Serologic and Urinary PCR Survey of Leptospirosis in Healthy Cats and in Cats with Kidney Disease

Abstract

BackgroundAlthough there is serologic evidence of exposure of cats to Leptospira spp., clinical disease is rarely reported in cats.ObjectiveTo compare the seropositivity and urinary polymerase chain reaction (PCR) status for Leptospira spp. between healthy (H) cats and cats with kidney disease (KD), to investigate the serovars potentially involved, and to evaluate potential risk factors.AnimalsTwo hundred and forty client‐owned cats.MethodsCats were prospectively recruited and classified based on physical examination, complete blood count, serum biochemistry profile, and urinalysis (125 H and 115 KD cats). Leptospira spp. serology (titers ≥1 : 100 considered positive) and urinary PCR were performed in all cats. Data assessing risk factors, obtained from a questionnaire, were evaluated using logistic regression models.ResultsSeropositivity for Leptospira spp. was statistically different between groups: 7.2% (9/125) and 14.9% (17/114) in the H and KD, respectively (P = .05). The proportion of PCR‐positive cats was not. The most common serovars detected serologically were Pomona (n = 16) and Bratislava (n = 8). Risk factors for seropositivity included outdoor and hunting lifestyles (P = .03 and P < .001, respectively), the presence of another cat in the household (P < .01), and the sampling period, with the greatest number of cases identified between June and August (P =.02).ConclusionsSeropositivity was significantly greater in KD cats, suggesting that the role of Leptospira spp. in KD in cats should be further investigated. The detection of urinary shedding of leptospires in several cats identifies a potential role in the transmission of the organism.

Letter to the Editor

“…We agree that reports of leptospirosis in cats are still rare and the role of cats as a source of contamination, as well as the role of leptospires in causing disease in that species might have been underestimated1.…”

“…In the referred study, although animals were seroreactive against Pomona1, employing only serology and PCR we cannot be sure about the real infecting serovar. Therefore, the bacteriological isolation of the agent from clinical species remains mandatory for a better understanding of leptospirosis in cats and the real role of those animals on the epidemiology of the infection.…”

“…We read with great interest the article “ Serologic and Urinary PCR Survey of Leptospirosis in Healthy Cats and in Cats with Kidney Disease ”1. We agree that reports of leptospirosis in cats are still rare and the role of cats as a source of contamination, as well as the role of leptospires in causing disease in that species might have been underestimated1.…”

Current Understanding of the Pathogenesis of Progressive Chronic Kidney Disease in Cats

“…67,70 A study by Rodriguez and colleagues has compared seropositivity and urinary PCR between CKD cats and non-age matched controls. 68 Seropositivity was significantly different between the two groups (7.2% non-CKD, 14.9% CKD cats) although PCR results were not. 68 However, a further study demonstrated no significant difference in seroprevalence between azotemic and non-azotemic cats.…”

“…[66][67][68][69] Experimental studies suggest that cats are largely resistant to acute leptospirosis although reports of clinical cases suggests that this is a possibility. 67,70 A study by Rodriguez and colleagues has compared seropositivity and urinary PCR between CKD cats and non-age matched controls.…”