{"topic_id":"evidence_feline_urolith_diet","category":"evidence","context":"---\ntopic_id: evidence_feline_urolith_diet\ncategory: evidence\ntitle: Evidence cluster — dietary management of uroliths in cats (peer-reviewed, Europe PMC + PubMed)\nlang: en\nsource_file: pdf-raw/evidence/europepmc_feline_urolith_diet_2026-07-22.txt\nsource: Europe PMC REST search (first-hand PMIDs) + PubMed efetch verbatim abstracts, pulled 2026-07-22\ndate_parsed: 2026-07-22\nmodel: codebuddy\nbatch: P0-EVIDENCE-6\nverified: 2026-07-22 substring_match 24/24 claims passed\npath: evidence/evidence_feline_urolith_diet/01_feline_urolith_diet.md\n---\n## Representative peer-reviewed studies (verbatim abstracts)\n\nThe following studies were retrieved from Europe PMC / PubMed and are reproduced verbatim. Interpretive synthesis is left to the API user.\n\n### PMID:41950383 — Revisiting feline urinary tract health: the role of diet and acidifying agents in urolith prevention and long-term cat health.\n- Source: J Anim Sci 2026\n1. J Anim Sci. 2026 Jan 8;104:skag115. doi: 10.1093/jas/skag115.\n\nRevisiting feline urinary tract health: the role of diet and acidifying agents \nin urolith prevention and long-term cat health.\n\nPezzali JG(1), Liu G(1), Chen Y(1), Kuhlman G(2).\n\nAuthor information:\n(1)Department of Grain Science and Industry, Kansas State University, Manhattan, \nKS, 66506, United States.\n(2)GXK Consulting LLC, Summerville, SC, 29486, United States.\n\nUrinary tract diseases are a common concern in domestic cats and a leading cause \nof veterinary visits. Urolithiasis is a major contributor to discomfort, \nclinical signs, and secondary complications, negatively impacting feline health \nand welfare. Diet is a manageable risk factor that can be leveraged in \ncommercial formulations to support urinary tract health and reduce urolith risk, \nparticularly struvite. Nutritional interventions primarily influence three \ninterrelated determinants of urolith formation: urinary pH, urine solute \nconcentrations, and crystallization potential. Controlled dietary acidification \nis central to struvite prevention, supporting the controlled use of urinary \nacidifier agents in cat food (eg DL methionine, sodium bisulfate, phosphoric \nacid, calcium sulfate) as an effective strategy. While the prevalence of \nstruvite stones in cats declined from the mid-1980s to the 2000s as scientific \nknowledge of such dietary strategies in commercial cat food has evolved, recent \nU.S. reports show an increase in struvite stones, warranting attention to the \npotential impact of commercial diets on this outcome. Regarding urinary \nacidifier agents, excessive intake of certain compounds (eg inorganic phosphorus \nor DL-methionine) raises potential long-term health concerns. At the same time, \n\"clean label\" trends may discourage efficacious acidifiers with no health \nconcerns, including sodium bisulfate, which can both acidify urine and, via its \nsodium content, support water intake. Predictive equations can help estimate \nurinary pH during cat food formulation. Still, they do not capture critical \nfactors, such as water intake and feeding behavior. Consequently, in vivo \nevaluation remains the gold standard, albeit costly and time-consuming, making \nit challenging for universal adoption in the industry. Additional challenges \nfaced by the sector include variability in mineral composition across \ningredients, limited data on mineral bioavailability, nutrient interactions, and \nother factors that affect the post-prandial concentrations of specific minerals \nknown to impact urolith formation. This review discusses the etiology of feline \nurolith formation, evidence-based dietary interventions, and the efficacy and \nsystemic effects of commonly used urinary acidifier agents, as well as \nchallenges in formulating commercial cat foods targeting urinary tract health, \nincluding precise nutrient balancing and regulatory considerations to support \nurinary tract health claims.