Why is my dog so thirsty?

There are several reason or things that cause a dog to get thirsty. If a dog has just had diarrhea or has been vomiting, it's obvious he is going to be thirsty because the dog's organism is trying to restore the water it lost. A dog that has a bleeding wound or a superficial burn also gets very thirsty because these things cause the dogs body to also lose water. Another thing that could cause a dog to be thirsty is if he is taking some form of medication such as steroids or diuretics. If your veterinarian ever prescribes these or other medications to your dog, he or she will probably advise you to have a lot of water available for your dog to drink so that the dog does not get dehydrated and for the medication to work. There are however, cases in which a dog gets thirsty for no apparent reason. If this is your dog's case, you should take him to the veterinarian to get a check up. If your dog is excessively thirsty make sure to write down the amount of water that your dog has drunken in the last 24 hours before taking the dog to get checked up in order to facilitate the diagnosis. It's also a good idea to take the veterinarian a urine sample.

Dog Thirst Questions and Answers
Q: My veterinarian has asked me to measure the amount of water my dog drinks in a 24 hour period. How should I do that?
A: You should start by filling the dog's water bowl and marking the exact amount of water it holds. During the 24 hours period, you should continue filling the dog's water bowl at the marked spot by using a measuring cup and count how many more cups you have had to add to the water bowl. After the 24 hour period, you will be able to multiply or sum up the added amounts.
Q: I have an older collie named Tubby. Tubby spends most of his day drinking water and eating, however he seems to be quite thin and his stomach is swollen. His eyes are also foggy. Could he have diabetes?
A: You need to take Tubby to the veterinarian right away. Fogginess in a dog's eye can be an indicator of cataracts and this is a problem caused by diabetes. There is no cure for cataracts but the sooner the problem is dealt with the better. Your veterinarian will explain how you will need to care for Tubby now since he will now have to get daily insulin shots. In some cases the veterinarians prescribe oral treatments.