Webinar: What's all the F.U.S.? It hurts when I pee! — Q&A follow-up



Lower urinary tract signs in cats are often attributed to crystals, stones and infection, but idiopathic disease is more common. 

In a 2-hour CE webinar sponsored by Blcare Lab, Margie Scherk, DVM, DABVP (feline practice) examined the most common causes of the syndrome of lower urinary tract disorders in cats (click here if you'd like to view the on-demand webinar). 

Following are the audience questions posed at the end of the webinar, along with Dr. Scherk's responses.  

Does a relationship exist between age of neutering and male cats' tendency to develop urinary tract obstructions?


Dr. Scherk: We used to believe this, but it has been shown that age at neutering does not affect cats' urethral width or risk of urinary tract obstruction.1


It seems like I've seen fewer urinary tract infections in cats overall, but I got three calls on Sunday in my emergency triage job related to blocked male cats. Do diet choices make any difference?


Dr. Scherk: Diet choices help, but are not a guarantee. Certain diets can help reduce urine specific gravity and mineral saturation and neutralize pH, but some cats are predisposed to urinary tract disorders. A susceptible individual in a provocative environment, such as a stressful situation and season or weather change, may exhibit cystitis, and any cystitis has the potential to result in obstruction. 


Which NSAID is your first choice for pain relief in cats with urinary signs?


Dr. Scherk: Meloxicam or robenacoxib. I have less experience with robenacoxib and like that I can more closely adjust the meloxicam dose. And I've seen more data on using meloxicam in cats perioperatively, and on using it long-term in cats with arthritis, even those with chronic kidney disease.2-5


Can you provide more specific analgesic recommendations?


Dr. Scherk: This depends on the condition being treated. In general, I may combine an opioid (such as injectable or transmucosal buprenorphine) plus an NSAID (such as meloxicam or robenacoxib) and, if the cat is obstructed, then I would add a urethral relaxant. I treat cats for at least five days (sometimes 10 days) to allow the pain, inflammation, and urethral spasm to resolve.


Do you use olive-tip catheters?


Dr. Scherk: When relieving a urethral obstruction in a male cat, olive-tip catheters are an excellent first device because they are rounded, smooth and short. In most cases, should you need to pass a catheter, you will need to follow up with a soft, nonreactive indwelling catheter made of silicone. 


Many owners decline urine bacterial culture because of the cost.  You mentioned using amoxicillin or sulfamethoxazole and trimethoprim. How do you feel about using injectable cefovecin if we have a reasonable suspicion of a urinary tract infection?  


Dr. Scherk: Cefovecin sodium is a third-generation cephalosporin with a broader spectrum and longer duration (21 days in cats) of activity than is typically needed and is not recommend for routine use.6 It should be reserved for use in cases in which other treatments are ineffective or oral treatment is not possible.6Enterococcusspecies are resistant to cefovecin.6 To avoid contributing to bacterial resistance to antimicrobials, it is important to use the correct antibiotic-for a confirmed and clinically relevant infection with a sensitive organism-for the correct duration.6,7


Whether bacterial culture is performed or not, analgesic therapy (e.g., an NSAID) should be initiated until culture results are received.6 If clients decline a urine bacterial culture, then I use amoxicillin or sulfamethoxazole and trimethoprim for three to five days. If bacterial cystitis recurs, the underlying cause should be sought. Repeated antimicrobial administration is unlikely to provide long-term cure. When bladder wall invasion is suspected, three to five days of treatment is reasonable unless persistent infection is suspected, in which case a seven- to 14-day course of therapy is warranted. I don't recommend amoxicillin-clavulanate because high concentrations of amoxicillin are achieved in the urine and evidence for any benefit from using clavulanic acid is lacking.


Explain to clients that urine bacterial culture and sensitivity testing helps them avoid paying for and using a drug that may be ineffective or have other potential problematic consequences.


Please see: https://catvets.com/guidelines/practice-guidelines/antimicrobial-in-cats


Can we use Kit4Cat (Coastline Global, Inc.) on a regular basis to monitor for hematuria?


