Skip to main content
Updated date:

Seromas: Bumps on a Dog's Surgery Incision

Adrienne is a certified dog trainer and former veterinarian assistant who partners with some of the best veterinarians worldwide.

Seromas are bumps filled with serous fluid often seen after a dog's spay surgery

Seromas are bumps filled with serous fluid often seen after a dog's spay surgery

A bump on a dog's surgery incision is likely the last thing a dog owner may want to see on their canine companion. After all, as pet parents, we all wish our dogs would recover uneventfully after surgery—with the incision healing well, smooth skin, and no redness or discharge.

Waking up to find angry skin with a suspicious lump or bump on the dog's incision can surely lead to worrisome thoughts. Is the swelling an abscess? Can it be a hernia? Fortunately, in several cases, the swelling turns out to be a simple seroma.

Veterinarian Dr. Ivana Crnec shares information on seromas in dogs what causes them to appear, what dog owners should do and how they are treated. You may also find it helpful to look at some pictures of seromas in dogs so that you know what they typically look like.

Several other causes of lumps and bumps on a dog's surgical incision are covered as well so that you know other potential causes for similar-looking bumps which turn out not to be seromas.

Of course, it's always important that you consult with your veterinarian if you notice anything unusual about your dog's surgical incision. Some surgical complications may be serious and require quick veterinary attention.

It's important to monitor your puppy's surgical incision daily for presence of seromas.

It's important to monitor your puppy's surgical incision daily for presence of seromas.

Understanding Seromas in Dogs

What are seromas in dogs? A seroma is a serous fluid accumulation that generally occurs at the incision site after surgery. The term "serous" indicates a specific type of fluid composed of blood plasma and inflammatory cells.

Seromas develop due to the dog’s movements post-surgery as well as the body’s reaction to the sutures used for closing the surgical incision.

Unless there are some significant complications, seromas do not require special veterinary attention and tend to resolve on their own over the course of several weeks.

However, their resolutions are quicker and smoother if medical intervention is performed. Treatment is also warranted in case of non-surgical seromas causing systemic issues.

For better understanding, canine seromas can be classified into two major groups:

  • Surgical seromas occur as a post-surgical complication above the incision line
  • Non-surgical seromas can occur anywhere on the body and are not associated with surgical procedures.

In this article, we will be mostly discussing surgical seromas.

Where Do Seromas Appear?

Seromas develop at incision sites and the accumulation of fluid is generally localized between the skin and subcutaneous tissue. However, on rarer occasions, fluid accumulation can occur between two layers of muscle.

Surgical seromas can occur on every incision line regardless of its location, but statistically speaking they tend to be more common on surgeries involving the ventral midline, or in simpler terms, the central part of the dog’s belly.

What Causes Seromas in Dogs After Surgery?

Dogs undergoing a surgical procedure in the ventral midline have a 10 percent chance of developing a seroma. This means that out of ten operated dogs one will develop a surgical complication in the form of seroma.

Seromas are typically a surgical complication most likely to occur after abdominal surgical procedures involving the central line. Common examples are spaying and neutering procedures.

Although the exact causes leading to seroma development are not fully understood, the chances increase in the following scenarios:

Read More From Pethelpful

  • If the veterinary surgeon performs an excessive dissection of the skin and subcutaneous tissue (this means removing more tissue than necessary)
  • If the veterinary surgeon traumatizes the tissues more than they can handle or in other terms practices poor or better said rough handling
  • If the veterinary surgeon does not close the incision properly and the body starts reacting to the suturing materials.

These factors are all related to the surgeon and its practices.

What Do Seromas in Dogs Look Like?

Seromas appear as soft and often painless masses. When a dog develops such a mass on or near an incision site, it is a telltale sign of a seroma. Usually, a dog with a seroma will manifest the following signs and symptoms:

  • Swelling of the incision area
  • Local irritation and reddening of the skin
  • Increased temperature around the site
  • Clear fluid leaking from the site
Picture of a seroma in dog. This bump over the surgical incision of a puppy I was fostering turned out being a seroma.

Picture of a seroma in dog. This bump over the surgical incision of a puppy I was fostering turned out being a seroma.

What Happens at the Vet's Office?

If your dog had recent surgery and now has a bump over the incision line, it is best to call your vet and explain the situation.

Depending on the circumstances, the vet may recommend close monitoring or a follow-up. In both cases, it is critical to follow his/her instructions.

Differential Diagnosis: Seroma Look-a-Likes

Because of how they look, seromas can often be confused with various other conditions and formations. Differential diagnosis is the term used by veterinarians to depict the process of ruling out similar conditions and look-a-likes.

