TG 2000 is listed as 11-Mike... Operations 6. It's an AAPD TG... could be for training. If it was a simple Animal Control incident, it would be on 2256 (12F). All police have 12F in their radios for interop with AC.
AA talkgroup 2000, as menioned is 11M Ops 6 on the TRS, and is used by the Special Operations Division and includes the K-9 unit. Talkgroups 1840, 1872, 1904, 1936, 1968, 2000 are Ops 1 through 6 for this purpose. Talkgroup 2032 (11N) is labeled PD SOS as the primary channel Special Operations Section. http://www.aacounty.org/Police/specialOps.cfm