Dr. Scherk: Kit4Cat is a hydrophobic sand that makes collecting cat urine at home easier. This is valuable for performing a complete urinalysis, but to monitor for hematuria, it may be excessive. The client needs a special litter, and has to have, store, and read separate urine test strips or bring the urine in for evaluation. In addition, the urine character changes over time (as occurs with any urine sample, regardless of how it is collected). The cat also must use a different litter rather than its own litter, which could potentially cause stress. 


With Blcare granules, clients can monitor for hematuria without using test strips and timing the color change. Any way that clients can monitor for urine changes (deterioration or improvement of the condition) gives them a sense of control and confidence. 


What are the histopathologic findings in cats with idiopathic cystitis?


Dr. Scherk: In short, histopathologic changes are generally nonspecific, and may include an intact or damaged urothelium with submucosal edema with minimal cellularity. But recently this has been extensively evaluated.8 


I was always warned against performing a cystocentesis on a blocked cat, yet you recommend it?


Dr. Scherk: Like you, I used to be leery of this. However, when a cat is obstructed, reducing pressure on the bladder, urethra, ureters and kidneys may be the most urgent need, and this can be done most quickly through decompressive cystocentesis. It provides relief of discomfort and, in most cases, the bladder won't rupture.9,10 If it does, it may have already been so friable that it would also have ruptured during the time needed to sedate and prepare the patient to pass a catheter. And passing a catheter is also not a risk-free procedure. By decreasing pressure on the kidneys and buying time to correct electrolyte imbalances and stabilize the patient, the outcome with decompressive cystocentesis could be more favorable. In fact, in many cases, urethral catheterization may be avoided completely. 


By reducing intravesicular and urethral pressure, passage of a urethral catheter may not be needed if urethral spasm and inflammation are the cause of the functional obstruction. Even in cats with mechanical obstruction caused by a urethral plug or urolith, by reducing antegrade pressure, retropulsion of the offending structure may be easier and may reduce the potential for iatrogenic urethral or bladder trauma.  


Can Blcare granules be obtained in the United States?


Dr. Scherk: Blcare is distributed exclusively by Royal Canin and is currently available in Florida. Product distribution will increase to include other states. Ask your Royal Canin representative about availability in your area.


Are nutritional supplements like glycosaminoglycans useful in cats with idiopathic cystitis?


Dr. Scherk: The best answer is that we don't know. They might help in some patients, but if the condition is similar to that in humans, we can say that the syndrome of idiopathic cystitis isn't the same in every patient, despite the clinical signs being the same.


For a cat that has been receiving a therapeutic diet because of struvite crystalluria, can the diet be changed to a non-therapeutic diet if the lower urinary tract signs have resolved and the cat is older than seven years of age?


Dr. Scherk: Possibly. But cats over seven years may still be at risk for calcium oxalate crystalluria or urolithiasis if they tend to form crystals or stones, so it would still be advisable for them to receive a therapeutic diet that promotes neutral urine pH and dilute urine, including a canned diet. 


Is crystalluria with eosinophilia a significant finding in cats with lower urinary tract signs?


Dr. Scherk: Eosinophilia is rarely seen with lower urinary tract signs so is likely unrelated. Eosinophils in the urine are rare and would be abnormal. Even with Capillaria plica infections,eosinophils may not appear in the urine.11 Eosinophils have a predilection for all epithelial surfaces and are present as sentinel cells. 


Is maropitant recommended to help with inflammation? Also, what duration of NSAID administration do you recommend?


Dr. Scherk: Using maropitant for inflammation at any site is theoretical and based on it being an NK1R antagonist. Results from a 2018 study of a mouse model of acute pancreatitis suggested that maropitant provided anti-inflammatory effects.12 I am unaware of studies evaluating the anti-inflammatory effects of maropitant in cats.


Pain differs in each patient. I think cats need an NSAID for at least three to five days, which doesn't differ from the duration of NSAID administration for postoperative analgesia or analgesia needed after dental extractions.


If obesity in cats is a risk factor for idiopathic cystitis, why do you recommend ad lib feeding over meal feeding? Most people aren't home to give a few pieces of kibble several times a day.


