Should I worry about a cyst on my dog’s skin?
A lump or bump on or under a dog’s skin can be a source of worry for many pet owners. Most lumps and bumps in dogs are benign, but there is a possibility that some could be malignant. Just like any other health issue, early detection and appropriate treatment can help improve prognosis and chances of a cure. The quicker you can have your dog’s lump checked by your vet, the better it will be, not only for your dog’s health and well-being but also for your peace of mind. Continue reading to learn how to identify common types of skin tumors in dogs and how they can be treated.
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Types of Lumps and Bumps on Dogs
Benign (Non-Malignant) Tumors in Dogs
Most benign or non-malignant tumors don’t cause health issues and won’t need veterinary intervention. However, if they appear infected, irritated, ulcerated, or they’re causing other problems for your dog, the vet may deem it necessary to remove them.
Below is a list of the most common types of benign skin tumors in dogs:
1. Fatty Tumors
These tumors are generally a part of the aging process. Fatty tumors can develop in any breed of dog, but larger breeds and those that are overweight or obese are more prone to having them.
2. Sebaceous Cysts
These pimple-like growths on your dog’s skin are blocked sebaceous glands. With time, sebaceous cysts often rupture, and their creamy contents are released. It’s not advisable to pop them because it can increase the risk of secondary bacterial infection. Most sebaceous cysts don’t cause problems for dogs, so there is not typically a need to remove them unless they’re infected.
Abscesses are swollen lumps containing pus and are generally associated with an underlying infection. They will need to be drained and flushed out with an antibacterial solution. Treatment also typically includes oral antibiotics and anti-inflammatory medication.
Hives develop when the skin has a hypersensitivity reaction to allergens such as bee stings. They appear as round, red welts that are swollen and very itchy. Depending on the severity, hives may resolve on their own or may need to be treated with antihistamines or steroids.
While they are benign growths, the ulcerated or reddish appearance of histiocytomas can be particularly worrisome for pet owners. They are often found on the limbs of young dogs and normally resolve on their own without any medical intervention.
6. Sebaceous Adenomas
These sebaceous gland-based tumors appear like a cluster of warts. Wooly-haired canine breeds, such as the Bichon Frise, Poodle, and Maltese, tend to have them more often compared to other dogs. Sebaceous adenomas are also more common among older dogs.
7. Perianal Adenomas
8. Papillomas (Warts)
Warts appear like small lumps on the skin. Puppies, senior dogs, and those that are immune-compromised are more prone to having them. These growths are caused by papillomavirus and are usually found on the dog’s head and face. Your dog can get warts from being in close contact with other dogs, such as in dog parks, kennels, or doggy daycare. Most resolve on their own after a few months without any treatment.
Granulomas appear as elevated red lumps with a crusted surface. Some can be found under the skin and are firm to the touch. Some cases of granulomas appear like malignant tumors, thus many vets recommend a biopsy or surgical removal to better evaluate the lump.
These tumors are composed of blood vessels and skin tissues. An important predisposing factor to their development is sun exposure, but other factors have been implicated. Hemangiomas can change over time and become malignant, thus surgical excision is often recommended.
Malignant (Cancerous) Skin Tumors in Dogs
Malignant growths are capable of metastasis, which means the tumor cells can enter the blood circulation or lymphatic system and spread to other parts of the body like the liver, bones, lungs, and brain. They can grow and aggressively destroy nearby tissues.
As soon as a lump or bump on your dog is confirmed to be malignant, surgery is performed to remove the malignant growth and prevent them from spreading.
Below is a list of the most common malignant tumors in dogs:
1. Mast Cell Tumors
Mast cell tumors (MCT) are tumors of the blood cells that make up the immune system. Mast cell tumors are most prevalent among dogs that are older than 8 years old.
These are locally invasive skin tumors that can grow rapidly. Many cases are seen in large dog breeds. Also called soft tissue sarcomas, fibrosarcomas can sometimes be mistaken as lipomas, thus fine needle aspiration (FNA) is necessary for diagnosis. Surgical excision is very important before it can spread to other organs.
Unlike humans, melanomas in dogs are not linked to sun exposure and tend to be less malignant. Melanomas involve the pigment cells in the skin and appear as dark lumps that grow slowly. These tumors can be benign or malignant. The more aggressive melanomas develop on the dog’s mouth and legs. Surgical removal is necessary, but they often tend to recur.
4. Squamous Cell Carcinomas
These are skin cell tumors that develop on hairless or unpigmented areas of the skin, such as the lips, vulva, nose, and eyelids. Squamous cell carcinomas appear as raised crusty skin sores that grow by local invasion of tissues. Because of their invasive nature, these tumors must be removed, or else they can grow and spread to other parts of the body.
5. Mammary Carcinomas
Also known as breast cancer, these tumors affect the cells and tissues of the mammary glands. Mammary carcinomas are more common among female dogs that have not been spayed. Take note that not all mammary gland lumps are malignant; some can be benign. But mammary tumors in male dogs are often always malignant. Breast tumors can spread to other mammary glands, lymph nodes, and organs. Surgical removal and chemotherapy are viable treatment options.
Diagnosis of Lumps and Bumps in Dogs
Any lump, bump, or cyst that has not been on your dog’s body before needs to be checked by your vet at the soonest possible time.
The most common diagnostic tools for lumps and bumps in dogs include:
1. Impression Smears
This method involves collecting cells from an ulcerated tumor which are then examined under the microscope.
2. Needle Biopsy (Fine Needle Aspiration)
A needle biopsy is made by inserting a sterile needle into the mass and aspirating cells for pathological examination.
3. Tissue Biopsy
This involves removing a piece of the growth which is then subjected to microscopic examination. Sometimes the whole mass is removed for evaluation.
4. CT Scans or MRIs
These diagnostic procedures are usually reserved for the examination of internal organs. A CT scan or MRI can help determine if the tumor has metastasized to other parts of the body.
5. X-ray and Ultrasound
Treatment for Dog Lumps and Bumps
Depending on the type of growth and degree of invasiveness, the following treatment options can be recommended:
Surgical excision is indicated for dangerous lumps and those that are causing a nuisance to the dog.
This treatment option is indicated for benign lumps and bumps. Liquid nitrogen is used to remove very superficial masses.
Certain medications are very toxic to cancer cells. Chemotherapy is often used in treating cancers that have metastasized. It’s generally the next step after the surgical removal of a malignant tumor.
Radiation therapy is often recommended when the location of the tumor makes it difficult to remove with surgery or the tumor doesn’t have well-defined borders. The procedure can be used in combination with other cancer treatment options.
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