(Adds further detail, background) LONDON, Feb 9 (Reuters) - Pet care firm IVC Evidensia has completed a 3.5 billion euro ($4.2 billion) private funding round ahead of a potential London initial public offering (IPO), as the pet care industry booms in the COVID-19 pandemic. The investment values IVC, which is owned by private equity firm EQT, at around 12.3 billion euros, IVC said on Tuesday. Silver Lake is making a “substantial minority investment” and existing shareholder Nestle is increasing its minority stake as part of the funding round, IVC added. Headquartered in Bristol, southwest England, IVC is a veterinary services provider with a network of more than 1,500 clinics and hospitals across Europe. It is among a number of firms expected to list in London later this year, with two sources telling Reuters earlier this year that it had appointed banks for a listing that would value it at 12-15 billion euros. The IPO will look to leverage the recent huge spike in demand for pet care services, with pet sales rocketing at a time when many people are isolated because of lockdowns across the world to try to contain the pandemic. Goldman Sachs and Jefferies acted as financial advisers to IVC. JP Morgan and Numis were financial advisers to Silver Lake.