5 Common Cancers in Dogs and How to Spot the Signs

Cancer in dogs is prevalent; it is the leading reason for non-accidental death in canines. In fact, 50% of dogs reaching 8years of age and beyond are likely to develop some type of cancer. This is considered true regardless of the dog breed.

1. Canine cancer

Technically, canine cancer refers to the abnormal or uncontrolled growth of cells in the body. The case can either be benign (removable) or malignant (cancerous and aggressive). Different types of dog cancer are named according to the part of the body or the specific tissue where it started.

A diagnosis of cancer in dogs may be one of the most devastating news to dog owners. However, it is also important to put in mind that not all types of cancer are incurable. Some are treatable and completely remediable. The earlier the warning signs are spotted, the bigger is the chance of successful treatment.

What are the signs of cancer in dogs?

• Bleeding from any bodily orifices such as nose and mouth.
• Difficulty in eating and breathing
• Discoloured spots on the skin
• Injuries or wounds that are not healing
• Lumps and bumps
• Severe diarrhoea and vomiting
• Swelling and pain
• Visible tumour/mass
• Weight loss

Getting acquainted with some of the most common canine cancer will help you deal with future complications.

2. Lymphoma

Lymphoma is one of the most common tumours in dogs. Although it can originate from any tissues in the body, most cases usually start in the bone marrow, lymph nodes, and spleen.

Breeds predisposed to lymphoma include the basset hounds, boxers, Airedales, and Saint Bernards.

Types of Lymphoma

1. Multicentric lymphoma
   It mainly affects the external lymph nodes in the body. Watch out for the following symptoms:
   • Anaemia
   • Difficulty in breathing
   • Excessive thirst and urinating
   • Fever
   • Loss of weight
2. Alimentary lymphoma
   It mainly affects the gastrointestinal tract either in the small or large intestine. Watch out for the following symptoms:
   • Lethargy
   • Malabsorption
   • Vomiting and diarrhoea
   • Weight loss
3. Mediastinal lymphoma
   It usually occurs in the lymphoid tissues of the chest, which later on affects the lungs. Watch out for the following symptoms:
   • Respiratory complications
   • Swelling in the neck, head, and forelimbs
   • Excessive thirst and urinating
4. Cutaneous lymphoma
   Affecting the skin, cutaneous lymphoma appears as red lumps and itchy at times. Watch out for the following symptoms:
   • Alopecia
   • Excessive itching
   • Scaling
5. Extranodal lymphoma
   Abnormalities may start from the breast tissue, skin tissue, ocular tissue (eyes), and oral tissue (mouth). It may be the rarest of all types of lymphoma. Watch out for the following symptoms:
   • Immobility or paralysis
   • Seizures

3. Melanoma

A melanoma tumour is a highly aggressive dog cancer. It usually starts in or around the mouth. This condition is categorised as a skin cancer that spreads deep into the skin, affecting vital organs. Breeds predisposed to melanoma include Dobermann pinscher, miniature schnauzer, and vizsla.

Types of malignant melanoma

1. Cutaneous malignant melanoma
   Cutaneous malignant melanoma occurs as a swelling or a discrete mass on the affected area, which is usually on the footpads or the nail bed.
2. Oral melanoma
   This is a type of tumour that starts smaller along the lip, the palate, or the gums, which may become bigger and spread to the head and neck. When left untreated, it can even spread to the lymph nodes, affecting vital organs.
3. Uveal or intraocular melanoma
   Uveal melanoma may occur in three types: iris melanoma (dark mass in the iris), ciliary body melanoma (dark mass protruding in the pupil), and choroidal melanoma (usually affects the retina). The worse the condition, the more it is likely to develop into blindness, glaucoma, and other eye complications.
4. Limbal melanoma
   Dogs age 5–6 are more susceptible to limbal melanoma. Affected dogs may appear with pigmented masses.

4. Hemangiosarcoma (HSA)

This is an occurring malignant cancer affecting the blood vessels. It is usually observed in older canines as well as golden retrievers, Labrador retrievers, and other larger breeds.

Types of hemangiosarcoma

1. Dermal – It commonly grows on hairless areas of the body.
2. Hypodermal – Affected areas are under the skin, depending on the location of a tumour.
3. Visceral – It is found in the heart, spleen, and the pericardium. Dogs suffering from visceral HSA may appear weak and lethargic.

Mast cell tumours

There are many cases of mast cells tumours in older dogs and mixed breeds. Mast cells comprise of enzymes and histamines that help protect the body. However, with the presence of tumours, the function of protection may attack against the immune system instead.

Breeds predisposed to lymphoma include the boxers, Boston terriers, beagles, and Labrador retrievers.

Symptoms may vary depending on the case. Tumours may appear as various lesions looking rubbery. It also affects the dog’s bone marrow, liver, and other abnormalities.

5. Osteosarcoma

Osteosarcoma occurs as a bone tumour in middle-aged to older canines. However, it is more predominantly observed in Great Danes, Rottweilers, golden retrievers, and Irish setters. This condition may affect any bone in the body but most especially on the dog’s limbs. First clinical signs may manifest as swollen areas or lameness.

What do you do when your dog has cancer? The very first step is to be willing to take full understanding on the certain condition. Next is to get help from a veterinarian with expertise on the said cancer. Dog cancer treatment greatly depends on the specific type of cancer or tumour. The earlier the diagnosis, the greater the chances for a successful treatment.