Hydrogen Water for Animals: What the Studies Show
Hydrogen-rich water is ordinary water with molecular hydrogen gas (H2) dissolved in it. Researchers have begun testing it in animals, mostly over the past decade. This page summarises the published studies we could verify, including their size and limits. The research is early. Most studies are small, short and from a single research group, and none of them tested the equipment we sell.
How to read this page
Each study is labelled by how much weight it can carry:
- Controlled study: animals given hydrogen-rich water were compared with a group given ordinary water.
- Pilot: very few animals, or a result that was a trend only.
We state the species, number of animals, how the water was given and what was measured. We do not extend a result from one species to another.
Dogs
Label: Controlled laboratory study, small
Twelve healthy male beagles were divided into two groups of six. One group was given 400 mL of hydrogen-rich water three times a day; the other was given distilled water. Researchers made small standard skin wounds under laboratory conditions and tracked healing for 28 days.
Reported result: average healing time was 19.0 days in the hydrogen-water group and 22.0 days in the control group (p < 0.05).
Limits: twelve dogs, one breed, one laboratory. The water was freshly saturated with hydrogen before each dose. This was a research setting, not home use.
Source: Qi et al., Veterinary Sciences, 2021, 8(11), 264
Pigs
Label: Controlled farm trial, short
Sixty newly weaned piglets were split into two groups for 14 days. One group's drinking line supplied hydrogen-rich water held at 2,000 ppb; the other received ordinary water.
Reported result: the diarrhoea rate was 9.22% in the hydrogen-water group and 27.38% in the control group (p = 0.001). Feed intake was slightly higher. Body weight gain did not differ between groups.
Limits: 14 days, one farm, castrated males only. The authors call for further work.
Source: Zhang et al., Biology (Basel), 2025, 14(8), 997
Horses
Label: Pilot, trend only
Five Thoroughbreds each completed a treadmill exercise test twice, once after hydrogen-rich water and once after placebo water, given by stomach tube 30 minutes beforehand.
Reported result: a blood marker of oxidative stress rose after exercise in both trials, and the rise tended to be lower after hydrogen-rich water.
Limits: five horses, and the water was given by tube, not drunk. A trend is not a confirmed effect.
Source: Tsubone et al., Journal of Equine Science, 2013.
Cats
We found no published studies of hydrogen-rich water in cats. Results from dogs, pigs or horses should not be assumed to apply to cats.
What is not known
- Whether any of these results repeat in larger, independent studies.
- Long-term effects in any species.
- What concentration matters. The studies used freshly prepared or continuously maintained hydrogen levels.
- Whether water in an open bowl holds enough hydrogen to be comparable. Dissolved hydrogen escapes from water quickly once exposed to air.
If you are considering it for your animal
Fresh, clean water matters more than anything dissolved in it. Hydrogen-rich water is not a veterinary treatment and is not a substitute for veterinary care. If your animal is unwell, or you are thinking of changing how it is watered, talk to your veterinarian first.
This page is a summary of published research for general information. It makes no claim that any product sold on this site prevents, treats or cures any condition in any animal. Last reviewed: October 2026.