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August 2023
Bexacat and the New Era of Feline Diabetes
Renee Rucinsky, DVM, DABVP(F), nerds out on endocrinopathy in the latest interview on Central Line: The AAHA Podcast.
A Conversation with Renee Rucinsky, DVM, DABVP (Feline)
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Endocrinopathy isn’t everyone’s cup of tea. “I think you either love it and think it’s super cool or wish that it would just go away,” said Renee Rucinsky, DVM, DABVP (Feline), in her latest conversation for Central Line: The AAHA Podcast. Fortunately for the veterinary community, Rucinsky falls firmly in the first camp, as evidenced by her work on the AAHA diabetes guidelines and the selected endocrinopathies of dogs and cats guidelines task forces.
A board-certified ABVP feline specialist since 2001, Renee has spent the majority of her career in feline exclusive practice, and she seriously knows cats. “Cats really are very humbling,” she said. “I really, truly believe that one of the main purposes of cats that come into my life is to make me look bad. But it’s fine! It’s an exercise in humility on an every-20-minute basis.”
Renee is also frequently the first name to come to mind when the topic of feline diabetes is raised. So naturally, she was the perfect person to discuss a new class of drugs for treating feline diabetes (SGLT2 inhibitors, or, by its brand name, Bexacat™ by Elanco). In this conversation, she addresses some FAQs regarding what this drug is, how to use it, and why it’s a gamechanger—as well as why it’s not the right choice for every diabetic cat.
Renee Rucinsky: [Bexacat] is an SGLT2 inhibitor, which stands for sodium glucose co-transporter 2. That’s too many words for me—I hate doctor words. I would just rather not work that hard, so we’re just going to call it a SGLT2 inhibitor.
One of the things that people have mentioned to me as the news of this comes out is, “Oh, the new insulin pill.” It is absolutely not an insulin pill; it is a completely different type of drug. What this drug does is reduce blood glucose levels. And so, for it to work, the body still has to be making insulin.
Typically, when there is high blood glucose, it gets filtered through the kidneys, and then the kidneys resorb it back up. An easy way to think about the way this drug works is if you think about the blood flow through the kidney as being like a highway, and the glucose is traveling down the highway. In a normal kidney, it gets off at all the exits and goes back into wherever it needs to go. With Bexacat—or with whatever other drugs that come out within this drug class—the off-ramps are blocked, so the glucose isn’t going to get back into the bloodstream; it’s going to go right into the urine instead.
So, instead of going back in and continually causing that blood glucose level to be high, the animal is able to clear that excessive glucose into the urine, which is going to be a whole different way of looking at these things. With the previous diabetic guidelines [aaha.org/diabetes, from 2018], we talked about using urine glucose measurements to help monitor these cats, and that’s just not going to be an option.
Katie Berlin: You’re going to freak out if you do that.
RR: Right, these cats are always going to be glucosuric, so that’s a whole different way of thinking about these things. There’s going to be a learning curve.
KB: Yeah, that’s really interesting. I was just thinking about that, how the task force had specifically said, we don’t really recommend using oral drugs—because this class of drugs wasn’t out at that time. It also said you can monitor the glucose in urine. And there are all these things available now to do that, like strips and special litter, and none of that would work in this case because [the urine] will always be full of sugar.
I was thinking about the reasons why we think about sugar in the urine, other than just that it signals high blood sugar to us. Does that make these cats more prone to UTI?
RR: You know, when I first started working with Elanco on this, that was my big concern too. I was like, okay, great, so now we’re going to have fat cats that are messy anyway, and now we’re going to create this perfect medium for bacteria to grow. The initial studies have not shown that to be an issue, which I was relieved about. I think that we’ll see what happens as time goes on, but at this point in time, it doesn’t seem to be the biggest concern.
“What [Bexacat] does is reduce blood glucose levels. And so for it to work, the body still has to be making insulin.”
—Renee Rucinsky, DVM, DABVP (Feline)
KB: How do we know what cases are appropriate? Because clearly this isn’t a drug that everybody’s recommending instead of insulin for diabetic cats in general.
RR: The patient selection for this class of drugs is going to be imperative. Back to what I initially said, the cat still needs to have a source of insulin. So if you think of the big, fat cats being more like a type-2 diabetic, they’re really insulin resistant, not insulin deficient. That insulin is still being produced by the pancreas, it’s still trying to get to where it needs to get and do its job.
