Water intake and urine hydration in adult dogs drinking tap

Abstract

Water intake and urine measures were evaluated in dogs offered tap water (TW) or a nutrient-enriched water (NW) supplement while fed dry food withTW in a bucket. Baseline (day-7) urine specific gravity (U) was analyzed from healthy, adult small breed dogs (= 21; 2-11 years). Dogs (= 16) were selected with &#x2265;1.015 U, then equally divided into 2 groups balanced for U. Groups received either TW or NW in a bowl for 56 days. Dose for each dog was 0.5:1 water-to-calorie ratio (mL:kcal ME/d) from days 1-49 to evaluate sustained intake of a moderate volume, or 2:1 water-to-calorie ratio from days 50-56 to evaluate short-term intake of a large volume, based on baseline food calorie intake. Daily food calorie and total liquid intake (TLI; g/d; sum of NW or TW in a bowl and bucket water) was used to calculate weekly intake. Uwas measured on days -7, 14, 42, 56. Calorie intake was not different (> 0.49). A significant (< 0.001) time-by-treatment interaction resulted for TLI with baseline similar between groups and no difference between weeks for the TW group. Following baseline, NW group had increased (< 0.05) TLI every week, except for week 2 (= 0.07). A significant (< 0.002) time-by-treatment interaction resulted for U, with baseline similar between groups and no difference between sampling days for the TW group (varied by &#x2264; 0.006 g/mL), whereas NW group was lower (< 0.01) on days 42 (1.018 g/mL) and 56 (1.014 g/mL) vs. baseline (1.026 g/mL). This study indicates that all dogs offered the NW supplement increased their TLI and produced a more dilute urine, which suggests an improvement in indices associated with chronic hydration.