• 
  Okeford Veterinary Centre Chagford

  Chagford
• 
  Old Courts Veterinary Centre - Brigg

  Brigg
• 
  Old Hall Vets

  Appleby-in-Westmorland
• 
  Old Mill Veterinary Practice

  Stornoway
• Old School Veterinary Practice - Harrapool, Broadford

  Isle of Skye
• Old School Veterinary Practice - Kyle of Lochalsh

  Kyle of Lochalsh
• 
  Old Stone Vets - Allendale

  Hexham
• 
  Old Stone Vets - Alston

  Alston
• 
  Oldstone Vets Ballymena

  Ballymena
• 
  Onca Vets

  Norwich
• 
  Orby Vets

  Skegness
• 
  Orchard Veterinary Centre

  Armagh
• 
  Orchard Veterinary Group

  Glastonbury
• 
  Orchard Vets - Ashurst

  Ashurst
• 
  Orchard Vets - Romsey

  Romsey
• 
  Orford Vets

  Warrington
• 
  Origin Vets Clinic

  Cardiff
• 
  OrtonVets

  Peterborough
• 
  Otter Vets - Ottery St Mary

  Ottery St Mary
• 
  Otter Vets - Sidmouth

  Sidmouth
• 
  Oundle & Thrapston Vets - Oundle

  Oundle
• 
  Oundle & Thrapston Vets - Thrapston

  Thrapston
• 
  Oval Pet Centre - Sidcup

  Bexley
• 
  Oval Pet Centre - Welling

  Bexley