Causes of Dehydration
Dehydration can be caused by a number of different disorders, diseases and conditions. To generalize, dehydration can be caused by reduced water (and food) intake or by increased water loss. Anything that causes inflammation or irritation of any part of the gastrointestinal tract, from the oral cavity to the rectum, can contribute to dehydration from fluid loss, including bacterial, viral or fungal infections, ulcers, excessive salivation, panting, gastrointestinal parasites and gastrointestinal obstruction. Vomiting and diarrhea are very common contributors to dehydration; of course, those conditions can be caused by many underlying causes as well. Kidney (renal) failure, skin damage from burns or large wounds and ingestion of toxic substances such as antifreeze (ethylene glycol) or any other substances that cause vomiting, diarrhea or renal failure, may cause dehydration. Other common causes of dehydration are diseases of the endocrine system, including diabetes mellitus, diabetes insipidus and hypoadrenocortism (Addison’s Disease). Heat stroke can cause a rapid loss of fluids as well. Fluid losses from the urinary and gastrointestinal tracts are the most common causes of dehydration in domestic dogs.
Regardless of the inciting cause, dehydration leads to an abnormally low total volume of circulating blood and intracellular fluids. This, in turn, adversely affects the hydration of body tissues and the delivery of oxygen through the blood to critical tissues and organs. It also causes the concentration of essential electrolytes to become out of balance, which can disrupt the normal function of virtually any body organ or system.
Prevention of Dehydration
The best ways to prevent a dog from becoming dehydrated are to always provide free access to fresh water and to promptly seek veterinary care when a dog stops eating or develops repeated episodes of vomiting and/or diarrhea.
Dehydration can range from mild to extremely severe. Severe cases can rapidly become life-threatening if the dog does not receive swift veterinary attention.