Dr. Scherk: Obesity isn't related to how often cats eat, but rather how much they eat. Feeding puzzles are an excellent way to help divide the daily caloric requirement into small portions that the cat nibbles on throughout the day, and they give cats something to hunt. Or place eight small plates with 10 to 15 pieces of kibble on each one throughout the house. Please see: http://foodpuzzlesforcats.com and https://catvets.com/guidelines/practice-guidelines/how-to-feed.


Where can I find the client handout on household resources for cats that you mentioned?


Dr. Scherk: https://files.brief.vet/migration/article/7256/household-resource-checklist-7256-article.pdf


For idiopathic cystitis or most blocked cats, do you prefer decompressive cystocentesis?


Dr. Scherk: Cats with idiopathic cystitis usually have a tiny bladder (urinating small amounts frequently), so decompressive cystocentesis isn't needed. Decompressive cystocentesis can be used in cats with obstructions caused by uroliths or urinary plugs from other debris. 


How can we increase these cats' water intake? I have heard of water additive products that increase water viscosity, or that increasing dietary salt helps. Is one method preferred over others if the cat doesn't readily drink water or prefers dry food?


Dr. Scherk: Use wide, large bowls (glass, metal or ceramic) filled with fresh, clean water. Clean the bowl and replace the water every few days. Some cats like ice cubes added to water, or flavored water (i.e., chicken, meat, fish broth) added, or circulating water fountains. Do not place water bowls near food, litter, appliances that make noise unexpectedly, or areas where cats might feel vulnerable to other cats, dogs or people. 


I am not aware of products that make water more viscous. I wonder whether such an alteration might be off-putting to cats.Adding salt is controversial. For cats that eat only dry food, try mixing a tablespoon of moist food with the dry, and if the cat accepts that and eats some of the moist food, then gradually increase the proportion of canned food added.


I always try a two-week course of analgesia for a declawed cat exhibiting signs of idiopathic cystitis (with no history of feline urologic syndrome and no response to 30 days of anxiolytic treatment). This can save a life!


Dr. Scherk: Better still, don't declaw cats. But in the case you are describing-i.e. a cat that has already been declawed and is eliminating inappropriately-I agree completely. Gaynor et al recommend a minimum of 21 days of analgesic treatment.13 It can take a long time to alleviate neuropathic pain. Using opioids plus NSAIDs plus an NMDA receptor antagonist together is likely to provide the best effect.


What psychogenic medication do you recommend, and what is your experience with bovine-sourced hydrolyzed milk protein? Also, if a cat has urethral obstruction but no crystalluria, do you still recommend a therapeutic urinary tract diet, or do you focus on environmental enrichment and behavior? What about calm/urinary diets?


Dr. Scherk: If crystalluria is absent but obstruction is present, the obstruction can still be mechanical (sloughing cells, plugs, calculi) or functional (urethral spasm). In either case, addressing environmental needs is indicated. Behavior-modifying agents may also be helpful but should be used in conjunction with behavioral and environmental modifications, not on their own, as tempting as it is to simply prescribe a pill. The appropriate behavior-modifying drug varies with the circumstance. For example, if the cat that is spraying or who has idiopathic cystitis is insecure, buspirone hydrochloride may be indicated. However, if the cat is overly confident, then fluoxetine may be best, or paroxetine, under other circumstances. One drug doesn't fit all in cats, just as it doesn't in people.


Please see: https://catvets.com/guidelines/practice-guidelines/house-soiling


Using a diet containing L-tryptophan and alpha-casozepine or using bovine hydrolyzed milk protein on its own may be beneficial, too. Such calming diets are designed for urinary tract health (appropriate pH and lower mineral saturation) as well. Be cautious about making too many diet changes or making them abruptly, as this can contribute to cats' stress. 


How do you motivate clients who tend to give up trying to prevent idiopathic cystitis, then come back to the clinic months later and complain we didn't do our job?


