Transmissible cancers in dogs and Tasmanian devils

Figure 1.

The Tasmanian devil, the world’s largest marsupial carnivore, is facing possible extinction in the wild due to a transmissible facial cancer known as Tasmanian devil facial tumour disease (DFTD) (Figure 1). DFTD is spread when living cancer cells are spread between animals by biting. In DFTD, the living cancer cell itself is the infectious agent of disease and it remains unclear why these cancer cells are not detected and rejected by the devil’s immune system. The distressing plight of the Tasmanian devil has drawn attention to the existence of transmissible cancers, parasitic cancers spread by the transfer of living cancer cells between hosts. However, it remains a surprisingly little-known fact that the only other transmissible cancer that bears any resemblance to DFTD is a dog cancer that is right under our noses here in Australia.

Canine transmissible venereal tumour (CTVT) is one of the world’s most remarkable cancers. It is a transmissible cancer that affects dogs worldwide. Usually spread during coitus, the disease is most prevalent in areas with large numbers of free-roaming sexually active dogs. The tumour affects both male and female animals, and appears to affect dogs of any breed. CTVT generally manifests itself in the appearance of tumours in and around the genital area, often at the base of the penis in males and in the vulva of females. Starting as small shiny pink/grey lesions, the tumours can progress to become very large and multi-lobulated (Figure 2). The tumour may aggressively invade surrounding tissues and become ulcerated and secondarily infected. However, a combination of surgical debulking and chemotherapy (using vincristine) is often curative.

Figure 2

Genetic studies have provided strong evidence that CTVT is in fact one living cancer cell line that has spread worldwide with dogs. Thus all CTVT tumours are derived from a single original tumour that arose once and has been transmitted through the dog population as a clone. The tumour itself bears closest genetic resemblance to wolves, suggesting that this tumour may have first arisen in a wolf before hitch-hiking its way into dogs through sexual contact. Genetic evidence suggests that the tumour may in fact be quite old, and that the original wolf that gave rise to the tumour may have even lived thousands of years ago. CTVT is by far the oldest known continuously growing cancer in the world. Continue reading Transmissible cancers in dogs and Tasmanian devils

Titanium teeth for prison dog

A valuable Victorian prison dog is showing off his new “smile” after receiving titanium incisors from veterinary dentist David Clarke. The German Shepherd, Axel, required the dental work after biting his bed board. Clarke, the owner of K9 Gums in Hallam, Victoria, has also treated big cats, gorillas and bears during his career.

“So much is spent . . . → Read More: Titanium teeth for prison dog

Essay: Decreasing undesired aggression in military working dogs and improving their welfare

This essay is one of a number selected for The Veterinarian magazine Prize for Written Communication for Sydney University third-year veterinary science students.

Military working dogs (MWDs) are employed worldwide to assist in law enforcement and military operations. They are trained to display controlled acts of aggression during defence situations, such as in the case of a serious threat or attack. However, some MWDs may direct aggression toward humans or animals outside the working context and this type of aggression is deemed undesirable (Haverbeke et al., 2004). Furthermore, MWDs are usually housed individually in kennels, an environment associated with high cortisol concentrations and stress-related behaviours such as stereotypies (Taylor & Mills, 2007). When under stress, dogs may react to otherwise neutral situations, showing fearful behaviour that can often lead to aggression (Rooney et al., 2009). Continue reading Essay: Decreasing undesired aggression in military working dogs and improving their welfare

ACVSc members – your vote is needed!

The Council of the Australian College of Veterinary Scientists will again present to its members a proposal to change its name to one that will appropriately reflect New Zealand’s involvement in all of its functions.

The new name being proposed is the Australian and New Zealand College of Veterinary Scientists (ANZCVS) and will be presented as part of the Annual General meeting on July 2, 2011.

A decision made 40 years ago when the College was beginning saw New Zealand omitted from the title. Ever since then New Zealanders have had to accept a qualification and title that does not truly reflect their origin and their training. Continue reading ACVSc members – your vote is needed!

RSPCA demands end to pig hunting

The NSW branch of the RSPCA is calling for an end to feral pig hunts using dogs in state forests.

The campaign comes on the heels of the NSW Game Council’s invitation to 24 hunters to participate in a trail using pig dogs to hunt feral pigs.

The trial commenced on April 30 in Nundle, Hanging Rock and Tomalla state forests in the New England area.

Continue reading RSPCA demands end to pig hunting