K9 Mark 2 was the result of the activation of the Mark I's onboard regeneration unit. He had only very limited memories of his past as the Mark I. He had many adventures with Alistair Gryffen, Jorjie Turner, Darius Pike and his new master Starkey. (TV: Regeneration, The Bounty Hunter) Orthrus was an attempt by Drake and the Department to replicate K9, but it was of vastly inferior design. (TV: Jaws of Orthrus)
K9 Mark III first appeared in "A Girl's Best Friend", the 1981 pilot for a series, K-9 and Company, which never materialized beyond the first episode. In this, the character is presented to the Doctor's former companion Sarah Jane Smith (Elisabeth Sladen); together, the two embark on what a number of adventures. Only the first of these is depicted on-screen; several are shown in comic book and audio play adaptations, and others are alluded to by the television series. Mark III made a brief appearance alongside Sarah Jane in the Doctor Who 20th anniversary ninety-minute special The Five Doctors (1983), before appearing properly and for the final time in the revived series' episode "School Reunion" in 2006. By the time of that story, Mark III has fallen into disrepair and eventually sacrifices himself to stop a plot by the alien Krillitane and defeat their leader, Lucas Finch (Anthony Head). In the episode's conclusion, the Doctor presents Sarah Jane with a new K9 to encourage her to continue investigating alien activity; the Doctor "rebuilt" him after the Mark III's sacrifice, implying that he had the same mind and memories as his predecessor while still being a "brand new model".
K9 had a personality very consistent across the models with some contact with the Doctor. He was polite and formal, with pedantry bordering on condescension. Though he often displayed feelings such as sorrow (TV: The Invasion of Time) and self-regard (TV: School Reunion), he often stated that he had not been programmed to have emotions. (TV: Invasion of the Bane)
Either Inspector Thorne or Lomax found out about K9's regeneration unit and decided to acquire it. Thorne joined forces with Freddie Maxwell, owner of Crashclub involving old robots being made to fight. K9 went undercover as a gladiator and made friends with the robot clowns Chuckles and Boris. He was called to fight the Pain-Maker, who was laced with the explosive solarmite. When he was set to self-destruct, K9 detected this and fled the explosion. (TV: Robot Gladiators) To regain his memory and find out his connection to the STM, K9's archive was scrambled. Directives from the STM almost caused him to self-destruct and lose all his memory. However, with Gryffen and Starkey's help he overrode the directives. (TV: Mind Snap) He helped Gryffen find the STM's temporal stabiliser from the fallen angel crash site in Canada, where it was revealed to be Korven technology. (TV: Angel of the North) He stopped haywire CCPCs when The Last Precinct's plan backfired. (TV: The Last Precinct)
When the Tenth Doctor created K9 Mark IV to replace K9 Mark III, he added a shiny metallic blue paint job and other improvements, including an omniflexible hyperlink facility. (TV: School Reunion) Later, though, K9 reverted to his old dark green colour. (TV: Invasion of the Bane) In battling Mr Smith (and following the battle) K9 displayed a teleport facility and a laser weapon similar to the previous K9s'. (TV: The Lost Boy)
Dallas K-9 Academy is the best and the most effective dog training available. Your dog is trained in your home (or place of business). We also offer board and train programs. Our effective techniques developed through more than 18 years of experience help you teach your dog to understand how he should behave in day-to-day situations. At the completion of training, we deliver your dog to your home and work diligently with all family members to assure you he will continue his newly learned behaviors.
K-9 University has spent years refining our services to offer the highest quality resort-like experience for your pet. We work hard to offer individualized attention so that every pet has a safe, comfortable stay while you are away. Our Plano and Garland Dog Day Care and Boarding Services encourage active fun. Dogs are evaluated and based on their similarity they are then sorted into play groups, creating an excellent fit for furry friends!

Solid K9 Training, founded by award-winning, internationally-acclaimed dog trainer Jeff Gellman, is one of the nations most effective and respected dog training services providing no-nonsense, "Real World" training methods throughout New England. Serving dog owners from Hartford, CT to Boston, MA in our multifaceted, secure and 24/7 staffed Solid K9 Training Center in Providence, RI, as well as all throughout the nation with Jeff's wildly successful RV Dog Trainer Tour. We will train any dog, regardless of breed, shape, size or history. We work to fix all dog behavior issues including excessive barking, growling, snapping, nipping, dog aggression (fighting), human aggression (biting), child aggression, pulling on leash, leash aggression, leash reactivity, skateboard reactivity, resource guarding, jumping on people, fear issues, anxiety issues, separation anxiety, chewing and destroying household items, running away, not listening, door bolting, stealing food, getting into the trash, cat aggression, chasing game, and killing animals/game. We also have a renowned reputation specializing in obedience training, which includes heeling and walking properly on a leash, sit/stay, down/stay, place, recall training (come to owner), and crate training. Our Training services include Board and Train behavioral modification, 1 on 1 Training, Obedience Classes, Puppy Training programs, Boarding / Board & Play, Daycare, and many free dog training resources including Dog training advice videos, dog training webinars, and Dog Training Q and A videos on Periscope on Monday and Wednesday nights. Our behavior modification training is cutting edge, using techniques like modern low level E-collar (remote collar) training and food and clicker training. Solid K9 Training has a worldwide reputation of being able to handle the most challenging dog behaviors and often times other dog trainers will refer their more serious cases to us. For more information on our services offered, as well as free dog training tutorial videos, please see my website and other social media pages:
Serving the surrounding areas of Dallas, Frisco, Allen, Richardson, Garland, & Mesquite. Since 1993, K-9 University has delivered high-class obedience training for dogs from our two serviceable locations in Garland and Plano. Since then, we have extended our services to include boarding, grooming, and doggy daycare. Our experienced and compassionate staff will train and care for your dog as if they were our own. Speak with us about our services by calling our location in Plano at (972) 801-9090 or Garland at (972) 530-7077.
After debuting in the final scene of "School Reunion" (2006), K9 Mark IV returned in spin-off series The Sarah Jane Adventures' premiere episode "Invasion of the Bane", where due to licensing issues with creator Bob Baker it is explained that K9 is sealing a black hole and can only communicate briefly and infrequently with Sarah Jane. The character makes an heroic appearance in the first series finale The Lost Boy, to do battle with rogue alien supercomputer Mr Smith (Alexander Armstrong), demonstrating new CGI teleportation and hovering features. K9 Mark IV's interfaces include at least one USB port.[2] Subsequently, the character appears briefly in the Doctor Who series four series finale "Journey's End" (2008), wherein K9 and Mr Smith assist the Doctor in returning Earth to its proper position. K9 next appears in the comedic Red Nose Day 2009 Sarah Jane mini-episode "From Raxacoricofallapatorius with Love".[3] A deal with the creators of K9 having been struck, K9 Mark IV became a regular character in The Sarah Jane Adventures in third series story, The Mad Woman in the Attic (2009), until the series four premiere The Nightmare Man (2010), where he accompanies departing series regular, Sarah Jane's adoptive son Luke Smith (Tommy Knight), to university. He appears again in series four finale, Goodbye, Sarah Jane Smith. Though he doesn't appear in the serial, it is mentioned in The Man Who Never Was (2011) that Luke invented a special dog whistle to summon him with.
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