Dr. Mark is a veterinarian. He works mostly with dogs and exotic animals.
Many Small-Dog Bites Are Never Reported
Since this is an article about dog bites that are never reported, it cannot be based on numbers from those reported by the CDC and AVMA (American Veterinary Medical Association). This is not a list of the 10 most aggressive dogs based on dog bites. There are plenty of those lists, and all of them are wrong.
Anyone who believes a mellow Siberian Husky is more aggressive than an angry Chihuahua does not understand dogs. There are a lot of people out there who will repeat that list and claim that it is true because it is has been reported in a study by a government agency, the Center for Disease Control. Government studies can be wrong.
According to a journal article from Applied Animal Behavior Science, the three most aggressive breeds are the Dachshund, Chihuahua, and Jack Russell Terrier. A University of Pennsylvania study interviewed 6,000 dog owners, and most thought that the smaller dogs were more aggressive. At least 20% of Dachshunds had bitten strangers.
The other breeds listed here tend to be aggressive but were not listed in the Applied Animal Behavior/University of Pennsylvania study. They are dog breeds that I have decided to add to the list.
So you can choose to believe in all or none of the studies. What dog breeds have I seen bite and go through life without being reported? These five are at the top of my list.
- Jack Russel Terrier
- Cocker Spaniel
- Yorkshire Terrier
This may be the breed most likely to bite. These dogs are usually playful and make great pets, but they do chase smaller animals, show aggression to strangers and new dogs, and if they develop separation anxiety, tend to be destructive and chew up the house.
The reason that they are not reported for aggression is a common one: They are small, so their bites do not cause serious injuries.
Sometimes a child in the family will need to go into an emergency room for a tetanus shot, and if the parent lists “dog bite” on the admitting form, the bite will be reported to animal control. But a lot of the time, that does not happen.
Other bites may happen when a Dachshund comes across a stranger in his house or yard. If the Dachshund bites a kid running through the yard, the parents may not even find out about it, much less animal control.
Doxies will probably go on biting and will probably not be blamed very often.
This tiny dog is often aggressive even when he does not want to be. They are not hunters like the Dachshund and are usually happy when left alone to curl up on the couch or in a warm basket of laundry just out of the dryer. A lot of times, they are not left in peace.
Since they are not able to do much damage when they bite, they may be teased by small children and by adults with nothing better to do. They are easy to provoke. Some breeds may ignore a provocation and go lie down elsewhere; a Chihuahua will get tired of all the foolishness and bite.
This dog is rated as one of the most aggressive and is one of the dogs most likely to bite and get away with it. If you don't agree with me, watch a few of the videos where they are teased.
3. Jack Russell Terrier
This dog is an active dog and can be one of the most aggressive, but when he is able to work, the aggression is not really a significant issue. JRTs were bred to dig down to dens to hunt fox, badger, and other small game, and aggression was a good quality in such a dog.
Working dogs that have nothing to do become bored and destructive. The JRT is no exception. If they cannot hunt, they should be taught to play flyball, compete in agility, or at least taken to obedience classes.
Not providing a JRT with an outlet for his energy encourages him to become aggressive.
4. Cocker Spaniel
The rating on this dog is only based on my personal experience. Anecdotal evidence does not count for much, but if I were to use the “official” ratings, the Great Dane would be next on the list. Most people would probably report a Great Dane bite. They would probably be embarrassed to report a Cocker bite.
The Cocker Spaniels I have worked with are great pets, but they are usually unhappy to be examined by a veterinarian and are willing to bite to get away. This may be due to shyness and poor socialization, not aggression, but it does lead to biting.
This breed also may develop a neurological disease called “Cocker Rage Syndrome.” When a dog is affected, he will have an epileptic-type seizure and bite anyone in the area.
Note: Although the techniques used to control the dog in the video below are not what I would use, the video is good in that it shows this breed, which many people consider mild and happy, displaying aggression.
5. Yorkshire Terrier
This dog was originally bred to work, and although he has become one of the most popular dog breeds, the Yorkie still has a lot of energy and a drive to be active.
They are not a small lap dog that will sit around and wait to be showered with attention. They will bark a lot, run at doors and act as a watchdog, and do their best to show how important they are.
I read an article about separation anxiety in which the owner complained that his Yorkie bit him on the ankle every time he came home. The owner put up with it for years, and eventually, the dog died of old age. If the dog was a pit bull, the owner probably would have reported him to animal control, and the dog would have been euthanized.
Do I know that Yorkie bites are never reported? No, this is just anecdotal information. They are known to bite but are almost never reported to do so on the statistics.