\n\nPlain Language Summary: Urinary tract diseases are a frequent health issue in \ncats and a common reason for veterinary visits. A major concern is urinary stone \nformation, which can cause discomfort and clinical signs in cats. Diet is a \npractical way to support urinary tract health and lower the risk of urinary \nstone formation, especially struvite stones. Many commercial cat foods have \nadopted strategies to support urinary tract health. These typically aim to keep \nurine slightly acidic, balance mineral levels, and support hydration to increase \nurine volume and reduce solute concentration. However, prioritizing these \noutcomes in formulation may not always align with marketing goals for other \nproduct claims. Current trends toward clean-label formulations may reduce the \nuse of synthetic urinary acidifiers, ingredients that help lower urine pH and \nhave proven efficacy. At the same time, some acidifiers may have potential \nadverse health effects, and their long-term effects in cats are not well \ncharacterized, while others do not pose this concern but may not be perceived \nwell by consumers. Consumer education and continued research into alternative \ningredients and formulation strategies are warranted. Above all, prioritizing \nurinary tract health in formulations is essential to support the health and \nwell-being of cats.\n\n© The Author(s) 2026. Published by Oxford University Press on behalf of the \nAmerican Society of Animal Science. All rights reserved. For commercial re-use, \nplease contact reprints@oup.com for reprints and translation rights for \nreprints. All other permissions can be obtained through our RightsLink service \nvia the Permissions link on the article page on our site—for further information \nplease contact journals.permissions@oup.com.\n\nDOI: 10.1093/jas/skag115\nPMCID: PMC13129198\nPMID: 41950383 [Indexed for MEDLINE]\n- Abstract (verbatim excerpt): \nJOURNAL:J Anim Sci 2026\n1. J Anim Sci. 2026 Jan 8;104:skag115. doi: 10.1093/jas/skag115.\n\nRevisiting feline urinary tract health: the role of diet and acidifying agents \nin urolith prevention and lon\n\n### PMID:41965667 — Aerococcus mictus as a cause of feline urinary tract infection: a case report.\n- Source: BMC Vet Res 2026\n1. BMC Vet Res. 2026 Apr 11;22(1):300. doi: 10.1186/s12917-026-05462-3.\n\nAerococcus mictus as a cause of feline urinary tract infection: a case report.\n\nUva A(1), Pirolo M(2), Cavalera MA(3), Tanas G(3), Guardabassi L(2), Zatelli \nA(3), Gernone F(3).\n\nAuthor information:\n(1)Department of Veterinary Medicine, University of Bari, Valenzano, Italy. \nannamaria.uva@uniba.it.\n(2)Department of Veterinary and Animal Sciences, University of Copenhagen, \nFrederiksberg C, Denmark.\n(3)Department of Veterinary Medicine, University of Bari, Valenzano, Italy.\n\nBACKGROUND: Bacterial urinary tract infections (UTIs) are a noteworthy cause of \nlower urinary tract disease both in humans and companion animals, especially in \npatients with systemic comorbidities or underlying anatomical or functional \nurinary tract abnormalities. Aerococcus species are increasingly recognised as \nopportunistic uropathogens in human medicine; however, their role in UTIs in \ncompanion animals remains poorly characterised. CASE PRESENTATION: The case of a \nneutered male European Shorthair cat with a history of antepubic urethrostomy \nand recurrent lower urinary tract signs, in which urine culture yielded a pure \ngrowth of Aerococcus mictus, is herein described. Species identification was \nachieved by whole-genome sequencing, which underscores the value of modern \ndiagnostic tools in recognizing organisms that are often misclassified by \nconventional methods. The cat was successfully treated with targeted \nantimicrobial therapy. CONCLUSIONS: To the best of our knowledge, this is the \nfirst reported case of A. mictus as a causative agent of UTI in a cat, \nsupporting its potential role as an opportunistic uropathogen in companion \nanimals, highlighting the risk of misidentification among closely related \nAerococcus species, and emphasizing the need for updated MALDI-TOF reference \ndatabases in veterinary microbiology.