Role in the film
Dr. Pruitt is first heard speaking on the phone with one of his clients and friends, Mark Garrison early in the morning about an upcoming baby delivery. A few moments later, as it turns out, it's Mark and his wife, Fran's pet Dachshund, Danke, who is about deliver puppies and whom they take to Dr. Pruitt, who is in fact, a veterinarian at the Animal Hospital. Dr. Pruitt helps Danke deliver three female puppies.
The next day, Dr. Pruitt is intrigued by Mark's wife's choice of names for the puppies: Wilhelmina, Heidi, and Chloe as he prepares some milk for a special puppy. Inside one of the cages, where dogs are kept, lies Dr. Pruitt's pet Great Dane, Duchess and her big litter of newborn puppies. Dr. Pruitt picks one up to feed him milk. When Mark asks if he's sick and why doesn't he put him back with his mother, Dr. Pruitt explains that due to a case of "too much litter and too little milk", his own mother picked him up and pushed him away as some dogs do to their own pups sometimes; making him the runt of the litter. So, Dr. Pruitt is forced to feed him and take care of him himself almost everyday.
When Dr. Pruitt tells Mark about the puppy's situation, Mark is shocked. However, realizing how much milk Mark and his wife's pet Dachshund, Danke has after giving birth to three female puppies, Dr. Pruitt quickly has an idea to give the Great Dane puppy to Mark and allow Danke to feed him enough milk until he is properly weaned and wet nursed. As much as Mark would love to have a Great Dane for a pet and to help him stay alive, he regretfully refuses since he has enough dogs in his own house now and being the Dachsie lover his wife really is, she would never agree to it either even though Dr. Pruitt is not trying to sell him or anything. So, Dr. Pruitt gives the pup to Mark to feed him some milk while he goes in to bring him Danke and her pups. As Mark begins to feed the pup one milk drop at a time, he changes his mind and decides to bring the pup back home momentarily.
A few weeks later, Dr. Pruitt is heard speaking on the phone with Mark about how the Dachsies and the Great Dane puppy now named Brutus are doing and Mark assures him that they're doing fine and that there are no feeding problems or objections about the Great Dane pup since Mark didn't tell his wife yet even though he tried to tell her at first. So, Dr. Pruitt reminds him that his wife isn't blind since she's bound to notice how big the male pup will eventually get but Mark thinks that he still has a couple of days left and the puppies aren't out of the basket yet and he wants to give his wife a chance to like the male pup. When Fran calls for Mark, Mark pretends he is now speaking with a "Mr. Harry Dayton" about some preliminary sketches for his magazine cover.
After the jig is up and the Great Dane pup has been weaned despite feeling sorry for all the nasty things she said to Mark about the puppy after he told her the truth, Fran makes Mark give the puppy back to Dr. Pruitt. At the vet, Mark, choiceless and regretful, returns the puppy to Dr. Pruitt, who is also disappointed about this, hopes that Dr. Pruitt will find a good home for him, and tells him his name is Brutus.
However, four weeks later, after seeing as to how miserable her husband has been without Brutus, Fran decides to buy or simply bring Brutus back from Dr. Pruitt and offer him to Mark as a birthday gift to cheer him up.
A few more weeks later, Dr. Pruitt attends an invitation to an oriental bacchanal held by the Garrisons at night in their garden with the help of Japanese caterers, Mr. Toyama and his assistant/nephew, Kenji. When Dr. Pruitt intends to try kombu, he quickly changes his mind when he learns it's actually stuffed seaweed. Then, he meets up with Fran. Dr. Pruitt asks Fran how are the dogs doing and Fran assures him that they're just fine; especially her favorite, Chloe, whom she thinks has the makings of a champion. This makes Dr. Pruitt tell her to ask Mel Chadwick, one of the guests and an expert on Dachsies, about her opinion on Chloe. Then, Fran reveals to Dr. Pruitt that she actually arranged this whole party to "get on Mr. Chadwick's good side." So, Dr. Pruitt reminds her to let Chloe out in the garden to show her to Mr. Chadwick eventually (even though the Garrisons agreed to keep the dogs inside) and then, regretfully accepts kombu from Mr. Toyama offering him such a dish.
