Knowledge Lab

Welcome to Tales from the Lab, where an ever optimistic veterinarian and slightly salty technician entertain listeners with true stories and tall tales revolving around laboratory diagnostics.

Names have been changed to protect the innocent, but the lab work is real.

You can listen on your lunch break, on your commute, or when you’re hiding from your kids in the bathroom.

Each episode, we hope to leave you a little smarter, a little brighter, and feeling more empowered in the lab.

And here is today’s tale from the lab, diagnostic testing and the NBA. Oh, no. Uk.

Oh, it’s recording.

Yeah. Okay.

So I’m Holly. I’m the clinical pathologist. It is me alone in the podcast booth as Jessica’s traveling this week. Probably a lot less laughter,

a lot less wittiness, but hopefully no less useful content.

So, seeing as this is a podcast about diagnostic testing,

I thought it might be worth an initial discussion on why we’re performing laboratory testing.

Right.

What sort of information are we gaining? What’s the critical importance to our patients? Many of our patients present with clinical signs that are nonspecific.

Right.

Our patients don’t talk.

Right.

And it can be very confusing for an owner to understand if a behavioral change they’re seeing at home is indeed just that. Is it behavioral? Did the dog skip a meal because they don’t like the change in food?

Is the cat under the bed because there was construction outside?

Is one of the animals upset because Aunt sue was visiting with her dog, let’s say.

Right.

So are those behavioral changes because of something happening in their environment, or is there something underlying it?

Right.

Is there a medical condition? We know the history we get from an owner may or may not be pertinent to what’s going on clinically. And if we think about the diagnostic process and how we are to figure out whether this patient, whether this pet is healthy or if there’s a clinical diagnosis,

it is a diagnostic process to figure that out.

Right.

We can’t take just the reported history from the owner and know what’s going on.

Right.

If they don’t present to the hospital with a clearly broken leg or maybe porcupine quills sticking out of their nose, Right. Where it’s very obvious just on physical exam what’s going on, we need to delve a little deeper, Right.

Sometimes a lot deeper to figure that out.

So our clinical signs can be nonspecific. That is common in veterinary medicine.

Right.

One of the more common presentations that we hear is an owner describing an ADR patient ain’t doing right. That’s how vague it can be. And our physical exam, you know, is not as objective as we would like it to be.

Right.

Or hope it could be in that, you know, we take a cat who has an elevated heart rate and does not like you palpating its abdomen. Is that just a cat in the hospital setting and in a vet’s arms, or is that a cat with a foreign body or GI obstruction?

We don’t know. And we see that cats and dogs mask their clinical signs. Right. In the office visit that we see a dog limping as it gets out of the car outside.

But in the exam room, it shows no sign of lameness.

Right.

An animal that the owner reports is lethargic at home, may be stressed in the hospital and hyperactive.

Right.

Again, masking the clinical illness. So we need to obtain more objective data.

Right.

So Dr. Dennis D. Nicola, many might know him as a fantastic clinical pathologist and he coined the phrase, you know, animals can’t hide their objective data.

Right.

So while they can mask many of their other clinical signs, and sometimes behavioral changes are indeed just behavioral, but sometimes there’s underlying pathology.

Right.

We need to get objective laboratory data from our patients. That is a great starting place to try to work down this diagnostic algorithm of figuring out what’s going on.

Right.

By running the appropriate diagnostics, by understanding the tests and using them deductively.

Right.

We can obtain more accurate diagnoses, we can get more appropriate treatment plans, and ultimately we end up with healthier pets. Right? That’s the objective. Better medical outcomes. And so when do we perform laboratory testing?

Right.

Certainly in periods of sickness or ADR patients.

Right.

When something has changed at home, something of concern to the owner. And we want to look for objective data to try and understand what’s going on in our senior patients.

Right.

Where we know that we can see subtle changes in function,

endocrine function and other organ function. And catching these disease processes earlier often allow for earlier intervention to keep them healthier longer.

Right.

