There is a toxin in Kalmias called andromedotoxin. It has been known to poison domestic livestock. Not sure about the effect on deer, probably none.
When deer are numerous enough they will eat just about anything. Fencing seems to be the answer for some of us.
Sam

We have resorted to feeding the deer corn, my thoughts are if I feed them corn they are more likely "not" to eat most of the shrubs/plants I've been planting. So far so good, except it looks like the hydrangeas have been hit...but not completely...yet. I've also used the tomatoe cages I made from concrete mess as winter protection for several other shrubs just happen to run out when it came to protecting the hydrangeas. Next year I'm starting with the hydrangeas to give them a better start next year.

Deer will be an ongoing battle in my experience I've found it is better to live with them then to try to fight them...not worth it. So every spring I loose most of my hostas, I just cut them back and fertilize and they return.

I have been wondering about the effect of feeding the deer. I had planted the rhododendrons and laurels among the trunks of a line of large hemlocks on the back border of my yard. The neighbors on the other side do feed the deer. And since they don't seem to want to mess up their nice lawn, they tend to spread the corn on the property line, in the shade of my hemlocks. Last year I noticed that when the corn would be gone, the hooved locusts would move onto the pines and spruces I had planted to fill in some gaps in the hemlocks. So I built wire cages around and then hooked them up to an electric fence charger. That worked amazingly well. I guess I'll have to do the same with the "poisonous" understory plants as well.

I vote against feeding deer. There have in fact been several tests by Ag Extension services in the Midwest that prove conclusively that feeding deer or providing salt licks, even when separated from the ornamentals by 100 yards, only succeeds in attracting more deer and increasing the damage to ornamentals.

Rhodos and mt laurels are not deer's first choice. Look at all the native mt. laurels growing wild in MD in areas also infested with deer. If deer are really really hungry they will eat mt. laurel.