I think the schedule below will work for you. Everyone has 6 different partners, plays against 4 members of the other team once, and plays against the other 4 members twice.
(CA3 CA1 v US2 US6) (CA5 CA4 v US1 US5) (CA7 CA2 v US7 US8) (CA8 CA6 v US3 US4)
(CA8 CA5 v US5 US6) (CA2 CA4 v US7 US4) (CA7 CA3 v US1 US2) (CA1 CA6 v US8 US3)
(CA2 CA8 v US2 US3) (CA6 CA7 v US7 US5) (CA1 CA5 v US1 US4) (CA4 CA3 v US6 US8)
(CA1 CA2 v US5 US3) (CA6 CA4 v US2 US7) (CA3 CA8 v US1 US8) (CA7 CA5 v US4 US6)
(CA6 CA2 v US1 US6) (CA8 CA7 v US4 US2) (CA3 CA5 v US3 US7) (CA4 CA1 v US8 US5)
(CA3 CA2 v US4 US5) (CA5 CA6 v US2 US8) (CA8 CA1 v US7 US6) (CA4 CA7 v US1 US3)