What this means
Swollen legs show as a thicker, rounder limb with a soft, puffy area of skin, and sometimes a dent stays when you press with a finger. One or several legs may be swollen, and the belly or chest may be too. A dog may move with more difficulty, play less or seem weighed down.
Legs can swell for very different reasons: too little protein in the blood, a problem with the heart or kidneys, an inflamed or injured joint, or poor drainage of lymph. A single swollen leg more often points to a local problem, while several legs or the belly together suggest that something is wrong in the body as a whole. Only a vet can tell which.
Note when you first saw the swelling, which legs are swollen, whether it is growing, whether your dog is drinking and urinating more, and whether it is vomiting, has diarrhoea, is losing weight or eating less. If you can, photograph the legs so the vet can see the change. Do not massage the legs or try to "squeeze out" the fluid yourself.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Protein loss through the gut
When the gut can no longer hold on to protein, the level in the blood falls and fluid collects in the legs or belly. Diarrhoea and weight loss often go with it.
About the condition: Protein-losing enteropathy -
Protein loss through the kidneys
Damaged kidneys can let protein escape into the urine, and then fluid builds up under the skin or in the belly. The dog may drink and urinate more and eat less.
About the condition: Protein-losing nephropathy -
A heart problem
When the heart no longer pumps blood well enough, fluid can collect in the legs, belly or chest. A cough or faster breathing may go with it.
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Local inflammation or injury
A single swollen leg often points to an injury, a bite, an abscess or an inflamed joint. It is tender and warm.
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Poor drainage of lymph
When lymph cannot drain freely, a leg can swell. A vet has to find the cause.
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Blood vessel or other disease
Sometimes swelling is caused by a blood vessel problem or another illness. It can only be recognised by examination and tests.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Which legs are swollen and whether the swelling is growing
- Whether a dent stays when pressed with a finger
- Whether the belly or chest has also enlarged
- Whether your dog drinks and urinates more than before
- Whether it is vomiting, has diarrhoea, is losing weight or eating less
- Whether your dog breathes harder, coughs or limps
When to book a routine visit
If your dog's legs have swollen, book a vet visit promptly. Say which legs are swollen, when you noticed it and whether your dog's thirst, urination, stools or appetite have changed.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Protein-losing enteropathy Digestion and liver This is a condition in which a damaged gut wall lets too much protein from the blood leak into the intestine, where it is lost. It is not a single disease but the result of various intestinal disorders, such as long-term inflammation or changes in the gut's lymph vessels. When protein levels in the blood fall, fluid can collect in the belly or under the skin, so this is a condition that needs a vet's attention.
- Protein-losing nephropathy Kidneys and bladder This is a kidney disease in which the kidneys' damaged filters start letting protein escape into the urine instead of keeping it in the blood. Over time the kidneys can weaken, and the loss of protein upsets the body's fluid balance and can affect other organs. There may be no signs at all in the early stages, so it is sometimes found only when the urine is tested.
Body systems: Digestion and liver Kidneys and bladder