays for the necropsies and surveillance testing of these birds, so there is no cost to the owners. It's a good way to encourage people to submit birds. And it allows the lab to keep at least a partial eye on reportable diseases in the backyard bird population that represent threats to the commercial poultry industry in the state. 

Unlike commercial poultry, which are usually submitted live, with as many as 10 to 20 birds per case, backyard birds are usually already dead when the owners bring them to the lab, and there is usually just one bird per case. 

I've seen enough backyard birds wrapped up in Walmart plastic bags or scented trash bags that just the sight (or smell) of either is enough for me to know it's a backyard bird necropsy. For the record, scented trash bags, and scented dog poop bags, make me gag. The smell of dog shit layered with "baby fresh" scent is just nasty. It still smells like shit, but now with extra steps. A dead bird wrapped in a scented trash bag is still just as dead.

Many backyard bird owners don't know much about livestock husbandry. Their intentions may be good but execution is often weak. We see chickens stuffed with intestinal worms, literally so many worms that the chicken starved to death because no food could pass the ball of worms in its gut. We see birds filled with tumors caused by the Marek's disease herpesvirus. That disease is reliably preventable with a vaccine administered by a hatchery at the day of hatch. We hear tales of woe in which the owner got some birds from a neighbor, from the nice lady at the flea market, from this guy over in Conway, and they put the new (surprise! diseased!) birds in their flock with no quarantine period, and ended up with a visit from a livestock inspector come to depopulate their entire flock because they now all have a very transmissible, reportable disease. I ask owners about their biosecurity measures, and get a puzzled head tilt from most of them. But all of that is ultimately a matter of education. 

One small problem with some backyard bird owners is that they wait too long to bring us a dead bird. Autolysis, the changes that happen to tissues after death, is rapid in birds. I don't expect most people to know about autolysis, but I do expect them to have at least a basic idea about the other thing that happens to dead animals that are outside for more than a few hours. And that thing is maggots.

I don't do maggots. 

Thankfully, the surveillance tests we conduct can be performed with a tracheal swab so I don't need to dive in and collect rotten tissues. I've had enough bird-shaped bags of maggots submitted for necropsy that my techs know that I won't even unwrap those birds all the way. Once I see maggots spilling out of the Walmart bag shrouds, I cut a hole in the bags for the head, flick maggots out of the bird's mouth to swab the trachea then tell my techs, I don't want to see any more of this. And away it goes to the incinerator, maggots and all. 

Changes, and A Tale of Cow Conjunctivitis and Pneumonia

Things have been grim this year. Pandemic. No toilet paper in the stores. Being afraid to even go in said stores. Losing my little old Mimi. 

I've decided to take the blog in a new direction. A bit of an experiment, just to see how it works. This is nothing new--CircusK9 has evolved more than once since I started it lo these dozen years ago. 

I want to talk more about my job. I love my job. Despite the inherent ick factor that some people might have about the subject, my job provides me with an endless stream of absurd and interesting tales.

Like this one. I have developed a good working relationship with a clinic in SW Arkansas. This three-vet practice sees all species, and they send most of their necropsy cases to the lab. Because of the distance from their clinic to Little Rock, and because they are not on the route of one of our regular couriers, the vets often conduct field necropsies of production animals and send us a "box of parts" instead of the entire cow. Cheaper and faster.

One of the vets has been working with a beef cow-calf operation for some weeks that is having a big problem with conjunctivitis in the herd. The usual bacteria responsible for this is Moraxella bovis. That's the one you learn about in vet school. But that's not what they got back from swab samples. They got a species of Mycoplasma. They started to treat the conjunctivitis but some of the cows began dying from respiratory disease.

Cows are prey animals and have an amazing capacity for hiding respiratory disease until things become pretty disastrous in there. I've opened up cows to find 80% or more of their lungs full of pus and bacteria, and heart and lungs stuck to each other and the body wall with expansive fibrin adhesions. This is not good. Most vets who work with these animals, including me, suspect that cows harbor subclinical bacterial pneumonias pretty much all the time, and are just waiting for some stressor--transportation, parturition, change in weather, change in feed--to cross that line into severe respiratory disease.

So my friend sent me two boxes of parts from two cows from the conjunctivitis herd. He also sent some horrifying pictures of the conjunctivitis--I will spare you. I never really got anything definitive from the parts other than confirming that it was a bacterial pneumonia. He kept calling me to talk about this Mycoplasma they had isolated from the eyes, not Moraxella. It was a species I had not heard of, and I initially thought I just wasn't understanding him clearly. He often calls me when he's in a windy field standing over a dead cow so there is lots of background noise. 

See, Mycoplasma bovis is a common culprit in bovine respiratory disease. Mycoplasmas are special bacteria--they don't have cell walls. They like to form microabscesses which are very difficult to treat. In fact, cows with Mycoplasma pneumonia are often not treated (they are culled). The lungs my vet friend sent to me did not look like Mycoplasma lungs. They looked like Mannheimia or Pasteurella lungs. But we failed to culture those bacteria. And you can't really culture Mycoplasma. We rely on PCR tests to identify that one. But I didn't initially request a Mycoplasma PCR because, well, the lungs didn't look like Mycoplasma lungs.

It's weird how distinctive these different bacterial infections can be. And after you see dozens of gnarly cow lungs, you get a feel for how the different bacterial pneumonias present grossly. My pathologist agreed--the tissue damage we saw on the microscope slides of the lungs was most consistent with Mannhemia. How come we didn't culture it? Sometimes that happens. Failure to culture doesn't mean it wasn't there.

But my vet friend kept going on about this "bovoculi"--and I finally put it together. 

Mycoplasma bovoculi--get it? bov = cow, oculi = eye--is a Mycoplasma implicated (link will open a PDF) in the past few years in a particularly nasty cow conjunctivitis. I found out that it likes to hang out with its friend Mycoplasma bovis. Which we found in the lungs of these cows when I had the PCR test run.

Some vet school adages really prove to be true, over and over. Common diseases commonly present uncommonly. I missed the Mycoplasma connection in this case, but I guarantee it won't happen again.