Whatever Dr. A. Thinks Necessary

There's a handful of vets who call me to ask for advice. Not for every case they handle, of course. They are excellent clinicians who see hundreds of cases for every one they might call me about. But they are all convinced that I can help them solve their particularly tough cases. I get calls from these vets once or twice a month, often when they are standing in a field looking at a sick cow or in their clinic with the sick pup in front of them. They've all learned that they will get far better diagnostics if they call me before they collect any samples.

I'll admit that I have found answers in some cases only by sheer luck. But the truth is, I am a careful observer, I think quickly on my feet, I am happy to toss crazy ideas back and forth, and I'm not afraid to be wrong. I also have time that these clinicians simply don't have to dive into all kinds of resources--the internet, my vet school lecture notes, textbooks, consultations with vet school classmates and teachers (I have my own advice network!), and so on. This combination means that, in fact, I am pretty good at my job.

Although it amazes me every time they ring me up to ask me what I think, I'm rather proud that I can apply my knowledge to help my colleagues out.

So I couldn't have been more pleased when one of my favorite vets, who regularly calls me up to chat about difficult cases, sent in this submission form along with the samples that I had advised her to collect, writing on the Tests Requested line, "Whatever Dr. A. thinks necessary."

That's an incredible gift of confidence and trust she gave me. After all, it's her client--she's the one who is treating the animal. But she willingly made me a partner, because in the end, she and I do in fact share the same goal--improve animal health.

Sniffing The Pole

 In AKC agility, there are several different kinds of faults. An off-course fault is somewhat obvious--the dog takes the wrong obstacle, or jumps a jump then jumps back over it. Elimination faults are more or less a failure to complete an obstacle--the dog knocks the bar off a jump, or fails to put a paw in the contact zone on one of the contact obstacles. AKC still uses the pause table in standard courses, so there are table faults too--the dog fails to stick the landing and slides off the table, or jumps on then jumps off before the 5-second count has finished.

Refusals are the most complicated fault type. There is a zone in which a refusal can be called for any obstacle that is based on distance between two obstacles, how close the dog is to the upcoming obstacle, and "refusal planes" defined by the edges of the obstacle and the angle of the dog's approach. Complicated. But some examples might help. A dog that runs up to a jump then stops will get a refusal fault. A dog that runs towards an obstacle but spins in circles instead of approaching the obstacle in a determined manner will get a refusal fault. A dog that runs around an obstacle will get a refusal. If that dog takes another obstacle before the handler can correct the refusal, the dog also gets an elimination fault. The faults can stack up fast! But a dog that runs up the Aframe, stops at the top to gaze around the arena, then continues down the other side will not get a refusal.

At the Masters level, where Archie competes, you can only qualify if you run clean, with no errors or faults. One error, no matter which type, means no Q, even if you finish the course.

At an agility trial this past weekend, I encountered a situation that I had never seen nor even heard about. Archie's run so far had been clean. We approached the weaves and in he went. His weaves are extremely solid, and he usually executes them quickly. Archie rarely makes errors in the weaves. Except that day, that day as he reached pole 8, he came to a screeching halt. Dust puffed up around his feet. He was stock still, every muscle engaged, sniffing the pole.

SNIFFING THE POLE.

I of course keep eye contact with Archie on the course so when he stopped, I screeched to a halt too. I stared at him, then started pleading, whining, c'mon, Arch, WEEEEEEEEAVE, WEEEEAVE! Arch! WEEEEEEAVE! Over and over. I tried to keep calm but I was starting to panic. ARCHIE! WEEAAVE! At the same time, my brain was endlessly looping, What is happening? What is happening! I was looking directly at Archie but the far peripheral vision of one eye was on the judge, trying to see if he raised his hand to call a refusal.

Archie just stood there, sniffing. He never moved his feet. It seemed like an eternity but it really was only about 8 or 9 seconds (actually, that is an eternity in agility). Finally he decided he had sniffed enough and finished the weaves without error. Somehow I managed to keep my plan together and we finished the course.

I ran out of the ring with Archie in my arms and people said, wow, that was incredible! I gasped, did the judge call a refusal? They said, no, he didn't!

A spirited debate ensued. Was that a refusal? Was that a failure to execute? He never left the weaves. He did all the poles correctly. We decided that although it was certainly unusual, Archie didn't incur any fault. The run was clean. Another Q.

I am so grateful for my crazy fox terrier. He never fails to amaze and amuse.

A Tired Dog Is A Good Dog

Earning all of these:

 

...resulted in this: 

The OKC-area trials tend to have a small but rather competitive 16" class. To qualify is great (yay Archie!) but to get a Q and a placement is a big deal for us. He worked hard for me all weekend, and I'm proud of those ribbons.

