Increased thirst in dogs (which is almost always associated with increased urination), should never be ignored. If you are unsure if your dog is drinking more than usual, you can quantify their intake to see if it’s above the normal range of ~ 50ml/kg/day.
In general, sudden or severe changes mark more urgent conditions like life-threatening infections or poisoning. Chronic changes are more likely to be associated with disease conditions like Cushing’s Syndrome or Diabetes.
Most causes of increased water-drinking are treatable, if caught early in the process, so always contact your veterinarian for help.