Feline lower urinary tract disease is a frustrating condition for cats, owners, and veterinarians. While feline idiopathic cystitis is the most common cause of lower urinary tract disease,

 urolithiasis is also common. During a session at the 2022 American Association of Feline Practitioners (AAFP) conference, Anne-Marie Germain, DVM, of Village Cat Clinic in Cambridge, Ontario discussed the management and prevention of feline urolithiasis.

Get the story straight: The importance of history and signalment

When it comes to creating a differential diagnosis list for causes of inappropriate elimination, “Never underestimate the power of a good history,” said Germain. “One really important thing I think we miss is confirming presence of lower urinary tract signs,” she continued. Lower urinary tract (LUT) signs include pollakiuria, dysuria, stranguria, overgrooming of the abdomen, and vocalization when voiding urine. While not all cats with uroliths will have LUT signs, the presence or absence of these signs will change the differential list. Hematuria is another clinical indicator that uroliths may be present, though it is not pathognomonic.

Additionally, Germain reminds veterinarians that they have to speak the same language as clients. When an owner says their cat is urinating more, it is important to clarify whether they are referring to the volume of urination or the frequency. Germain suggests comparing the sizes of the balls of urine in the litter box to known objects, such as fruits. Uroliths may be present with both polyuria and pollakiuria, but other differentials will vary between the two presentations.

The signalment of cats should also help to shape the differential diagnosis list. FIC is uncommon in cats less than 1 year of age and older than 10 years of age.

 Struvite uroliths are more common in cats less than 7 years of age and rare over the age of 10.

 Calcium oxalate uroliths are more common in cats over the age of 7.

 These are the two most common types of uroliths in cats, but stones composed of or containing urate, apatite, dried solidified blood (DSB), and silica are also possible.

 There is a breed predisposition for urate stones in Egyptian Mau, Siamese, and Ocicats.

Once a suspicion of urolithiasis is formed based on signalment, history, clinical signs, and physical examination, diagnostics should be undertaken to determine if stones are in fact present. “There’s a huge discrepancy in what we do in theory and what we actually do,” said Germain. Ultrasound, which is often used to aid in obtaining urine samples by cystocentesis can help determine if stones are present and may be the only way to diagnose non-radiopaque stones, such as urates.

However, radiographs are essential for the diagnosis of uroliths as they can aid in predicting stone composition and allow for measurement of stones to track dissolution.

 Because struvite stones are the only type of stone that can be dissolved by therapeutic dissolution diets, predicting the likelihood of a struvite stone can help to prepare owners for the chance of successful dissolution. Calcium oxalate stones are the most radiodense, tend to be round to spiculated and often have multiple stones (more than 3-5).

Additionally, the vast majority of renoliths are calcium-based, so in patients with renoliths, calcium-containing uroliths in the bladder are more likely.

 Struvite stones are also radiodense, but tend to be ovoid and occur in smaller numbers, usually less than 3 stones.

 The Urolith Center at the University of Minnesota has an app that can help to predict stone type based on radiographic appearance and patient data.

Urinalysis results can also provide important information to predict stone type but should be interpreted in light of collection method, storage, and handling. The pH can provide important information as to the type of stone, as struvite stones tend to form close to neutral pH.

 Crystals may or may not be present. Germain reminds practitioners to “Never rule out a stone if there aren’t crystals in the urine.”

Medical management of uroliths should always be attempted first.

Dissolution diets are effective for struvite uroliths, and clinical signs should improve quickly after starting the diet. “They can dissolve as fast as one week,” shared Germain. In general, struvite stones should be reduced by 50% in the first two weeks, and most will be gone within 4 weeks. Germain prefers to radiograph patients every 2 weeks to monitor dissolution but noted that this is not financially feasible for some clients. In these cases, waiting 4-6 weeks to radiograph is appropriate if the patient’s clinical signs are improving.

While using a dissolution diet, pain medication to address associated discomfort from stones should be utilized. Additionally, while most struvite stones in cats are sterile, stones do predispose to infection, which should be treated if present. Finally, environmental modification to reduce patient stress should also be introduced.

