The reasons a puppy may drink excessive amounts of water include dehydration, medication, diet and medical conditions. According to WebMD, it is not easy for the average person to determine if a dog is drinking an excessive amount of water, so it is best for concerned dog-owners to seek advice from a veterinarian.
Dehydration in a dog can be caused by heat, exercise or illness. In addition to increased thirst, symptoms that a dog may be dehydrated include lethargy, dry gums, dry tongue and thick, rope-like saliva. Dehydration can be life threatening and veterinary care should be sought immediately.
Sometimes, a poor diet may make a dog drink more. Excessive drinking may be caused by salty or sugary foods or it could be an allergic reaction to food. Dry food or low-protein diets can also increase a dog's thirst.
Some medications may cause the dog to suffer from excessive thirst. Medications used to treat inflammation, heart failure or seizures may have side effects that include excessive thirst.
Kidney disease, liver disease, diabetes, adrenal dysfunction, thyroid dysfunction, certain cancers, hormonal imbalances, urinary tract infections and other illnesses can cause dogs to drink excessively. As many of these medical conditions are life threatening, it is important for dog-owners to consult with a veterinarian any time a dog's drinking pattern changes significantly.