[00:00:06] Speaker A: Welcome to All Cats Considered, a new podcast from the American Association of Feline Practitioners, where we interview professionals from across the veterinary world and take deep dives into the latest evidence based research developments, studies, and guidelines that improve feline health and well being. My name is Dr. Kira Ramdis, president of the AAFP, and I'm proud to introduce this new podcast. We are the home for veterinary professionals seeking to improve the care of cats through high standards of practice, continuing education, and evidence based medicine. In each podcast, you will hear interviews from a variety of experts throughout our field covering a wide range of topics and recent developments in the practice of feline health, sharing the key points you need to know to improve your patient's care. Let's dive in and take a listen with this week's experts.
[00:01:01] Speaker B: Hello, everyone. I am Dr. Ashley Sapphire. I am a feline practitioner in Columbus, Ohio, and I'm here to discuss with Dr. Julie Byron from Ohio State University some things about ureteral obstructions in cats and what we do when we come across them in practice. So from a general practice point of view, these cats often come in for us. They seem to show up in an emergency situation. They're acutely painful. They might be vomiting. We might run some lab work and see some elevated renal values. We might take an X ray and see some concerns for a possible ureteralith. And so sometimes our question is, when is it right to maybe start with some supportive care, like IV fluid therapy, pain meds, antimedics, see if we can get this stone to move versus moving forward with something like a suburbal bypass?
[00:01:59] Speaker C: Yeah, I think that it's not wrong to certainly give these guys some fluids first, because, as you mentioned, this is one of those things with acutely vomiting cats. I think we see people especially vomit with ureteral obstruction when they're passing kidney stones. And I think we see the same thing in our cats. They really have abdominal or almost back pain, and they kind of get hunched up and things like that. So they're not going to be drinking or eating. They're going to be dehydrated. Even if the owners are like, yes, gung ho, we want to go for surgical intervention. They really need to be rehydrated and sort of gotten back to that best place that they can be for any sort of surgical intervention. But only maybe about 25% of these cases or even less are going to be able to be realistically medically managed. And those are usually the cases that have the stone in the distal third of the ureter. I'm not going to say I haven't seen him actually one of our surgery residents, her own cat, we ran him on fluids for two days, and we literally watched the stone pop through into his bladder. Of course, he needs surgery to get it out then, but he only needed a cystotomy and didn't need any bypass placed, but I think that it's not wrong to do it, especially a good twelve to 24 hours of IV fluids. Pain meds? Definitely.
I suppose you could consider using Prazacin for ureteral spasming and antimetics and just kind of get them to a place where their hydration is good. Not overhydrate, of course, but where their hydration is good. And another good thing to do is if you have the capability to do an ultrasound and are comfortable finding the kidneys and maybe learning how to measure the renal pelvis, because that's a big tell about whether or not the cat's going to need surgical intervention or not, but usually by about 48 to 72 hours. If not much is changing, they're probably going to need surgery.
[00:03:46] Speaker B: Yeah. And sometimes in our practice we'll start them on fluids, just same protocol. And with the ultrasound, I think it's a really good point that renal ultrasound is becoming more readily available in general practice. So a lot of people have the ability to look at kidneys. So if you feel like a kidney looks radiographically normal, the side that might have the stone and the pain is well controlled and the cat seems comfortable, it seems reasonable to give them a little extra time and see if it would continue to move. What happens if the stone stays in place? It doesn't really move and the owner might not be able to pursue surgery is there? What would be the risks that we'd be looking for?