Often our patients have comorbidities as they become senior patients. And so we may be looking at lameness in the treatment of degenerative joint disease, but we don’t want to miss the fact that there’s a splenic mass or miss the fact that they have another inflammatory focus or miss the fact that they have concurrent development of hyperadrenocorticism.

We run lab work in our pre anesthetic patients so we can choose the most appropriate drug protocols. We don’t take any unnecessary risks, so we use their fluid therapy appropriately.

Above all else, do no harm, right? So we need to make sure we have an assessment of the health of the patient before we take any risk with anesthesia. Our patients who are on long term medications, keeping an eye on liver function, renal function or other processes that could be affected by those drugs,

bone marrow function, right. We want to keep an eye on them again, making sure that we are not doing more harm than good with our therapy. And what about in our young, healthy pets, right.

From a perspective of a clinical pathologist, you know, my rationale would be, you know, as we look at reference intervals as they currently stand, right, we’ll have a reference interval for an adult dog and a reference interval for an adult cat.

And those reference intervals even in health are necessarily very wide.

Right.

If we take, we understand the establishment of these reference intervals that we’ll take large number of dogs and this would be dogs of any breed. It’ll be dogs of any age of maturity from maybe a year to maybe nine years of age.

We take dogs of different sizes, everything from a teacup poodle all the way through a St. Bernard, right. We have males and females intact and neutered quite a wide variety of animals.

And so you would imagine that each animal’s laboratory data, even in the face of health, might vary widely,

right. The different analytes that we’re looking at, we know that for an individual patient, right, Their hematocrit is fairly stable throughout their life, right. When they’re euhydrated, right. We know that creatinine, once they’re mature body weight, their creatinine is also very stable throughout their life unless they have muscle loss.

So if we can take, we can use wellness testing. If we can look at laboratory data from our individual patients when they are healthy now, we have a very narrow reference interval for health for that patient.

We know sort of their set point, if you will, such that we can much, much more sensitively detect abnormalities with a rise or a fall in the different parameters that we’re measuring.

We’re going to capture these abnormalities much earlier, hopefully while disease is still occult, when we can make interventions before they become more sick.

So also performing lab work yearly allows us to distinguish what are historical changes in the laboratory work for a particular patient versus acute changes, right. The reason they may be presenting for clinical illness.

And you’ll hear me say a lot, basically, if you don’t look, you won’t know. If we don’t look at the data and try and get objective measurements of what’s going on, we won’t have the full Picture of what’s going on for our patients.

So the case I’ll be discussing today is going to actually be our own cat, right? My own cat, Brian Scalabrini,

named after a big white guy from the NBA with orange hair. As Brian is a large male cat with white and orange fur.

So Brian has a quite assorted past. So we are definitely past his ninth life. Currently Brian’s now a 16 year old male neutered domestic shorthair. We adopted him when he was maybe a little over a year of age and he’s been an awesome fit for our family.

So fairly early on it was obvious that Brian suffered from allergies. He has environmental allergies, he had food sensitivity, his asthma. And in some of the earlier years we treated him with steroids and maybe not knowing better, often gave him long acting steroids like depo medrolence stayed in his system for a while and worked very well against his allergies.

But Brian became polyuric and polydipsic. And for those who have indoor cats that are cleaning the litter box, I think often these polyurec and polydipsic animals, meaning peeing more and drinking more, are often discovered because you’re maybe you’re cleaning the litter box more because they’re urinating more.

And that was the case for Brian. I think a lot of these disease processes are sometimes a little insidious in their onset. So it took a while, I think, before I was realizing, you know what, he’s been peeing more and you know what, now I see him at the water bowl a little bit more.

So of course I couldn’t guess which of the myriad of issues he may have.

Right.

Just based on those behavioral changes. I don’t know if it’s his kidneys, I don’t know if it’s endocrine disease, I don’t know if he has a bladder infection. Right. These are all possibilities,

right? And I wouldn’t want to hazard a guess and get on the wrong treatment protocol.

Right?