\n\nDOI: 10.1186/s12917-026-05462-3\nPMCID: PMC13196155\nPMID: 41965667 [Indexed for MEDLINE]\n\nConflict of interest statement: Declarations. Ethics approval and consent to \nparticipate: Not applicable. Consent for publication: Written informed consent \nfor publication of this case report was obtained from the cat’s owner. Competing \ninterests: The authors declare no competing interests.\n- Abstract (verbatim excerpt): \nJOURNAL:BMC Vet Res 2026\n1. BMC Vet Res. 2026 Apr 11;22(1):300. doi: 10.1186/s12917-026-05462-3.\n\nAerococcus mictus as a cause of feline urinary tract infection: a case report.\n\nUva A(1), Pirolo M(2)\n\n### PMID:41641807 — The hitchhiker's guide to feline xanthinuria.\n- Source: J Feline Med Surg 2026\n1. J Feline Med Surg. 2026 Mar;28(3):1098612X261424299. doi: \n10.1177/1098612X261424299. Epub 2026 Feb 5.\n\nThe hitchhiker's guide to feline xanthinuria.\n\nKim MM(1), Velie BD(2), Sheehy PA(1), Courtman NF(1), Pritchard EC(3), Haase \nB(1).\n\nAuthor information:\n(1)Sydney School of Veterinary Science, Faculty of Science, University of \nSydney, NSW, Australia.\n(2)School of Life and Environmental Sciences, Faculty of Science, University of \nSydney, NSW, Australia.\n(3)Animal Referral Hospital, Homebush, NSW, Australia.\n\nFeline xanthinuria is a rare autosomal recessive disorder of purine metabolism \ndue to genetic mutations in the xanthine dehydrogenase (XDH) gene. It is \ncharacterised by excessive excretion and accumulation of xanthine in the urine, \nwhich can lead to the formation of xanthine uroliths. Xanthine uroliths may be \npresent in both the upper and lower urinary tracts, causing clinical signs \nassociated with renal disease and feline lower urinary tract disorders (FLUTDs). \nHallmark diagnostic findings of xanthinuria are elevated xanthine and \nhypoxanthine, and reduced uric acid concentrations in serum and urine. Uroliths \ncan be submitted for compositional analysis to confirm the presence of xanthine \nand definitive diagnosis for xanthinuria. Management involves dietary \nmodification to purine-restricted diets and increased fluid intake. Commercially \navailable renal diets are preferred over urinary diets because of their lower \nprotein composition, and consulting a veterinary nutritionist is strongly \nrecommended. Urinary alkalisation is not considered an effective method for the \ndissolution of xanthine uroliths owing to their poor solubility. Despite these \ninterventions, recurrence of xanthine urolithiasis is possible. Given the \nlimited treatment options and risk of recurrence, feline xanthinuria is a \nlifelong condition that requires ongoing management and monitoring to mitigate \ncomplications. This review will provide an overview of the current understanding \nof the pathophysiological, metabolic and genetic aspects of the disorder and \ndiscuss current diagnostic approaches, management strategies and clinical \nexpectations of feline xanthinuria. Findings from this review highlight the need \nfor greater recognition of feline xanthine urolithiasis as a cause of FLUTD, \ngiven current gaps in diagnostic methods and treatment options. A deeper \nunderstanding of the condition will help veterinarians accurately differentiate \nit from other causes of FLUTD and support further research aimed at improving \nthe detection, prevention and management of xanthinuria.\n\nPlain Language Summary: Feline xanthinuria is a rare inherited condition caused \nby mutations in the xanthine dehydrogenase (XDH) gene, leading to high levels of \nxanthine in the urine. This can result in the formation of xanthine stones \n(uroliths) in the urinary tract causing signs of kidney disease or feline lower \nurinary tract disorder (FLUTD). Diagnosis involves detecting high levels of \nxanthine and hypoxanthine, and low levels of uric acid in blood and urine. \nUrinary stone samples can be submitted for laboratory analysis to confirm \nxanthine composition of the stone. Managing xanthinuria requires a low-purine \ndiet and increased water intake. Renal diets are preferred over urinary diets \nbecause of their lower protein content; seeking advice from a veterinary \nnutritionist is strongly recommended. Unlike other types of stones, xanthine \nuroliths do not dissolve easily; therefore, altering the pH of urine is not \neffective. Even with treatment, stones may recur, making lifelong monitoring \nessential. This review outlines the current understanding of the genetic, \nmetabolic and clinical aspects of feline xanthinuria. It also highlights the \nneed for greater awareness of xanthine uroliths as a cause of FLUTD and calls \nfor improved diagnostic tools and treatment options. Better recognition of this \ncondition will help veterinarians distinguish it from other urinary disorders \nand support future research to enhance care for affected cats.