[00:04:25] Speaker C: So unfortunately, some of these cases are not really going to do very well if we don't have surgical intervention. If you have the ability to look at the renal pelvis, that plus and the creatinine are the two major things we could look at. Since we can measure the creatinine relatively quickly in most of our practices, even if it's a twelve hour turnaround and has to be sent out, it's a good idea to watch that creatinine and measure it on the same machine. If you're using an in house machine, keep measuring it on that machine and see if it's dropping. If it's dropping and the cat seems to be more comfortable, even if the stone's not moving radiographically, or even if you're maybe not seeing the renal pelvis get any smaller, if the creatine is going down, that's usually a pretty good sign. That especially if this is a case where it can't go to surgery, that continuing medical management is probably worth doing. If the renal pelvis is not getting any smaller and the creatinine is not budging or it's going up, and especially if their potassium is going up, that's when we worry a little bit more that this animal is not going to do well unless surgery happens. And the owners probably need to be preparing themselves for a life ending decision.
[00:05:39] Speaker B: So say we are successful and we are able to either see passage of the stone or a sub is placed and the cat's doing great. Is there any way to prevent more stones from developing in the future?
[00:05:52] Speaker C: Well, most of these stones, probably 99% of them, are going to be calcium oxalate stones. And occasionally we get those bloodstones people talk about, which personally, I've never really seen one. But then again, we're not taking them out, so we aren't always checking what they are.
Calcium oxalate stones. No diet is really going to prevent calcium oxalate stones if the cat has hypercalcemia, particularly idiopathic hypercalcemia. Always a good idea to address that.
We have cats who have rarely hyperparathyroidism and are Hypercal because of that, so those things need to be addressed. But if the cat's not hypercalcemic, what I usually recommend is still a stone friendly diet because they're going to be non or limited acidification, sort of keep a more neutral PH, reduces that calcium excretion. And then I will oftentimes get these guys immediately on potassium citrate supplementation and hydrochlorothiazide, actually, which I think most of us may not have as much experience using it in cats, but most of them actually tolerate fairly well. I start with a low dose to prevent vomiting, and then we'll kind of ramp it up. And then I have the owners either catch urine or bring urine in, or I will get urine on like a tech appointment or something and make sure that we can get their urine concentration down below 1030 or 1025, if at all possible. I know it's tough, but fountains, flavored waters, dripping, faucets. I got a lot of clients who have their faucets dripping all day, anything to get that urine concentration down. Those are really the best things to look for or to try and do to reduce the stone formation. But the reality is they're going to probably form. And frequently these cats have stones already in their renal pelvis that are just sitting there and may or may not become a problem.
I think one of the challenging things with ureteral obstruction is the conversation with the owners, because once we recognize that this might happen, in particular if you radiograph the cat and see that it has a big kidney and a little kidney. So that Bklk syndrome. That tells us the other kidney is probably already obstructed previously, and that bigger kidney has sort of taken over the job of both of them. And usually the owners may have no recollection of the cat ever even being sick. Maybe the cat vomited for two or three days and got better on its own, so it never ended up in your hospital. But now the bigger kidney, which is doing all the work, is the one that obstructed. And now it's time for you to have to do something.
Having the conversation with the owner about the benefits of medical management, but then also the likelihood that it will need surgical intervention, the costs of surgical intervention and where they can get it, depending on your location. Probably a good idea for Feline practitioners to have a relationship with a surgeon who they can refer these cases to and kind of have an idea of what their cost estimate is and the process of getting them in. Because Feline practitioners absolutely are going to see this, and we're seeing this way more frequently than we have in the past. I'm not sure why. It's probably related to the same reason we see an uptick in calcium oxalatestones in general in cats over the last 15 years.
[00:09:03] Speaker B: When they do have the placement of the sub. Is the follow up care, is that something that maybe the referring vet would be able to learn how to manage and help them?
[00:09:14] Speaker C: Absolutely. Flushing a sub is really not that technically difficult. I mean, quite honestly, I don't do any surgery. I'm an internist. And the idea of doing a spay to me, even in a cat, is terrifying.