Later, Dr. Pruitt meets up with Mark when he reveals his wife's wish to him. Of course, Dr. Pruitt can see that Mark's sympathies lie with Brutus as demonstrated when Mark shoos Chloe away from the food stand and asks how Brutus is and if he can see him. As they go to see Brutus, who is tied up to a pole in the backyard to avoid causing a mess at the party, Mark offers him a bone. Dr. Pruitt seems impressed with how well Brutus has grown since the last time he saw him as a puppy; considering him the best Dane he ever bred. He then asks Mark if his wife is getting used to having him around now and Mark simply states that she's adjusted to it since the Dachsies are more her pets; especially Chloe and that she won't be happy until Chloe wins a blue ribbon. This makes Dr. Pruitt ask him if he's thinking about entering Brutus in the dog show but Mark says he doesn't want any "spoiled and pampered showoffs" on his hand. Then, Dr. Pruitt and Mark get back to the party when Fran comes in and calls for them when she can't seem to find Chloe anywhere. However, once they leave, Chloe tricks Brutus into letting go of his bone and steals it from him, which causes Brutus to break free from his bond and begin chasing her around while causing a mess at the party and people to panic except Dr. Pruitt, who is simply just dismayed by the results of Brutus' chasing.
The next morning, after the mess, Fran tells Mark that she called Dr. Pruitt to tell him that he will be taking Brutus back to him in the afternoon; much to Mark's objection on Brutus' behalf. However, Fran changes her mind after Brutus manages to save Chloe from a garbageman's close mistake.
Later, after Dr. Pruitt has diagnosed Chloe with a simple rash and minor skin irritation since Fran intends to enter her in a dog show within six days as she did with her mother, Danke before her daughters' births, Dr. Pruitt tends to Brutus when he sees Brutus not obeying Mark when it comes to heeling. Seeing as to how beautiful and perfect he grew up to be as he figured he would, Dr. Pruitt thinks about making him a fine show dog to work with and teach him a few tricks but Mark refuses since one champion is enough for him but when his wife begins to doubt him about teaching Brutus obedience and training and shows him her way with Chloe's obedience, he changes his mind about Brutus despite Dr. Pruitt's former reluctance and the little time they have left to prepare him for the dog show as long as Fran remains oblivious to the plot.
During the next six days, Brutus begins to undergo some training despite all the faults. Although Brutus has shown some improvements in the end, Dr. Pruitt is not convinced since he feels that Brutus lacks consistency and a "proud, Dane look" because of the old "Dachsie influence", so, they have until tomorrow to figure out how to persuade Brutus that he isn't a Dachshund by tomorrow at the show.
The next day, at the dog show, Dr. Pruitt and Mark are seen grooming Brutus. At first, Brutus is almost recognized by Fran and Mark and Dr. Pruitt are almost caught when she unexpectedly appears in the room she's not supposed to be in with Chloe but Fran fails to recognize him and leaves despite Chloe knowing otherwise. When it is time for the Great Danes to perform, Brutus and Mark enter the show. Before the show, Dr. Pruitt wishes them good luck. During the show, Brutus performs perfectly well until he notices another lady's Dachshund and starts thinking and acting like a Dachshund again, which makes him and Mark the embarrassment and laughingstock of the show. When the judge notices Brutus acting weird, he asks them to stop. Then, he asks Mark if Brutus is sick or tired but Mark simply simply states he's just suffering "stage fright". At first, Brutus seems reluctant to stand up like a real Great Dane as Mark tells him to and probably gives up until he notices a lady with her female Harlequin Great Dane, thus, prompting him to stand up and act like a real Great Dane. When the judge notices Brutus acting normally, he suspects him to be a "different dog" and asks Mark how he managed "switching dogs" to avoid having him thrown out but Mark says he didn't. When he says he's having a hard time believing it's the same dog, Mark states he can't believe it himself. It's not until Dr. Pruitt tells Mark that it was because he saw the female Dane that made Brutus want to show off for her.
Later, the judge asks Mark, another man, and their dogs only to walk them again. Luckily, Dr. Pruitt manages to hide the lady's Dachshund when she stands next to him so as to remove the old "Dachsie influence" off of Brutus once and for all, thus, allowing him to perform perfectly well without any trouble or embarrassment this time. Finally, when it's over, Brutus and Mark are awarded the first place blue ribbon as the judge states to Mark that he "sure had him fooled the first time around", congratulates him, and compliments Brutus.
Then, Brutus is left to be judged with Dr. Pruitt for best of breed while Mark goes out to show Fran his prize after she and Chloe had won second place as they apologize and reconcile with each other. Finally, Brutus and Dr. Pruitt are awarded the best of breed ribbon as Mark, Fran, and Chloe watch them perform perfectly well at the show.
At night, after the Garrisons earn a matched set of ribbons, Mark reveals to Fran that he gave the first place blue ribbon to Dr. Pruitt since he deserved it for all the help he provided for him and Brutus.