The final edition of O'Grady's seven-part fly-on-the-wall show for ITV drew 4.73m and a 19.3% share, adding a further 257k (1.1%) on ITV1 +1.
Clashing with BBC One's popular EastEnders, For the Love of Dogs has become ITV's most successful format in its Monday 8pm filler slot in the 21st century.
For the Love of Dogs has also outperformed the presenter's Friday night chat show Paul O'Grady Live, which was dropped after two series following unspectacular viewing figures.
There was also good news for ITV in O'Grady's old stomping ground, as The Chase commanded 2.89m (20.5%) at 5pm (+1: 219k/1%), beating Pointless's 2.58m (10.6%) for BBC One.
However, ITV's success didn't run into the 9pm hour, where James Nesbitt's Monroe sunk to 2.77m (11.9%) at the mercy of New Tricks, which remained solidly high with 7.26m (31.1%).
Elsewhere, University Challenge (2.68m/11.9%), Nigellisima (2.24m/9.3%) and Wonderland (1.54m/6.6%) were fairly consistent for BBC Two. Strictly Come Dancing: It Takes Two dazzled 1.91m (9.4%) at 6.30pm.
Meanwhile, Channel 4's 999: What's Your Emergency climbed to 2.07m (8.9%) at 9pm (+1: 439k/2.6%), and Channel 5's highest-rated programme was once again 8pm's Classic Car Rescue with 991k (4.1%).
Overall, BBC One topped primetime with 23.3% over ITV1's 21.9% (+1: 0.8%). BBC Two claimed third place with 6.9%, ahead of Channel 4's 5.2% (+1: 0.9%), and Channel 5's 3.7% (+1: 0.2%).
Witch drama Switch, starring Lacey Turner, premiered on ITV2 with 574k (3.4%) at 10pm, beating the return of Made in Chelsea which attracted 452k (2.7%) and 101k (1.2%) on E4 +1.
BBC Four's Only Connect was the most-watched digital broadcast with 860k (3.5%) in its usual 8.30pm slot - the gameshow also helped 9pm's World War Two, which interested 654k (3%).
BARB ratings data supplied by Attentional