So the first time this happens, because obviously I’m going to keep referring back to this. The first time he’s pupd, polyuric and polydipsic, peeing more and drinking more. We run his lab work, right?

And at that point he had a hyperglycemia and he had a glucosuria meaning excess glucose in his urine. And it turned out that Brian had become a diabetic.

So Brian was a diabetic, probably in response to his steroid therapy. Long acting steroids increased his risk of developing diabetes we were able to look beyond, you know, certainly a cat in the practice setting.

A cat that is stressed can develop a transient hyperglycemia. Now, Brian’s a pretty chill cat, and he actually doesn’t mind travel or coming to the animal hospital or the phlebotomy, actually.

So we don’t really see a lot of excitement or stress changes in his lab work.

But other cats, you could, you could absolutely see a stress hyperglycemia from their travel to the veterinary office. How our blood, how glucose is handled by our bodies once it’s in the blood, right, is that it’s freely filtered through the glomeruli or the filter apparatus of the kidneys, and then it gets reabsorbed in the proximal tubules of the kidneys.

And it’s usually completely reabsorbed such that there is no glucose detectable in the urine. But if the glucose gets too high in the blood, we exceed that reabsorption threshold and the glucose will spill over into the urine.

Right.

So we run a urinalysis and we look at the chemistry strip. We can detect a glucosuria. Now, again, that could still be from a transient episode of hyperglycemia.

Right.

So there’s an additional test that we can do, and that is looking at the fructosamine that basically assesses over the past couple weeks, how was this patient’s glucose control.

Because if we remained hyperglycemic, that will increase that fructosamine level.

Right.

So it’s a look at how our glucose was being handled over the past couple weeks. And so that would go beyond a stress hyperglycemia. And with the fructosamine elevated, then we have more support that there was a pathologic hyperglycemia, as it wasn’t Brian.

So he did have an increase fructosamine as well.

So Brian was diagnosed as a diabetic. He did receive insulin. We also changed his diet from a dry food diet with high carbohydrate that he was able to free feed and turned him into a cat that will eat canned food only because a lower carbohydrate level means their blood sugar does not stay high as long during the day,

which decreases their insulin needs. So he was meal fed canned food only he received insulin. And after almost, maybe between nine months and a year of receiving insulin, he actually no longer required it to maintain his normal glucose.

He had been a transient diabetic, fortunately. And so we made it through that episode in his life. Right. Transient diabetics. So his first time Being pupd, Brian was a diabetic.

That we found out from checking his blood sugar level. We checked his urine, which had increased glucose as well, and we confirmed it with looking at fructosamine level in his blood.

Next up, years later, Right. So maybe, maybe even five years later, Brian is again, appears to be peeing more, which I notice first because I’m the one cleaning a litter box.

So larger volumes of urine and more frequently, and then I start to notice them again at the water bowl. So how does diabetes come back? Maybe.

Right.

Maybe he’s diabetic again. Maybe he’s got another endocrine disease. Maybe he’s got a urinary tract infection. Maybe his kidneys are failing.

Right.

These are all possibilities. And we don’t know unless we test.

Right, you don’t know unless you test.

So we bring him back to the hospital,

we’re checking his blood, we’re checking his urine, and this time he comes back, no hyperglycemia, no glucoceria. We checked his fruitosamine, and that was normal. So no increased insulin needs.

But this time, his blood work comes back showing a high T4, a total T4 measurement. He was hyperthyroid.

So cats most commonly become hyperthyroid in response to benign adenominous growths on their thyroid. Thyroid gland. So these benign proliferations on the thyroid gland increase the production of thyroid hormone, or thyroxin.

And we see a lot of different systemic effects of that. And for Brian, that was also the case because he had developed a heart murmur. And with their increased heart rate in response to the increased thyroid hormone, that can sometimes be a consequence of hyperthyroidism.

For cats, they can develop a thickening of the heart from the increased effort. And he did show some early signs of cardiomyopathy. He also was experiencing some weight loss.

