Dehydration In Cats: Symptoms, Risk Factors & Treatments

With their body made up of almost 80 percent water, your cat needs to regularly replenish their inner fluid levels to keep healthy and happy. However, most felines don’t have the strongest desire to drink, leading them to be potentially at risk of dehydration.

Dehydration occurs when your puss’s water and electrolyte levels fall out of balance, putting a strain on many of their biological and physical functions. Allowed to drop and your cat can become seriously dehydrated, which can be a life-threatening situation. Signs of dehydration in your kit can also indicate an underlying medical problem which will need to be investigating.

So how do you recognize dehydration in your feline friend, and know when it is simply down to a lack of water or something potentially more serious? We take a look at dehydration in cats to answer all your questions.

What is Dehydration?

As with all mammals, water is essential for your cat, who depends on an adequate daily intake of fluid to maintain optimum health and wellbeing. With your kit’s body made up of almost 80% water, they need H2O for all their biological functions as well as to replace fluid lost through urine, feces, and respiration.

Dehydration occurs when there is an imbalance of water and electrolytes (minerals such as sodium, chloride, and potassium) in your cat’s body – excess fluids are lost or absorbed, and not enough water is entering the body to replace it. This process is called hypohydration and happens when their fluid level drops by five percent. Severe dehydration occurs when fluid levels drop by 10 percent or more, while your feline will struggle to survive a fluid loss of more than 15 percent.

Dehydration in your cat can simply be caused by an inadequate water intake to maintain their fluid levels or can be a symptom of an underlying physical or biological cause.

How Much Water Does My Cat Need?

The amount of water your cat should be drinking each day does depend on numerous factors, including the size of your kit, the weather, and temperature as well as whether your cat eats a wet or dry food diet. Dry food is only around 10 percent water whereas wet and canned cat food can be as much as 80 percent so a cat on a dry food diet is going to need to drink more water each day to reach the optimum.  As a general rule of thumb, a cat typically needs to drink between 3.5 and 4.5 ounces of water per five pounds of body weight per day, adjusted to take into account the varying factors.

Symptoms of Dehydration in Cats

It’s important to be able to recognize the early warning signs that your puss may be dehydrated so that it can be rectified or checked out before it becomes a serious situation for your pet. One simple way to see if your cat is not sufficiently hydrated is to gently lift the scruff of their neck (the area of fur between their shoulders) and see if it immediately returns back to its smooth state. If the scruff stays raised for longer then this reduced skin elasticity could be a sure sign that all is not right with your cat’s bodily fluid levels.

Other signs that your cat may be dehydrated include:

• Sunken eyes: Reduced fluid levels will leave your cat’s eyes looking dull, sunken, and with a drowsy look.
• Lethargy: Dehydration is going to sap your pet’s energy levels, meaning he will be less inclined to interact or move around. If your cat is uncharacteristically lazy, is sleeping more and simply not interested in play time, then lowered fluid levels could well be the cause.
• Elevated heart rate: The normal heart rate for an adult cat is around 160-240 beats per minute, depending on their size. Reduced hydration can cause the blood to thicken, meaning a cat’s heart will have to beat harder to get it moving around the body, so increasing their heart rate.
• Reduced urination: Your cat has fewer fluids to remove so will be using their litter tray less frequently, so keep an eye on their toilet habits if you suspect dehydration, especially if they also appear to be off their food. Your cat’s kidneys will be detecting dehydration when there is a reduction in blood volume so it will reduce the amount of urine produced to help conserve water. Constipation can also be an issue in a dehydrated cat. Check out our guide on the best cat food for constipation for more info.
• Dry mouth: Dehydration will slow down the refilling of your cat’s capillaries and mucus membranes. A hydrated cat’s mucus membranes in their mouth will be pink and moist, whereas they will be paler, dry and tacky to the touch if their hydration levels are below par. This can also be the case for the mucus membranes in their inner eyelids. You can check if your cat’s capillary refill time has been reduced by pressing on their gums gently for a couple of seconds. When you release the pressure, their gums should return to pink within 1-2 seconds. If it takes longer than this, then your cat has some level of dehydration.
• Panting: This is unusual behavior in a cat, so if your puss is breathing fast with their mouth open could be a sign of overheating, which can lead to dehydration.

Factors that Can Increase the Risk of Dehydration

Left unchecked or untreated, dehydration is going to cause harm to your cat and even at a lower level can lead to long-term health complications. Always ensuring your cat has access to a supply of fresh, clean water can keep the symptoms of dehydration at bay, but there are also other factors that can increase the risk of dehydration in your cat, especially if they are elderly, nursing or have a complex medical history.

The main factors that can increase the risk of dehydration in felines include:

• Heatstroke

It goes without saying that your puss will lose fluids in hot weather as their body works to regulate their temperature. As cats only sweat from the exposed parts of their body such as nose and paws and don’t normally pant, they are as risk of overheating, which also pushes up their rate of fluid loss, leading to dehydration. Check your cat’s body temperature, anything 103°F and above, seek veterinary advice.

