diff --git a/toolkit/components/telemetry/TelemetryHistograms.h b/toolkit/components/telemetry/TelemetryHistograms.h
index 09f963fa3d6..8f0c96a55f2 100644
--- a/toolkit/components/telemetry/TelemetryHistograms.h
+++ b/toolkit/components/telemetry/TelemetryHistograms.h
@@ -289,20 +289,24 @@ HISTOGRAM(UPDATE_STATUS, 1, 16006, 20, LINEAR, "Updater: the status of the lates
 /**
  * Thunderbird-specific telemetry.
  */
-#ifdef MOZ_THUNDERBIRD
+// Disable this application-specific #ifdef ftb. (See bug 710562)
+// #ifdef MOZ_THUNDERBIRD
 HISTOGRAM(THUNDERBIRD_GLODA_SIZE_MB, 1, 1000, 40, LINEAR, "Gloda: size of global-messages-db.sqlite (MB)")
+// THUNDERBIRD_CONVERSATIONS_TIME_TO_2ND_GLODA_QUERY_MS is used by Thunderbird Conversations add-on.
+// https://addons.mozilla.org/en-US/thunderbird/addon/54035/
 HISTOGRAM(THUNDERBIRD_CONVERSATIONS_TIME_TO_2ND_GLODA_QUERY_MS, 1, 10000, 30, EXPONENTIAL, "Conversations: time between the moment we click and the second gloda query returns (ms)")
 HISTOGRAM(THUNDERBIRD_INDEXING_RATE_MSG_PER_S, 1, 100, 20, LINEAR, "Gloda: indexing rate (message/s)")
-#endif
+// #endif
 
 /**
  * Firefox-specific telemetry.
  */
-#ifdef MOZ_PHOENIX
+// Disable this application-specific #ifdef ftb. (See bug 710562)
+// #ifdef MOZ_PHOENIX
 HISTOGRAM(FX_TAB_ANIM_OPEN_MS, 1, 3000, 10, EXPONENTIAL, "Firefox: Time taken by the tab opening animation")
 HISTOGRAM(FX_TAB_ANIM_CLOSE_MS, 1, 3000, 10, EXPONENTIAL, "Firefox: Time taken by the tab closing animation")
 HISTOGRAM_BOOLEAN(FX_CONTEXT_SEARCH_AND_TAB_SELECT, "Firefox: Background tab was selected within 5 seconds of searching from the context menu")
-#endif
+// #endif
 
 HISTOGRAM_BOOLEAN(INNERWINDOWS_WITH_MUTATION_LISTENERS, "Deleted or to-be-reused innerwindow which has had mutation event listeners.")
 HISTOGRAM(XUL_REFLOW_MS, 1, 3000, 10, EXPONENTIAL, "xul reflows")