Table 6.2 Neoplasms in dogs.
| Neo plasm | Association | Age a factor |
| Epithelial neoplasia | Account for approximately 48.3% of dog tumours* | Incidence increased in dogs over 5 years age † |
| Mesenchymal neoplasia | Account for approximately 24.6% of dog tumours* | Incidence increased in dogs over 7 years age † |
| Oropharyngeal neoplasia | Account for approximately 10.3% of dog tumours* Brachycephalic breeds |
Incidence increased in dogs over 10 years age † |
| Skin neoplasia | Most frequent tumours in dogs (24-30%) of which 20% are malignant* Breeds at high risk: boxer, Boston terrier, Scottish terrier and others |
Median age for cutaneous tumours in dogs is 10.5 years, and for cats 12 years |
| Mammery neoplasia | A common tumour in dogs (11.4%); 50% are malignant*. Over 97% of
cases occur in females hence female sex hormone-related Entire females have 7 x risk of neutered females. Bitches neutered before first oestrus have 0.5 risk of those neutered afterwards |
|
| Prostatic neoplasia | Male sex hormone-related | |
| Perianal adenoma | Male sex hormone-related Male dogs have 7.3 x risk of females |
|
| Lipoma | More frequent in females than males Infiltrative lipoma occurred in dogs with a median age of 6 years and 87% of them weighed over 20kg body weight More common in obese than non-obese animals |
Aged dogs were labrador retrievers (Bergman et al. 1994) |
| Gastrointestinal tract neoplasia | Account for 15.1% of tumours in dogs, of which 50% are malignant* | |
| Haematolymphatic system neoplasia | Account for 10.9% of tumours in dogs, of which 90% are malignant German shepherd dogs increased risk for splenic haemangiosarcoma |
Haemangiosarcoma was most common in dogs aged 8-13 years (Prymak et al. 1988) |
| Bone tumours - osteosarcoma | Large and giant breeds of dogs at high risk - usually appendicular skeleton, e.g. great Dane, Irish wolfhound, rottweiler, St Bernard, German shepherd dog | Common in younger animals as well as old dogs |
| Tonsillar carcinoma | Mainly occur in urban environments. ? Air pollution a factor (Cohen et al. 1964) |
|
| Lung carcinoma | Mainly occurs in urban environments. ? Air pollution a factor (Brodey 1961; Brodey & Craig 1965) |
|
| Bladder cancer | ? Industrial pollution a factor (Hayes 1976) | |
| Mast cell tumours | Mean age 10.2 yrs |
(*Theilen and Madewell 1987; † Dorn et al 1968b)