Cats are said to have nine lives, but W. Bruce Campbell’s weird tale of doggie reincarnation suggests that canines run them a close second. The story of Bailey, begun a couple of years back with “A Dog’s Purpose,” continues in this sappy sequel, and by the end he has completed eight. Viewers who embraced the first movie might find “A Dog’s Journey” just as lovable; others may find it an equally strange mixture of juvenile humor, mawkish melodrama and insufferable cuteness. It’s like an overeager puppy constantly demanding attention however he can get it.

In the first installment (which was directed by Lasse Hallström, here taking an executive producer credit), you may remember, Josh Gad voiced Bailey, who became the beloved pet of a young Michigan farm boy named Ethan, played by KJ Apa. The dog died after the kid went off to agricultural school, and proceeded through a series of lives as other breeds before making it back, as a big mutt, to his first master, now in the person of Dennis Quaid. Both were overjoyed to have found one another again.

“Journey” (directed blandly by Gail Mancuso) begins a few years later, after Ethan and his new wife Hannah (Marg Helgenberger, replacing Peggy Lipton) have taken in Gloria (Betty Gilpin), her son’s widow, and Gloria’s toddler daughter CJ (Emma Volk). Gloria is an unhappy young woman (and a dog-hater to boot), who stalks off with the kid in a huff, cutting off Ethan and Hannah altogether. When Bailey dies, Ethan asks his departing soul to look after CJ. It turns out to be a tough assignment, since Gloria proves a totally irresponsible mom, desperate to find a man and prone to drink too much.

No wonder the now-adolescent CJ (Abby Ryder Fortson) decides to adopt a beagle called Molly, actually the reincarnated Bailey, when her best friend Trent (Ian Chen) chooses Molly’s brother. She hides the pooch from her mother, who reluctantly allows the kid to keep her when she finds out (and CJ threatens to turn her in to CPS).

Skip ahead a few years, and CJ (now Kathryn Prescott) gets into trouble with a slimy boyfriend named Shane (Jake Manley), who literally drives her off the road after she’s broken up with him and had a final fight with Gloria. In the ensuing car crash. Molly emerges unhurt and begins a trek to points unknown as—you guessed it—an aspiring singer/songwriter. But Molly dies in the accident.

Not to worry. Bailey’s reborn again, this time as a huge mongrel that becomes the pet of Pennsylvania gas station owner Joe (Conrad Coates). Who should stop by the place one day on her way to New York but CJ, who drives off before Big Dog, as he’s now called, can catch up to her; but again he dies, and is immediately reincarnated as Yorkshire terrier Max, who somehow winds up at a NYC shelter where, inevitably, CJ adopts him.

She has a boyfriend in the city, but who should show up unexpectedly but Trent (now played by Henry Lau), who has a girlfriend on his arm but not for long. At this point “Journey” ventures into “Fault in Our Stars” territory as Max, remembering his training from CJ’s stint in community service way back when, sniffs out Trent’s cancer just in time to get him to a doctor so he can undergo life-saving chemotherapy. After he’s recovered (in a montage that makes the whole episode seem like little more than a bad cold), he decides to drive CJ back to reunite with her grandparents, and bent-over Ethan recognizes Max as his Bailey once more. By the time the movie ends, everyone is happy—even Gloria has reformed and returned to the family fold—though, of course, Max’s time with them all is limited. His work is done.

As can be discerned from this précis, “A Dog’s Journey” is as awash in coincidences as it is in jokes about gobbling up bacon from the floor and gags involving doggie-doo. Of course, perhaps some higher power is assumed to be directing the persistently reborn Bailey into running just as persistently into CJ, but that’s never made explicit. (It’s probably better that way, even if God is Dog spelled backwards.)

The humans in the cast play second fiddle to the canines, all of whom seem well-trained, but Prescott (who resembles a young Jodie Foster) is engaging, and though Quaid’s old-age version of Ethan is about as convincing as the late Tim Conway’s little old man, he brings the requisite gravity to the part. Gilpin comes on awfully strong as the mean-as-nails Gloria, but Lau is likable as the older Trent. As for Gad, he’s as ebullient in a gee-whiz way as he was the first time around, which one will find either charming or irritating, depending on your point of view. The picture has the glossy look of Disney live-action movies from the fifties, courtesy of Rogier Stoffers’ lensing, and Mark Isham’s score oozes sentiment.

One thing virtually everyone should be able to agree on is that after all his frantic lives, Bailey deserves a good, long rest. In other words, no third installment, please; this dog has had its day, and then some.