Water is the dog's most important nutrient. A dog needs daily about half a decilitre of water per kilogram of body weight. Thus, for example, a generally healthy 10 kg dog should drink about half a litre of water per day. The daily water requirement is also affected by how much and how intensively the dog exercises, the air temperature, and whether the dog eats dry food or wet food.
Wet foods contain mainly about 70–80% water, and a dog eating wet food has a lower water requirement than a dog eating dry food. In summer heat or after heavy performance, water needs increase in both people and dogs due to sweating and evaporative cooling, and therefore in hot weather it is important to ensure the dog stays sufficiently hydrated. If a dog does not drink enough fluid, its body can become dehydrated. Heavy training and high activity can raise a dog's water need to several litres per day. Heavy sweating uses up salts and electrolytes from the body, which can be replenished with various dog recovery drinks and electrolyte preparations. Fluid loss and dehydration are also caused by diarrhoea, vomiting, or heat stroke, which at worst can lead to organ damage or even death. Symptoms of dehydration include, for example, dry and pale gums, tiredness and a decline in general condition, loss of appetite, and loss of skin elasticity.
Sometimes a dog suffering from dehydration refuses to drink, and in that case a solution can be to try to give water by hand or to give water into the mouth with a syringe. A severely dehydrated dog needs veterinary help and intravenous fluids.
If it seems that the dog is not drinking enough, you can try to increase fluid intake with, for example, the following tricks:
- keep several bowls available that the dog can drink from
- keep the bowls always clean, and keep the water fresh and clean
- add water into the food
- try flavoured water
- try offering water from your hand
What is too much?
Sometimes an owner may notice increased drinking. Changes in drinking and urination are symptoms that can be connected to different illnesses, such as a urinary tract infection or uterine infection, kidney problems, or diabetes. Pain can also cause increased drinking. If a dog drinks more than usual, it is important to find out the reason for the increased drinking. If a dog drinks more than 80–100 ml/kg per day, it is a good idea to contact a veterinarian for examinations.
Excessive drinking can cause water intoxication, although it is quite a rare condition. Water intoxication can sometimes occur in dogs that spend a lot of time in water. While swimming a lot, a dog may gulp water and thereby get too much. Water intoxication can also, at worst, be dangerous, and in these cases the dog should be taken to a veterinarian.
