And most often forgotten …
Did you know? Your fur kids can live for weeks without any food, using their own body fat and muscle for energy production, but a loss of only 10% of their body water can result in death. It is also one of three nutrients that do not contribute any calories to the diet.
Within the body, water functions as a solvent that facilitates cellular functions and as a transport medium for nutrients and the end products of cellular metabolism. Water is able to adsorb much of the heat that is generated during metabolic reactions with a minimal increase in temperature. Water also helps to transport heat away from the working organs through the blood.
Water is an essential component of the normal digestive process because it is necessary for hydrolysis. Hydrolysis is the splitting of larger molecules into smaller ones through the addition of water. Elimination of waste products, through the kidneys, also requires a large amount of water, which acts as both a solvent for the toxic metabolites and as a carrier medium.
Water is involved in regulating oncotic pressure (a form of osmotic pressure exerted by proteins a blood vessel’s plasma, or blood / liquid, that usually tends to pull water into the circulatory system) that helps the body to maintain its shape. One of the manifestations of loss of oncotic pressure, as seen with dehydration, is the loss of skin elasticity. Water is found in all the body fluids and also helps to lubricate the joints and eyes, provides protective cushioning for the nervous system and aids in gas exchange in respiration by keeping the alveoli (anatomical structure that has the form of a hollow cavity particular to mammalian lungs) moist and expanded.
Water accounts for the largest proportion of any of the nutrients in your fur kids body, varying from 40% to 80% of the total amount. The percent of water varies with species, condition and age. Generally, lean body mass contains 70 – 80% water and 20 – 25% protein, with adipose (adipose tissue or body fat or just fat is loose connective tissue composed mostly of adipocytes) tissue containing 10 – 15% water and 75 – 80% fat. The younger and leaner your fur kid, the more water it contains. The more obese your fur kid, the lower its water content.
Because of water’s role as a solvent, the potential exists that other substances can enter your fur kids body that hadn’t been planned for. Salinity (water’s salt content), nitrates, nitrites, inorganic chemicals and microbial contamination are examples of only a few contaminants that can be found in water supplies.
There is some debate concerning whether tap water is adequate, or whether bottled or distilled water is preferable. No published studies prove one type of water is better than another, or that any type of water causes disease in fur kids. Today, city water has chlorine and fluoride and other substances that are not desirable. While this causes concern to some pet parents, chlorination also kills various bacteria that could cause food poisoning in pets if the bacteria were present in high numbers.
For yourself and your fur kids, we suggest taking a look at your water. At the very least, a water filter pitcher can take some of the toxins out. Some water purifiers take out the minerals – we want to leave the minerals in the water.
Voluntary Oral Intake
The type of diet being fed as well as the composition can dramatically affect voluntary oral intake of water. A study by Case LP. et al (pp. 3 -14.)1 on dogs found that when the test animals were fed a diet containing 73% (typical biologically appropriate raw food diet) moisture, they only needed to obtained 38% of their daily water needs from drinking water. When they were abruptly switched to a diet containing only 7% (typical dry matter or kibble diets) water, voluntary oral intake immediately increased to around 95% or more of the total daily intake required.
When cats are fed only canned food, their voluntary oral intake is likewise low compared to dry foods, in fact, when cats are fed a food with high water content; cats can maintain normal water balance without the need to drinking additional water. This could be seen with liquid or gruel (a type of food consisting of some type of cereal – oat, wheat or rye flour, or rice – boiled in water or milk) recovery diets, as well as some commercial canned diets, with a high amount of sauce.
If fresh, palatable, clean water is available, and proper amounts of a balanced diet being fed, most dogs and cats are able to accurately self-regulate their water balance through voluntary oral intake. Normally, thirst ensures that water intake meets or exceeds the body’s requirements. Inadequate water intake can reduce appetite, reduces production on a number of levels including growth, lactation, reproduction and physical activity.
Did you Know? One of the 1st things you will note once having switched to raw diets, is that your fur kids will drink less water than normal. This is due to them obtaining between 60% and 80% (depending on the formula) of their daily intake via their diet, and therefore only need to acquire between 20% and 30% of their intake orally.
References and Research
- 1.Case LP, Carey DP, Hirakawa DA, Daristotle L. Canine and Feline Nutrition: A Resource for Companion Animal Professionals. 2nd ed. St Louis: Mosby Inc.; 2000. https://www.cabdirect.org/cabdirect/abstract/20001415076.