Every Dog Is Unique
Do not be so quick to condemn a breed of dog that you are told “bites a lot.” Statistics are wrong. Some data indicate 1 in 12 Dachshunds bite their owner. What if it is 1 in 10? What about 1 in 8? No one knows.
The studies available on aggression are not enough to decide which breed is most likely to bite. Since small dogs may not do much damage, or the damage may even be ignored, the statistics on dog bites are definitely meaningless.
Siberian Huskies, one of the most aggressive dogs according to the CDC, were also rated in this Animal Behavior study. They were found to be as docile as the Greyhound and Golden Retriever. No one can say a Boxer is aggressive and meant to be feared.
Can anyone tell you the top 10 most aggressive dog breeds? No. Can anyone tell you the dogs most likely to bite? It is not possible.
The only thing we can be sure of is that every dog is an individual. Come to think of it, so are we!
Gershman KA, Sacks JJ, Wright JC, Which dogs bite? A case-control study of risk factors., Pediatrics, 1994 Jun;93(6 Pt 1):913-7.
Farhoody, P., Mallawaarachchi, I., Tarwater, P. M., Serpell, J. A., Duffy, D. L., & Zink, C. (2018). Aggression toward Familiar People, Strangers, and Conspecifics in Gonadectomized and Intact Dogs. Frontiers in veterinary science, 5, 18. doi:10.3389/fvets.2018.00018
This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
Questions & Answers
Question: My lab was attacked twice by a friends dog when there was food around. Now my lab is aggressive towards other dogs (but not our pug). Is there any hope for our lab to be able to interact with other dogs again?
Answer: You are fortunate in that your Lab still gets along with your Pug. Dog-dog aggression is difficult to deal with and when it is in a home is one of the worst situations you can deal with.
When out taking a walk, some things can be done. Read this article, and you may find some solutions: https://hubpages.com/dogs/dog-to-dog-aggression.
Question: Are Cavalier King Charles spaniels aggressive?
Answer: No, Cavs are one of the sweetest and most affectionate dog breeds around. They are great lap dogs.
Question: Are pugs aggressive?
Answer: Though Pugs are not usually known as a dog breed that bites, I have known dogs that bite. They were unhappy to be at the vet because of numerous visits.
At home, around their families, Pugs are not an aggressive dog breed.
Question: Are chihuahuas aggressive?
Answer: No dog breed should be considered aggressive. Chihuahuas are small dogs and often teased since people consider their bites such a joke.
© 2013 Dr Mark
Stella Lambton on April 01, 2020:
Miss Celany you are SO wrong! The smaller the worse bite. Their teeth are INCREDIBLY RAZOR SHARP
Bob joe on July 09, 2019:
Any animal that has teeth can bite...
dogs, cats, rodents, wild animals, sea animals... whatever the animal might be they can bite if they have teeth.
Nightly on August 29, 2017:
I have to admit, I'm terrified of Chihuahuas. I've had Malamutes, Pitbulls, Labradors, Boxers, JRTs; heck, I've had a wolf-dog, but Chihuahuas scare the life out of me. I really don't know why.
Karen on April 06, 2017:
I think it's hilarious how Siberian huskies are said to be aggressive when they are the most chilled calm and loyal dogs I've ever known.
miss cellany on September 14, 2016:
And yet it doesn't matter if these little dogs bite so often because they are little and do little damage. No one reports hamster bites either and those little things are far more aggressive than chihuahuas or dachshunds.
If I get bitten by a small dog, it's annoying but I don't panic - I'm not scared of tiny dogs no matter how aggressive they are (just as I'm not scared of hamsters). A large dog that can do serious damage is a different matter entirely. The list of "most dangerous dogs" doesn't include small dogs because small dogs aren't really dangerous. You can pick them up and hold them by the scruff or throw them away from you or a small child - you can't do that to a 50 lbs or up dog.
Dog trainer on August 28, 2016:
If your dog (any breed) has teeth ....it can bite
Dogtrainer7 on August 28, 2016:
Interesting and very true article.
I have been a dog trainer for over 35 years.
I'm an AKC evaluator, breeder and compete in obedience, agility and field trials.
Now seeing that most all dogs on your list are small breeds want to offer some advice I tell all dog owners that come to me with problems or training.
"Don't coddle your dog". Sure he or she is a cute little dog or even the larger breeds for that fact, and most all of us love our dogs. But 9 out of 10 times the dogs that show aggression in all the dogs I evaluate prior to training are the dogs that the owners coddle too much.
