Reducing Risk Of Mammary Tumours

[stonecutter]

Hi all - so I've read the Sanborn article on long-term health pros and cons of desexing and am particular interested in the mammary tumour (breast cancer) section. Apparently it is the most common form of cancer for bitches.

I'm making the tough decision about whether to desex my JS now (she's 5 months) or wait until she's fully grown and consider it at the 12-18 month mark. I understand that once she's had 3 seasons and then desexed, her cancer risk is the same as any intact bitch. She is on the main register (originally to be kept for breeding by her breeder) and at the moment I'm not showing her - but might in the future (1. I'm a little scared! 2. I've heard showing in my breed is a little on the political side and I don't want to get drawn into it, 3. She hates baths)

Desexing before first season reduces the risk of tumours to a very small level, and for entire bitches the rates seem high - but these seem to be based on results of studies that look at a broad range of dogs.

Are there any breeds that are more susceptible to mammary tumours? From my reading of the research - some breeds keep popping up - Pomeranian, Doberman, Alsatian. Though, I could see this could be due to a number of reasons - 1. these breeds are more likely to be intact, and therefore tumours are more likely. 2. these breeds might be more popular and therefore as a whole, tumours are also more likely. 3. There's something that predisposes them - genetic makeup?

I haven't really found anything that says whether Japanese Spitz's (or Spitz breeds in general) are more susceptible.

The sorts of papers I looked at were the lit review in this thesis

http://openmed.nic.in/2251/01/Dr._Vitthal_Dhaygude_M.V.Sc._Thesis.pdf

Some articles also talk about the increase use of soy and high levels of oestrogen in dog foods as a contributing factor - I noticed Black Hawk is soy-free.

So for all those who are breeding/showing - is there anything you do to reduce the risk of your girls developing mammary tumours? Is this something people consider at all or am I being paranoid?

[Staranais]

Most important thing is to regularly monitor your bitch's mammary glands, especially the rear ones, and especially as she ages. Approx 50% of mammary tumours are malignant, many of those metastasise to the lungs. Tumours detected earlier are less likely to have metastasised & more likely to be successfully treated by excision.

Giving megestrol acetate ("Suppress") or other progestins increase the risk of mammary cancer. Bitches that are obese at a young age are also more likely to eventually suffer from mammary cancer, and the type of food you feed may also have some type of influence. There's an article in the Journal of Small Animal Practice about it (by Perez Alenza et al in 2000), but that is the gist.

Edited June 6, 2011 by Staranais

[stonecutter]

Thanks Staranais!!

I'll get my vet to teach me how to check her