I'm puzzled because if she has the correct pliant skin for a Basenji, it would get fewer wrinkles if she was too fat. I stand to be corrected here but thats what happens to mine!!
I think she looks very good and that she has no need to lose any weight. Her coat is gleaming. Congratulations to you for keeping her in such lovely condition!
I've only ever had to remove ticks from our collies - the Basenjis have never had one but I can understand that you feel the need to give medicine but personally I only give conventional medicine to a Basenji if I (and my vet) consider it totally necessary.