Other health problems

Signs of Severe Dehydration in Cats

 
Laura García Ortiz
By Laura García Ortiz, Veterinarian specialized in feline medicine. January 23, 2025
Signs of Severe Dehydration in Cats
Cats

See files for Cats

To stay hydrated, cats in the wild rely more on prey than fresh drinking water. Domestic cats have the benefit of their guardians to provide drinking water, either in water bowls, fountains or other drinking devices. This is important, especially if they eat kibble which is low in moisture compared to wet food or actual prey. While providing this form of water intake is important, other factors can lead to cat dehydration. These include environmental factors, issues with our care or even health issues which have dehydration as a clinical sign. Extreme dehydration in cats is rare if their needs are appropriately met, but there are circumstances when it can occur.

At AnimalWised, we look at 8 signs of severe dehydration in cats. If a cat has not drunk water for over 48 hours or if illness has caused them to lose fluids, dehydration signs will begin to manifest. In addition to sharing these symptoms, we look at how dehydration in cats can best be prevented.

You may also be interested in: How to Tell if a Cat is Dehydrated
Contents
  1. Loos of skin elasticity
  2. Dry mucous membranes
  3. Sunken eyes
  4. Lethargy and loss of appetite
  5. Increased capillary refill time
  6. Increased density of urine
  7. Bad breath
  8. Signs of shock
  9. Treatment for a severely dehydrated cat

Loos of skin elasticity

Reduced skin elasticity can be seen when the cat's skin is manipulated, but does not return to its original position. While elasticity of a cat's skin can vary a little due to other factors, a well-hydrated cat should have firm skin with good elasticity. This is one of the first signs of dehydration in cats and it will worsen if the problem is not addressed.

When a cat's degree of dehydration is between 5-8%, loss of skin elasticity will begin to manifest. A complete loss of skin elasticity is seen when this rises to 8-10% dehydration. In these cases, the skin will move very slowly when returning to its original position after being pinched. The skin will stay in place once the dehydration level in the cat is greater than 10-12%.

Skin not returning to its original position after being pinched is a clear sign of severe cat dehydration. You will also see other symptoms due to the organism of the feline shutting down. We look at these other signs below.

Signs of Severe Dehydration in Cats - Loos of skin elasticity

Dry mucous membranes

Although a cat's fur will deteriorate over time if they have health concerns, dehydration is a process which can act quickly on their body. For this reason, loss of coat conditioning is not usually a sign of severe dehydration because the cat can die before this happens. We may not be able to observe dehydration in the mucous membranes are affected. As with skin elasticity, loss of moisture in the mucous membranes is one of the first signs of dehydration in cats.

Dehydration causes them to be drier than normal, appearing slightly sticky and dry to the touch in the case of 5-8% dehydration. They become even drier and stickier when dehydration exceeds 8%. An example where they are usually seen is in the gums, which are normally pink and moist. In a severely dehydrated cat this moisture is lost.

Learn about how to treat mild dehydration at home with our related guide.

Signs of Severe Dehydration in Cats - Dry mucous membranes

Sunken eyes

As with the previous symptom of dehydration in cats, if it is around 8-10%, the eyes begin to look drier and sunken than normal. This becomes more noticeable as the degree of dehydration of the small feline increases as a result of lack of nutrition. An extremely dehydrated will have an almost completely different expression than normal due to their very sunken eyes. It will also appear as if it is difficult to open and close them properly.

Signs of Severe Dehydration in Cats - Sunken eyes

Lethargy and loss of appetite

Another of the main symptoms of dehydrated cats is that they are weaker and lethargic as a result of the loss of electrolytes and fluids. In addition, they also tend to lose or reduce their appetite, which further increases dehydration.

When a cat is extremely dehydrated, they will move slowly. Eventually, they will not be able to move at all and will stay in the same spot. As they become weaker, it can be more difficult to provided water for the animal. They can often be too weak to drink or eat on their own. In these cases, intravenous fluid therapy may be required, one of the reasons it is important to consult a veterinary professional if a cat is severely dehydrated.

Discover some of the reasons a cat is not eating or drinking in our related guide.

Increased capillary refill time

Capillary refill time is the interval it takes for the blood capillaries in the gums to fill with blood after having mechanical pressure exerted on them. In a well-hydrated cat, this process occurs instantaneously. In cats which are dehydrated at a level of 10-12%, the capillary refill time is lengthened. This delay time increases as the degree of dehydration becomes more severe.

Increased density of urine

Urine specific gravity is a test which is carried out as part of urinalysis to determine the level of water in urine. This is because water-soluable molecules in the urine will be of a greater concentration when they are dehydrated due to the presence of less fluid.

A dehydrated cat will have a urine specific gravity greater than 1.035, this will be noticeable to guardians because the cat will urinate less and the urine will be darker in color. In some cats with polyuria and a reduced ability to concentrate urine, the specific gravity may be normal or even low. In these cases, the cat will be in an isosthenuric, hyposthenuric or mildly hyposthenuric state, despite having a fluid deficit.

Signs of Severe Dehydration in Cats - Increased density of urine

Bad breath

Bad breath in a dehydrated cat can be a sign that their body is struggling to balance fluid levels. Dehydration can affect kidney function, leading to a buildup of waste in the blood. This is a process known as uremia. This excess of waste and toxins can produce an unpleasant odor on the breath, often described as an ammonia-like smell. A dry mouth due to dry mucous membranes can also contribute to this smell.

Our related article shared other reasons why a cat's breath stinks so bad.

Signs of shock

When a cat is severely dehydrated, their organism will start to shut down. If this progresses without being able to establish fluid levels in the body, the cat will go into shock. This can start to occur after the cat exceeds a dehydration level of 12%. Some of the signs of shock in cats include the following:

  • Changes in heart rate (e.g. bradycardia or tachycardia)
  • Hypotension
  • Low quality pulse
  • Warmth of the mucous membranes
  • Syncope (fainting)

In cases where these signs of severe cat dehydration are observed, it is considered a veterinary emergency situation. We will need to take them to a professional immediately as they are at risk of death.

Learn about what happens when a cat goes into shock due to an allergic reaction with our article on the signs and symptoms of anaphylactic shock in cats.

Signs of Severe Dehydration in Cats - Signs of shock

Treatment for a severely dehydrated cat

When we are providing for their daily life, we can provide ways to encourage water intake in cats. These include refreshing their water regularly, providing wet food instead of dry kibble and installing water fountains around the home.

For a cat that is severely dehydrated, these solutions won't be enough. In extreme dehydration, the cat's life will be under threat and they will be at risk of death. In these cases, we will need to take them to a veterinarian. The professional will likely provide intravenous fluid therapy to restore fluids and electrolytes. The most commonly used fluids are Lactated Ringer's solution or 0.9% saline solution.

The underlying cause of their dehydration will also need to be addressed, but the priority will be based on stabilizing them. Once fluids have been replaced, the symptoms of extreme dehydration we have shared will start to subside. Deciding the best course of action is the responsibility of a professional, so we should not try to treat a cat at home if they are severely hydrated.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Signs of Severe Dehydration in Cats, we recommend you visit our Other health problems category.

Write a comment
Add an image
Click to attach a photo related to your comment
What did you think of this article?
1 of 6
Signs of Severe Dehydration in Cats