If your large dog has a soft, squishy swelling on the point of the elbow, it may be a hygroma. It forms when the skin over the elbow bone is pressed against hard ground again and again, and it is far more common in big and giant breeds. [1] Left alone, it can become harder to treat, so an early vet check is worth it. [1][2]
What is a hygroma?
A hygroma is a pocket of fluid that builds up under the skin over a bony pressure point, most often the point of the elbow. Researchers describe it as a capsule of tough, fibrous tissue filled with serum-like fluid. [1]
It is linked almost entirely to large dogs, because their weight presses the skin over the elbow onto the floor every time they lie down. In a study of 373 dogs kept in breeding kennels, hygromas turned up only in giant-breed dogs housed on concrete floors. [1]
What it looks like
Most owners notice a rounded, soft swelling on the outer tip of the elbow. A hygroma can be on one or both elbows. In a study of 21 elbow hygromas in 19 dogs, 11 were on the right elbow, 6 on the left, and 4 dogs had one on each side. [2]
A hygroma is not the same as an elbow callus, which is a thick, often darker, hairless patch of skin over the same pressure point. Calluses also come from repeated pressure and friction, and the elbow is their most common site. [1] Other lumps can also appear near the elbow. See lumps and bumps on dogs, and let your vet check any new swelling.
Why it matters if it lasts
The longer the pressure goes on, the more the swelling can grow and the harder it can be to fix. Researchers note that non-surgical treatment has mixed results and often does not clear the swelling completely. [1] The skin over a hygroma can also break down: in the 19-dog study, one dog developed an open sore over the elbow after treatment. [2] Red, broken or oozing skin over the swelling is a reason to see your vet promptly.
How vets treat hygromas
Your vet will first make sure the swelling is a hygroma and not another kind of lump. Treatment depends on its size and how long it has been there. Options described in the veterinary literature include: [1][2]
- Softer bedding and less pressure on the elbow, which can slow the problem down.
- Surgical drains, sometimes left in place for some time.
- Partial or complete surgical removal, depending on how severe it is. Wounds over the elbow are under tension, so they can open up after surgery.
In the 19-dog study, 12 hygromas were first treated with a surgical drain and 9 were removed completely. Four of the 12 drained hygromas came back and were then removed surgically; the dog with the open sore needed a skin flap to close it. [2] All the dogs were healthy at a median follow-up of 16 months, and the authors judged complete removal to be effective, with fewer problems after surgery than drains. [2] Your vet will advise which option suits your dog.
Soft bedding helps prevent it
Because hygromas come from repeated pressure on hard surfaces, cushioning is the main way to prevent them. Researchers recommend soft bedding for large dogs, as it takes pressure off the elbow and helps slow the condition down. [1] Ask your vet about bedding and padding that suit your dog, especially for large or older dogs who spend a lot of time lying down.
When to see your vet
Book a visit if your dog has:
- A new swelling on the elbow or another pressure point
- A swelling that is growing
- Red, broken, ulcerated or oozing skin over the swelling
- Signs of pain, heat or limping
FAQ
Is an elbow hygroma dangerous?
It is usually not an emergency, but it can grow and become harder to treat, and the skin over it can break down. [1][2] It is best to have it checked early.
Will a hygroma go away on its own?
Not reliably. Treatment without surgery has mixed results, while soft bedding can slow the problem by taking pressure off the elbow. [1] Ask your vet whether yours needs treatment.
Which dogs get hygromas?
Mostly large and giant breeds, because of repeated pressure on the elbow when they lie on hard floors. [1]
Can a hygroma come back after treatment?
It can. In one study, 4 of 12 hygromas treated with a drain came back and were then removed surgically. [2]
The bottom line
An elbow hygroma is a fluid-filled swelling caused by repeated pressure on hard surfaces, most often in large dogs. Early vet care and soft bedding help keep it small; long-standing hygromas can be hard to clear and may need surgery.
This article is for general information and is not a substitute for veterinary advice. If your dog has a swelling on the elbow, please see your veterinarian.
Sources
- Stella J, Gomes P, Shreyer T, et al. A cross-sectional study to investigate associations between flooring substrates and prevalence of limb and paw abnormalities of dogs housed in commercial breeding facilities. Front Vet Sci. 2025;12:1466390. Open access (CC BY). https://pmc.ncbi.nlm.nih.gov/articles/PMC11880895/
- Angelou V, Papazoglou LG, Tsioli V, et al. Complete surgical excision versus Penrose drainage for the treatment of elbow hygroma in 19 dogs (1997 to 2014). J Small Anim Pract. 2020;61(4):230-235. PMID 32043576. https://pubmed.ncbi.nlm.nih.gov/32043576/