Dog skin cancer is the most common type of cancer found in dogs but full blown skin cancer does not appear suddenly on a dog’s skin, it usually starts out as a bump, lump etc. and this is good news for every dog owner because early detection of those strange and foreign swellings on your dog’s body increases the chances of survival if these growths turn out to be cancerous.
Since dog skin cancer usually starts out as visible swellings or lumps on the dog’s skin, it is imperative to have some basic understanding of the different types of lumps that may appear a dog’s skin. This knowledge will be very helpful in many ways including calming your frazzled nerves.
The different types of lumps or wounds on dogs’ body
The onset of cancer on a dog’s skin begins as swellings or lumps that starts out small and quickly develops into cancerous cells or manifest as a wound (lesion); in the case of the later it means the cancerous cells causes visible damage on the dog’s skin. Some of the most common visible wound or lumps on a dog’s body are:
- Skin tags.
Lesion: is an injury, a wound or a damage caused to the living tissues of the body, it can occur both on the skin and in internal organs; basically lesion can afflict any part of the body that consist of soft tissue or where tumor can be found; lesion that is caused by a tumor is classified as benign or malignant. Tumors are therefore classified as lesions however lesions are not necessarily tumors.
The most common causes of lesions in dogs include abscess, excessive self licking (Acral lick dermatitis), mite, flea, fungal or bacterial infection; but they can also be the result of certain dog skin cancer such as basal cell tumor, squamous cell carcinoma, epitheliotrophic lymphoma, lymphoma, mast cell tumor and fibrosarcoma.
Warts: these are common skin lumps found on aging dogs and they have been linked to over vaccination; for the most part warts are benign but they could also be cancerous. The physical appearance of warts on dog’s skin usually indicates if it may turn out to be cancerous; a wart that remains the same in shape and size is largely harmless but when it begins to grow in size and shape then it is essential to have it checked by the vet as this type of wart could be cancerous.
Skin tags: these are visible harmless, small growths hanging from the dog’s skin and consist of fatty deposits. When the dog’s skin cells grows excessively it results in skin tags and like warts they are usually seen in older dogs; while they are generally benign any random growth of skin tags could suggest a cancerous tendency and should be checked by a vet.
Cysts: these are slow growing sacs that are filled with pus, fluid or semi solid material and they are usually painless and non cancerous however they can grow within cancerous or malignant lumps. Cysts are formed as a result of the blockage of the sebaceous glands or due to infection; false cysts, true cysts, dermoid cysts and follicular cysts are non malignant. Some dog breeds such as the Cocker Spaniel have predisposition to sebaceous cysts.
Tumors: an abnormal tissue growth due to uncontrolled cell division, it serves no useful purpose in the body and can either be malignant or benign.
Malignant and benign tumors
|Malignant dog skin cancer||Benign dog skin cancer|
|Basal cell carcinoma||Basal cell tumor|
|Mast Cell Tumor||Lipoma|
|Squamous cell carcinoma||Benign melanomas|
|Hemangiosarcoma of the skin||Hair follicle tumor|
|Fibrosarcoma of the skin|
Different types of skin cancer in dogs
Basal cell tumor: a very common slow growing dog skin cancer that occurs on the outer layer of the dog’s skin (epidermis). An overgrowth of the basal cells will either be benign (basal cell tumor) or malignant (basal cell carcinoma). Like most tumor the cause of basal cell tumor is unknown but permanent cure can be achieved with surgical removal; this means that the prognosis is good.
Basal cell tumor are commonly seen in older dogs of some breeds such as Wirehaired Pointing Griffon, Cocker Spaniel, Kerry blue terrier, Poodle and Wheaten terrier
Mast cell tumors: these are cells that occur mostly in the skin and can also be found in some other tissues of the body such as respiratory tract; they are also a natural component of the immune system. The tumor is produced from these mast cells.
The exact cause of mast cell tumor is unknown but it has been linked to hereditary as seen in some breeds such as English bulldogs, pugs, boxers and Boston terriers.
Mast cell tumor can either be benign or malignant and common symptoms include blood in the stool and vomiting. Mast cell tumors are rated on the three level of increasing severity with the third level (grade III) considered to be the most aggressive and malignant while grade I is benign.
Surgical removal is usually the first port of call in the treatment of mast cell tumor and this will usually take care of grade I & II. Radiation and chemotherapy are the other treatment options available and the prognosis is much better for the lower grade mast cell tumors that are in their early stages than the higher grade.
Lipomas: one of the most common fatty skin tumors that are formed underneath the dog’s skin; they are benign masses that have a tendency to grow bigger and even replicate on the body but unlike other tumors these replication does not suggest malignancy. They are quite common in adult and overweight dogs.
Usually the vet will recommend that the tumor should not be touched while keeping a watchful eye on it but when it is located in a part of the dog’s body that could impede movement or if it is causing discomfort only then will attempt be made to remove it. Some dog owners will request to have the tumor removed for cosmetic reasons.
Sometimes the lipoma may be infiltrative and would invade other tissues around it; in situations like this the lipoma would have to be removed. Therefore any type of lump or tumor should always be brought to the attention of the vet for further examination.
Papillomas: this benign tumor sometimes referred to as dog warts are either caused by viral infection or may be spontaneous and non viral in origin. The viral papilloma is also referred to as oral papilloma because it is usually found in the mouth of young dog and will normally go away as the pup’s immunity develops. The non viral papilloma affects the dog’s skin (cutaneous) and is commonly seen on the feet, head and eyelids of older dogs.
Melanoma: is a very common dog skin cancer which can also infect the mouth; it is the abnormal and excessive growth of the cells that are responsible for pigmentation that result in malignant melanoma. Melanomas are either benign or malignant depending on which part of the surface of the body it occurs; they are generally grouped as oral malignant affecting the lip, gums and tongue and non oral malignant which are usually seen on the around the eyes, foot, nail and skin.
Certain dog breeds appear to have a greater predisposition to this tumor such as Doberman pinscher, Scottish terrier, Springer Spaniel, Boston terrier and Cocker Spaniel.
Treatment of melanoma is basically through surgical removal or vaccination and the prognosis is a function of how advanced the tumor is and the location on the dog’s body. Chemotherapy has not been too successful in the treatment of melanoma.
Hair follicle tumor: this is almost entirely a benign tumor which is as a result of the disorderly or abnormal growth of the hair follicles and they are permanently cured through surgical removal; the prognosis is generally good. The exact cause of hair follicle tumor is unknown though there is some suggested genetic links.