Belgian Malinois Breeder Wanted

We have had our 11 yr. old German Shepherd cross on Previcox for about 6 months but found that a cost of $4.00 each to be extermely expensive even though he only needs 1/2 a tablet per day. I found ,ordered & received a delivery from U.S.A.for half that price but now need to order more.Unfortunately that website ordering service is no longer advertising.Where can I buy from in Australia without a prescription?