We don't have many relays with filtered content yet, today all relays are all more or less the same mess, but if you are into cats here is something for you: nostr:nevent1qqstdeudu2kfw55eueeyzmcq9tng76wpr32s7xtxhvwk84udwrgztaqpzpmhxue69uhkztnwdaejumr0dshsz8thwden5te0vfhhxarj9e3xjarrda5kuarcda4k7tnrdakj7qgwwaehxw309ahx7uewd3hkctcm0sz6j

You can use https://nostrrr.com/relay/catstrr.swarmstr.com to browse.