Even taking a tooth out of a cat scares me. But flushing a sub is really very straightforward. If you have a practice, certainly if you have a feline only practice, and if you have a practice where you see a fairly number of cats, then you probably should touch base with the local surgeon or local internist who you send these cases to and ask if they'll train you how to do an injection. We trained our techs how to do them. Even our techs can do them. Our residents can do them, our interns can do them. All they have to do is watch you do it, and then they can do it once. And then as long as they have an ultrasound that they can look and see that there's bubbles coming into the kidney and the bladder, they can do the sub flushes. I think that's fine. If you don't have an ultrasound, it makes it a little more challenging only because they're not going to have as good a sense of the patency unless they're willing to put iohexal into the sub so they can do it and radiograph the cat. It's just more kind of a pain. And they also have to keep iohexol around, which not everybody wants to, and it's also been on back order and all these other things. But I think that if you have an ultrasound, as many practices do, it's pretty straightforward to do it.
[00:10:32] Speaker B: Yeah, that sounds great.
[00:10:34] Speaker C: You just need a special kind of needle called a huber needle. And it does make life easier, quite a bit easier for the client, too, especially if they have to travel a bit to get to a specialist. Okay.
[00:10:43] Speaker B: Yeah, it definitely seems like if you're in an area where you don't have a specialist close by, it's good to have that plan in place for when you are presented with a case like this, to know just sort of have your plan of what you're going to talk to your owner about, what your prognosis is, what your options are, or what the patient's options are, and help them make the best decision moving forward.
[00:11:04] Speaker C: People sometimes ask about putting stents in these guys because initially, that's what we did probably about 1015 years ago. And stents are just more technically challenging to place in a cat because they're ureters. The inside of the ureter is basically the diameter of, like, two OT suture. It's tiny. And even though there is going to be some dilation, you have to get the stent through the entire ureter, not just the dilated part, but also through the distal part that's going to be more normal, and it can be quite challenging to do. And so even those people I know who have quite a bit of experience with doing stents and cats still now prefer to do Subs. The other reason not to do a stent is that the way the tube going into the bladder is, it's got a little curly cue on it, and there's quite a bit of it sitting in the bladder. Whereas with Subs, especially the newer 3.0 Sub that we're using, the piece that goes into the bladder is fairly short, and there's not a pigtail on it. So if you think about what the size of the bladder of a cat is, that stent with the curly cue on it is going to bounce around the inside of the bladder. And I see a lot of cats that will develop sort of lower urinary tract signs with it. They get blood in their urine, they're irritated, they're palac uric in and out of the box. And so they're not that comfortable with it's, just not that comfortable. And so the smaller bit that's in the Sub is much less irritating.
[00:12:28] Speaker B: And you said, just to recap, that the best candidate would be those that might have a stone that's settled in the distal third of the ureter.
[00:12:35] Speaker C: For medical management. Okay, yeah, for medical management. Medical management, yeah. Anybody who has a stone that's in the proximal or middle third, I generally prep the client that they're going to most likely have to go to surgery. If they can't afford it, then we will do medical management. I certainly won't deny that, because we might get lucky and actually, the ureter might dilate around the stone and we can get some urine flowing again. But the ones that I will really push medical management a little harder may be the ones where the stone looks much closer to the bladder and we might get lucky and pop into the bladder.
[00:13:07] Speaker B: Okay, great. Awesome. Well, this was a really good conversation because I do think it's something that makes everybody a little bit nervous when they come in, just since they're not super common, but they're common enough that we do see them. And it's good to have a plan in place and know what to advise your caregivers. So thank you.
[00:13:24] Speaker C: Thank you.
[00:13:24] Speaker B: Dr. Sapphire, nice to see you.
[00:13:26] Speaker A: Thank you for listening to this episode. Of all cats considered. We hope you enjoyed this interview. For more information on the topics discussed during the episode, please be sure to head over to Catvets.com and explore the links in the podcast description. And please be sure to subscribe to this podcast and your platform of choice so that you don't miss the episodes as we release them. Have thoughts or ideas about the interview you heard today? Share them with us, leave us a comment on our Facebook page, or shoot us an email at
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