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A lump on a dog's belly following spay surgery may be an unexpected finding that may cause dog owners a sense of alarm. What is this lump? How did i form? And what should dog owners do if they identify it?

 Veterinarian Dr. Ivana provides information on dog seromas following surgery and the importance of keeping an eye on and protecting the incision. 

Seromas in Dogs 

A seroma is a newly formed pocket filled with serum. Serum is the serous part of the blood – a clear (sometimes pale pinkish) fluid that does not contain red blood cells. The new pockets usually form in incision sites or areas of the body that experience frequent and substantial movements.

According to some definitions, seroma develops when there is serum accumulating outside the blood vessels. This definition supports the previous explanation of newly formed pockets.

Upon touch, seromas feel like slightly moveable, water-filled balloons. They vary in size but under normal circumstances, they should be painless, normally colored and normally temperate.

Where do seromas develop? Seromas can develop virtually anywhere on the dog's body, but they are more frequently reported in high-motion places, such as knee, shoulder, wrist. However, they can also form under the skin (known as subdermal seromas), in the ears, in the head or brain or in any other organ.

This lump on a dog's belly after surgery turned out being a seroma.

This lump on a dog's belly after surgery turned out being a seroma.

Seromas in Dogs After Spay Surgery

Seromas are most common in dogs that underwent a surgical procedure in which cases the seroma develops at the site of the incision. 

Surgery-related seromas occur when the surgeon leaves too much dead space when closing the incision. The term dead space refers to the empty space left between the abdominal wall muscles and the fatty layer of tissue just beneath the skin.

Why do seromas develop? Seromas are a relatively normal part of the healing process. Namely, when the body sustains trauma – in this case the spay incision, an inflammatory state is initiated.

 When there is an inflammatory process occurring anywhere in the body, the immune system is triggered to go into war at the trauma site. The aim of the immune system’s war is to combat potential infections and achieve faster and smoother healing process. 

Basically, the newly formed pocket is in fact the battlefield where the immune system combats potential threats.

Seroma vs. Hematoma in Dogs

It is important to differentiate between a seroma and hematoma. The seroma is filled with serum – a portion of the blood that does not contain red blood cells. 

On the contrary, a hematoma is filled with full blood – red blood cells, white blood cells, platelets and everything. 

Can Seromas Lead to Complications?

Well, seromas are a complication on their own. However, generally speaking, seromas are not painful and are a self-limiting occurrence. 

Namely, more often than not, over time, the body will reabsorb the accumulated fluid, redistribute it around the body and solve the problem naturally.

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Rarely, if the seroma gets too big it may cause discomfort. Under such conditions, the risk of infection is also greater. Therefore, if your dog developed a seroma after a spay procedure, have the seroma checked by your trusted vet. 

Based on what the vet sees, he/she will be able to advise you how to act upon it and prevent further complications.

When Do Seromas in Dogs Require Treatment?

As already mentioned, seromas are a self-limiting occurrence and if there is nothing worrisome, the vet will allow nature to take its course. 

This approach is acceptable when the seroma is small and the vet determines there are no signs of complications. Based on the exact situation, the vet is likely to advise going home and closely monitoring the seroma while applying cold or warm compresses (depending on the phase of the seroma development). 

Meanwhile, to prevent further problems, the vet will suggest keeping the dog calm or possible, cage resting. However, the vet will recommend adequate treatment in the following scenarios:

  • The seroma is large or seems larger than before
  • Upon touch the seroma feels hard or hot
  • The skin above the seroma is discolored – usually red or purple.

If the seroma is large and there are no additional complication signs, the vet will perform a draining procedure. This may sound complicated, but is in fact quite simple and efficient. 

Namely, the vet will poke the seroma with a wide needle and let the accumulated fluid drain or slowly extract it with a syringe. The procedure is quick and most dogs tolerate it well and awake.

If the seroma gets infected, the treatment of choice would be drainage followed by antibiotics. In some cases, the seroma may fill up again and require additional drainage. However, if it re-fills this time it will not grow in size as much as the first time.

Seromas in dogs after surgery can be prevented by keeping the dog quiet. 

Seromas in dogs after surgery can be prevented by keeping the dog quiet. 

Preventing Lumps on a Dog's Belly (Seromas) After Spay Surgery

The best way of preventing seromas is following your vet’s postoperative care tips and instructions.

Perhaps the most important instruction regarding seroma prevention is keeping the dog less active for couple of days. More precisely, recovering dogs should perform no strenuous physical activity for 7 to 10 days.

Keeping a dog less physically active is easier said than done. Most dogs recover from spay surgeries really quickly and are back to their usual and active selves in no time. However, here are some useful tips on restraining lively, rambunctious and overly-playful dogs:

  • Practice crate time when you cannot supervise and restrict your dog’s movement. Do not think of the crate as a punishment method – the crate time is for your dog’s own safety and should be perceived as a safe place.
  • When going outside for peeing and pooping, keep your dog on a leash. Once she does her business take your dog back home. You will have plenty of time for walks as soon as she fully recovers.
  •  If your dog feels overly-excited whenever approached delegate one room of the house as her personal recovery room.
  • If you have kids explain them what is going on and how your dog needs a few days of uninterrupted rest.
  • Last but not least, the vet will advise to keep the Elizabethan collar on your dog during the healing period. If your dog has a seroma, and the seroma is continuously licked, it may rupture and infect.

About the Author

Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.


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