Causes of lower urinary tract disease in Czech cat population

Abstract

This study was done to investigate epidemiological data and to report causes of lower urinary tract disease in a population of cats presented at the Small Animal Clinic of the University of Veterinary and Pharmaceutical Sciences Brno. Cats presented with lower urinary tract disease signs that had undergone a thorough physical examination and urinalysis (dipstick, urine specific gravity, urine sediment and dipslide urine culture) were included in the study. Urine samples were collected only by cystocentesis or sterile catheterization. Bloodwork, abdominal ultrasound, and abdominal radiographs were performed in 118 (66%), 170 (96%) and 9 (5%) patients, respectively. Cats that were treated with antibiotics or glucocorticoids during an episode of feline lower urinary tract disease (FLUTD) or during the foregoing month and which had undergone perineal urethrostomy or catheterization in private practice, were excluded. The study population consisted of 177 cats. Forty-one (23%) cats were diagnosed with a urethral plug, 26 cats (14%) with a urinary tract infection (UTI), 9 cats (5%) with urolithiasis and 101 cats (57%) with feline idiopathic cystitis (FIC). The cats diagnosed with UTI were significantly older than the cats with FIC, urethral plugs and urolithiasis. Urinary tract infection was diagnosed significantly more often in patients older than 10 years, and in female cats. The diagnosis of urethral plug was made significantly more often in males. Feline idiopathic cystitis and urethral plugs are the most common causes of FLUTD, and the causes are significantly age and sex-related. FLUTD, UTI, LUTS, urethral plug, urolithiasis, feline The term “Feline Lower Urinary Tract Disease” (FLUTD) summarizes a spectrum of clinical signs related to diseases of the urinary bladder and/or urethra. By aetiology, FLUTD covers multiple disorders such as urolithiasis, urinary tract infections (UTI), neoplasia, congenital or acquired morphological abnormalities, and feline idiopathic cystitis (FIC). Cats with FLUTD are often presented for stranguria, haematuria, periuria, pollakiuria, overgrooming of the genital area and inner thighs, and behavioral changes (i.e. aggression) (Gunn-Moore 2003). These lower urinary tract signs (LUTS) or their combinations are not specific for any particular disease as lower urinary tract reacts to all kinds of irritation in the same manner (Osborne et al. 1996). Feline idiopathic cystitis is a diagnosis of exclusion (Forrester and Towell 2015). A diagnostic work-up including urinalysis (dipstick, urine sediment examination and urine culture), survey radiographs for identification of radiodense urethrolits/cystoliths and/or ultrasonographic examination for the identification of radiolucent uroliths or neoplastic changes should be performed to rule out other specific causes (Kruger et al. 2009). Many authors agree that FIC is the most common cause of LUTS (Kruger et al. 1991; Lekcharoensuk et al. 2001). Significant differences regarding the prevalence of UTI in cats presenting for FLUTD were found. European studies (Netherlands, Switzerland, Norway, Germany and Poland) revealed a higher occurrence of FLUTD cases due to bacterial infection, ranging from 7.8% ACTA VET. BRNO 2019, 88: 433–441; https://doi.org/10.2754/avb201988040433 Address for correspondence: MVDr. Barbora Hřibová University of Veterinary and Pharmaceutical Sciences Brno Palackého tř. 1946/1 612 42 Brno, Czech Republic Phone: + 420 541 562 357 E-mail: [email protected] http://actavet.vfu.cz/ to 22% (Kraijer et al. 2003; Gerber et al. 2005; Eggertsdottir et al. 2007; Dorsch et al. 2014; Lew-Kojrys et al. 2017) compared to studies from USA which had a prevalence up to 3% in cats less than 10 years of age (Kruger et al. 1991; Lekcharoensuk et al. 2001). Older female cats are generally at increased risk for the development of urinary tract infection (George 1996; Litster et al. 2009). The aging process and/or concurrent diseases, which are commonly seen in geriatricpatients, could contribute to reduction of natural urinary tract defense mechanisms against infection in older cats (George 1996). The occurrence of UTI is also increasing in cats with concurrent disorders such as chronic kidney disease, diabetes mellitus, or hyperthyroidism (Bailiff et al. 2006; Mayer-Roenne et al. 2007), after repeated catheterizations and perineal urethrostomy (Lekcharoensuk et al. 2001). Mayer-Roenne et al. (2007) found an association between decreasing urine specific gravity (USG) and increasing frequency of UTI in cats with diabetes mellitus. However, another study failed to prove this association (Bailiff et al. 2008). Urethral plugs are believed to be the most common cause of urethral obstruction. In one study, urethral plugs were found to be the cause of obstruction in 55% of patients, with urolithiasis in 12%, and the cause remaining unknown in 30% of cats (Kruger et al. 1991). The aim of this retrospective study was to investigate epidemiological data and to report causes of lower urinary tract disease in a population of cats presented at the Small Animal Clinic, University of Veterinary and Pharmaceutical Sciences Brno (UVPS). Materials and Methods Medical records of cats which had been admitted to the Small Animal Clinic at UVPS from January 2013 to February 2019 with LUTS (pollakiuria, stranguria, haematuria, periuria, abnormal grooming of the genital area, vocalization on urination, straining to urinate) and diagnosed with FLUTD (obstructive or non-obstructive form) were reviewed and included in the study. Data retrieved from medical records included: breed, age, sex, neutering status, season of presentation (winter [December, January, February] spring [March, April, May] summer [June, July, August] autumn [September, October, November]), presence of urethral obstruction, urinalysis results, and final diagnosis. Cases were identified by searching medical records for “FLUTD”, “FIC”, “dysuria”, “haematuria”, “periuria” and “urethral obstruction”. Cats that presented with their first episode were included along with cats with previous episodes of FLUTD. Animals that had been treated with antibiotics or glucocorticoids during the episode of FLUTD or during the foregoing month and that had undergone perineal urethrostomy or catheterization in private practice, were excluded. A thorough physical examination and dipslide urine culture were performed in all of the included cats. Bloodwork, abdominal ultrasound, and abdominal radiographs were performed in 118 (66%), 170 (96%) and 9 (5%) of the patients, respectively. The patients were divided into four groups (FIC, UTI, urethral plug, urolithiasis) based on defined diagnostic criteria. A diagnosis of UTI was made when urine culture was positive with significant bacterial growth (≥ 103 colony forming units per ml), and no concurrent uroliths were identified. A urolithiasis was diagnosed via abdominal ultrasound or radiographs. Obstructive FLUTD was considered in cats with overdistended, rigid, and painful urinary bladder that was unable to express by gentle palpation. In cats which had obstructive FLUTD caused by urethral plugs detected on radiographs or during catheterization, uroliths or significant bacterial growth had to be eliminated. If no urolith was identified on abdominal ultrasound/radiographs, no urethral plug was observed and urine culture returned negative, the diagnosis of FIC was made.