Limb Amputation

amputationThe idea of amputation might seem very difficult to accept, but the truth is that most pets adapt very well to having a limb removed. In fact, you’ll find that most dogs and cats that go through amputation go back to walking and playing remarkably fast. This is in part because the techniques used to amputate a limb are highly sophisticated and a multimodal pain management strategy reduces post-surgical pain, so pets are able to recover quickly.

In most cases, if an animal needs an amputation it is due to severe trauma or a tumor causing pain in the affected limb, therefore many animals are not using the painful limb at all and having it amputated is so much more comfortable and they have less weight to carry around on the three good limbs. Also, animals don’t suffer the psychological trauma associated with having a limb removed, so they simply adjust to their new reality and keep going. In general, losing a rear leg for cats and dogs tends to be a bit easier for them adapt to, this is because they bear 65-70% of their body’s weight in the front.

Reasons for Amputation

Amputations are never recommended lightly. We will look into all options and possibilities for treatment before suggesting amputation. However some of the most common reasons amputation might be recommended include:

  • Osteosarcoma: Osteosarcoma, a very aggressive, excruciatingly painful bone cancer, is the most common reason for the removal of a leg in dogs. It can also be diagnosed in cats, but is much less common. By amputating the limb, the primary tumor is completely removed. It is important to understand that with osteosarcoma the surgical amputation is primarily recommended for pain control. In a large number of cases, the primary tumor has already metastasized to the lungs and or lymph nodes. The average life span of a dog after amputation due to osteosarcoma is about four months, but certainly can be shorter or much longer.
  • In some cases, amputation can be a cure if the tumor has not already spread. It is very difficult to detect micro-metastasis to the lungs, but a chest x-ray is always recommended prior to surgery to look for evidence of metastasis.Osteosarcoma is more common in large breed dogs, but can occur in any breed. While it can occur in young dogs, it is also more likely to appear in older animals.
  • Other types of cancer: Soft tissues sarcomas, carcinomas, and round cell tumors are cancers that damage the skin, muscles, tendons and ligaments. They can affect any part of the body, but often appear on the legs. If the tumor is aggressive in nature and growing rapidly, it may become too large to completely remove the mass with clean margins. When this occurs and it is causing the animal chronic pain, bleeding, or infection, sometimes removing the limb is not only the easiest therapy for the patient, but may also be the most effective way of controlling the spread of the disease.
  • Soft Tissue Injuries: Trauma such as being hit by a car, falling out of a window, or being in a fight with another animal can result in severe injuries to muscles or ligaments that are damaged beyond repair. If the pain and suffering of the patient will be drastically reduced with amputation, it can be a viable option.
  • Fractures: Multiple fractures to a limb or pelvis can result in a type of injury that cannot be effectively repaired with surgery, may require multiple surgeries, or can be too costly for some pet owners to afford. Because animals tend to do remarkably well with a missing limb, removing the limb can be the most effective solution for your pet’s quality of life and for your budget in some of these cases.
  • Nerve Damage: Damage to nerves from trauma or a tumor can be an excruciatingly painful experience for your pet. The most common nerve injury that requires limb amputation is the Brachial Plexus Nerve avulsion resulting from the affected front limb being pulled away from the body or a direct blow to the underarm area. This nerve bundle is located within the animals armpit and trauma to it from an accident or a tumor causes the pets elbow to be dropped and the paw to be in a flexed position with the inability to bear weight on the affected limb. In some traumatic injury cases, with minimal nerve damage, they can regain use of the limb, but unfortunately in many cases of injury and all cases of tumors this is not the case.
  • Most animals with a severe Brachial Plexus Nerve injury or a tumor that impinges on and damages the nerves results in loss of feeling in the paw which can result in them dragging the paw on the ground or can produce a tingling sensation leading to the animal chewing on their own paw. Either of these scenarios can lead to such extensive tissue damage that amputation is needed because the soft tissue cannot be repaired, will not heal well, and is the only way to stop the tingling sensation.

What Happens During the Surgery

Before surgery, we will recommend to perform a series of tests depending on the cause for the amputation. At a minimum a full blood panel prior to anesthesia will help determine if there are underlying abnormalities that need to be addressed prior to surgery. In the case of a tumor being present, we will recommend chest x-rays, a lymph node biopsy, and possibly an abdominal ultrasound to help determine whether the disease has spread to vital organs. This will significantly affect recovery and prognosis, so we will discuss this in great detail with the specifics of your pets needs. In regards to an injury, we will need to assess all possible injuries, the prognosis, and the stability of your pet prior to scheduling anesthesia. Specific tests will be recommended based on the abnormalities found on your pets exam and their medical history.

How much of the leg needs to be amputated depends on the extent of the problem and type of injury or tumor. For example, if a tumor is located low on the leg, it might not be necessary to amputate the whole leg. However, in many cases, to optimize the success of the surgery and for cosmetic reasons the amputation is performed by removing the entire front limb including the scapula or at the hip joint in a rear limb.

While general anesthesia is always used during amputations, a local nerve block and/or epidural should always be administered prior to severing large nerves when removing the limb. This dramatically helps reduce post-operative pain caused by the cutting of nerves.

Once your pet goes home, he will have to take pain medications such as such as anti-inflammatories and a narcotic. Antibiotics are also given to help treat and prevent bacterial infection at the surgery site. Pets rarely need physical therapy after an amputation. This is partly because many pets stop using an injured leg long before the surgery – so by the time the limb is removed, they are already used to walking around without relying on it. In addition, tumors on the legs are often very painful, so dogs feel immediately better after the amputation and are eager to move around again.

When We Wouldn’t Recommend an Amputation

In cases where a pet has severe underlying, uncontrolled medical issues (ie heart disease, kidney failure, liver disease, auto-immune diseases, etc) unrelated to the limb injury or tumor, an amputation may not be in the best interest of the pet. If an animal has severe arthritis in the unaffected limb or limbs, getting around after amputation may be quite painful and very difficult. If the cancer has obviously spread to the lungs, heart, or other vital organs, such a poor prognosis may not justify putting your pet through the surgery and recovery process of an amputation. The most important deciding factors for recommending an amputation are as follows: is it going to benefit your pet, improve their quality of life by eliminating pain without causing pain in other limbs, and have the potential to lengthen their life. If all of these criteria are met, then an amputation is likely the best choice for your pet with a severe limb injury or illness.