\n\nDOI: 10.1177/1098612X261424299\nPMCID: PMC13018673\nPMID: 41641807 [Indexed for MEDLINE]\n\nConflict of interest statement: Conflict of interestThe authors declared no \npotential conflicts of interest with respect to the research, authorship, and/or \npublication of this article.\n- Abstract (verbatim excerpt): \nJOURNAL:J Feline Med Surg 2026\n1. J Feline Med Surg. 2026 Mar;28(3):1098612X261424299. doi: \n10.1177/1098612X261424299. Epub 2026 Feb 5.\n\nThe hitchhiker's guide to feline xanthinuria.\n\nKim MM(1), Vel\n\n### PMID:40243255 — Cystoscopy-assisted urolith retrieval via a perineal urethrostomy stoma in male cats.\n- Source: J Feline Med Surg 2025\n1. J Feline Med Surg. 2025 Apr;27(4):1098612X251325716. doi: \n10.1177/1098612X251325716. Epub 2025 Apr 17.\n\nCystoscopy-assisted urolith retrieval via a perineal urethrostomy stoma in male \ncats.\n\nCantrall R(1), Langlois DK(1), Antezana A(1), Spinner M(1).\n\nAuthor information:\n(1)Department of Small Animal Clinical Sciences, Michigan State University, East \nLansing, MI, USA.\n\nObjectivesWe sought to characterize cystoscopy-assisted urolith retrieval via a \nperineal urethrostomy stoma (CUPU) initially in a cadaveric model and then in \nclinical cases. We hypothesized that a CUPU would provide a reasonable \nalternative to the traditional approach of performing a cystotomy after perineal \nurethrostomy in male cats with complex or recurrent urolithiasis-associated \nurethral obstruction (UO).MethodsA perineal urethrostomy (PU) was performed in \n20 male cat cadavers. A randomly assigned number of synthetic calculi (SynC) was \nplaced retrograde into the urinary bladder, and an endoscopist blinded to the \nSynC number, performed CUPU using a flexible ureteroscope and basket retrieval \ndevice. Procedure characteristics were summarized with descriptive statistics. \nAfter completion of the cadaver phase, two male cats with naturally occurring \ncomplex or recurrent urolithiasis-associated UO that warranted PU were recruited \nto undergo CUPU. Clinical features and outcomes of these cases were \ndescribed.ResultsFour cadavers were excluded because of urethral tearing during \nSynC placement. A narrow urethral lumen precluded ureteroscope passage in two \ncadavers. In the 14 remaining cadavers, a median of 7.5 SynC (range 3-9) were \nplaced in the urinary bladder. The CUPU median procedural time was 13.2 mins \n(range 6.1-24.0) and all 99 (100%) SynC were successfully retrieved from the 14 \ncadavers. Scope-associated tearing of the urethra or surgical site was not \nobserved in any cadavers. Two client-owned cats with struvite \nurolithiasis-associated UO underwent a PU followed by CUPU. All uroliths were \nsuccessfully retrieved, and periprocedural complications were not observed. Both \ncats had normal stoma sites 4 weeks postoperatively and neither cat had \nowner-reported dysuria 3 months postoperatively.Conclusions and relevanceThis \nstudy highlighted that CUPU is a feasible procedure with the potential to \nobviate the need for abdominal surgery in some cats with cystolithiasis and \nurolithiasis-associated UO that warrant PU.