Table 1—

Days postonset (DPO) of clinical signs for dogs with confirmed or probable leptospirosis (n = 52^*) between January 1, 2016, and June 30, 2017, in Maricopa County, Ariz, in which blood and urine samples were collected before or after antimicrobial administration for detection of Leptospira DNA by PCR assay.

PCR assay sample type and result	All samples (n = 105)		Samples collected prior to antimicrobial (n = 50)†		Samples collected after antimicrobial (n = 41)†
	No. (%)	Median (range) DPO	No. (%)	Median (range) DPO	No. (%)	Median (range) DPO
Blood
Positive	15 (29)	2.0 (0–8)‡	12 (46)	2.0 (0–8)§	0 (0)	0
Negative	37 (71)	8.0 (0–165)‡	14 (54)	7.0 (0–15)§	19 (100)	26.5 (3–165)
Urine
Positive	33 (62)	6.0 (0–128)	18 (75)	4.0 (0–15)	11 (50)	21.0 (4–128)
Negative	20 (38)	7.5 (0–165)	6 (25)	2.0 (0–8)	11 (50)	27.0 (3–165)

^*4 dogs had samples collected for PCR assay at > 1 time point.

^†Excludes samples (n = 14) collected from 7 dogs with a record of antimicrobial prescription but without a recorded date of antimicrobial initiation.

^‡Significantly (P < 0.01) different from each other.

^§Significantly (P < 0.05) different from each other.