# Does the police force us K-9 because it sounds like canine? **URL:** \ **Category:** Factual Questions\ **Created:** [April 8, 2009, 10:51pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447 "2009-04-08T22:51:29Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![breakthesky](https://avatars.discourse-cdn.com/v4/letter/b/a698b9/32.png) [@breakthesky](https://boards.straightdope.com/u/breakthesky)\ **Post date:** [April 8, 2009, 10:51pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/1 "2009-04-08T22:51:29Z")
I’ve always hoped there was a reason behind it besides the fact that police officers are into chatspeak. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [April 8, 2009, 10:56pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/2 "2009-04-08T22:56:45Z")
Wikipedia’s entry is sort of mixed: > [@](#): > > A police dog is a dog that is trained specifically to assist police and similar law-enforcement personnel with their work. Police dogs are often referred to by the term K9, which sounds like the term canine, a word that generally refers to the dog and its relatives.this is a bunch of bullshit so change this crap about dam dogs ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [April 8, 2009, 11:04pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/3 "2009-04-08T23:04:54Z")
Perhaps not a definitive source, but [allwords.com’s entry](http://www.allwords.com/word-K9.html) confirms “k-9” = “canine.” Personally, I’d be surprised if the etymology were anything else. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [April 8, 2009, 11:18pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/4 "2009-04-08T23:18:31Z")
People into having sex with dogs also use “K9” . . . according to a lot of the spam I keep getting. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [April 8, 2009, 11:23pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/5 "2009-04-08T23:23:32Z")
And then there’s the Doctor’s companion, companion, companion. (There were three, right? Well, four, but the last was a replacement after an explosion.) Are you sad that police would use such a pun? Doesn’t the military use K9 too? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [April 8, 2009, 11:24pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/6 "2009-04-08T23:24:48Z")
Dunno if it true but I heard K-9 is a dental reference. One of a dog’s main fangs is labelled K9 in dentistry and it fits with canine. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [April 8, 2009, 11:25pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/7 "2009-04-08T23:25:24Z")
Interestingly I have recently begun to see K9 used in Spanish where it makes no sense unless you know it is taken from English and what it means. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [April 8, 2009, 11:34pm UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/8 "2009-04-08T23:34:03Z")
> [@Whack-a-Mole](#): > > Dunno if it true but I heard K-9 is a dental reference. One of a dog’s main fangs is labelled K9 in dentistry and it fits with canine. That’s backwards. Canine teeth (humans have them too) are so called because they resemble a dog’s fang. If they’re labeled K9 on an X-ray it’s because it sounds like canine. ---
**Author:** ![Morbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/morbo/32/389_2.png) [@Morbo](https://boards.straightdope.com/u/Morbo)\ **Post date:** [April 9, 2009, 12:09am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/9 "2009-04-09T00:09:17Z")
> [@Yllaria](#): > > And then there’s the Doctor’s companion, companion, companion. > > (There were three, right? Well, four, but the last was a replacement after an explosion.) Huh? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [April 9, 2009, 12:13am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/10 "2009-04-09T00:13:02Z")
> [@Morbo](#): > > Huh? Doctor Who. ---
**Author:** ![Morbo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/morbo/32/389_2.png) [@Morbo](https://boards.straightdope.com/u/Morbo)\ **Post date:** [April 9, 2009, 12:16am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/11 "2009-04-09T00:16:53Z")
Oh. Wiki sorted me out. (I’ve only seen the new ones) ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 9, 2009, 12:42am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/12 "2009-04-09T00:42:40Z")
> [@friedo](#): > > That’s backwards. Canine teeth (humans have them too) are so called because they resemble a dog’s fang. If they’re labeled K9 on an X-ray it’s because it sounds like canine. What are the other teeth labeled? ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [April 9, 2009, 12:50am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/13 "2009-04-09T00:50:32Z")
> [@Reply](#): > > What are the other teeth labeled? Incisors, bicuspids, tricuspids, molars. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [April 9, 2009, 12:56am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/14 "2009-04-09T00:56:28Z")
> [@Fear\_Itself](#): > > Incisors, bicuspids, tricuspids, molars. Wikipedia has a good article on [canine tooth](http://en.wikipedia.org/wiki/Canine_tooth). The dog in the picture looks slightly perturbed. 😛 ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 9, 2009, 1:10am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/15 "2009-04-09T01:10:36Z")
> [@Fear\_Itself](#): > > Incisors, bicuspids, tricuspids, molars. lmao. I _had_ to ask. I was expecting K3 or E9 or something. Note to self: Dentistry =/= Battleship. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [April 9, 2009, 1:23am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/16 "2009-04-09T01:23:22Z")
> [@Reply](#): > > … I had to ask. I was expecting K3 or E9 or something. Note to self: Dentistry =/= Battleship. Actually, > [@](#): > > … The number of teeth of each type is written as a dental formula for one side of the mouth, with the upper and lower teeth shown on separate rows. The number of teeth in a mouth is twice that listed as there are two sides. In each set, incisors are indicated first, canines second, premolars third, and finally molars. For example, the formula 2.1.2.3 for upper teeth indicates 2 incisors, 1 canine, 2 premolars, and 3 molars on one side of the upper mouth. > > The dentition can be expressed as a dental formula. Teeth are numbered starting at 1 in each group, except the premolars which end at 4. This means that the [carnassials](http://en.wikipedia.org/wiki/Carnassial) are always the fourth upper premolar and the first lower molar. Thus the human teeth are I1, I2, C1, P3, P4, M1, M2, and M3. …[RIGHT][CITE](http://en.wikipedia.org/wiki/Dentition)[/RIGHT] For some purposes: Dentistry = Battleship. 😃 CMC fnord! ---
**Author:** ![Reply](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/reply/32/15952_2.png) [@Reply](https://boards.straightdope.com/u/Reply)\ **Post date:** [April 9, 2009, 2:09am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/17 "2009-04-09T02:09:44Z")
> [@crowmanyclouds](#): > > Actually,For some purposes: Dentistry = Battleship. 😃 > > CMC fnord! The truth can never just be simple, eh? Ok, but to clarify, I take it “K9” is still slang for “canine”, even in dental context, because the “dental formula” only goes up to 4, right? ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [April 9, 2009, 7:41am UTC](https://boards.straightdope.com/t/does-the-police-force-us-k-9-because-it-sounds-like-canine/492447/18 "2009-04-09T07:41:59Z")
> [@Reply](#): > > … the “dental formula” only goes up to 4, right? For placental mammals the maxs are I3/3 C1/1 P4/4 M3/3, non-placentals (marsupials) I5/4 C1/1 P3/3 M4/4. CMC fnord!