Well, It depends of what the breed is, I don't think there is an answer of how many dogs die at age 5, It varies.
Phenergan(promethazine) is generally used for allergies, motion sickness, and headaches. So theoretically you could. You'd have to check the dosages though.
12-24 hrs it can be fertile after ovulation
It should knock out atleast 99% to 100% of UV-A and UV-B radiation.