Let's Take A Look At Some Dog Food Labels

 I get asked quite often what I feed my dogs. I am quite willing to share that information. Purina, Hills, and Royal Canin are all good choices. I feed Archie a regular Purina diet, the cat gets a Hills prescription diet to prevent urinary blockages, and Azza thrives on Royal Canin's Ultamino hydrolyzed protein diet. The prescription diets made by these three companies are incredibly useful for a wide array of diseases. Nothing magic here, we know that diet can reduce and delay clinical signs of many types of disease for both people and animals. A managed diet can improve performance. It can help a beef cow put on more weight faster, and can help a "no antibiotics ever" broiler chicken have a healthier gut to reduce bacterial infections. 

But the important point is that all three of these companies conduct feeding trials using real dogs to determine the nutritional profiles of their foods. Other companies analyze samples of their food in a lab only, for example burning it in a crucible to determine protein content. These kinds of assays are certainly useful, but they provide no information on bioavailability of important nutrients. Only feeding a living animal the actual food can tell you if that protein can be digested and used by the animal. If a dog food label says "food is formulated to meet the nutritional levels established by AAFCO," that food has only ever seen the inside of beakers and test tubes, not the inside of a dog. Grain-free? "Human-grade" ingredients? "Natural"? All marketing. All bullshit. All to make you, the human with the credit card, feel good. 

So this windy opening sets the stage for Archie's current situation. He got a stick jammed in the roof of his mouth a month ago or so, and some pieces of it broke off and were left behind in the tissues around his left upper molars. His bad breath prompted me to take a look in there...where I found this nasty hole in the roof of his mouth surrounded by friable, brown (necrotic) tissue. It bled when I touched it. I managed to get a large piece of stick out of the hole but even after starting some antibiotics, things weren't improving as much as I would have liked.

Of course, my imagination immediately went to the worst case scenario--abscess, lysis of the bony palate, formation of a fistula (an inappropriate hole between two spaces), damage to the roots of those huge molars. All Very Bad Things. I had to get a referral to another vet to get some dental radiographs made since my vet doesn't have dental rad equipment (it's specialized). That vet flushed a couple more small pieces of stick out, and helped calm my worst fears. She added a second antibiotic to go after the anaerobic bacteria, and recommended that I feed Archie a canned diet for two weeks to give the roof of his mouth a rest. 

Archie had not shown any evidence of pain or reluctance to eat or play, but he's a pretty stoic dog in general. Two weeks of canned food seemed reasonable. Except that I haven't calibrated any canned diets. I have no idea how much canned food to feed him. 

See, I feed Archie a calculated number of calories per day, including treats. He currently eats 1 cup of Purina Pro Plan Performance 30/20 Chicken and Rice kibble per day, divided into two meals, plus two tablespoons of plain yogurt, between 20 and 40 g of frozen green beans, and 10-20 kcals of treats. I adjust this basic plan for training and trialing days when he gets lots more treats. The kibble has 484 kcal/cup, so on most days Archie consumes around 510 kcal.

Let's examine three canned food options. Rachel Ray's Nutrish dog food comes in small plastic tubs. It looks and smells like human stew. The lamb and rice stew label says to feed an adult dog 1.5 tubs per 10 pounds per day. Archie weighs about 24 pounds so according to the label, I would need to feed him THREE tubs per day. Each tub is calculated to contain 244 kcal. Let's do the math, shall we? If I gave Archie THREE tubs of this stuff a day (not sure I could get this volume of food into him, but he certainly would give it a go), he would consume 732 kcal each day. If I give him the chicken and rice stew at the recommended volume, at 290 kcal/tub, he'd be getting 870 kcal per day. That is astonishing!

I also bought some Canidae Small Breed canned food. The chicken, salmon, and pumpkin recipe, which looks and smells as gross as that sounds, contains 123 kcal/can. The label recommends 2 cans per 6 lb of weight, so if I follow those recommendations, Archie is supposed to eat EIGHT cans of this per day. EIGHT! That's 984 kcal per day. OMG, that's even worse than the Nutrish stew. That's almost TWICE the numbers of calories that Archie needs each day.

ProPlan Focus canned food is my third example. If fed as recommended, Archie would need to eat 1.5 13-ounce cans per day of the (large breed) chicken and rice formula (their "small breed" options are grain-free and I don't feed grain-free). That comes out to about 475 kcal per day, which is in line with what he actually needs. So not only is the Purina food tested on real animals, the feeding guidelines are reasonable, not grossly over the top.

