Citigroup initiated coverage of VCA Antech (WOOF

) with a sell rating and set an $18 12-month target.

Analyst Matthew Ripperger says VCA Antech is the leading provider of veterinary services through a national network of veterinary hospitals and diagnostic labs. His sell rating is based on his concern that the company's core markets are becoming more competitive.

He also cites continued same-store declines in its hospital volumes, recent weakness in lab volumes, and concern over the recent acquisition of Sound Technologies which represents a deviation from its past strategy. Ripperger notes a material spike in insider sales over last six months. His current valuation is at a historical high relative to comparable sales and historical average.