\n\nPlain Language Summary: Urinary bladder stone removal with minimally invasive \nscope technique after an indicated urethral obstruction relieving urinary \nsurgery in male cats.Cats are prone to the development of bladder stones, which \ncan cause various complications, including urinary blockages. Life-threatening \nblockages most often occur in male cats when small stones become lodged in the \nsmall urethra. In some affected male cats with recurrent or refractory disease, \na penile amputation is performed thus enabling urination through the wider \nremaining urinary tract opening (stoma) and decreasing the likelihood of future \nblockages. This surgery is termed perineal urethrostomy. However, most cats that \nundergo perineal urethrostomy surgery still require simultaneous full abdominal \nsurgery to remove the stones that are remaining in the bladder. We sought to use \na minimally invasive technique to remove bladder stones in male cats undergoing \nperineal urethrostomy so that a full abdominal surgery could be avoided. After \nan indicated perineal urethrostomy was performed in selected cadavers and \nclinical cases, the research team used a small fiberoptic camera, an endoscope, \nto evaluate the urinary tract and remove urinary bladder stones. When indicated, \na perineal urethrostomy stoma was capable of accommodating successful endoscopic \nremoval of urinary bladder stones in most patients. No evidence of complications \nwas reported among clinical patients 4 weeks after the procedure. The authors \nhope the newly described technique offers an alternative approach for stone \nremoval in some cases.\n\nDOI: 10.1177/1098612X251325716\nPMCID: PMC12035374\nPMID: 40243255 [Indexed for MEDLINE]\n\nConflict of interest statement: Conflict of interestThe authors declared no \npotential conflicts of interest with respect to the research, authorship, and/or \npublication of this article.\n- Abstract (verbatim excerpt): \nJOURNAL:J Feline Med Surg 2025\n1. J Feline Med Surg. 2025 Apr;27(4):1098612X251325716. doi: \n10.1177/1098612X251325716. Epub 2025 Apr 17.\n\nCystoscopy-assisted urolith retrieval via a perineal urethro\n\n### PMID:40859964 — Lower urinary tract obstruction secondary to <i>Corynebacterium urealyticum</i>-associated struvite urolithiasis in a female cat.\n- Source: JFMS Open Rep 2025\n1. JFMS Open Rep. 2025 Aug 23;11(2):20551169251362828. doi: \n10.1177/20551169251362828. eCollection 2025 Jul-Dec.\n\nLower urinary tract obstruction secondary to Corynebacterium \nurealyticum-associated struvite urolithiasis in a female cat.\n\nWoerde DJ(1), Palm CA(2), Cutolo EC(1), Philp HS(3), Westropp JL(2).\n\nAuthor information:\n(1)William R Pritchard Veterinary Medical Teaching Hospital, University of \nCalifornia-Davis, Davis, CA, USA.\n(2)Department of Veterinary Medicine and Epidemiology, University of \nCalifornia-Davis, Davis, CA, USA.\n(3)Department of Surgical and Radiological Sciences, University of \nCalifornia-Davis, Davis, CA, USA.\n\nCASE SUMMARY: A 10-year-old female neutered domestic shorthair cat presented \nwith stranguria. The cat was bradycardic and had a firm urinary bladder on \nphysical examination. On initial laboratory testing, the cat had severe azotemia \nwith a creatinine of 15.8 mg/dl (reference interval [RI] 1.1-2.2), blood urea \nnitrogen of 217 mg/dl (RI 18-33) and potassium of 8.9 mmol/l (RI 3.5-5.0). \nAbdominal radiography revealed three cystoliths, with one cystolith suspected of \nbeing lodged within the trigone. Ultrasound of the abdomen showed marked \nsuspended echogenic debris within the urinary bladder. Corynebacterium \nurealyticum was isolated from aerobic bacterial urine culture. A cystotomy was \nperformed, and crystallographic analysis of the removed cystoliths showed they \nwere composed of 94% struvite and 6% calcium phosphate. The cat recovered well \nand was discharged 2 days postoperatively. Three weeks postoperatively, the cat \nshowed resolution of all clinical signs and azotemia.\nRELEVANCE AND NOVEL INFORMATION: Urethral obstruction is common in male cats \nbecause of the narrow diameter of their urethra. In contrast, it is rare for \nfemale cats to experience lower urinary tract obstruction (LUTO). Identifying \nthe underlying cause of LUTO is crucial for providing appropriate and targeted \ntreatment. This case report describes a unique cause of LUTO resulting from C \nurealyticum associated with struvite urolithiasis in a female cat.\n\n© The Author(s) 2025.