The importance of hydration
“Water is the driving force of all nature.”
Leonardo Da Vinci
Hydration is a critical aspect of canine health, particularly for active and working dogs with high physical demands.
Many existing studies have shown the importance of providing sufficient protein, fat, vitamins and minerals to working dogs. Those studies also suggest that a dietary deficiency can be tolerated for days (or even longer) before any discernible adverse effects to performance or health.
Dehydration, on the other hand, can diminish performance within hours. And in severe cases, even worse.
To understand why the effect of dehydration is so rapid, we first need to appreciate the vital role played by water in nearly every bodily function. Water accounts for around 60% weight of a healthy dog. Water is essential for life: it is a building block, a carrier of nutrients and waste, a lubricant for joints.
For working and hunting dogs, hydration is particularly important as it maintains olfactory capacities. Water keeps the mucous membranes in the nasal passages moist: if these membranes dry out, the dog’s ability to pick up different scents will be significantly impaired and their performance directly affected. The problem here is that highly motivated working dogs that are hyper-focused on their tasks may not respond to the signs which would normally drive thirst.
But hydration isn’t only important for working dogs and very active dogs: one study[1] has shown that dogs can become mildly dehydrated during just 15 minutes of exercise like chasing a ball. The combination of exercise and panting can also play a role in dehydration[2]. The simple fact is that when dogs exercise, they lose total body water and dehydration also leads to a loss of electrolytes, such as potassium, sodium and chloride. Hydration has also been shown to dilate urine and reduce the formation of urinary stones, which are not uncommon in dogs.
It’s our responsibility to monitor dehydration, plan rest and provide hydration. We should always remember that dehydration is generally easier to prevent than to treat.
A simple but very useful real-time method for determining dehydration is “skin tent time” (SkTT), which measures skin turgor (or pliability). The skin on the forehead is pinched to create a “tent” and the time it takes for “tented” skin to return to normal gives an indication of hydration. A common sign of dehydration is a delay before the skin flattens back out.
Our aim is to maintain “healthy” hydration, especially for dogs with a low first drive. It’s more than just providing a bowl of water. Also crucial are electrolytes and nutrients such as sodium, potassium, chloride, magnesium and calcium.
In fact, the factors that contribute to dehydration in dogs are so complex that it is practically impossible to calculate a precise daily water requirement. In nature, the intake and output of water is regulated by complex system that allows the dog to remain hydrated. In theory, dogs will drink as much as they need provided there is water available. The problem in trying to keep working dogs hydrated is that there isn’t always water available when they’re thirsty and they aren’t always thirsty when the water is there. Sled dogs are a perfect example: for many years, mushers flavoured water in an attempt to encourage consumption of large amounts during the relatively short times when water was available. This technique is known as “baiting the water”.
Even now in a domestic setting, palatability is recommended as a means of encouraging water consumption and studies have been carried out into the use of nutrient-enriched water to improve water intake. One study investigated the difference in hydration between normal tap water and water that was nutrient-enriched[3]. The findings indicated that “healthy dogs can have greater total water intake and improved indices (…) when a palatable nutrient-enriched water is supplied daily for drinking”. The study confirmed a significant increase in the liquid intake of dogs fed the nutrient-enriched water (which it attributed in part to the poultry flavour).
Domestic options
There doesn’t appear to be consensus on daily water intake for dogs. There are so many variables, including breed, age, weight, ambient temperature, humidity, activity level, body composition, diet, conditioning, and acclimatization.[4][5]
I know that given the choice, my dog (a) prefers to drink from a river or pond but (b) failing that will drink a diluted broth or even a diluted chicken topping with great relish, whereas she’ll leave the bowl of tap water standing. Because of her low thirst drive she needs encouragement to drink, especially after exercise and in hot weather, which I do by providing “enhanced” drinks and food.
Perhaps the best known method of rehydration is a chicken or fish broth: as the broth simmers, the minerals from the bones, including potassium, release into the water. Studies have shown that enhanced solutions are effective, simply because dogs will drink more of what is offered. And oral hydration strategy is the best defence in the heat.