Dr. Scherk: This is where having a way to monitor for the recurrence of hematuria at home to help identify when or whether a cat is stressed is a great tool. You still have to help clients understand the role of environment in allowing their cat to express species-appropriate behaviors. Compliance is tricky because all the education in the world won't work unless the client has an active understanding, is engaged (i.e., wants to be part of the solution), and can perform what is required. For some clients, successful outcomes require education along with follow-up and support from the clinic.


How long do you wait until you catheterize a cat?


Dr. Scherk: As a general rule, a few hours. If a cat is really distressed, I give sedation first, but otherwise I perform decompressive cystocentesis first to relieve the pressure and pain and obtain a urine sample. Then I place an intravenous catheter, collect blood, and start a balanced electrolyte solution, the composition of which depends on the cat's heart rate. (If clients have financial constraints, I give subcutaneous fluids and omit the blood tests because I can gauge serum potassium concentration based on heart rate because hyperkalemia [the only time potassium would be contraindicated] causes bradycardia.) Next, I give an opioid (buprenorphine), a single dose of meloxicam at 0.05 mg/kg, and start relaxants (midazolam and prazosin). I place the cat in a quiet, dimly lit space where the cat can hide but still be observed.


Please see: https://todaysveterinarypractice.com/feline-urethral-obstruction-diagnosis-management/


Do you have a favorite anesthesia protocol? I work in emergency practice and frequently see blocked cats.


Dr. Scherk: The anesthetic protocol will differ with the patient, as some cats are more fragile or have comorbidities. 


Is the high salt content of Royal Canin Feline Urinary SO dry diet a concern if fed long-term?


Dr. Scherk: AAFCO maintenance trials were performed on Royal Canin Urinary SO and the company positions this diet as designed and safe to be fed long-term. The sodium levels in the Urinary SO formulas fall within the safe limits for cats recommended by the National Research Council (NRC 2006) and FEDIAF Nutritional Guidelines 2016. A recent review on sodium in cats indicated that there is no evidence of any deleterious effects of a moderate increase in dietary sodium in cats.14


The Royal Canin Feline Urinary SO + Calm diet is also designed to be fed as a maintenance diet and would be good for a urolith-prone cat living in a stressful situation such as a multicat indoor household. As needs change in older pets, the Royal Canin Feline Urinary SO Aging 7+ + Calm diet is also positioned as a maintenance diet designed to provide the same calming benefits and urinary protection for senior cats, including cats with early International Renal Interest Society (IRIS) stages of chronic kidney disease.


Which spasmolytics do you use? Do you use prazosin, bethanechol or benzodiazepines?


Dr. Scherk: Acepromazine, phenoxybenzamine, and prazosin are alpha-receptor antagonists and cause smooth muscle relaxation. But because smooth muscle is located only in the proximal portion of the penile urethra, midazolam or diazepam is needed to relax the rest of the urethra, which is composed of striated muscle. One study showed that cats with urinary tract obstruction that received prazosin were less likely to re-obstruct than cats that received phenoxybenzamine – possibly due to the more rapid onset of action of prazosin.15


If the bladder doesn't contract properly when empty (atony), then I add bethanechol.


After the obstruction is relieved, prazosin with a benzodiazepine should be continued for at least five days.


Can you tell us how to do a Wright block?


Dr. Scherk: Please see: O'Hearn AK, Wright BD: Coccygeal epidural with local anesthetic for catheterization and pain management in the treatment of feline urethral obstruction. J Vet Emerg Crit Care 2011;21(1):50–52) doi: 10.1111/j.1476-4431.2010.00609.x  

Also see: https://www.youtube.com/watch?v=_oruduRgYkU


Where can I obtain more data pertaining to Blcare granules?


Dr. Scherk: Questions about internal data, property of BlcareLab, can be sent to: info@blucarelab.com. 


What is the difference between Pandora syndrome and idiopathic cystitis?


Dr. Scherk: Pandora syndrome refers to a cluster of comorbidities, one of which may be Idiopathic cystitis. Pandora syndrome is believed to occur as a result of neurologic, endocrine and immune system crosstalk in utero and beyond. This results in chronic clinical signs referable to many organ systems. Please see: https://todaysveterinarypractice.com/feline-medicine-pandora-syndrome-in-cats-diagnosis-and-treatment/



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