Here are some common differential diagnoses and how to reach them.

Seromas Versus Hernias

Seromas are often confused with hernias, especially when occurring at incision lines. Hernias occur when an internal organ pushes through a weakness in the muscle protruding out.

However, statistically speaking, hernias are far less common complications than seromas. Although uncommon, just to be sure, the vet will palpate the mass and if necessary, perform ultrasonography to examine the content of the formation. The ultrasound image will reveal whether the content is fluid (seroma) or organs (hernia).

Seromas Versus Hematomas

To make this differentiation, the vet will have to extract some of the fluid from the formation. The basic difference between a seroma and a hematoma is in its contents: seromas are filled with serous fluid while a hematoma is filled with blood.

The serous fluid is made from blood plasma and inflammatory cells – it does not contain red blood cells. On the other hand, the typical hematoma is filled with full blood and contains red blood cells.

Seromas Versus Abscesses

Once again, the vet will have to extract some fluid in order to differentiate the two. Abscesses are filled with pus and just looking at the fluid composition is enough to make a differentiation. Pus has higher consistency, is cloudy, and is characterized by a repulsive smell. On the other hand, the fluid contained in a seroma is clear, transparent, and scentless.

Seromas Versus Tumors

Touching the formation can provide the vet with useful information. Namely, seromas are soft and squishy while most tumors are typically hard. However, if the veterinarian suspects a tumor, he/she will need to either extract fluid and perform a fluid analysis under a microscope or take a tissue sample for more in-depth analysis.

Treatment Options for Seromas in Dogs

After confirming the presence of a seroma, the next step is deciding what treatment option to pursue. When it comes to managing canine seromas, there are two main options:

The first option is to let the seroma resolve on its own. Basically, the body will absorb the serous fluid in around 10 to 20 days.

The second option is starting a treatment plan which may consist of various steps. If you and the vet agree on treating the seroma, or the 20-day timeframe passed and the seroma is still present, here are some treatment options.

  • Fluid extractions: The vet will use a large needle and syringe to extract as much fluid as possible. This is not always an efficient method as the body may start generating new fluid as soon as the old one is removed.
  • Seroma drainage: If the extraction does not work, the vet will place a drain to ensure constant drainage of the fluid and prevent accumulations. The drain can be left for a couple of days and then removed if the build-up stops.
  • Antibiotics: These meds are used in conjunction with other treatments when dealing with an infected seroma. Yes, seromas may get infected and infected seromas may progress to an abscess.
  • Analgesics: They are also used in conjunction and in situations where the seroma is causing pain.
  • Corticosteroids: These can be used to decrease the swelling and manage the local inflammation process.
  • Surgical correction: This is the treatment of last resort and is usually undertaken when there is no other option. Surgical treatment of the seroma is indicated in situations where the accumulated fluid forms a protective capsule that prevents its extraction and drainage.
My puppy's seroma went down after several days, just in time for adoption day!

My puppy's seroma went down after several days, just in time for adoption day!

Can You Prevent Seromas in Dogs?

There is no method for ensuring a seroma-free procedure and 100 percent prevention. However, the chances of developing a seroma can be decreased through certain practices occurring during the surgery itself and in the post-operative recovery period.

During surgery

These tips apply to how the surgeon handles the procedure. Namely, the veterinarian performing the surgery should remove as little tissue as possible and avoid leaving so-called empty spaces that the body tried to fill with serous fluid.

The vet should also handle the tissues gently and with extreme care. Finally, the veterinary surgeon must close the incision properly. This means choosing the right suture material, not leaving gaps, and not applying too much pressure.

During Recovery

During the recovery period, seroma prevention is based on several aspects, including:

  • Applying compresses over the wound
  • Keeping the dog in a quiet place to prevent unnecessary movements
  • Using the Elizabethan collar to stop the dog from licking the surgical site and triggering infections.

The Bottom Line

Seromas in dogs are a potential complication after any surgery. However, they are not a reason for avoiding surgical procedures especially if they can improve the dog’s quality of life or prolong their health.

If your dog develops a seroma, it is best to follow up with the surgeon performing the procedure. In most cases, the vet will recommend careful monitoring and recommend treatment only if there is a risk of worsening or developing additional complications.

All in all, every surgical procedure can be followed by seroma formation as a complication, but luckily, more often not, seromas are a benign issue that is either self-limiting or easily solvable.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2021 Adrienne Farricelli

Related Articles