The short answer
22,039 lb is the most weight any single dog has moved in a weight-pull federation's published results. It was pulled on rails at a Unified Pulling Federation (UPF) event in Pittsburgh, Pennsylvania on 9 May 2026, and it was pulled twice. CR's Sun Wukong, a 164 lb Boerboel, moved it in 23.22 seconds; his littermate CR's Mr. Wednesday, 186 lb, moved it in 25.03 seconds. UPF's sheet lists them as "Sun Wukong" and "Wednesday", owner "CR".
The figure is documented, not ratified: no organization in this sport certifies an all-time mark. UPF's site has no records page, and neither "record" nor "world" appears on any of its results, points, rules or information pages; the phrase "world record" belongs to the event sponsor, Bully Max, to the press that carried its release, and to the kennel's website. UPF's archive lists 1,504 events across the 13 seasons from 2014 through 2026. Fifty-five of those sheets are for mill races, wall climbs and lure courses; of the 1,449 weight-pull sheets, the editorial team read 1,436 (13, ten of them from 2014 and none later than 2024, could not be read) and found nothing heavier.
Guinness World Records lists no strongest-dog title. Its one dog-pulling weight record is a team entry: 145,302 lb (65,910 kg) by 210 sled dogs at Whitehorse, Yukon on 22 October 2000, roughly 692 lb per dog.
Everything else is a claim, graded below. Which breed is strongest is a separate question, answered in the strongest dog breed, measured four ways.
Why there is no single record
Surface comes first. Snow gives the most friction, wheels on dirt, grass or carpet less, and rails the least. The United Kennel Club's rulebook writes the gap into its entry bar: to qualify, a dog must move 3 times its own weight on snow, 8 times on wheels and 10 times on rails, 16 feet in 60 seconds or less.
Second, every federation keeps its own results and ratifies nobody else's. UPF publishes event sheets, points leaders and national winners. The International Weight Pull Association (IWPA) publishes a record table but says records are set only at its Championships, and that table covers wheels and snow only, never rails. The American Pulling Alliance (APA) lists results by event and profiles by dog, with no records page. The World Wide Weight Pull Organization (W3PO) published rails sheets in 2015; its site now shows a "Coming Soon" placeholder.
Third, the UKC scores in multiples of body weight: placings go to the most weight per body pound, and points and withdrawal caps are set at multiples such as 35 times body weight. A UKC result is a title and a ratio, so there is no UKC poundage record to list.
So an honest claim names the federation, the surface and the date; the rows below show which claims can.
The ledger
Three statuses. "On a federation result sheet": a sanctioning body's event sheet or dog profile carries the pull with body weight and date. "Secondary report": a dated newspaper or printed reference carries it, and no sheet does. "Unverified": repetition only. Sheets print pounds moved and pounds per pound of dog (UPF heads that column "Percent", APA "Perc." and W3PO and IWPA "%", but all four print the multiple: 22,039 divided by 164 is 134.38). UKC and UPF place on the second; this ledger ranks the first.
| Claim | Figure | Federation, surface, place, date | Status |
|---|---|---|---|
| CR's Sun Wukong (Boerboel, 164 lb) and CR's Mr. Wednesday (Boerboel, 186 lb) | 22,039 lb each | UPF, rails, Pittsburgh PA, 9 May 2026 | On a federation result sheet |
| Sun Wukong (Boerboel, 158 lb), the press-release figure | 16,917 lb | UPF, rails, Pittsburgh PA, 8 November 2025 | On a federation result sheet |
| Moose (American Pit Bull Terrier, 104 lb) | 16,146 lb | W3PO, rails, Monroe MI, 18 April 2015 | On a federation result sheet |
| Dezzy (Greater Swiss Mountain Dog, 100 lb) | 14,445 lb | APA, rails on carpet, Knoxville MD, 27 May 2023 | On a federation result sheet |
| Mafia (American Pit Bull Terrier, 75 lb), an "AAPBA" record | 13,042 lb | No surface, venue or date | Unverified |
| Ryettes Brandy Bear (St Bernard, 176 lb), retired Guinness entry | 6,400 1/2 lb | No federation; wheeled carrier on cement, Bothell WA, 21 July 1978 | Secondary report |
| Tank (Mastiff, 187 lb) | 6,075 lb | IWPA, wheels on carpet, Grand Rapids MI, 1 May 2022 | On a federation result sheet |
| Delbert (Alaskan Malamute, 150 lb) | 5,400 lb | Mid-Atlantic Weight Pullers event; surface not stated; Suffolk VA, March 2017 | Secondary report |
| Barbara-Allen's Dark Hans (Newfoundland, 97 lb), the meme's "Guinness strongest dog" | 5,045 1/2 lb | No federation; cement, Bothell WA, 20 July 1979 | Secondary report |
| Gaitor Red, "the official dog pull record" | 5,022 lb | Year stated as 1995; nothing else | Unverified |
What each row rests on
22,039 lb, twice. UPF's "Spring Into Bully Max" sheet, rails, class 120 lb and over, lists its finishers as Conquest, 128 lb, 21,336 lb; Amarillo, a 125 lb Presa Canario, 19,834 lb; Sun Wukong, 22,039 lb; Wednesday, 22,039 lb. They placed in that order because UPF ranks a class by that "Percent" column, pounds pulled per pound of dog: 166.69, 158.67, 134.38 and 118.49 times body weight. Sun Wukong's row carries the remark MWP (most weight pulled) and Wednesday's does not; the sheet gives no reason, and the two rows differ only in body weight, pounds per pound and time, Sun Wukong's 23.22 seconds being the faster.