We want these cats to be healthy cats. These are the cats that come in for their regular annual or semiannual visits that we notice have lost weight, but they’re eating really well, and they’re still drinking great, and they pee like everything. They don’t come in with vomiting, they don’t come in with a plantigrade stance normally, because those cats will have been sick for a while. They don’t come in with concurrent pancreatitis. They are just these cats [in whom] we are diagnosing diabetes almost incidentally. Cats are still going to need insulin if they’re sick at all.
“At this point in time, and probably for the foreseeable future, this class of drugs is purely for the brand new, newly diagnosed diabetic cat”
—Renee Rucinsky, DVM, DABVP (Feline)
KB: And those moderately sick cats who clearly aren’t well, but they’re managing and they’re still eating and stuff—if those cats go on insulin, is there a chance that they’ll eventually be able to transition over?
RR: Once the cat is on insulin, then that’s it. At this point in time, and probably for the foreseeable future, this class of drugs is purely for the brand new, newly diagnosed diabetic cat.
KB: Say we’ve picked the right patient and the case is right; are there complications or side effects that we should watch for or warn people about?
RR: The cool thing about this class of drugs is that we don’t have the normal “diabetic cat on insulin” complication; the odds of a cat becoming hypoglycemic on this class of drugs is practically zero. Which is absolutely amazing! But the flip side of that is that when they do get sick, we can’t necessarily look at hyperglycemia as being one of the red flags.
The complications will mainly occur if, for some reason, the cat is no longer producing enough endogenous insulin. That would be diabetic ketoacidosis [DKA], which is going to be a little bit more challenging to diagnose because they’re not going to be hyperglycemic. The phrase “euglycemic diabetic ketoacidosis” is going to be much more prominent in the vernacular because these cats are going to potentially be very, very sick, with ketones, but normoglycemic.
KB: So ketones in the urine can still be a diagnostic aid there?
RR: You shouldn’t see ketones in the urine of one that’s doing well. But because the main monitoring with these guys is a [blood] ketone level, the recommendation is to have a hand-held ketone monitor. BHB is the ketone that we’re looking at.
The cool thing about these little hand-held ketone meters is that they look just like your bedside glucometer. It’s one drop of blood. It’s an instant read, and that’s what we’re going to use to monitor these guys both before we start and then as you start the initial treatment. They’re very inexpensive, and […] I truly believe that you should not be using this drug without one of those in your hospital, because if you have to send it out to a reference lab and it takes 24 to 36 hours or more to get that back, that cat could be in really, really bad shape. You have to have this in your hospital if you’re going to start treating these cats with this kind of drug.
KB: Do you see cats go into remission on this drug?
RR: Will they go into remission on this? I don’t know. We can start this drug, we can aggressively work on weight loss and diet change and other things without that inherent risk of administering insulin twice a day. So maybe when we’re able to work on everything else that’s contributing to that cat’s diabetes, we can take them off of this drug. I don’t see why we wouldn’t be able to if we take care of all the reasons why they were diabetic in the first place.
KB: What conversations do we need to make sure we have with clients before we start this?
RR: Well, before we talk about what we tell clients, think about just what we’ve had to go through educating cat owners about the potential of their cat being diabetic.
Most every cat needs twice-a-day insulin, so that’s a lifestyle change for the cat, it’s a lifestyle change for the human—now they’ve got to be home when they can administer this drug and make sure that cat ate. It’s very stressful. And as much as we explain to owners that this needle is tiny and the cats typically don’t care, there are still people that are afraid of needles, and there are still cats that are like, yeah, I don’t want to get poked twice a day. So then that affects the relationship between the owner and their pet. Even before it starts affecting their relationship, once people hear the diagnosis of diabetes, there’s a fair number of cats that will get euthanized at that point or some time within the first several months of being on insulin.
So, the opportunity to have a once-a-day chewable medication that they can either break up and take like a treat or get mixed in food with no risk of hypoglycemia and no chasing the cat around the house and ruining that relationship—if the cat’s a good candidate for it, I think that’s going to be a complete game changer.
It’s going to be a different sort of education. Now, instead of spending all of our time educating on how to give insulin and the timing and the storage and all of that, we’re going to be talking about monitoring that cat for how they’re feeling. If they start feeling icky, is it because of something else, or is it because they’re developing DKA? The development of DKA is not that common with the cats that are on this drug, but when it happens, like any DKA, it needs to be addressed super quickly. Having the owners be aware that that’s a complication if they have to go to the emergency vet, who may not know yet that these cats aren’t going to be hyperglycemic—it’s going to be really important to get that message out too.