• Diarrhea or vomiting

Just like humans, a vomiting cat, or a cat stricken with diarrhea is going to lose fluids quite quickly and if it is not sufficiently replaced, at risk of dehydration. There can also be added complications in the case of diarrhea as it increases the loss rate of electrolytes, leading to mineral and pH imbalances in the body. While a vomiting cat is less likely to want to drink water, gently encourage them to do so and if their diarrhea or vomiting is prolonged and their hydration levels are seriously reduced, seek veterinary intervention.

• Kidney problems

For a cat with kidney or renal disease, dehydration can be a serious problem. The kidneys’ job to filter the blood, remove toxins and then recycle/re-absorb water back into the body but if the kidney function is compromised, the ability to complete this task is reduced, leading to increased urination. If your cat’s fluid intake levels remain insufficient, eventually less urine is produced as their renal systems start to fail. Prompt veterinary treatment to intravenously replace your cat’s fluids can help to reverse the effects of dehydration. Take a look at our review of cat food for kidney disease for more options.

• Diabetes

Feline diabetes often presents itself as frequent urination – or polyuria caused by increased glucose levels in the blood – and excessive thirst, which can also be a sign of associated dehydration.  As your diabetic cat goes to the loo, the volume of urine can be increased to get rid of the filtered-out glucose, leading to a loss of vital fluids and ultimately a dehydrated puss.

• Hyperthyroidism

As a metabolic condition, feline hyperthyroidism can raise your cat’s body temperature, leading to the removal of vital fluids from the body and the risk of dehydration. Other symptoms of hyperthyroidism include vomiting and diarrhea, which can also lead to fluid loss, as well as an increased thirst in your pet.

• Dry cat food

Most cats don’t have a naturally high thirst as they tend to get most of their water from the food they eat. This comes from the wild where, as predators, cats absorbed the water from the bodies of their prey. However, many domestic cats are fed dry cat food and so, unless they are given sufficient supplementary water to make up the fluid shortfall from their food, are susceptible to dehydration.

Dehydration Treatments

Dehydration in a cat that is not alleviated by freshly supplied water as well as taking your pet out of any risk situations such as hot temperatures should be investigated as it could indicate a serious underlying problem.

If your cat is able and willing to drink, move them to a cool, calm and quiet place in your home and provide them with some fresh, cool water. To encourage them to drink, try using a cat water fountain or adding the juice from a canned tin of tuna or salmon into their water.

If you suspect dehydration in your cat that you cannot relieve, then take them straight to your vet, where the professionals can provide an accurate diagnosis and appropriate treatment. The aim of your veterinarian will be to replenish not only your cat’s fluid levels but also the essential minerals they have also lost, which means they could also need an additional electrolytes solution to help their body absorb water again. These fluids will be administered to your cat either intravenously (into a vein) or subcutaneously (under their skin). If the suspected cause of your cat’s dehydration is vomiting or diarrhea, then they may also be given medication to stop this happening.

Once your cat’s immediate hydration levels are raised and controlled, your vet may then recommend further tests to investigate any potential underlying causes for their dehydrated state. You may also be given guidance on how to continue the re-hydration process for your cat at home.

Preventing Dehydration in Cats

If any underlying causes for potential dehydration has been ruled out then there are easy, practical steps you can take to ensure your puss is always happily hydrated.

• Always ensure your cat has access to clean water at all times and as cats can be fussy when it comes to taste and hygiene, change it frequently to make sure it is always fresh and keep their water bowl sparkly clean. Find out more about water bowls for cats here.
• Try to match how you provide your cat with water to how they prefer to drink. Some cats do not like drinking water next to their main food bowl in case it gets dirty or would respond better to several water bowls placed around his favorite spots in your home. Many cats like to drink from free running water – if your cat likes to hop onto the counter to drink from the kitchen faucet then there’s a good clue – so consider buying a cat water fountain he can use.
• Aim to pre-empt potential dehydration and nip it in the bud. Monitor your cat’s typical daily fluid intake and work out how much they should be drinking for their size and weight.
• Look at ways to encourage a reluctant cat to drink more often – this can be through an attention-grabbing pet water fountain or by adding a little flavor to their water with a few drops of tuna or chicken broth.
• Ensure they get supplemental hydration from their food by feeding your kit high quality wet cat food, which can contain up to 80 percent water. If they simply won’t give up their dry kibble, then always make sure they have a filled water bowl close to hand.

The Final Word

Dehydration in cats should be taken seriously and owners should make sure they know how to recognize the early warning signs. In many cases, with a little quick-thinking and some remedial action, you can nip their fluid loss in the bud and put your feline back on their hydration track. However, there can also be an underlying medical problem causing your cat to be dehydrated so it is always wise to seek professional veterinary help if you suspect your cat’s fluid levels are under par. This way they can get the correct treatment they need and put back on a healthy hydration track.