Cayla Iske, PhD
“Provide multiple water sources at all times.” “Make sure your pet is getting enough water.” “Increase water intake.” As a pet parent, you’ve likely heard these recommendations in various places – online, through your veterinarian, within product feeding directions and elsewhere. Is water really that important for pet health? Absolutely! The notion that water doesn’t contain any nutrients is a common and unsafe misconception. We drink water every day, so we forget that water itself is a key and essential nutrient just as important for life as protein, fat, carbohydrates, vitamins, and minerals. But why?
What Does Water Do?
Water makes up about 60% of an animal’s body weight, humans included. More specifically, mammalian cells are composed of nearly 70% water. Cells are the foundation of all tissues in the body and are essential for performing functions to keep a body operating properly including nutrient absorption, immune function, body structure, and everything in between. A body is made up of trillion of cells and in order to properly and efficiently function, every single one of those needs water.
Waters importance goes far beyond cellular activity. It also helps with joint lubrication to reduce long-term issues, moistening of tissues including the mouth and nose to improve sense of taste and smell, and facilitating the elimination of waste products from the body thereby reducing strain on the liver and kidneys. Water is also key in body temperature regulation which is essential for life. Adequate water intake provides moisture which can be evaporated to cool the body. Evaporation can occur through the skin for animals that have the ability to sweat (perspiration), or via airflow through the lungs and mouth during panting. Water is even essential to proper skin and haircoat formation and maintenance which facilitates a soft, smooth coat. Furthermore, skin is the largest organ in the body and serves as the first line of defense against the outside world. If not properly hydrated, it can lose its structure and barrier function, reducing its role in immunity and leaving the body more vulnerable to pathogens and toxins in the environment.
Specific Importance for Rabbits and Guinea Pigs
All of the aforementioned purposes of water are important for all exotics companion mammal species, but excretion of waste products is especially vital to rabbits and guinea pigs because of their unique physiology. In a previous blog, we talked about how rabbits and guinea pigs are prone to bladder sludge and even bladder stones (Cystic Calculi) as excess calcium is excreted through urine via the kidneys. Filtering urine is one of the normal functions of the kidneys but factors such as excessive calcium or low levels of hydration put additional stress on the kidneys. Increasing water intake dilutes the urine and eases the stress on the kidneys by helping to flush them out. Secondly, it helps to flush more fluid through the bladder which minimizes calcium sediment and the potential of bladder stone formation. This can lead to healthier kidneys and a reduced risk for bladder sludge.
Another important role of water for rabbits and guinea pigs is support of the digestive system through maintaining a hydrated environment. When these animals consume pellets, hay, or other food items that are often relatively low in moisture they need to be lubricated to ensure proper digestion and motility through the GI tract. If direct water consumption is inadequate, the GI tract pulls fluids from internal tissues or blood to properly hydrate these food items, increasing risk of dehydration. When the GI tract and its cells are properly hydrated, they are not only healthier, but more efficient in digestion and motility as well. As a result, proper hydration can mitigate the occurrence of GI stasis.
How Much is Enough?
Water can be supplied either by the diet or through drinking. Pelleted diets and hay that make up a majority of your animal’s diet are very low in water, but fresh greens and veggies are typically about 90% water and will contribute to water intake. However, dietary water alone will not adequately supply your animal. The body is constantly using and losing water so fresh water should always be available. This is even more important when conditions are warm because more water is used for cooling purposes. Typical water intake for exotic companion mammals generally falls around 50-150 mL per kilogram of body weight (National Research Council, 1995), which can serve as a good general guideline for your pet. Rabbits have been shown to drink more water from open dishes rather than nipple drinkers (Tschudin et al., 2011) but it is important to have multiple sources of water to suit the preference of your animal.
Monitoring your animal’s water intake can alert you to changes in health that may be of concern. Observations of reduced water intake may indicate a wide range of issues from dental disease to arthritis while increased water intake may be related to stress, kidney problems, or many other issues. If you notice changes in water intake in your animal, you should consult your veterinarian to assess your animal’s overall health.
Harcourt-Brown, F. 2011. Importance of water intake in rabbits. Veterinary Record. 185; 189-190.
National Research Council. 1995. Nutrient Requirements of Laboratory Animals. Fourth Revised Edition. Washington, DC: The National Academies Press.
Tschudin, A., Clauss, M., Doron, D. & Hatt, J-M. 2011. Preference of rabbits for drinking from open dishes versus nipple drinkers. Veterinary Record. 168; 190.