Dear Petal Pusher:
It is kind of hard to know, as many things will cause bud drop on
Phalaenopsis, but I can give several thoughts on the matter.
1. Sudden spikes in conditions (I talk about this at length on a few
other letters posted here) can cause this.
2. If your cat, in playing with the plant punctured the bud, this
could easily cause it to abort.
3. If this is a first bloom seedling it may only have had the strength
to open two flowers, and gave up trying to mature the third bud.
4. If this plant is blooming for you a second time (perhaps purchased
in bloom last year)and has produced fewer buds than last year, you
might be keeping it in sub-optimal conditions. This would limit the
number of buds produced and increase the liklyhood of bud drop. Make
sure your light is bright enough, that the night temperatures remain
above 60 (except perhaps for a few weeks in the fall), and that the
plant is being allowed to dry between copious watering.
Although we have links to AOS culture sheets on the site, those links
appear to have broken, so look in a few days for the Phalaenopsis
culture sheet that will explain the conditions they prefer in detail.
Hope this helps!
Dennis