Alonso graduated from the Veterinary School of the Complutense University of Madrid in 1998 and then went to work for two of the busiest RSPCA hospitals in the UK (Manchester and Harmsworth Hospitals) for four years where he was also involved in the BBC television series Animal Hospital. Alonso joined the Mandeville Hospital in 2002 and is now a senior clinician. He has published several papers in veterinary medicine journals both in the UK and internationally. He holds a Certificate in Feline Practice (European School of Veterinary Postgraduate Studies) and is a PhD holder in Pharmacology and Toxicology. As an Official Veterinarian [OV] Alonso is authorised to issue pet passports and complete export health certificates. Alonso has two rescue cats from the MVH and is a music lover and enjoys playing saxophone in a band during his spare time.