Eighty-five dogs with lymphosarcoma were included in a retrospective s
tudy. The mean and median ages were seven and nine years, respectively
. There was no sex predilection. Breeds at increased risk were, in ord
er of decreasing odds ratio, the Gordon Setter, Deerhound, Irish Wolfh
ound, St Bernard, Collie, Fox Terrier, Boxer, and Bull Terrier. Dogs i
n stages I to III comprised 42.4%, stages IV and leukaemic dogs compri
sed 30.6%, and dogs with the extra-nodal forms comprised 27.0%. The li
st of breeds found at increased risk and the proportion of dogs with e
xtra-nodal lymphosarcomas are different to previous Australian and int
ernational reports, and may represent regional differences in the appe
arance of canine lymphosarcoma.