I was told by my insurance agent that the MOST COMPLAINTS for dog bites are against . . . Cocker Spaniels.  Who are not considered 'aggressive breeds' by same. Common Core metrics, no doubt.

Small breeds are more likely to bite (out of fear mostly).  All breeds can be trained to be vicious, but in general no one breed is a bad breed.

I had a catahoula leopard that bit and chewed everything, especially the kids because she was a herding dog.

Is there just one? I know chihuahuas can be pretty nasty

it's probably a small whimpy breed.... 

Probably not the ones most people think.  I sure hope this doesn't turn into a pit bull bashing session or any breed for that matter.  Pitties are awesome.  

Conrad Allen little late for this question- I just saw your answer..

The pit bull...sorry I cheated. I saw your answer earlier. 

Pit bulls.

Pit bulls

     I will take a Rottweiler, a Pit Bull, or a Doberman any day of the week over a yip-yip lap dog that bounces around non-stop.

I think I read you said it was 47% were pit bulls? That does not surprise me...

No clue.  

Which breed of humans bites dogs most often?

Probably little ones.

My experience has been with smaller dogs being the biters.

My guess would be Pit Bulls for the most documented attacks/bites.  But I will say cocker spaniels are really tempermental and my brother's was a biter. 

Conrad, 

Chihuahuas is my guess.  They can be very nasty little creatures.  A

I'm going with the little ones too.  Although it's probably any dog whose owner says don't worry they don't bite.

As a dog lover I'll just say it's all about training and good socialization. Any dog will bite under some circumstances. 

Cocker Spanial for human bites

Tiny dogs are just ankle biters

Pits for dog on dog agression

Eve

Pit bull or german shehards

Conrad Allen I would say chihuahuas. My Uncle had one and it would bite everything in sight.

I would say those little yappy ones ... chihuahuas among them.

I've only been bitten by Chihuahuas on three separate occasions and all while showing homes. No real damage but they do head for the Achilles tendon for some reason. I cannot fault them for protecting their homes.   

Smaller dogs bite out of fear and usually not out of aggression. A large strong prey drive dog like a Rotty ,G.S.  or Pitt probably doesn't bite as much but when they do they inflict bad injuries hence the publicity. I have had 3 Pitts through the years and they never even growled at anyone.  We presently have Shitz Tzus and they all have beautiful temperaments. I think its just the luck of the draw. Some dogs bite and some don't.

A small breed no doubt, Lapso or Chihuahua's my guess.

Chi-wa-wa or however you spell it. 

Pitt Bull probably now and Rottweiler has to be close; mostly because of training!

The small breeds!

Chihuahua's !   I have bit marks on my shoes to prove it. 

I have no idea, but I would guess it's a small dog.

I know it's the pit bull, but really it feels like those little yappy dogs with sharp little teeth.

Don't know - but guess is one of the smaller breeds and probably somewhat unexpected. Both dog owners and friends/family and strangers of dog owners are much more likely to take precautions regarding so called agressive breeds so I doubt its one of them.

No idea.