If medical dissolution fails in the face of appropriate dietary compliance, environmental management to reduce stressors, and confirmation that a urinary tract infection is not present, stone removal should be pursued. Both the American College of Veterinary Internal Medicine and AAFP consensus statements on urolith management recommend minimally invasive procedures as the preferred option.

 These include voiding urohydropulsion, cystoscopic basket retrieval, intracorporeal lithotripsy, and percutaneous cystolithotomy.

 Cystotomy should be the last intervention but is necessary in some patients, especially in male cats, whose anatomy limits the use of many non-invasive options.

One essential piece of information when it comes to urolith prevention is knowing what type of stone the patient had. All stones that are retrieved physically from a patient should be sent to a laboratory for quantitative analysis. “There’s no urolith too small,” said Germain, “That sand and grit is precious.”

Once the type of stone is identified, an appropriate therapeutic maintenance diet can be selected. There are numerous diets on the market and some diets that manage multiple concurrent conditions. Germain encourages veterinarians to “Reach out to the different companies because [diets] aren’t all the same.” Additionally, knowing the type of stone may prompt investigation of concurrent medical conditions, such as hypercalcemia or portosystemic shunts. Management of these conditions may contribute to prevention of future uroliths.

A primary goal in urolith prevention is dilution of the urine, which increases frequency of urination and creates a flushing action and dilutes the concentration of stone precursors. There are many ways to try to dilute urine. The primary way is to try to increase voluntary water intake, which can be difficult in some feline patients. Using running water fountains, adding water to the food, feeding a canned diet, increasing the frequency of meals, and decreasing calories can all be strategies to dilute urine. Additionally, increasing the number of litterboxes available and utilizing pain medication for arthritic cats may also help to increase the frequency of urination. Diluting the urine can be difficult in some cats and multiple strategies may need to be used concurrently to maximize success.

He C, Fan K, Hao Z, et al. Prevalence, risk factors, pathophysiology, potential biomarkers and management of feline idiopathic cystitis: an update review. 

https://doi.org/10.3389/fvets.2022.900847

Dorsch R, Remer C, Sauter-Louis, et al. Feline lower urinary tract disease in a German cat population. 

Kopecny L, Palm CA, Segev G, et al. Urolithiasis in cats: Evaluation of trends in urolith composition and risk factors (2005-2018). 

https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/jvim.14559

Dunn M, Kornya M, Lulich J. 2022 AAFP consensus statement: Approaches to urolithiasis treatment. Available at 

https://catvets.com/public/PDFs/Consensus%20Statements/Consensus%20Statement%20Urolithiasis%20FINAL.pdf

Lulich JP, Berent AC, Adams LG, etc al. ACVIM small animal consensus recommendations on the treatment and prevention of uroliths in dogs and cats. 

Boatright, a 2013 graduate of the University of Pennsylvania, is a practicing veterinarian and freelance speaker and author in western Pennsylvania. She is passionate about mentorship, education, and addressing common sources of stress for veterinary teams and recent graduates. Outside of clinical practice, Dr. Boatright is actively involved in organized veterinary medicine at the local, state, and national levels.

Articles

Uroliths are one potential cause of lower urinary tract signs in cats. Management varies by type but can be guided by clinical suspicion based on appropriate history, signalment, and diagnostics.

Tips for managing feline urolithiasis from a feline practitioner 

At the 2022 Fetch dvm360® Conference in San Diego, California, Ashley S. Bourgeois, DVM, DACVD—also known as “The Derm Vet”—shared expert advice for general practitioners on successfully flushing ears in the hospital setting.

 Some of the goals of ear flushing include relieving discomfort, removing debris, and eliminating infection. Additionally, “Flushing is not just therapeutic, but it also serves as a diagnostic,” said Bourgeois.

She noted the importance of having a variety of at least 3 to 4 ear flushes at the practice that work for you and can tailor to each patient’s needs. Before selecting the cleanser, perform swab cytology, identify which flush to use based on the infection and inflammation, and evaluate the debris. “I select my flushes based on what’s going on in that ear. If there’s a bunch of [rod-shaped bacteria] in that ear, I’m going to pick a way different flush that’s going to help me with that infection versus if it’s a bunch of Malassezia.”

