Notice from the British Goat Society
The only licensed dewormer for goats in the UK is Eprinex
(Eprinomectin) which is a pour on. It has zero withhold time for milk. This has only been licensed in the last few months. However it should be used infrequently because pour ons are more likely to produce resistance. Always make sure that you use the correct dose. In general it is better to use oral dewormers
All the other dewormers have a milk withhold time of at least 7 days. Oramec is not licensed for goats but can be used under the cascade regulations. It specifically states not to be used in lactating animals and that milk should only be used for human consumption 60 days after dosing.
Hope this helps