AUTHOR=Zanghi Brian M. , Gardner Cari L. 

TITLE=Total Water Intake and Urine Measures of Hydration in Adult Dogs Drinking Tap Water or a Nutrient-Enriched Water

JOURNAL=Frontiers in Veterinary Science

VOLUME=5

YEAR=2018

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2018.00317

DOI=10.3389/fvets.2018.00317

ISSN=2297-1769

ABSTRACT=<p>Water intake and urine measures were evaluated in dogs offered tap water (TW) or a nutrient-enriched water (NW) supplement while fed dry food with <italic>ad libitum</italic> TW in a bucket. Baseline (day-7) urine specific gravity (U<sub>SG</sub>) was analyzed from healthy, adult small breed dogs (<italic>n</italic> = 21; 2–11 years). Dogs (<italic>N</italic> = 16) were selected with ≥1.015 U<sub>SG</sub>, then equally divided into 2 groups balanced for U<sub>SG</sub>. 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. U<sub>SG</sub> was measured on days −7, 14, 42, 56. Calorie intake was not different (<italic>P</italic> &gt; 0.49). A significant (<italic>P</italic> &lt; 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 (<italic>P</italic> &lt; 0.05) TLI every week, except for week 2 (<italic>P</italic> = 0.07). A significant (<italic>P</italic> &lt; 0.002) time-by-treatment interaction resulted for U<sub>SG</sub>, with baseline similar between groups and no difference between sampling days for the TW group (varied by ≤ 0.006 g/mL), whereas NW group was lower (<italic>P</italic> &lt; 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.</p>