Active ingredients in ear flushing products to be mindful of depending on your case include:

Bourgeois advised to incorporate a combination of techniques for the best result. For large debris she recommends using: 

Ear curette: Can scrape off debris adhered to the deep ear canal or tympanum

Bulb syringe: Can be forceful, so take sterile saline or water, keep the bulb clean, and rinse until solution is clear

For small debris, she recommends using the red rubber feeding tubes, and noted that 8F is what is used in a handheld otoscope and 5F is used in a video otoscope (VO). These tubes can be attached to the syringe for flushing. Bourgeois is a strong proponent of using the VO as this tool improves the image and provides intense lighting so you can view the tympanum and detect better what is going on in the ear.

To begin flushing, start with a cerumenolytic to loosen debris, flush with a sterile saline, follow up with a disinfectant, and visualize with the otoscope after cleaning.

Because tube flushing is very stimulating for pets, Bourgeois suggested to use sterile saline at room temperature, so its not as shocking for them. She added that multiple flushes are required and to use a bowl of flushing solution or ear flushing units. “The benefits of [ear flushing units] are that with the push of button you’re flushing or your sucking,” she noted. Having patients under general anesthesia is ideal to help to avoid stimulation and it protects the pharynx. However, according to Bourgeois, “In the real world, not everyone can afford to do general anesthesia every time they do an ear flush so one thing you can do to kind of help is elevate. If you have a wet table, you can put some towels under it so then at least if there is fluid that ends up in the pharynx or oral cavity, gravity will help us out a little bit.”

Some adverse effects of ear flushing can include hearing loss, vestibular signs, and Horner’s syndrome. “You want to inform owners of the [risk of developing Horner’s syndrome], usually if that happens, with time and supportive care and steroids to decrease inflammation most of [these patients] will resolve, but it’s something you want to let them know about because it’s really scary when it happens,” said Bourgeois.

Bourgeois also emphasized further educating clients on at-home ear flushing techniques as regular cleaning improves efficacy of topical antibiotics, treats active infections, and maintenance therapy is important particularly for chronic otitis cases. She advised to provide clients resources or have veterinary staff inform them for success in between veterinary visits. 

Bourgeois A. Don’t forget to flush! Deciphering ear flush ingredients and selecting appropriate techniques. Presented at: Fetch dvm360® Conference; San Diego, California. December 2-4, 2022.

Your go-to guide for performing successful ear flushes at the clinic

Ear flushing tips and tricks for the general practitioner

Well, I had to bring our panelists back up. So we can have some final closing remarks, too. So Dr. Grimes, any final closing remarks, comments?

Carolyn Grimes, DVM, DACVP (Clinical Pathology): 

Yeah, I want to say I love how well it the cases that came up today demonstrate this concept of the right test being chosen at the right time for the right patient, that concept of diagnostic stewardship. And anyone who's talked to me knows that I really believe that being a GP veterinarian is one of the hardest jobs in the world. What other doctor is expected to in the course of a single day, manage an unregulated diabetic, diagnose glaucoma, do a wellness visit on a one year old puppy, then, you know, do a splenectomy and oh, by the way, a hit by car just came in, not to mention the the emotional roles and business roles that they're expected to play. Our medical leadership team, we are passionate about diagnostic medicine, laboratory medicine, we study it, we know it, we care about it. And we are experts in it. And we want to help veterinarians by partnering with them to be...provide the best care they possibly can. I just hope that clinicians understand that we want to partner with you. To help you choose the right test to help you interpret the right test. Nobody expects you to remember everything that you learned in vet school, we have specialists to support that. And we want to provide that for you. And there's just so much more information you can get out of your diagnostic lab by picking up the phone calling talking to a specialist and letting us letting us help help you and the other thing that I want to mention is that A lot of veterinarians aren't aware that human laboratory medicine that the quality standards are federally regulated. What those standards are, and how they're met is, is regulated by accrediting bodies, such as the College of American Pathologists. in veterinary medicine, quality standards are not mandatory, they're not regulated. It's up to each diagnostic laboratory to decide what quality standards are going to uphold. The ASPCP, the American Society for Veterinary Clinical Pathologists, is starting to develop the standards on these guidelines for quality standards in laboratory medicine. But these set of standards is, in its essence, its beginnings. So they're not nearly as comprehensive as as they are for human medicine. Where the ASPCP has determined guidelines for quality standards, we follow those and where those standards don't yet exist in quality medicine. We model our quality management system after the College of American Pathologists, which is the the human, the human gold standard.

