I'm sorry to hear that you lost your two chameleons at such a young age.
I'm not a vet but I have kept/raised/hatched chameleons for about 20 years now.
Questions...what does "wnl" mean??
Why was the baytril used?
Look at what you used to gutload/feed the insects and look at the supplements that you used for vitamin D3 and PREFORMED vitamin A. These are the two that are fat soluble and can build up in the system. I can't tell you exactly how much of each they need....but I can tell you what I do with my veileds and that my female veileds usually live to be 6 to 8 years old and the males live even longer. I have also heard of people giving too much of both which then seems to bypass MBD and results in renal failure.
Here's what I do...
I dust with Rep-Cal (phos.-free calcium) powder at almost every feeding (lightly) to help make up for the poor ratio of calcium to phos. found in most feeder insects.
I dust twice a month (lightly) with a vitamin powder that contains a beta carotene (prOformed) source of vitamin A. (There is controversy as to whether all species of chameleon can convert beta carotene or not...but by using this I don't have to worry about overdosing the vitamin A while I ensure that they get all the other vitamins.) If the chameleon shows signs of hypOvitaminosis A, then a touch of prEformed vitamin A can be given by touching a bit from a vitamin A gel cap on an insect and feeding it to the chameleon. I'm sure you know this, but I will mention it anyhow...prEformed vitmain A can build up in the system. Excess prEformed vitamin A can prevent the D3 from doing its job. The two are antagonistic to each other.
Because my chameleons only get UVB from tube lights I also dust twice a month (lightly) with a phos.-free calcium/D3 powder. I don't want the D3 (from supplements) to build up in the system, but I do want to ensure that the chameleon gets enough.
I feed the crickets a variety of greens (dandelion, kale, collards, curly endive, escarole, mustard greens, (once in a while) ROMAINE lettuce, etc.)and veggies (carrot, sweet potato, sweet red pepper, celery leaves, squash, zucchini, etc.). I use no commercial feeds.
I make sure that I maintain suitable basking temperatures to aid in digestion and I make sure that I water them well each day.
Imbalance in the prEformed A and D3 is only one reason for renal failure...chronic dehydration, exposure to toxins, etc....but I assume you are sure that its hypERvitaminosis?
Here are some articles that you might find interesting...
http://web.archive.org/web/20060421082042/www.chameleonjournals.com/vet/index.php?show=6.Vitamin.D3.and.Calcium.html
http://web.archive.org/web/20060502074401/www.chameleonjournals.com/vet/index.php?show=5.Vitamin.A.html
Hope this helps!