Oh, yeah. So back to when Brian was pupd the first time.

Right?

For his diabetes, I forgot to mention that there was some weight loss during this process. Right. It was a little protracted. I think I was a little slow on the uptake to realize that something was wrong.

And he had lost some weight. So again, polyureth, polydipsic with weight loss. So that’s happening again this time.

Right.

Round two, polyuric, polydipsic with weight loss. So we bring Brian in for his blood work. We find at this time he’s hyperthyroid. So feline hyperthyroidism, not uncommon in our aging cats.

We actually ended up treating him initially first with oral methimazole, and he had that uncommon but reported reaction of facial excretions, or he gets really, really itchy in their face as they react unfavorably to the drug.

So, unfortunately, treating him medically was not an option and we ended up getting radioiodine therapy. So Brian’s treated successfully for his hyperthyroidism with radioactive iodine,

and we haven’t looked back, so that’s great. Treated successfully for his hyperthyroidism. I think that had to be four years ago. And now Brian’s PUPD again. Polyuric, polydipsic. Notice first in the litter box.

And he’s, uh, now drinking more. And he definitely has some muscle loss, especially over his dorsum, like around his spinous processes.

We’re concerned now. Again, third time polyuric, polydipsic. Losing weight again. If you don’t look, you won’t know, Right. If you don’t do the testing, you’re not going to figure this out.

Right?

Is it return of the diabetes?

Right.

Is it return of hyperthyroidism? Once in a while, the tissue can regrow and they require repeated treatment. We bring him for his blood work, and this time the changes are more subtle.

The thyroid gland’s fine, his T4 levels are fine, his glucose levels are fine. And actually there wasn’t much off on his CBC or his chemistry that were out of the reference interval.

But this hearkens back to how wide reference intervals are.

Right.

And so that can be very insensitive in detecting abnormalities. But I have years worth of blood work on Brian to know where his individual reference intervals are.

Right.

For health, for him. And there’s a subtle change in his albumin.

So while not beneath the reference interval for a whole myriad of healthy cats of different ages, of different weights, of different sizes of different breeds, right. That were used to establish a reference interval of health for albumin in those cats.

For Brian specifically, if I trend his data, right. I see that this is low for him.

Right.

So now he has a hypoalbuminemia without one of these other metabolic problems.

Right.

And that led us to get an abdominal ultrasound. He has a severely thickened gut, some changes that seem most suggestive of possible GI lymphoma.

It’s amazing to me that now we are dealing with our third presentation, right, Where I’d be reporting as a client to the hospital that he’s peeing more and drinking more and he seems to be losing muscle mass or losing weight.

Right.

And if you don’t do the testing, you’re not going to know, Right. If you think it’s secondary to some to renal disease. Right? That one we haven’t had yet. That might be his fourth time, right?

His kidneys continue to do fine, right? Probably one of the most common reasons for cats to drink more and pee more as they age might be progressive kidney disease. That’s actually something he doesn’t have yet.

It should knock on wood, right? But the first time diabetes. The next time hyperthyroidism. The next time IBD or lymphoma. Right? Do the testing.

Right?

Run the diagnostics. Get the answers for these clients.

Right?

They’re coming in with presentations that can be very non specific.

Right.

Very nonspecific. We cannot assume based on a history and even a fairly limited physical exam of objectivity.

Right.

What’s going on in many of our cases. Right. And certainly many of our medical cases.

Right?

But do the testing to get the answers.

Right.

This is how we’re going to keep our pets healthier.

Thank you for listening to today’s Tale from the Lab. Jessica will be back next time. In the meantime, please like and subscribe to stay informed about new episodes soon to be released.

You can also email any feedback, questions or requests for future content to tales from the labtetechmail.com thanks again for your support.

Tales from the Lab is a production of Antech Diagnostics. The intent of this podcast is to provide education and guidance with the understanding that any diagnostic testing and treatment decisions are ultimately at the discretion of the attending veterinarian within the established veterinarian patient client relationship.