Dehydration in Cats & Dogs

Reading progress

Dehydration is a serious concern for both humans and our pets, particularly during the summer months. If your pet doesn’t drink enough water on a warm day, dehydration may set in quickly, so it’s important to know the cause, signs, how to treat it, and when to see your veterinarian.

What is dehydration, and what are the causes?

Dehydration is a condition that can affect any species of pet, and occurs when more fluid is lost from the body than is taken in. This may be caused by symptoms of disease such as vomiting and diarrhoea, chronic kidney disease, untreated diabetes mellitus or simply not having access to enough clean water.

Dehydration may be further associated with conditions such as heat stroke, as it also plays a role in maintaining normal body temperature in the heat.

It is therefore important to ensure that your pet always has access to fresh, cool water at all times.

Are certain animals prone to dehydration?

Although any cat or dog can become dehydrated, young (especially infants) and geriatric animals are more at risk. Additionally, any cat or dog that is older or nursing a litter is more prone to dehydration.

What are the signs & symptoms?

Depending on how dehydrated your pet is, and the cause of dehydration, symptoms of dehydration may include:

• Loss of appetite

• Lethargy and/or weakness

• Vomiting and/or diarrhoea

• Dark, concentrated urine

• Excessive panting

• Sunken eyes

• Loss of skin elasticity and prolonged skin tenting

• Very pale or bright red gums

If you’re worried that your pet isn’t drinking enough but isn’t showing any of the signs of dehydration mentioned above, they may be fine.

Wet pet food has a high water content, so it is possible they may be receiving enough daily water from their diet. However, if your pet suddenly stops drinking as much as usual, it’s best to speak to your veterinarian for advice.

How to prevent dehydration in cats & dogs

There are a number of ways you can help your pet to maintain an adequate water intake by ensuring your pet has access to fresh water at all times.

Bacterial prevention: fresh, clean drinking water

Both the food and water bowls need to be thoroughly cleaned once a day to prevent slime and bacteria from accumulating.

Placing the bowls out of direct sunlight will also help decrease the speed at which bacteria can grow and keep water cooler for longer.

Supply the right quantity of water for your pets

If you have more than one pet, use multiple water bowls so that each pet has their own water supply.

Take water on the go

If you plan to take your pet for a long walk, running or hiking, you should always carry a supply of water with you.

Schedule activities for when it is cooler

Try to avoid going out at the hottest times of the day around noon, and limit your pet’s activity levels at these times and during hotter days as far as possible. Early morning and late afternoon/early evening are better times to go out with your pet to avoid heat-related dehydration.

Cats: Location, location, location

Many cats do not like to drink water that is located anywhere near their food source. To ensure your cat is drinking enough, try placing their water somewhere else at home, such as in the bathroom or in a corner of the kitchen.

They can also be fussy about drinking from a bowl – if this seems to be the case, try using a large mug to sip their water from.

Image source: Hill's

When to see a vet for dehydration in cats & dogs

If your pets are presenting any of the more severe symptoms mentioned above, seem to be in pain, are not eating, or are experiencing vomiting and/or diarrhoea, you should seek veterinary attention immediately.

SPCA Case Study

Cape of Good Hope SPCA Veterinarian Dr Stephan Spamer BVSc (UP) gives the background of a recent dehydration case at our Animal Hospital

The staffie was a previous patient that came in and was diagnosed with a suspected partial laryngeal paralysis. This meant that the integrity of his upper airway was compromised. As it was a staffie, it is also a brachycephalic breed, (literally translated to “short face”) which in essence means that the upper airway is shortened. In many cases, staffies have some degree of compromised breathing ability.

Brachycephalic breeds have shortened upper airways, meaning many staffies have some degree of compromised breathing ability.


In this particular case, the owners took the dog for a walk in the afternoon,  around 3-4 pm. The dog had had a history of some respiratory difficulty when walking, but in this case, it was significantly more severe. The dog went into complete respiratory distress and started to turn purple. As the respiratory system is part of the normal temperature maintenance system of the dog through panting, and this breed is compromised in this regard, he could not cool down effectively. In addition, due to the increase in heat, his body temperature started climbing, his metabolic rate increased and oxygen demand also increased. As he started becoming distressed with the overall lack of oxygen (a combination of heat stroke and difficulty in getting enough air due to anatomic configuration) the dog went into complete respiratory distress in addition to the heat stroke.

He was brought into the SPCA and the theatre team spent the next 30-40 minutes intensively managing the case. This was a combination of 100% oxygen supplementation, light sedation to lessen distress, intravenous fluid therapy and cooling the dog down, among other things. The dog came in with an initial temperature of 41.5º (normal 37.5º-39º). After intensive treatment, we managed to get the temperature down to 38.3º, after which the dog was admitted to our ICU for continued fluid therapy and monitoring. The dog was able to be discharged over the weekend and is very lucky to have made a complete recovery.

This is a prime example of a dog being taken for exercise at a sub-ideal environment (in this case heat, and a dog that cannot breathe properly) that ended up with a life-threatening condition.

Heat strokes can result in death, especially in compromised breeds. Complications may include multiple organ failure which may well result in the death of a pet.

Dehydration is a condition that can affect any species of pet, and occurs when more fluid is lost from the body than is taken in.

Share This



Thank you for helping our Animal Hospital to deliver veterinary care to the hundreds of animals who come through our doors.

Thank you for everything you do to help make this a better world for all animals.

Contact Our Inspectorate

The SPCA is the only organisation that offers a 24-hour Inspectorate service.

Contact our Inspectorate by calling us on
(021) 700-4158/9
083 326 1604 (after hours)

Hospital SPCA 1 By BRIGFORD -103

A Gift That Lasts Past A Lifetime

It was a bequest made by the late Val Gorfinkel that enabled our Animal Hospital to receive a much-needed revamp about 16 years ago. That upgrade helped ensure that 40 000 animals received veterinary help during the past year.

Find out how to become an Animal Guardian by leaving a gift for us in your will.

More Hospital News

Shopping Basket