Dgaim wrote:

My Fantin-Latour, for the past year, has had deformity of most new
canes. There will be healthy canes, healthy canes with some distorted
leaves, and diseased canes. I have pruned off all diseased canes
with sterile pruners and destroyed them. I don't know how else to
describe the damage. Affected mature leaves are shriveled and don't
open. There's a spiky-witches broom appearance to the affected canes.
I've looked in all my books without success.

Sorry to hear this. It seems unlikely that it is Roundup damage for a
whole year, but on the off chance you have the good luck *not* to have
rose rosette, take a look at what Roundup damage looks like on Baldo's
page:

http://www.sactorose.org/rosebug/iabioticdisorders.htm