Regarding our pet friends, according to the veterinary cancer society in the United States that one in four dogs and one in five cats are likely to develop cancer.

Remember that cancer is a disease whose outcome tends to be better when diagnosed early.

Veterinarians advise you to monitor and consult when certain characteristic clinical signs appear, to make sure we detect this life-threatening disease before it's too late:

• Swollen lymph nodes (more easily detectable behind the jaw or behind the knee)
• Presence of a mass or bump that grows rapidly or changes texture or shape.
• Inflated and distended stomach
• Chronic weight loss
• Repeated and unexplained vomiting or diarrhoea
• Bleeding
• Cough (although there are also many other causes of cough in dogs and cats)
• Unexplained lameness
• Difficulties urinating, defecating or breathing
• Smelly mouth or chewing food differently
• Easily fatigued

The most common types of pet cancer are:

• Lymphatic system cancer (Lymphoma)
• Skin and soft tissue cancer (Melanoma, Mastocytoma, Fibrosarcoma, Carcinoma…)
• Cancer of the blood vessels (Hemangiosarcoma,..)
• Hepatic (liver) or splenic (spleen) cancers
• Cancer of bones or joints (Osteosarcoma)
• Breast cancer (mammary carcinoma)
• Cancer of the bladder and urinary tract (Carcinoma)
• Anal sac cancer (Adenocarcinoma)
• Oral cancer (Melanoma).

Veterinary societies around the world have established national registries that aim to estimate the frequencies of occurrence of the main cancers of pets. These data depend on the countries and continents concerned, the different races, age groups and, of course, the sex of the animals.

As an example, one study reports the incidence of spontaneous tumours in northern Italy.

Vascellari M, Baioni E, Ru G, Carminato A, Mutinelli F. Animal tumour registry of two provinces in northern Italy: incidence of spontaneous tumours in dogs and cats. BMC Vet Res. 13 oct 2009;5:39.