Treating Lipoma in Dogs - Fatty Tumor Removal

Before we look at the treatment of a lipoma, we need to know what it is. A lipoma is a type of neoplasm, an umbrella term for an abnormal growth of cells, otherwise referred to as a tumor. As stated in the introduction, there are many different type of tumors, some of which can be benign. A lipoma is a type of benign tumor which is considered mesenchymal as it affects connective tissue. More specifically, they affect adipose tissue, also known as body fat.

This doesn't mean your dog has to be overweight to contract a lipoma, although obesity is considered a risk factor. Lipomas are most commonly subcutaneous and can form as a singular growth or be found in multiple lumps. Their texture is soft, yet firm, and has a spongy consistency. They are most common in older dogs, specifically those over 8 years of age^[1].

Although rare in cats, lipomas are relatively common in dogs. They are more frequent in female dogs than males, especially if they are overweight. In most cases, they can be found within a connective capsule of tissue, but there are times when they are difficult to delimit. This is due to two rare forms of lipoma in dogs known as diffuse lipomatosis and infiltrative lipomas. In the former, the lipoma mixes with normal adipose tissue, and the latter can be intra- or intermuscular. These types of lipoma are more challenging to operate on.

While lipomas are considered benign, they can grow to be large in size. They can cause practical problems and be inconvenient for the dog. They can also be confused easily with other types of tumor such as a liposarcoma, one of the reasons why it is so important they are diagnosed by a veterinarian. In some cases, lipomas can even cause discomfort due to their size and location, leading to mobility issues or irritation in the affected area.

Our understanding of the causes of lipoma in dogs is limited. However, we do know that there is a genetic factor, as can be seen in its higher prevalence in certain dog breeds. Dog breeds which are more likely to develop lipoma include:

• Doberman
• Cocker Spaniel
• Labrador Retriever
• German Shepherd
• Dachshund
• Braque Francais
• Pinschers

Dogs most susceptible to lipoma are overweight female dogs from these breeds which are over 8 years of age. However, it is important to know that lipoma can develop in dogs of any age, breed, or sex.

Other causes of lipoma in dogs

In addition to the genetic factor, there are other risk factors which might predispose a dog to lipoma. Perhaps due to a low-performance metabolism, overweight or obese dogs tend to be at a higher risk of fatty tumors. This is because they are not as able to metabolize fat from their diet, resulting in the accumulation of adipose tissue.

An inability to adequately detoxify toxins in the liver, intestines, or kidneys may be influential in the development of lipoma. It is also possible that a lipoma can be associated with trauma, as the damaged tissue might be linked to the tumor development. However, there is insufficient evidence to confirm this as definitive. Environmental factors, such as exposure to certain chemicals or pollutants, have also been suggested as potential contributors, but further research is needed to establish a direct link.

Canine lipomas can vary in size, some being less than a centimeter, others being up to several centimeters. Large lipomas in dogs can compress the tissue around them and cause agitation in the animal. They may cause the dog to try to scratch or bite the area, something which can be dangerous if the tissue is damaged. In general, most dogs do not show any specific symptoms other than the presence of the fatty tumor itself.

Lipomas can be singular or appear in clumps. The consistency of a lipoma is:

• Firm
• Gentle
• Soft
• Encapsulated
• Well defined borders (exceptions stated above)

These tumors are usually located in the subcutaneous tissue of the extremities, neck, abdomen or chest. They tend to have good mobility as they generally do not develop into deep tissues, something more indicative of malignancy. This is why they are often seen to be hanging tumors. However, they can sometimes grow in muscle tissue, appearing firmer, harder, and less mobile without indicating that they are malignant tumors (intramuscular lipoma).

The malignant variety of lipoma is known as liposarcoma (a type of soft tissue sarcoma), which can metastasize to other locations in the dog's body. These can include bones, lungs, or other organs. It is a tumor with the appearance of a lipoma but is infiltrating, specifically affecting muscle tissue and fascia. Since lipomas can be small and present with many little lumps, we need to differentiate them from other types of inflammation. For example, skin diseases in dogs can cause the animal to present with lots of small bumps, but they are not necessarily tumors. It is crucial to monitor any changes in size, shape, or behavior of the lumps over time, as rapid changes can be a sign of a more serious condition.

Clinical diagnosis of lipoma in dogs is vital. Since tumors can be either benign or malignant, it is very important we determine which type of neoplasm is present. To diagnose lipoma in dogs, a fine-needle aspiration biopsy will be carried out. This is when the veterinarian will insert a very fine needle to remove some of the tissue (aspirate) and examine it as a biopsy.

The veterinarian can determine whether the tumor is a benign fatty tumor or something more serious. This will require a differential diagnosis, as lipoma can also be confused with:

• Liposarcoma
• Mastocytoma
• Soft tissue sarcoma
• Sebaceous cyst
• Epidermoid cyst
• Histiocytoma

The aspirate from the fine-needle aspiration will have its cellular content placed on a slide and viewed under a microscope. Here a multitude of adipocytes will be seen, clarifying the diagnosis. Adipocytes are seen as cells with vacuolated cytoplasm and a small, pyknotic, flat, and eccentric nucleus. In the case of suspecting that it affects deeper tissues, advanced imaging tests may be necessary. These will also help the surgeon to plan a removal. Advanced imaging techniques, such as ultrasound or MRI, can provide more detailed information about the tumor's size, location, and involvement with surrounding tissues.

You can find out about other types of neoplasia in dogs with our article on brain tumors in dogs.

Finally, we examine the treatment of lipoma in dogs. If a lipoma has been diagnosed, it is possible we can remove it through a surgical intervention. If the lipoma has not gone further into deep tissue and presents as an encapsulated fatty tumor, it should be fairly straightforward to remove, although this may depend on its location. However, with diffuse and infiltrative lipomas, this may be more difficult as more tissue may need to be removed.

Another option for canine lipoma treatment is actually to do nothing. If canine lipoma has been diagnosed, it means the dog may not have a problem. Their quality of life may not be diminished, so surgery may not be necessary. The reason this is the case for many is because surgical intervention may be too expensive. Since these tumors do not metastasize, there is little to no risk of fatality. In some cases, non-invasive treatments, such as weight management and dietary changes, are recommended to help reduce the size of lipomas or prevent new ones from forming.

Some people may ask how much does it cost to remove a dog lipoma? Unfortunately, this will depend on many factors. Veterinarians will generally set their own prices, so you will have to speak to them to see if it is something suitable for you. Your insurance may also claim it is an elective procedure, so you may need to cover it yourself. This will depend on your insurance agreement. The cost can also be influenced by the complexity of the surgery, the size of the lipoma, and the geographical location of the veterinary practice.

This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.

If you want to read similar articles to Treating Lipoma in Dogs - Fatty Tumor Removal, we recommend you visit our Other health problems category.