To tell if a dog is dehydrated, it may help to first take a glimpse into how a well hydrated dogs appears in the first place. Don't take your dog's normal appearance for granted, instead carefully look at how your dog looks when he's feeling well. That way, you may be able to quickly recognize signs of illness. Dehydration in dogs is something that needs closer investigation with the help of your vet. Veterinarian Dr. Ivana Crnec goes over how to tell if a dog is dehydrated and what may cause dogs to get dehydrated in the first place.
Dehydration in Dogs
When talking about medical emergencies, among the first things that come to mind are heat strokes, traffic accidents and shock. Although, it rarely comes to mind, dehydration is considered a life-threatening condition that requires immediate medical attention.
Dehydration is a state that develops when the body loses more fluids than it is taking in. Dogs, just like any other mammal, require water to maintain proper bodily function. Under normal circumstances, dogs need one ounce of water per day per pound of body weight.
Water is necessary for a variety of functions: lubricating the dog's joints, cushioning the internal organs, regulating the body temperature, absorbing nutrients from food and aiding digestion.
Normally, throughout the day, the dog’s body both gains and loses water. Dogs gain water through drinking and eating. On the flip side, they lose water through processes like breathing, panting, urinating, defecating and evaporation through the paws. Under normal circumstances, these processes are balanced – the gain and loss are equal and tend to compensate for each other.
If the fluid intake is smaller and fails to make up for the water loss, the dog becomes dehydrated. A dehydrated dog will have reduced fluids volume. When the total volume of fluids is reduced, the body responds by reducing blood flow and consequently reducing the oxygen delivery to internal organs.
When a dog loses too much water, it also loses important electrolytes such as sodium, potassium, magnesium and chloride. These electrolytes have several functions such as balancing the body’s pH, facilitating muscle function, regulating nerve function and moving nutrients into cells. Severe fluid shortages may cause irreversible kidney damage and eventually trigger other organs failure. Puppies, senior dogs and nursing mothers are at higher risk of becoming dehydrated. The risk of dehydration is also higher in toy dog breeds.
What causes dehydration in dogs? Generally speaking, dehydration occurs by either insufficient water intake or increased fluid loss. The insufficient water intake may be due to lack of water access or reluctance to drink water.
The increased fluid loss (through urination, vomiting, diarrhea and blood loss) may be due to a plethora of health issues such as endocrine problems (diabetes mellitus, diabetes insipidus, Addison’s disease), burns and large skin injuries, toxin ingestion (ethylene glycol), gastrointestinal tract inflammations and irritations.
All in all, while some dogs refuse to drink water unless encouraged to, other dogs refuse to drink due to an underlying cause.
Signs of Dehydration in Dogs
The signs of dehydration become visible when the dog’s total fluid volume drops 5 percent. The most common dehydration signs include:
- Dry nose
- Decreased skin elasticity
- Sunken, dry-looking eyes
- Thick saliva
- Dry, sticky gums
Significant dehydration leads to shock. Shock manifests with:
- Rapid heart rate
- Weak pulse
- Pale gums and mucous membranes
How to Tell if a Dog is Dehydrated
You can easily check if your dog is dehydrated. There are 2 main dehydration tests: checking the skin's elasticity and checking the capillary refill time.
Checking a Dog's Skin Elasticity
You can gently pinch your dog’s skin between its shoulders with your thumb and forefinger. You need to grasp enough skin to lift it an inch or two away from the body. In hydrated dogs, when you release the skin it should retract immediately. As the skin loses its moisture it also loses its ability to retract. In severely dehydrated dogs the skin may not pull back at all. Simply put, if the skin stays up like a tent, the dog is dehydrated.
It is advisable to check your dog’s skin elasticity when it is healthy and well hydrated. That way it will be easier for you to notice potential elasticity changes. This applies particularly for wrinkly breeds such as Bulldogs, Shar-Peis and Neapolitan Mastiffs because even under normal circumstances their skin is not very elastic.
Checking a Dog's Capillary Refill Time (CRT)
Capillary refill time in dogs is checked by looking at the gums. First you need to lift your dog’s lip to check the color of the gums. Once the gum color is checked it is time to check the CRT. All you need to do is press the gums with your index finger and then keep pressing until the spot turns white. Then, release the pressure and observe how long does it take for the color to return to normal. The time needed for the color to return is actually the capillary refill time. In healthy dogs, the color returns immediately while in dehydrated dogs the color return can be delayed for up to 3 seconds.
An experienced veterinarian can say that a dog is dehydrated by simply looking at it. However, determining the underlying cause is much more challenging. Depending on the dog’s overall clinical manifestation, the vet may suggest diagnostic tests and procedures such as complete blood count, serum biochemistry panel, urinalysis, fecal examination, X-rays and ultrasound imaging.
At the Vet's Office
There are various ways veterinarians can confirm cases of dehydration through a variety of diagnostic tests. Dogs with moderate to severe dehydration usually have: increased packed cell volume, increased total plasma protein levels and abnormally altered urine specific gravity.
When dealing with a dehydrated dog, there are three main goals: 1) replacing the lost fluids, 2) correcting the electrolyte abnormalities and 3) identifying and resolving the underlying cause.
Dehydrated dogs should be offered small sips of water every few minutes. The water can be fortified with electrolyte replacement powder. Another alternative is to offer ice cubes which the dog will slowly lick. If a dehydrated dog takes in too much water too quickly it is likely to vomit, which only exacerbates the dehydration.
Dehydration can be prevented in dogs by offering plenty of fluids. It is advisable to put several bowls of water so that your dog has easy access. If going for a walk, bring bottled water and portable bowl with you. Every meal should be backed-up with a bowl of clean, fresh water.
If your dog refuses to drink water for a longer period of time or if it drinks normally but looks dehydrated, do not hesitate to contact your trusted vet.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia. She is a certified nutritionist and is certified in HAACP food safety system implementation.
She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.
Ivana’s research has been published in international journals, and she regularly attends international veterinary conferences.