KB: How do we train teams to be aware and know what’s important for them to know and what messages to relay?
RR: Many times, as veterinarians, we’re not always the first people in the building. Our front desk staff needs to know that all this training they’ve had to prevent hypoglycemia doesn’t apply to the SGLT2 inhibitor class of drugs.
“Our front desk staff needs to know that all this training they’ve had to prevent hypoglycemia doesn’t apply to the SGLT2 inhibitor class of drugs.”
—Renee Rucinsky, DVM, DABVP (Feline)
If a cat continues to take his SGLT2 inhibitor and isn’t feeling well, those are the cats that we need to say, “You know what, we need to do a spot check at least of this ketone.”
As far as going to the ER […], I think that there will [eventually] be something that the owners can always have with them to help inform the emergency staff going forward to make sure that everybody is set up for success.
KB: In terms of a cat who comes in with vomiting and is sick and turns out to have DKA, and then that cat needs insulin at the hospital even though they’re euglycemic, is that cat ever going to go home on Bexacat again, or is that cat now on insulin?
RR: No. That cat will now be on insulin.
KB: When you start a cat on Bexacat, can you just send it home and tell the owners what to watch for versus having to do extensive monitoring like you would if you started it on insulin?
RR: It’s just different. As we’re starting to learn this new class of drugs and monitoring, we’re going to ask that those cats come back relatively frequently for the first little bit. They’re still sick cats, they still have a major disease, so we have to monitor that. And just like diabetic cats that are on insulin, they still need to be monitored even once they’ve got their right dose. Where the difference is going to be is that there’s just one dose.
KB: Do you think we’ll see a time, once we’re a little more comfortable with the drug, where we send ketone meters home with owners the way that we do glucometers now and have them check ketones at home?
RR: Absolutely. I don’t see why we wouldn’t. Just like with handheld glucometers, it’s not going to be a replacement for our regular work-ups, but it will definitely be one of those things where owners can check that at home and decide whether this is a panic moment or okay, I can have a little breathing room to figure out if it’s something else.
My biggest concern is that that patient selection won’t be as careful as it needs to be. I think that because it’s not a needle, because it’s once a day, because there’s no risk of hypoglycemia—I think there’s going to be a lot of pressure from the owners when they hear about this. […] I think it’s going to require a lot of saying no and sticking up for the patient. Is this the best thing? If answer is no, then I’m really sorry, but I don’t want to kill your cat. I think we can be that blunt about it. If we choose incorrectly, the cat will not survive. That’s not meant to sound ominous; it’s just that we have to be so careful.
A baseball pitcher has four or five different pitches he can throw based on the kind of batter that’s up. You don’t throw a fast ball to a fast ball hitter. Maybe there are cats that you can correct their hyperglycemia by putting them on a high-protein, all-can diet, and that’s good enough. Maybe another cat gets an SGLT2 inhibitor. It’s just another tool in our ever-growing arsenal of how to take the best care of our patients.
KB: It’s a new era of feline diabetes, and it’s a big deal.
RR: Absolutely. We recently had a newly diabetic cat who’s been a patient, and her owner has been a client for forever. [When] her cat came in and was a perfect candidate for this, you could just see her face relax, you could see her blood pressure go down. We are optimistic that this cat will continue to do well; she’s doing great so far. It’s just kind of fun. Sometimes it’s fun to be a vet.
Central Line: The AAHA Podcast is generously sponsored by CareCredit.
Catch the full episode, and every other episode of Central Line: The AAHA Podcast, on major podcast platforms, YouTube, and at aaha.org/podcast.
Renee Rucinsky, DVM, DABVP (Feline), is a graduate of the University of Missouri College of Veterinary Medicine, and has been a board certified feline specialist for over 20 years. She is owner and veterinarian at Mid Atlantic Cat Hospital and Mid Atlantic Feline Thyroid Center in Maryland. In addition to routine feline wellness care, her hospital has become a busy referral center for complicated feline internal medicine cases, especially for diabetic cats. |
Katie Berlin, DVM, CVA, is AAHA’s Director of Content Strategy. |
Photo credits: shironosov/iStock via Getty Images Plus, vgajic/iStock via Getty Images Plus, ©AAHA/Robin Taylor