Oh, wow. Fantastic. Thank you for sharing all that. It's wonderful. Dr. Brent? Yeah, any final comment you'd like to share?

Laura Brandt, DVM, MS, DACVP (Clinical Pathology): 

Yeah, I just want to remind folks that when they're thinking about their CBC, what type of CBC is appropriate for what patient? If you have a sick, elderly patient, you really need to have that blood smear examined. I think it's great for all patients, but especially in those specific populations. So definitely opt for that comprehensive CBC that evaluation. And if you're inclined to please, please, please also make your own blood smear and send that along with your EDTA sample so that we can get the freshest possible sample to look at assess some of these morphological changes.

Beautiful feather edge too. Yes, Dr. Rankin.

So I'd like to just follow up on what Dr. Grimes said about quality. The Veterinary Antimicrobial Susceptibility Testing Committee for the Clinical Laboratory Standards Institute have put together a really great document. It's called vet or name. And it is available for veterinarians to purchase so that they can understand how we do what we do in a clinical microbiology lab. Or you can just send your specimens to the clinical microbiology lab as a way as reference labs, and we can take care of all of that hard work for you.

Oh, nice. Wow. Thank you. Thank you so much. Wonderful. And finally, Dr. Gailbreath.

Yeah, I think my take home message would be to get to know your pathologist and try and build that kind of community and stewardship relationship that we've been talking about. Pathologists like to get to know clinicians and we like to talk to the same clinicians more than once. And so please get to know somebody that you'd like to send stuff to that applies to dermatopathology and any kind of pathology or any kind of cytology, you know. And ask. The other thing about that is, is when you have that relationship, it's a lot easier to provide your pathologist with the information that they need there, they're going to be able to get in touch with you easier and find out the questions and answer the questions that they might have. So that that relationship building is a huge thing for diagnostics in general, but about for pathology.

It's all about that collaboration because you know, teamwork makes the dream work. Well, we want to thank our friends at Zoetis and also our esteemed colleagues here for the sharing their insight with their great cases and feedback. This has been fantastic. Thank you so much for tuning in. And we'll see you right here next time here at dvm360.

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Final thoughts from the panel on how Zoetis Reference Laboratories differentiates itself from the competition

Closing words from the Zoetis Reference Labs team

So you have a case that you're gonna present with us, too. So you could walk us through the journey of that case, right. So tell us about it.

Yeah, so this was a seven year old Golden Retriever named Lily. And she came in to the clinic with a long history of allergic dermatitis. And it had originally responded to some some treatments and then wasn't responding so well. And so that's kind of the time when you start thinking about a biopsy with a derm case. And so they biopsied it and sent it into the lab and probably didn't indicate that they wanted a dramatic pathologist potentially on the on the form. And so it went to a pathologist, and they read it out as this is getting technical superficial perivascular dermatitis, which is a very common reaction pattern that's consistent with allergies, but doesn't give you a whole lot more information. So that's, that's what came out on the report. And then so the clinician saw that and said, "Okay, well, that's kind of what I thought was going on, but it's still not responding clinically. So this isn't making sense." So they refer that case to a dermatologist. And the dermatologist said, "Okay, this isn't making sense. I want somebody who specializes in dermatopathology to look at this case." So they got to re cut and send it to me. And I and I looked at the case and the other thing that that clinician did was gave me a lot more detailed history than the original pathologist probably had on that case, a really good description of all the lesions, a really good description of what drugs were used and whether or not the patient responded. And so I got all that information. And I looked at it, and I, I saw what wasn't there instead of what was there. So it's really easy to look for the inflammation that's there and focus on the things that are that are not supposed to be there that are, but in this case, the interesting key, which is something that a person with a lot of dermatopathology experience picks up on a little bit easier than someone who doesn't look at it a lot was what wasn't there in this case. So there were no sebaceous glands, which is what happens in a condition called sebaceous adenitis. And so that was the key. And so this dog had allergic dermatitis, but it also had sebaceous adenitis. And so sending that sample in with a little bit more history that pointed to some of these things that didn't make sense with allergies, and then also making sure it went to someone with some dermatopathology. Experience and interest really helped.

