Use continues as an 'animal feed additive' for the purposes of flavouring, although it has not been licensed for use in animal medications at present.
Personally, I am not prepared to give my animals something which I may not legally use on myself.
Since it has not been licensed, it is unclear how a safe dose is arrived at and production methods & quality are also unregulated, which appear to have led to problems in the past.
The Foods Standards Agency has current information here:-
This is an interesting paper :-
Kava use is a controversial subject, particularly since our ban has had unwelcome effects on the indigenous populations who had hoped to earn income from exports and work is being done to find a way of producing a safe product.
However, the problem of liver damage is very worrying and there have been many cases recorded from use of Kava produced by solvent extraction methods in the West, although deaths have apparently been recorded amongst people who have used Kava produced by traditional methods.
Hopefully, a safe form will be licensed soon.
In the meantime, using a 'DAP' product can be a useful method of helping pets through the firework season and vets are able prescribe safer products.