16,917 lb, the press figure. The November 2025 release credited Sun Wukong alone with 16,917 lb and called it a "UPF-recognized world record". The pull is on UPF's sheet for 8 November 2025: 158 lb, 107.07 times his body weight. The release leaves out that he was the sole entry in his class that day, and that Wendy, a 97 lb Presa Canario, moved 16,884 lb, 33 lb less, at 174.06 times hers.
16,146 lb. W3PO's sheet for pull 15-10 (Monroe, Michigan, 18 April 2015, rails, chief judge Toni Yoakam) shows Moose, a 104 lb American Pit Bull Terrier, at 16,146 lb in 25.84 seconds, 155.25 times body weight. It is the heaviest figure the editorial team found in any body's results other than UPF's; 22,039 lb exceeds it by 5,893 lb, about 36 percent, on the same surface.
14,445 lb. APA's profile for Dezzy, a Greater Swiss Mountain Dog under the owner "Starr/Collins", runs to 240 rows; the best is 14,445 lb at Knoxville, Maryland on 27 May 2023, rails on carpet, 100 lb, 18.62 seconds, 144.45 times body weight. APA's breed field is owner-typed free text and its results by event were not read in full, so this is the heaviest APA figure the editorial team found on a profile whose pounds-per-pound column matches the arithmetic, not a confirmed APA maximum.
13,042 lb. The Mafia figure traces to a single forum reply from 19 June 2009, pasted in under the caveat "Not sure how current", citing an organization, "AAPBA", for which the editorial team found no results site. The same reply gives a second dog, Big Boi, 87 lb, exactly the same 13,042 lb; neither has a sheet, venue or date.
6,075 lb. Tank is the one row here that a federation itself labels a record. IWPA's table lists him, a Mastiff handled by Darwin Lumbattis, as the Unlimited wheels/artificial record, Grand Rapids, 2022; the Pull 77 sheet adds 187 lb, 15.34 seconds, 32.49 times body weight, carpet over asphalt, sole Unlimited entrant.
5,400 lb. The Suffolk News-Herald of 27 March 2017 reported that Delbert, a two-year-old, 150 lb Alaskan Malamute owned by Debbie Lee, moved 5,400 lb at a Mid-Atlantic Weight Pullers event in Suffolk, Virginia. The paper describes it as a track record and attaches no federation to the figure. Delbert is a documented IWPA dog: IWPA's tables list him at 4,475 lb (wheels/artificial, Spokane, 2017) and 3,800 lb (wheels/natural, Estes Park, 2019).
5,022 lb. A 3 March 2003 feature in The Union of Grass Valley, California states in one sentence that "the official dog pull record is 5,022 pounds", set in 1995 by a dog called Gaitor Red, with no organization, breed, surface, body weight or venue; the name is absent from IWPA's tables. Without asserting a link, the editorial team notes that the mark Tank displaced, Sly's 5,002 lb at St. Louis, dates from 1995.
The Guinness title nobody holds
The most repeated version of the strongest-dog claim is a Newfoundland with a 5,045 1/2 lb Guinness pull; a December 2023 post at NotABully.org opens with it and gives the dog's weight as 97 lb.
Guinness has no such title. The editorial team searched its record database under "strongest dog", "dog weight pull" and related terms. Its only dog-pulling weight record is the 210-dog team entry from Whitehorse. No single-dog entry turns up under any wording, though Guinness's site search does not surface every record page by title.
The Newfoundland is misfiled rather than invented. Printed Guinness editions from 1981 to 1989 carry an entry for "most proportionate weight hauled": Dark Hans, 97 lb, 5,045 1/2 lb (2,289 kg), 52 lb for each pound of dog, on cement at Bothell, Washington, 20 July 1979; the 1990 edition dropped it. The same books carry the entry the meme omits, "greatest load shifted by a dog": 6,400 1/2 lb, moved by Ryettes Brandy Bear, a four-year-old, 176 lb St Bernard, on a four-wheeled carrier over cement, 15 feet inside 90 seconds, at Bothell on 21 July 1978. Both came from the annual hauling contest at Bothell, which the Guinness-era references place at the Northwest Newfoundland Club's meet, not from a federation event, and no result sheet is published for either.
