Loner narc Dooley (Belushi) is after a drugs kingpin, so is assigned a partner - Jerry Lee, the equally difficult- but equally adept at policing - alsation.
Bickering police partners are nothing new, but this latest variation is police partners of a different species. Dooley (Jim Belushi) is a San Diego cop with a bad attitude; a loner operating in the narcotics division. He's after a drugs baron, but can't get the evidence he needs. To find it he reluctantly teams up with a drug-sniffing expert from the K-9 division named Jerry Lee (because he's a killer, geddit?). Jerry Lee is a randy, farting, chilli-chomping alsatian.
Before long the antagonistic duo are behaving like any other pair of cops in the movies - fighting over the same woman, aggravating their colleagues, nibbling bad guys and saving each other's lives.
Belushi, improving with each film, has dropped a ton of weight to give a reasonable impersonation of a macho action lead. K-9 milks every comic possibility inherent in the One Man And His Dog premise, but is basically a slick cop thriller with all the GBH, shootings, car chases, broken glass one could desire. Much of the cheerful humour is not particularly hilarious, but there are a lot of good one liners and some very funny vulgar gags. We're not talking Noel Coward here, we're talking doggy apprehending hoods by the balls, cop pretending to be blind, officer Lewis distracted from duty by a be-ribboned poodle temptress and cop threatening dog with Old Yeller's fate.
The biggest laughs come at the expense of any realism whatsoever, but that has been dispensed with early on when we find Dooley living in an impossibly swank home with an impossibly chic woman (Mel Harris, Hope from thirtysomething, who has little to do but wander round in a lot of expensive underwear).
The dog is brilliant. Training (by veteran Karl Lewis Miller), and 'dog vocals editing' have lent this handsome pooch more human mannerisms and expressions that any critter outside the classic Disney adventures in anthropomorphism. Despite Belushi's efforts, Jerry Lee is quite the most attractive and sympathetic character, and it would come as no surprise were someone to hatch a follow-up TV series around him.
This is actually better than it may sound, though rather less charming than it would like to, and needs to be.