So my two key takeaways from that history, history, history.

And pictures, images, right, too? Is it a requirement to submit pictures to a dramatic pathologist prior to submitting?

So it's not. I mean, we'd like to say, yes, it's a requirement, you absolutely have to Yeah, sure. Yeah. I mean, we're gonna read the case, if we don't get clinical images, for sure. And but I think sometimes the dermatologists and even the dermatopathologist, if it's a case, it's really not making sense, and we really feel like those clinical images would help us, we will call and ask for him, yes, and even even images taken by the owner, because by this time that the patient's not in hospital anymore. So the owner can take some, you know, everybody has a cell phone and send those in those help. So...

Yeah, it's such a great case of just collaboration overall, you know, we were talking just earlier with the panelists, you have the dermatopathologist such as yourself reviewing the case. That dermatologist, the referral veterinarian, you know, so it's just a great, I just love the teamwork approach to veterinary medicine. And that's just such a great example that that shows that.

Yeah, and I think one of the take homes, that I think, kind of how could this case have gone better? And what was in a perfect world? How can this have really worked out not having to send for a second opinion, you know, we prefer not to have to do that, if we can, we'd like to get it. The first time is to make sure that if something doesn't make sense, when you get the result back to call your pathologist and ask. And as pathologists, we're always happy to get a second opinion. You know, I think sometimes people feel like if you ask for a second opinion, that's like, insulting in some way. And it's totally like, we want to we want to talk to people about cases, we want to talk to our colleagues about cases. So I'm always calling talk to your pathologist about things that don't make sense. And so at us, we, I mean, it's great to talk to clinicians, we talk to each other all the time, we like to have new new voices in the fray. So we really like to talk to people about the animals they're touching every day.

So Oh, that's fantastic. Well, thank you so much, Dr. Gailbreath.

A closer look at how the relationship between GP and dermatopatholgist can enhance patient care

See how a dermatopathologist helped zero in on a diagnosis in this case study

James Smith-Williams and a dog at a local shelter in Arlington, Virginia (Images courtesy of Purina).

James Smith-Williams, defensive end for the Washington Commanders, wore custom-made cleats during his game against the New York Giants in support of The Purple Leash Project as part of the My Cause My Cleats campaign. The Purple Leash Project is a national initiative established by Purina and the nonprofit RedRover in 2019 to provide grants, resources, and support to help domestic violence shelters be better equipped to serve the needs of domestic abuse survivors with pets.

"Over the past several months, I've had the opportunity to partner with Purina and RedRover to see the pet-friendly shelters and services the Purple Leash Project provides for domestic violence survivors and pets," said Smith-Williams, in an organizational release.

 "As a pet owner and domestic violence advocate, I'm honored to lace up on December 4 in support of the Purple Leash Project, further spotlighting the issue and the critical importance that pets play in the lives of survivors as companions, healers, and four-legged family members."

James Smith-Williams custom-designed cleats highlighting the Purple Leash Project

 the My Cause My Cleats program lets players pick a cause important to them and they represent that organization through custom-design cleats on game day during week 13. Then, all players can donate the cleats to an action where fans can place bids on the cleats. 100% of the proceeds from the auction go toward each player's organization. For Smith-Williams, the proceeds raised from his cleats auction will go to the Purple Leash Project.

"James shares our passion for pets and supporting survivors, he's been an integral part of the Purple Leash Project off the field this year," said Nina Leigh Krueger, CEO, and president of Purina. "We're excited to see James lace up his Purple Leash Project cleats in support of domestic violence survivors with pets on the field this Sunday. By working together, we can continue to broaden conversations around this issue and help more survivors and their pets escape abuse and heal together."

Bids for the cleats will be accepted through December 11, 2022, on the Washington Commanders' website.