Here's the bottom line. Read labels. Don't be fooled by marketing. Measure your pet's food and calculate kcal per serving (can, cup, etc.). Are they healthy now? Figure out how many calories they eat per day--including all treats. Kibble is always going to be more nutritionally dense than canned food, which is mostly water. The volume of canned food will always be more than the equivalent kilocalories of dry food. And consider feeding Purina, Hills, or Royal Canin.

The Messy Matrix of Post-Mortem Diagnostics

 I was texting with a vet school classmate last night, and mentioned that we take radiographs of some of our necropsy cases. You take post-mortem rads? She was clearly surprised. After thinking it over, I realized that it does sound odd to a GP vet that we would do that.

There are three types of necropsy cases for which radiographs can be quite helpful. The first type is gunshot suspects--we want to see if there are any metal fragments in the body and where they might be. The second type is abuse suspects--we want to look for, and document, any bone fractures. Animal rescue groups and municipal shelters and animal control usually submit these two kinds of cases, but I've had vets submit gunshot cases directly. In one memorable case, I discovered what looked like projectile entry wounds on a dog when I was examining it before starting the necropsy. But the submission form didn't mention a thing about gunshots! So I called the vet, and she admitted that she had not seen the animal herself. The neighbors had taken the dog to the vet, but it unfortunately died on the way, and the vet clinic passed the dog directly on to the lab without a thorough examination. Using the radiographs that I made, I was able to find a lead pellet lodged in the descending aorta that was the cause of the animal's death. The third type of case is a more generic legal case in which radiographs are another diagnostic tool. Racehorses sometimes fall into this category. They are usually insured to the gills, and we are asked by owners or the racetrack vet to perform a complete necropsy, even though, for example, the fractured cannon bone in a front leg is the obvious problem.

Our veterinary diagnostic lab does not have any radiographic equipment. So we rely on the generosity of the State Crime Lab which is literally next door to us. We all get gold stars for the inter-agency cooperation, but I try not to abuse the privilege. They are a busy lab. The State Crime Lab handles cases of humans who died under suspicious circumstances. Which means they have dead people there. Lots of dead people.

When I need rads for a necropsy case, I text one of the techs at the Crime Lab and set up an appointment. For small animals, we get rads before starting the necropsy. One of my techs and I will load our case, double bagged, into the back of a vet lab truck and drive next door. We back up to the dock of the Crime Lab and unload our case onto one of their gurneys. A human-sized gurney. We then follow the Crime Lab techs into a large, walk-through cooler where they store their cases. Dead people, each one enclosed in a body bag. It's super fucking creepy, and after the shock of my first trip through, I keep my eyes forward and try not to glance around. I've seen that cooler room stacked with literally dozens of bodies. Super. Fucking. Creepy. One of my techs refuses to even go to the Crime Lab, and I don't blame him for a second. 

We keep our cases bagged at all times out of respect for our Crime Lab colleagues. They don't want to see what is in our bags any more than we want to see what is in theirs. 

Their xray room is just beyond the cooler room. They have a very nice rig, all digital, quite similar to what I've seen in vet clinics, except that the table is human-sized. I bring a flash drive with me.

Taking clear, diagnostic radiographs of humans and animals is both a science and an art. There is a balance between resolution, energy of the beamed particles, and radiation damage to the patient and techs. But since neither lab is dealing with living patients, there is a lot less fiddling and more just blasting some xrays and taking a look at the result on the monitor. We don't use radiographs to FIX a problem, we use them to FIND a problem.

Horses represent a unique situation since the Crime Lab doesn't have a hoist, or any facility that could deal with such a large animal. We usually remove the part of the horse that we are interested in, most often the leg. But I did have a case in which the racetrack vet insisted that we do a more thorough examination of the caudal (neck) vertebrae. Without going into a lot of detail, my techs and I removed the neck, all seven caudal vertebrae plus the first two thoracic vertebrae, and bagged that up to carry to the Crime Lab. The rads revealed an old, poorly healed fracture in C7 and a new fracture in C2 that happened when the horse fell over as it was dying. It died from something called EIPH, exercise-induced pulmonary hemorrhage, a progressive, chronic disease. In this case, all of the horse's lungs filled up with blood very rapidly. That's a lot of lung, and a lot of blood. But that C2 fracture wasn't compatible with life either. Once we got back to the necropsy floor, we used the radiographs to precisely section the neck and photograph the fractures directly. Very interesting case that was greatly enhanced by post-mortem rads.

Working up a necropsy case requires an array of qualitative and quantitative diagnostic tools--gross examination (sight, touch, smell), bacterial culture, PCR tests, radiographs, even blood tests. The art comes in navigating the messy matrix of making a good differential list, obtaining the right samples, and selecting the right diagnostics for each case. Sure, anybody can run all the tests on every case, but what's the purpose of that? It is far more challenging, and satisfying, to find the most elegant path through the matrix.