You can take a dog to water…
It isn’t easy to persuade dogs to drink enough water. To keep an otherwise healthy dog hydrated on hot days, even without strenuous exercise, I offer home-made healthy treats like ices, broths and nutrient-enhanced water throughout the day. Toppings and fresh food – and even snacks like watermelon – also contain moisture. A sort of “eat your water” principle, if you like: ensuring moisture intake as a means of prevention rather than cure.
Conclusion
I’ll leave the conclusion to the experts:
“The rationale for studying oral electrolyte solutions in dogs is based on clear evidence that water absorption is enhanced with the addition of sugar, amino acids, and electrolytes. While plain water can address hydration needs, evidence suggests that dogs drink more total water when offered an oral electrolyte solution in addition to plain water.”[6]
Why not try these recipes to help keep your dog hydrated:
World Dog Day hearts
Cucumber and courgette hydrating drink
Cucumber and courgette ices
Quick chia ices
Kefir and blueberry lolllies
References:
[1] Goucher, T. K., Hartzell, A. M., Seales, T. S., Anmuth, A. S., Zanghi, B. M., & Otto, C. M. (2019). Evaluation of skin turgor and capillary refill time as predictors of dehydration in exercising dogs. American Journal of Veterinary Research, 80(2), 123-128. Retrieved May 10, 2024, from https://doi.org/10.2460/ajvr.80.2.123
[2] Baker MA, Doris PA, Hawkins M. Effect of dehydration and hyperosmolality on thermoregulatory water losses in exercising dogs. Am J Physiol. (1983) 244:R516–21. 10.1152/ajpregu.1983.244.4.R516
[3] Zanghi BM, Gardner CL. Total Water Intake and Urine Measures of Hydration in Adult Dogs Drinking Tap Water or a Nutrient-Enriched Water. Front Vet Sci. 2018 Dec 18;5:317. doi: 10.3389/fvets.2018.00317. PMID: 30619899; PMCID: PMC6305449.
[4] Larsen JA, Farcas A. Nutrition of aging dogs. Vet Clin North Am Small Anim Pract. 2014 Jul;44(4):741-59, vi. doi: 10.1016/j.cvsm.2014.03.003. Epub 2014 May 6. PMID: 24951344.
[5] Lee JA, Cohn LA. Fluid Therapy for Paediatric Patients. Vet Clin North Am Small Anim Pract. 2017 Mar;47(2):373-382. doi: 10.1016/j.cvsm.2016.09.010. Epub 2016 Dec 8. PMID: 27939859; PMCID: PMC7124297.
[6] White paper: The basics of canine hydration
Want to know more? These studies may be useful:
Steiss JE, Wright JC. Respiratory alkalosis and primary hypocapnia in Labrador Retrievers participating in field trials in high-ambient-temperature conditions. Am J Vet Res (2008) 69(10):1262–7. doi:10.2460/ajvr.69.10.1262
Goldberg MB, Langman VA, Richard Taylor C. Panting in dogs: paths of air flow in response to heat and exercise. Respir Physiol (1981) 43(3):327–38. doi:10.1016/0034-5687(81)90113-4
Important Considerations:
- Always consult your veterinarian before making any significant dietary changes, particularly where there are pre-existing health conditions or dietary restrictions.
- If you are feeding commercial food, check the label for ingredients before giving more. Excessive intake of any foods can have adverse effects.
- Ensure (where possible) that you use high-quality, organic products specifically formulated for pets (or better still, human grade ingredients) to avoid any potential adverse effects.
- Introduce new foods gradually to avoid adverse effects such as gastrointestinal upset or diarrhoea.
- I provide nutritional information purely as a helpful guide. Nutritional information on ingredients is obtained from the US Department of Agriculture’s FoodData Central site (https://fdc.nal.usda.gov/index.html) and any nutritional information provided in recipes is based on an online calculator: calories and other information will vary based on brands, ingredients and other factors.
- Check nutrient levels and recommendations for your dog’s weight, age and activity. For example this nutritional guideline produced by FEDIAF.
- I am not a professional nutritionist. I am sharing recipes that I have created and tested in my kitchen and that have been tasted and approved by our doggy friends.