PURINA AND REDROVER TAKE THE FIELD WITH WASHINGTON COMMANDERS' JAMES SMITH-WILLIAMS TO SUPPORT DOMESTIC VIOLENCE SURVIVORS AND PETS DURING MY CAUSE MY CLEATS CAMPAIGN. News release. Purina. December 2, 2022. Accessed December 5, 2022. 

https://prnmedia.prnewswire.com/news-releases/purina-and-redrover-take-the-field-with-washington-commanders-james-smith-williams-to-support-domestic-violence-survivors-and-pets-during-my-cause-my-cleats-campaign-301692188.html

The Washington Commanders' defensive end wore custom cleats over the weekend in support of The Purple Leash Project 

James Smith-Williams supports The Purple Leash Project during the My Cause My Cleats campaign

Keynote speaker Dr Mariana Pardo (left) all smiles before her presentation with dvm360® chief veterinary officer Dr Adam Christman (right).  

According to Mariana Pardo, BVSc, MV, DACVECC, it’s a recurring theme in history for people to be hesitant to implement new technology in medicine because they find it cumbersome. She began her keynote presentation

 on the final day of the Fetch dvm360® conference in San Diego, California, by quoting John Forbes in the 1800s and his thoughts on the stethoscope at the time: “That it will ever come into general use, notwithstanding its value, is extremely doubtful; because its beneficial application requires much time and gives a good bit of trouble both to the patient and the practitioner.” Now the stethoscope is universally used for each visit in both human and veterinary medicine, and Pardo aims for the same to be done with the ultrasound.

Therefore, she outlined the basics and practical skills for incorporating point of care ultrasounds in daily practice to bolster patient care. “There’s so much information that you can get from using ultrasounds on your day-to-day basis and it might seem that it requires a lot of knowledge, but I’m going to try to simplify it for you and show you how much information you can garnish that will just become complementary to what we are doing,” Pardo said.

Pardo recommended to first choose the appropriate ultrasound probe based on the application:

: applications for soft tissue, musculoskeletal, pediatric, ocular, thyroid, thoracic, most procedures, DVT, appendicitis, testicular

Features include: high-frequency transducer, best resolution out of all probes, shallow structures, and rectangular field

: applications for general abdomen (ig, gallbladder, liver, etc), eFAST, renal, aorta, IVC, bladder, bowel, OB/Gyn

Features include: low-frequency transducer, large/wide footprint (better lateral resolution), curved field, deep structures

 (also called “cardiac probe”): applications for cardiac, abdominal, eFAST, renal, bladder, bowel, IVC

Features include: low-frequency transducer, small and flat footprint (easier to get between ribs), and deep structures

There are 4 main movements when performing ultrasounds including to slide, tilt, rotate, or rock it back and forth.

“Start getting used to using your hands with ultrasounds, practice on every single patient. If you don’t recognize normal structures, how are you going to recognize a patient who’s not doing well? So honestly for me, my ultrasound exam is part of my whole physical exam.”

: After turning on the ultrasound machine, select the correct ultrasound transducer you will need.

: Select the correct application preset for that transducer.

: Adjust the depth, meaning how deep you want to be able to scan. The right side of the screen will have dots or lines that correspond to the depth in centimeters.

: Adjust your gain, meaning how bright or dark you want the image to appear. This increases or decreases the strength of the returning ultrasound signals that you visualize on the screen.

“You want to try to have the place of interest you’re looking at to be in the center of the screen,” Pardo advised. “Once you get that image where you want, then you’re going to keep that depth at that point and normally you can just scroll up and down and that’s going to show you measurements of how deep you are.”

To conclude, Pardo summarized that using point of care ultrasounds requires an understanding of it and how to use all the knobs and settings. Not to mention, practice makes perfect when it comes to identifying normal versus abnormal structures to offer patients the most high-quality care. 

Pardo M. Hocus Pocus! Integrating ultrasound in your day-to-day practice. Presented at: Fetch dvm360® Conference; San Diego, California. December 2-4, 2022.

Fetch San Diego keynote speaker Dr Mariana Pardo breaks down performing ultrasounds to encourage their use on each patient 

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