There was filler because the manga was still running. Over a third (but under a half) of the first run of the anime was filler.
Even with 143 episodes and 11 OVAs, I don't believe the original anime got fully through Volume 22 of 38. The OVAs touch a few of the additional arcs from later, but barely cover the content in the high 20s, skipping some one-off chapters and mini arcs that are also great. They only barely get to Ranma's mother appearing and don't resolve that plot thread and especially don't conclude Ranma and Akane's relationship, which is very pleasant.