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What is Mediastinal Mass Removal?

The mediastinum is a space within the dog's upper chest that contains a variety of organs including (but not limited to) the heart, esophagus, trachea, and an organ known as the 'thymus'. The thymus is a component of the body's lymphatic system, essentially performing many of the same duties as lymph nodes throughout the body such as filtering out toxins from the surrounding tissues and producing cells that fight infection. Unfortunately, parts of the lymphatic system can on occasion become home to unwanted growths. Although these growths may not be dangerous by themselves, they may still have a negative impact on the health of the dog, causing a vet to recommend surgically removing them.

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Mediastinal Mass Removal Procedure in Dogs

Before the surgery can begin, the dog will be rendered unconscious with a general anesthetic to prevent them from moving during the operation. Depending on the exact location within the mediastinum of the mass to be removed, the dog may have a spot on its back or side shaved and disinfected. Next, the vet will make an incision across the ribs, revealing them so that they can be cut with a bone saw. After this, the tissues beneath will be moved aside to reveal the inner mediastinum and to provide a good view of the growth. The surgeon will then remove the mass from the relevant organ before suturing the healthy portions back together in the same manner as a resection. In the case of the esophagus or trachea, surgical staples may also be used to ensure the tube solidly joins back together. The ribs can then be reattached (using either wires or metal fixtures) and the skin sutured shut.

Efficacy of Mediastinal Mass Removal in Dogs

Surgically removing a mass from the mediastinal cavity is one of the most direct courses of action when it comes to stopping the impact that such a growth may be having on the function of the nearby vital organs. Furthermore, it can prevent future complications such as infections internal bleeding from occurring. That said, the procedure may not be suitable for dogs with malignant tumors, as the cancer may already have taken root in adjacent tissues. As an alternative, the vet will commonly advise dog owners to opt for courses of chemotherapy and targeted radiotherapy, in order to make sure that the mass does not release cancerous cells into the rest of the body.

Mediastinal Mass Removal Recovery in Dogs

Following the surgery, the dog will need several weeks until it is completely healed, with older animals needing almost as much as two months to fully recover. The dog may require regular attention during this period, with the owners having to check that the sutures are kept intact and administer painkillers and antibiotics as needed. In cases where cancer was present, the vet will often want to book additional appointments so that the animal can receive additional treatment to prevent the disease from reappearing at a later date. 

Cost of Mediastinal Mass Removal in Dogs

The price of surgery performed on the mediastinum can vary significantly depending on things such as the age of the animal and the location of the growth that has to be removed. The removal of a tumor located on the thymus for example, would be less expensive than the removal of a tumor located in the heart. For this reason, owners can expect to pay between $1,500 and $3,000 for the procedure. Alternative treatments, meanwhile, can cost much less, with the average price of a course of chemotherapy being several hundred dollars and antibiotics costing less than a hundred in many cases.

Dog Mediastinal Mass Removal Considerations

Despite the undisputed effectiveness of surgical removal of mediastinal masses, some owners may still be given pause for thought by some of the potential drawbacks of the procedure. Firstly, elderly dogs are particularly at risk of respiratory failure during surgery, which may worry a proportion of people who are investigating the procedure, as older dogs are especially susceptible to cysts. That said, the vet will perform their own analysis of the dog, in order to determine if they are a suitable candidate for the surgery. Secondly, some owners may be worried about potential problems when removing diseased tissue from the heart. Although many procedures will be successful, it is not unknown for dogs to develop cardiovascular problems or internal bleeding in the aftermath of heart surgery. This means that the vet will have to perform their own analysis of whether surgery is the right option for the dog in question.

Mediastinal Mass Removal Prevention in Dogs

Although it can be very difficult to detect many cancers owing to their hereditary nature, genetic screening is not without merit. This is because it can still let owners know that they must be vigilant for the symptoms of certain types of cancer, thereby helping to catch the disease in its early stages before surgery becomes necessary. Cysts, meanwhile, can be caused by a variety of genetic and environmental factors, including exposure to infectious bacteria and certain harmful substances. By maintaining a sanitary living environment for the dog, the risk posed by such environmental factors can be substantially reduced.

Mediastinal Mass Removal Questions and Advice from Veterinary Professionals

Border Collie/English Springer Spaniel
12 Years
Serious condition
0 found helpful
Serious condition

Has Symptoms


I put my dog down about a year ago and I still have unanswered questions about her condition and whether I made the decision to euthanize too soon or whether treatment would have helped. I never consulted with the internal specialist because I had decided that I did not want to pursue surgery (she was 12.5 years old) and didn’t want to submit her to more vet visits which she really hated, but I can’t help but wonder if I should have at least looked into surgery.

My border collie/english springer mix had a mass in her mediastinum and in her liver (taking up 1/3 of her abdomen; it’s not clear if they were connected or separate), she had a heart murmur and an enlarged heart. There was fluid in or near her liver, but a biopsy found that it was not cancerous, she had elevated liver enzymes, and minor hemorrhage. She had lost a lot of weight (while her belly was huge the rest of her body was skinny). She was still drinking and eating (but only meat- not kibble or even her favorite treat, peanut butter). She was lethargic but also restless, and panting a lot.

My question is, do you think surgical removal or another treatment would have been a viable option? Would it have required two separate surgeries?

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Springer spaniel
13 Years
Serious condition
1 found helpful
Serious condition

Has Symptoms


Hello my name is Rhona.
My 13 year old springer spaniel has recently developed a cough. His vet has done X Rays and found he has dorsal displacement of the trachea and an enlarged heart. Ultrasound found his heart is functioning well and all blood results are good. He has no other symptoms. He is around 5kg overweight. The vet wants to perform CT to find out what is causing the tracheal displacement. My question is ...Could mediastinal fat cause the displacement or not?

Dr. Callum Turner, DVM
Dr. Callum Turner, DVM
3320 Recommendations

Tracheal displacement may be caused by an enlarged heart, but if there is displacement of the trachea cranial to the heart then a mediastinal mass or enlarged lymph node may be to blame. Excess fat may be a culprit, but mediastinal mass is more likely; a CT would be the next step to determine the cause of the deviation. Regards Dr Callum Turner DVM

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