Is a Post-Abdominal Surgery Lump Normal in Cats?

Cat getting examined by a Veterinarian
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It is not uncommon for a cat to develop a lump after abdominal surgery like spay (ovariohysterectomy). Is this lump normal or a cause for concern?

Reasons for a Lump at the Surgery Site

A postoperative lump or swelling at the surgery site can mean a few different things. First things first: if you see a lump near your cat's surgery site, you should contact your veterinarian as soon as possible. Your vet is the best source of feline health advice.

Because surgery involves cutting into healthy tissues, it obviously requires some healing afterward. Some swelling at the incision is to be expected as the body heals. However, major swelling is not normal and requires immediate attention.

Suture Knots

If you see a small bump at one end of the incision may simply be the knot of the sutures. If your cat has visible stitches, you are only seeing the outer layer. Surgical closure involves a few layers. First, the vet sutures the body wall. Next comes the closure of connective tissue and fat between the body wall and skin. The skin closure is the final layer and may be done in a way you cannot even see the stitches (tissue glue may be used to help close the skin here). However, the sutures still need to be secured in place. Vets do this by tying a knot. Often, this knot is buried to keep it out of reach of a grooming cat. Under the skin, this knot may look like a worrisome lump. However, it is not a concern as long as it isn't red irritated, oozing, or painful.

Fluid Buildup

Mild to moderate swelling may occur when the body has a minor reaction to the suture material. This can cause fluid to build up, called a seroma. However, if your cat is developing an infection, the fluid may be pus. If you notice a lump that is getting larger, is warm or hot to the touch, or is oozing fluid, you will need to see your vet. Your cat may need antibiotics or other medications.

Scar Tissue

As wounds heal, the body makes scar tissue. If there's an excess of scar tissue, it can look like an abnormal lump. Scar tissue typically feels firm and ropy. It should not be painful or leak any kind of fluid.

When to Contact the Vet

Your vet will give you post-surgery instructions upon the discharge of your cat. It is important that you read and follow these as they were made specifically for your cat. These instructions will often tell you what you should watch for as your cat heals.

When in doubt, contact your vet. You will need to take your cat to see the vet if you notice any of the following:

  • The area of swelling is painful when touched gently
  • The skin over the swelling is discolored
  • The swollen area feels warm or hot to the touch
  • Bleeding or discharge is coming from the incision
  • The incision appears open or irritated
  • Your cat is still lethargic or not eating several days after surgery
  • Your cat has a rectal temperature over 103.5 degrees Fahrenheit
illustration of post-abdominal surgery lumps in cats
Illustration: Kelly Miller. © The Spruce, 2018

Post-Surgical Home Care Tips

Good communication with your personal veterinarian is key after any animal surgery. However, there are a few general tips that can help ensure your cat has a successful recovery and reduce the risk of a postoperative lump at the surgery site.

  • Monitor Carefully: Over the two weeks that she's healing it's important that you keep an eye on all of your cat's activities and her body. Inspect the incision site one or two times a day so you can recognize any changes. Inspect her urine for blood (a tiny bit may be normal in the first 24 hours) and her stool for any abnormalities. Look for those warning signs mentioned above such as her appetite, discharge, or swelling.
  • Keep Your Cat Within Sight: Surgery can be a temporarily traumatic event in a cat's life. Many cats instinctively want to hide after the experience. If she finds a hard-to-reach hiding place, you may not be able to monitor her properly. Do your best to block off any places in your home where she can potentially hide out of your reach, like the closets, the basement, or under furniture.
  • Prevent Licking: Cats groom themselves all the time, but their tongues are also filled with bacteria. Do your best to prevent your cat from licking the surgical site. If needed, an Elizabethan collar (called an "E-collar" or "the cone") can and should be used during the healing time. Though she may not like it at first, most cats get used to it.
  • Limit Activity: It is important to keep your cat as inactive as possible while she's healing. Vigorous movements or excessive play can cause the incision to open up. It's often best to confine her in a quiet room or spacious carrier when you won't be around to monitor her activity. Also, try to maintain calm in your household to help keep her at ease.
  • Administer Vet Meds Only: Your vet may have prescribed pain medication or other home treatments for your cat. It's important not to give your cat any other medications without consulting your vet. Never give a cat human medication or apply any ointments, creams, or similar products to the incision site.
  • Avoid Baths and Water: Although this applies more to dogs, some cat owners give their cats a bath as well. Do not do this while she's healing because the water may open up the incision. If your cat is one of the rare few that love water, make sure you keep her away from it while she heals.

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