The Last Family in England: Matt Haig

Meet the Hunter family: Adam, Kate, and their children Hal and Charlotte. And Prince, their Labrador.
Prince is an earnest young dog, striving hard to live up to the tenets of the Labrador Pact (Remain Loyal to Your Human Masters, Serve and Protect Your Family at Any Cost). Other dogs, led by the Springer Spaniels, have revolted. As things in the Hunter family begin to go badly awry – marital breakdown, rowdy teenage parties, attempted suicide – Prince’s responsibilities threaten to overwhelm him and he is forced to break the Labrador Pact and take desperate action to save his Family.