Hygroma on dogs is a condition that may sound unfamiliar to many dog owners, but it's relatively common—especially among large and giant breeds. This article explores what a hygroma is, why it develops, how it's diagnosed, and what you can do to treat or prevent it.

What Is a Hygroma?

A hygroma is a fluid-filled swelling that typically forms over a bony prominence—most commonly the elbow (olecranon) in dogs. It occurs when repeated pressure or trauma leads to the accumulation of serous fluid (a clear, watery liquid) within a newly formed sac under the skin.

These swellings are generally non-painful and not infected, though complications can occur if the hygroma becomes secondarily infected or ulcerated.

What Causes a Hygroma?

Hygromas are caused by repeated trauma or pressure, typically due to lying on hard surfaces. Dogs most at risk include:

  • Large and giant breeds (e.g., Great Danes, Mastiffs, Saint Bernards)

  • Dogs with thin skin or short coats (e.g., Greyhounds, Dobermans)

  • Older dogs or those with limited mobility, who lie in one position for long periods

  • Dogs recovering from surgery or illness and spending time in confined spaces

The constant pressure damages small blood vessels and tissue under the skin, leading to localized fluid buildup.

Common Locations

  • Elbows (most common)

  • Hocks (ankles)

  • Hips

  • Occasionally, the sternum or other pressure points

Symptoms of a Hygroma

A hygroma typically presents as a:

  • Soft, fluctuant swelling over a joint or bony area

  • Non-painful to the touch

  • Not warm or red (unless infected)

In some cases, a hygroma may grow quite large (up to several inches in diameter). If the dog continues to lie on hard surfaces or if the hygroma is left untreated, skin ulceration or infection may occur.

Diagnosis

Diagnosis is generally straightforward and based on:

  • Physical examination

  • Fine needle aspiration (drawing fluid to confirm the diagnosis and rule out abscess or tumor)

  • X-rays (to rule out bone involvement or concurrent joint issues)

Treatment Options

1. Early-Stage/Small Hygromas (Non-infected)

  • Protective padding or elbow pads

  • Soft bedding (thick foam or orthopedic beds)

  • Limiting hard surface exposure

In mild cases, improving the dog’s resting environment may lead to gradual resolution without further intervention.

2. Large or Persistent Hygromas

  • Needle aspiration: This removes fluid but has a high recurrence rate.

  • Draining with a Penrose drain: Risky, and often leads to complications.

  • Surgical removal: Considered only for severe, infected, or ulcerated hygromas. Healing can be slow due to the poor blood supply in these areas.

3. Infected or Ulcerated Hygromas

  • Antibiotics

  • Wound care

  • Surgical drainage or excision, in combination with protective measures

Do Hygromas Go Away?

In many cases—especially if caught early—hygromas can resolve without surgery by simply reducing pressure and protecting the affected area. However, once a hygroma becomes large or complicated by infection, more intensive treatment is required, and recurrence is possible.

Prevention Tips

  • Provide thick, cushioned bedding—especially for large-breed or senior dogs.

  • Encourage your dog to shift positions frequently.

  • Use elbow pads or wraps for at-risk dogs.

  • Keep your dog’s weight in check—obesity increases joint pressure.

  • Avoid prolonged crate confinement without padded flooring.

When to See a Vet

You should consult a veterinarian if:

  • You notice a new swelling over your dog’s joint

  • The lump is growing rapidly

  • There is redness, heat, or discharge

  • Your dog seems uncomfortable or in pain

Prompt veterinary care can help prevent minor hygromas from turning into more serious issues.

Final Thoughts

Hygromas in dogs are usually benign and manageable, especially if caught early. For pet owners of large-breed dogs or those recovering from surgery, proactive prevention is key. With the right care, most dogs recover well and can avoid surgical intervention.

If you're ever in doubt, it's best to have any new lump or swelling evaluated by your veterinarian.