Oh CR*P.

It does look VERY suspicious. Very.

Have any of the affected buds actually bloomed/opened? If it's RRD, the sexual parts (stamens, pistils) will be malformed, or even missing. And have any of the red leaves matured enough to tell if their general outline is atypical? The red leaves alone aren't a sure indicator, but red leaves that never mature to a typical (for the cultivar) outline and color are. Are the affected stems larger in diameter than the stems they arise from, or at least abnormally "robust"?

I will say that the last photos of the trimmings do look to me like RRD, even without the thorns. I know how heartbreaking it is to find it on a beloved rose. I've been through it many times.

If you're the brave and patient kind, you can trim the affected canes right down to the ground, then watch the remainder of the plant like a hawk.. There's a possibility that even if it is RRD that the infection has not become systemic yet. If it's just now showing up, then that means it's a recent infection, and not one carried over from last year. If it were infected last season, the symptoms would have presented in the first new growth of Spring, and the plant would be unsalvageable.

Renae is a vigorous rose, and even if the majority of canes are affected, if the ROOTS and remaining canes are uninfected, you might yet save her. By cutting the affected parts as low as possible, on a plant infected in the current season, I've saved several roses this way.

You may not want to take the chance, but there is (slight) hope. In any case, best of luck.

John

Agree with John, since its a treasured old plant, trim each affected cane to the ground ASAP. Then keep a vigilant watch for RRD type growth on any new shoots. I’d say I had been about 50% successful with this when I lived in North Texas. If the plants did not develop suspicious behavior after more than 2 seasons, it seemed it never came back.

Maybe try to root a few cuttings as backup, too.

If it’s an easily replaceable plant, I’d just dig out the whole thing and dispose it.

Thank you, Jeri, John and Ben. Appreciate your reply. I will keep an eye on her and keep you updated.

in agreement with taking that cane all the way down, as well as any adjacent canes it may have rubbed against.

RRV is phloem transmitted so the end of that cane may not show it. It appears to have come in on that cane in that place.

Good luck.