The figure is genuine; the title is not. Dark Hans held a pound-for-pound entry, and his load was not the heaviest in the same book. Both rows are secondary because a printed compilation is not a result sheet.
How much weight can a dog pull?
The multiple depends on the ground more than the dog, so an answer with no surface attached is not an answer. The UKC rulebook fixes both ends: qualifying pulls of 3 times body weight on snow, 8 on wheels and 10 on rails, and automatic withdrawal caps that top out, in Division B, at 25 times on snow, 35 on wheels over carpet and 65 on rails.
The best field evidence is IWPA's 2022 Championship weekend in Grand Rapids: hard-packed artificial snow inside an ice arena on Saturday 30 April, carpet over asphalt on Sunday 1 May, largely the same dogs. Median of 42 completed snow pulls: 9.94 times body weight (range 2.60 to 29.57). Median of 49 completed carpet pulls the next day: 25.2 times (range 7.23 to 57.69). Tank went from 2,000 lb to 6,075 lb at the same 187 lb; a 54 lb American Pit Bull Terrier listed as A.I.D.E.W. went from 1,597 lb to 3,115 lb. Nothing about the dogs changed overnight. The friction did.
Rails run higher still: the 31 completed pulls on the 9 May 2026 UPF sheet span 64.71 to 482.42 times body weight.
The December 2023 post that repeats the Guinness Newfoundland also says a fit dog can likely pull about three times its own weight; give that a surface and it is the UKC's snow minimum, the hardest ground in the sport.
Has any dog pulled more than 22,039 lb?
Not in any published federation result the editorial team could read. The test for a larger figure is the pounds-per-pound column every federation prints beside the poundage; a figure that contradicts its own pounds-per-pound column is a transcription error, not a pull. Both 22,039 lb rows agree with theirs. Of the 12,009 dog rows on the UPF sheets that could be read, 21 either fail that arithmetic check or could not be read in full: nine on 2018 European sheets with decimal body weights, one from 2020 and eleven on 2025 sheets. The heaviest of the 21 is 4,475 lb. The only larger published dog-pulling figure of any kind is the Guinness team record, and that is 210 dogs.
One qualifier: UPF's top figures cluster. The eight heaviest pulls in the sheets the editorial team could read all come from the two latest Bully Max events in Pittsburgh, and five of the eight are Boerboels entered by CR. The heaviest from any other breed in the results the editorial team read: 19,834 lb, two Presa Canarios, that same sheet.
The two record dogs, and who bred them
The sheet says "CR". The registry says more. OFA's public pages for CR's Sun Wukong (AKC WS80296527) and CR's Mr. Wednesday (WS80296528) carry the same whelp date, 18 March 2023, the same sire number, WS79897802, and the same dam number, WS72008704, and each lists the other as a littermate. The dam's number belongs to Black Iron's The Man Eater of Njombe, a brown female whelped 19 January 2021 who carries the Black Iron Boerboels prefix; her OFA record lists her AKC number and her SABBS number, 416056.
The sire is Peterbuilt Hakeem. OFA files him under his SABBS number, 413160, a male whelped 11 July 2021. OFA lists a third AKC littermate, CR's Breaker of Chains, and a fourth pup registered through SABBS, CR Koda, whose record names sire 413160 and dam 416056: Peterbuilt Hakeem and Black Iron Njombe by their SABBS numbers. CR's page on the record refers to "their sire" without naming him, so the sire's identity here rests on the registry chain.
Who ran the event
Three facts about 9 May 2026 belong next to the number. UPF's event page names the organizer as "Bully Max/ Erica Noseworthy", the chief judge as Erica Noseworthy and the sponsor as Bully Max; the sheet shows dogs entered under her name in several classes, one of them the only finisher in its class. Bully Max, whose November 2025 release had billed the 16,917 lb pull a "UPF-recognized world record", is the party that called the 22,039 lb pull a world record, in a video it posted on 10 June 2026. And the owner of Sun Wukong, named in the November 2025 release as Eli Carver of CR (the kennel's page says he owned and handled both dogs), appears on UPF's published roster of U.S. weight-pull judges, under Florida. The kennel's page states that he competed as owner and handler, did not judge his own dogs, and that six judges were present; that is the kennel's statement. It is why the row is graded on the sheet, not the release. The three Pittsburgh events, and the Boerboel's results across every federation, are the subject of Boerboel weight pull: what the result sheets actually show. What this directory will and will not print is set out in its editorial standards.