I've heard pardalis are notorious for this. Some CB's simply will not mate.
With my deremensis, there was a need to make them fight. i had to get the males riled up before they'd notice the girls. Usually took 2 weeks of harassment. Using a mirror usually worked, but another male worked better. Introduce the male, see what happens. If the male ignores the intruder, have to try again later. Usually, they'd act shy, and submissive. Then I remove th eothe rmale - as if he was chased away. A few times like this, and the male will become defensive, and stand his ground. They'll even become downright aggressive. I di dthis a few years ago, an dthe male that was shy just a week or two earlier charged so fast I had to pull the other male away fast - and I got stabbed in the process!
i tried this with deremensis 3 or 4 times. in all cases, the males began courting the females within a week of their "expulsion ' of the intruder.
You might want to try somethign like this - make them go a little hungry, a little dry, and a little cool for a few weeks. then shower them, warm them up and feed them like crazy. Veileds, which can mate year round, respond to this very well.
I got no experience with panthers, so listen to those that do!
