What Happens If A Dog’S Tumor Burst Open?

Tumors in dogs are unfortunately quite common, especially as dogs age. While some tumors are benign and do not spread, others can be cancerous and aggressive. When a tumor ruptures or bursts open, it can create a serious medical emergency for the dog.

Understanding what causes tumors to rupture, recognizing warning signs, and knowing how to respond quickly and appropriately can help save a dog’s life. Ruptured tumors lead to sudden internal bleeding, which can rapidly become life-threatening if not treated right away. Being informed and vigilant are key to catching a rupture early and improving the dog’s prognosis.

This article provides an in-depth overview of what happens when a tumor ruptures in dogs, including the causes, effects, emergency response, diagnosis, treatment options, and outlook for recovery. Knowing how to prevent, identify, and properly treat ruptured tumors is crucial for any dog owner.

Causes of Tumor Rupture

The most common tumors in dogs that tend to rupture are hemangiosarcomas and other vascular tumors like lymphosarcomas. These tumors develop from the cells lining blood vessels and tend to grow rapidly into large masses

Hemangiosarcomas often form on the spleen, liver, heart or skin, locations where trauma can easily damage the tumor and cause rupturing. The spleen is especially prone to rupture as it is not protected by the ribs. According to VCA Animal Hospital, rupture can occur spontaneously in visceral vascular tumors, without any traumatic injury (source).

The location of the tumor impacts the likelihood of rupture. Tumors on the spleen or liver are very fragile and can rupture and bleed into the abdomen even without trauma. Tumors in other locations like the heart or skin are less likely to rupture unless significant trauma occurs.

The growth rate of the tumor also plays a role. Fast-growing tumors have higher internal pressure and weaker outer walls making them prone to rupturing. Hemangiosarcomas are known for their rapid growth rate which contributes to their tendency to rupture (source).

While spontaneous rupture is common, any kind of trauma to the body region where the tumor is located can also cause rupture. Things like being hit by a car, falling, being attacked by another animal, or even rough play with minimal trauma have potential to rupture a tumor.

Signs of Impending Tumor Rupture

There are often warning signs that a tumor may be about to rupture in dogs. According to VCA Animal Hospitals, sudden growth or swelling in the area of the tumor is one sign that rupture may be imminent [1]. As the tumor expands, it can outgrow its blood supply and will eventually burst. Owners may notice a rapidly enlarging mass on their dog’s body.

Another warning sign is skin redness or irritation overlying the tumor, according to PetMD [2]. As the mass expands under the skin, it can cause inflammation and skin changes. This is the body’s reaction to the tumor putting pressure on surrounding tissues.

Dogs may also demonstrate behavior changes as a rupturing tumor causes discomfort. According to WagWalking, they may pace, whimper, or act agitated [3]. These are signs of pain or distress related to the impending rupture.

By being alert for sudden tumor growth, skin changes, and behavior alterations, owners may detect warning signs of rupture. This allows them to seek prompt veterinary attention to prevent or manage a rupture episode.

What Happens When a Tumor Ruptures

When a tumor ruptures, it releases blood and cancerous cells into the body, causing significant internal bleeding. According to VCA Animal Hospital, “Rupture can occur spontaneously, without any traumatic injury, and cause bleeding into the abdomen.”

The bleeding from a ruptured tumor can be severe and life-threatening if not treated quickly. As blood pools in the abdomen, it puts pressure on the organs and restricts blood flow. PetMD states that with hemangiosarcoma, “When a tumor ruptures, a large amount of blood is released into the abdomen, causing severe and rapid blood loss.”

A ruptured tumor often becomes infected from the release of bacteria into the body cavity. The bleeding and infection cause inflammation, pain, and damage to the surrounding tissues. According to WagWalking.com, “A ruptured tumor causes rapid blood loss and is extremely painful.” Treating the ruptured tumor and internal bleeding is an urgent medical situation for the dog.

Diagnosing a Ruptured Tumor

Diagnosing a ruptured tumor starts with a thorough physical exam by the veterinarian. They will check for signs of sudden weakness, collapse, pale gums, rapid heart rate, abnormal heart sounds, difficulty breathing, abdominal swelling, and shock which can all indicate internal bleeding from a ruptured tumor (VCA Animal Hospital). The veterinarian will also feel for fluid in the abdomen that could be blood from a ruptured tumor.

Imaging tests like X-rays, ultrasound, or CT scans are often used to find the cause of bleeding and look for tumors that may have ruptured. These images can identify tumors, fluid in the chest or abdomen, and internal bleeding. Ultrasound allows direct visualization of tumors in organs like the spleen, liver, and heart that commonly develop hemangiosarcoma (WagWalking).

Finally, a biopsy may be taken by needle or during surgery to identify if a tumor is present and determine the tumor type. Examining a tumor sample under a microscope can confirm if a cancer like hemangiosarcoma is causing bleeding (PetMD).

Treating a Ruptured Tumor

The main goals when treating a ruptured tumor are controlling bleeding, preventing infection, and removing the tumor. As ruptured tumors can cause life-threatening internal bleeding, the first priority is to stabilize the dog and control any hemorrhaging.