\n\nDOI: 10.1177/20551169251362828\nPMCID: PMC12375161\nPMID: 40859964\n\nConflict of interest statement: The authors declared no potential conflicts of \ninterest with respect to the research, authorship, and/or publication of this \narticle.\n- Abstract (verbatim excerpt): \nJOURNAL:JFMS Open Rep 2025\n1. JFMS Open Rep. 2025 Aug 23;11(2):20551169251362828. doi: \n10.1177/20551169251362828. eCollection 2025 Jul-Dec.\n\nLower urinary tract obstruction secondary to Corynebacter\n\n### PMID:42157750 — Serum and Urine Nerve Growth Factor and Glycosaminoglycan Levels in Obstructive and Non-Obstructive Feline Urolithiasis and Interstitial Cystitis.\n- Source: Vet Med Sci 2026\n1. Vet Med Sci. 2026 May;12(3):e70968. doi: 10.1002/vms3.70968.\n\nSerum and Urine Nerve Growth Factor and Glycosaminoglycan Levels in Obstructive \nand Non-Obstructive Feline Urolithiasis and Interstitial Cystitis.\n\nMaden M(1), Sarıkaya A(1), Gülersoy E(2), Marangoz H(3), Sayın Z(3).\n\nAuthor information:\n(1)Department of Internal Medicine, Veterinary Faculty, Selçuk University, \nKonya, Türkiye.\n(2)Department of Internal Medicine, Veterinary Faculty, Harran University, \nŞanlıurfa, Türkiye.\n(3)Department of Microbiology, Veterinary Faculty, Selçuk University, Konya, \nTürkiye.\n\nBACKGROUND: Feline interstitial cystitis (FIC) results from complex interactions \nbetween the urinary bladder, nervous system, adrenal glands and the cat's living \nenvironment. Following FIC, urolithiasis is the second most common cause of \nfeline lower urinary tract disease (FLUTD), often producing clinical signs that \nmimic those of obstructive FIC.\nOBJECTIVES: This study aimed to assess the diagnostic utility of serum and urine \nconcentrations of nerve growth factor (NGF) and glycosaminoglycans (GAGs) in \ncats with urolithiasis or interstitial cystitis, under both obstructive and \nnon-obstructive conditions.\nMETHODS: The study included 90 cats, comprising 80 cats with clinical signs of \nFLUTD and 10 healthy controls. Group classification was based on clinical, \nlaboratory and ultrasonographic examinations, as well as multimodal \nenvironmental modification (MEMO) evaluation criteria. Cats diagnosed with \nurolithiasis or FIC were further categorised into obstructive \n(urolithiasis/obstructive [URO/Ob], FIC/Ob) and non-obstructive \n(urolithiasis/non-obstructive [URO/Non-Ob], FIC/Non-Ob) subgroups.\nRESULTS: Mild changes were noted in CBC and serum biochemistry. Serum and urine \nNGF levels were elevated in URO/Ob, FIC/Ob and FIC/Non-Ob groups but not in \nURO/Non-Ob. Serum and urine GAG levels were reduced in all groups except URO/Ob. \nIn obstructive cases, serum (AUC = 0.693) and urine GAG (AUC = 0.629) showed \nmoderate/acceptable diagnostic performance in distinguishing URO/Ob from FIC/Ob. \nIn non-obstructive cases, serum (AUC = 0.622) and urine NGF (AUC = 0.612) \ndemonstrated limited to moderate ability to differentiate FIC/Non-Ob from \nURO/Non-Ob.\nCONCLUSIONS: Elevated serum and urine NGF concentrations in cats with FIC have \nbeen associated with increased severity of bladder inflammation and tissue \ninjury. In contrast, reduced urine GAG concentrations, observed in all groups \nexcept the URO/Ob group, may facilitate bladder inflammation by increasing \nurothelial permeability. Accordingly, serum and urine GAG levels in obstructive \ncases and serum and urine NGF levels in non-obstructive cases may provide \nclinically relevant insights into both the pathophysiology and diagnostic \nevaluation of FLUTD.\n\n© 2026 The Author(s). Veterinary Medicine and Science published by John Wiley & \nSons Ltd.\n\nDOI: 10.1002/vms3.70968\nPMCID: PMC13240338\nPMID: 42157750 [Indexed for MEDLINE]\n\nConflict of interest statement: The authors declare no conflicts of interest.\n- Abstract (verbatim excerpt): \nJOURNAL:Vet Med Sci 2026\n1. Vet Med Sci. 2026 May;12(3):e70968. doi: 10.1002/vms3.70968.\n\nSerum and Urine Nerve Growth Factor and Glycosaminoglycan Levels in Obstructive \nand Non-Obstructive Feline U\n\n","sources":[],"tokens_estimated":4282,"generated_at":null,"tip":"Use /api/v1/topics to discover more topics. /api/v1/nutrient for precise single-point queries. /api/v1/cross_compare for 2-3 standard comparisons."}