Even if a rabbit drinks little or no water due to a diet rich in fresh foods, fresh water should always be available. Factors such as heating, temperature changes, diet adjustments, or illness can suddenly increase a rabbit’s need for water. Without adequate water, there is a risk of internal dehydration, which can be fatal.

The Ideal Water Bowl
A suitable water bowl for rabbits should be stable and tip-proof to prevent spills. Sturdy options include cat water fountains, large, heavy ceramic bowls with an inward-curved rim, or bird bowls that can hang securely on the cage grid. The bowl should be placed slightly elevated (on a shelf, roof of a hideout, or a stone) to keep it clean, or on a bedding-free surface to avoid contamination.

„Water was noticeably less preferred from nipple drinkers compared to open bowls. Water should always be available ad libitum to avoid triggering compensatory mechanisms, particularly in the kidneys (TSCHUDIN 2010). These mechanisms reduce water intake, which over time can lead to urolithiasis, especially with high calcium levels in the diet (KAMPHUES 1991). This is particularly important when calcium intake exceeds the rabbit’s needs (FEHR 1999a).“

A., K. Korn (2016): Dental and Jaw Changes in Rabbits. Diagnostics, Occurrence, and Heritability.

Sources of Drinking Water

Regular tap water is generally safe for rabbits as long as it is not chlorinated. Alternatively, still (non-carbonated) water can be purchased from beverage stores or supermarkets.

Does Your Rabbit Keep Tipping Over the Bowl?
There are simple ways to prevent this!

Sources:

Coenen, M., & Schwabe, K. (1995): Wasseraufnahme und‐haushalt von Kaninchen, Meerschweinchen, Chinchillas und Hamstern bei Angebot von Trocken‐bzw Saftfutter. Tagungsbericht der Deutschen Veterinärmedizinischen Gesellschaft zur, 148-149.
Kamphues, J., Carstensen, P., Schroeder, D., Meyer, H., Schoon, H. A., & Rosenbruch, M. (1986): Effekte einer steigenden Calcium‐und Vitamin D‐Zufuhr auf den Calciumstoffwechsel von Kaninchen 1. Journal of Animal Physiology and Animal Nutrition56(1‐5), 191-208.
Schwabe, K. (1995): Futter-und Wasseraufnahme von Heimtieren verschiedener Spezies (Kaninchen, Meerschweinchen, Chinchilla, Hamster) bei unterschiedlicher Art des Wasserangebotes (Tränke vs. Saftfutter), Diss. Hannover
Tschudin A., Clauss M., Codron D., Hatt J-M.: Preference of rabbits for drinking from open dishes versus nipple drinkers, in: Veterinary Record
Tschudin, A., Clauss, M., & Hatt, J. M. (2011). Umfrage zur Fütterung und Tränke von Kaninchen (Oryctolagus cuniculi) in der Schweiz 2008/2009. Schweizer Archiv für Tierheilkunde, 153, 134-138.
Tschudin A., Clauss M., Codron D., Liesegang A., Hatt J-M.(2008): Water intake in domestic rabbits (Oryctolagus cuniculus) from open dishes and nipple drinkers under different water and feeding regimes, in: Journal of Animal Physiology and Animal NutritionWolf, P.: Daten zur Wasseraufnahme bei Kleinsäugern und deren Bedeutung für die Heimtierhaltung
Wolf, P., Bucher, L., Zumbrock, B., & Kamphues, J. (2008): Daten zur Wasseraufnahme bei Kleinsäugern und deren Bedeutung für die Heimtierhaltung. Kleintierpraxis7(4), 217-223.