Veterinarians will start by providing supportive care such as IV fluids and blood transfusions to maintain blood pressure and oxygen delivery. Antibiotics may also be given to prevent infection from contaminating the abdominal cavity. According to the VCA Animal Hospital, “Dogs are very prone to developing infection and sepsis when blood leaks into their abdomen so prompt surgical removal of the spleen is recommended.” [1]

Once the dog is stable enough for anesthesia, surgery will be performed to fully remove the ruptured tumor and spleen in a procedure called a splenectomy. The surgeon will also thoroughly examine the abdomen for any signs of spread. As noted by AVIM, “The only way to obtain a definitive diagnosis of the type of splenic mass present is by histopathology.” [2] This analysis helps determine next steps for follow-up treatment and monitoring.

After surgery, the dog will need additional supportive care, pain management, and close monitoring during recovery. Strict rest is required for at least 2 weeks post-surgery to allow the incision site to fully heal.

Recovery and Aftercare

After the tumor rupture surgery, your dog will need proper aftercare while they recover. This usually involves care of the incision site, restricted activity levels, and monitoring for complications. Following your veterinarian’s discharge instructions closely is crucial for proper healing.

To care for the incision site, you’ll need to keep it clean and dry. Your vet may prescribe antibiotics and recommend cleaning the area gently with a warm washcloth. Do not allow your dog to lick or scratch at the incision as this can cause infection. An Elizabethan collar may be necessary to prevent irritation of the site. Monitor for increased redness, swelling, discharge or any other signs of infection and contact your vet if detected. Stitches are usually removed 10-14 days after surgery.

Your dog will likely need to be restricted to leash walks and no high impact activity for 7-14 days after tumor rupture surgery to allow healing. Jumping, running, and rough play should be avoided during the recovery period. Provide a comfortable, quiet space for your dog to rest as their energy levels may be lower after surgery. Follow your vet’s specific instructions on appropriate activity levels.

It’s important to monitor your dog for any signs of post-surgical complications like bleeding, fever, loss of appetite or lethargy. Contact your vet immediately if you notice anything abnormal in the days following the procedure. With proper aftercare and close observation, your dog can make a full recovery after tumor rupture surgery.

Outlook and Prognosis

The outlook and prognosis for a dog after a tumor rupture depends on several factors, including the tumor type, size, location, and whether it has metastasized. Hemangiosarcoma, a common tumor in dogs that affects blood vessels and tends to rupture, is extremely aggressive with a poor long-term prognosis. Even with surgery and chemotherapy, average survival times range from just 6-12 months.[1] Larger tumors that have metastasized typically have a worse prognosis. Smaller, localized tumors that are able to be completely removed surgically generally have a better outlook.

Without treatment for a ruptured tumor, most dogs will only survive a few days to weeks. Immediate emergency care to stabilize bleeding is critical. This may buy some time, but without treatment of the underlying cancer, survival past a couple of months is unlikely. With prompt surgery and follow-up care, dogs have a chance at an improved quality of life for a longer period, though long-term cure is unlikely with malignancies like hemangiosarcoma.

Working closely with an oncologist to determine the best personalized treatment plan based on the individual tumor type, location, and other factors provides a dog with the best chances. While the overall prognosis may still be guarded, treatment can provide months or even over a year of quality time in some cases. Staying vigilant about signs of rebleeding and being prepared to act quickly are also essential. With a prompt, informed, and dedicated approach, the outlook can be extended and improved to a degree.

[1] https://www.petmd.com/dog/conditions/cancer/hemangiosarcoma-dogs


There are a few ways to help prevent tumor rupture in dogs:

Early detection through regular veterinary checkups and imaging tests can identify tumors before they grow large enough to rupture. Dogs prone to certain types of cancer like hemangiosarcoma should receive more frequent screening.

Closely monitoring any existing tumors for signs of rapid growth can indicate higher risk. Tracking the tumor’s dimensions and looking for visual changes allows assessing whether it may rupture soon.

Gentle handling and restricting activity with at-risk dogs reduces chances of trauma that could lead to rupture. Dogs with known splenic masses should avoid intense exercise, rough play, and situations with falls or collisions which could tear the tumor.

According to the VCCA Animal Cancer Center, the risk of rupture may be reduced through supplements like Yunnan Baiyao, I’m-Yunity, and turkey tail mushroom. However the effectiveness is still under study. Prevention involves vigilance, knowing the warning signs, and mitigating trauma risks.

Source: https://www.ethosdiscovery.org/blog-post/prevent-misinformed-euthanasia-for-splenic-tumor-rupture-in-dogs/

When to Seek Help

If your dog experiences a sudden onset of symptoms like weakness, collapse, lethargy, pale gums, swollen abdomen, or trouble breathing, you should seek emergency veterinary care immediately, as these are signs that a tumor may have ruptured and is causing internal bleeding (https://vcahospitals.com/know-your-pet/vascular-tumors). A ruptured tumor is a medical emergency that requires swift treatment.

Some of the most concerning signs that warrant an urgent vet visit include (https://wagwalking.com/condition/hemangiosarcoma):

  • Sudden collapse or lethargy
  • Trouble breathing or rapid breathing
  • Swollen or distended abdomen
  • Weakness or inability to stand
  • Very pale gums
  • Coughing up or vomiting blood

If a tumor has ruptured, every minute counts in getting life-saving treatment for your dog. Call your vet right away or go directly to an emergency animal hospital at the first signs of a rupture.

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