Sure love on your dog all you want but ONLY ON YOUR TERMS, not when the dog demands your attention.
That can be as simple as constantly rubbing against you, jumping on your lap (what so many small breeds do) and what so many are guilty of, or constantly carrying or picking up your pup.
Actions like these lead to what we in the dog world call "resource guarding" and guess who the resource is, you the owner.
LOVE ON YOUR DOG ALL YOU WANT, but only on YOUR TERMS.
I don't care what breed or size your dog is you don't want this to happen.
Let's not blame the dog or dog breeds for bad habits the owners create in them.
They are not toys or dolls they are living beings who's natural traits and instincts will always surface.
Make sure that when you purchase a pup that you get it from a reputable breeder that knows how to evaluate temperament in the litter. Even 6,7,8 week old pups already show submissiveness or dominance. Don't just get the one that came running up to you or looks the prettiest.
So many of these end up being in shelters.
And while I'm mentioning shelters if you tend to desire rescuing a dog from a shelter be sure to take someone with a temperament testing background with you, their is a reason that dog ended up in a shelter. Most shelter staffs are ill equipped to truly evaluate a dog's behavior.
Having visited my local shelter and reading the notes on each dog, signs of aggression, great with kids, loving animal, etc, I almost got bit by one that the notes read, great family dog.
Folks please do your research or bring someone with you that has a good knowledge of dog behavior.
I hope my comments are helpful and give you readers more insight to dog and human interaction.
Remember, God gave dogs 4 paws for a reason, they belong on the floor.
Jenny on March 12, 2016:
Thanks this was helpful! I was thinking about getting a chihuahua
Not anymore though now that I saw this. Maybe a Corgie?
pie on June 02, 2015:
You certainly use every opportunity to talk about how great pitbulls are, get off your soap box and stick with your story. We all know bad pits are due to breeding or bad owners. People don't think about the fact that pits are TERRIERS. Hyper, busy, needs lots of attentiin, fresh air and play time and very very smart. If left bored and alone they get aggressive , just like one thats mistreated. People are just dense.
Carl Belken from Mokane, Missouri on December 25, 2014:
The Dachshund breed is being ruined by it's very popularity. Puppy mills and bad back yard breeders breed and sell them for profit only without caring about health and temperment. It's no wonder people are being bitten by them.
The German Shepherd breed was almost ruined in the same manner. The breed was saved by reputable breeders importing GSD's from Germany where breed purity is prized.
Liz Elias from Oakley, CA on September 07, 2013:
Good points. I don't care for small dogs. My husband says the only dog that ever bit him was a stupid little Chihuahua. He prefers big dogs, especially Labs.
I have was told years ago (by a humane society official), that German Shepherds actually have more of a biting reputation than Pit Bulls. I don't know if that is true.
Thanks for an interesting article.
Dr Mark (author) from The Atlantic Rain Forest, Brazil on May 16, 2013:
Thanks Krishna I am glad this information can be of some help. Since you are in Bangalore, please consider looking at some of the native Indian breeds! I have information about them in another hub.
Thank you for sharing.
rahul from Bangalore on May 16, 2013:
dmark1961,i have number of dogs in my locality,but i have very little knowledge about them.Your hub about "dog breeds that bite" is quite informative.Therefore i am voting it up and sharing.
Dr Mark (author) from The Atlantic Rain Forest, Brazil on May 10, 2013:
That JRT pic made me think of all those Pit Bull pictures out there. Unfortunately I have seen several of them on HP.
Sorry, I don't think I say "I love you" to all those dogs out there! (They probably deserve it though.) I am more of an old-fashioned type guy, and just tip my hat to the canines I meet and say "howdy" or "opa" (Brazilian slang sort of like Howdy), depending on where we happen to meet.
I try not to hug, since most dogs think that is too weird. (Some humans, too!)
LKMore01 on May 06, 2013:
The photo of the Jack Russell made me laugh out loud. I remember watching the cocker spaniel episode of the Dog Whisperer. All I can say is I am so happy that Maddie was so sweet and affectionate. My next dog will be a cocker spaniel too. Once again I love your HUBS. A question for you. Is it normal to say,"I love you" to all the dogs you see ? Maybe you can give me some psychological insight into why I do this! Thank you.
Dr Mark (author) from The Atlantic Rain Forest, Brazil on April 20, 2013:
Thanks for the input, Ghost. I lost my Collie/GSD cross for the same reason. He was chasing cattle...
I was bitten by our Pekingese as a little kid,and I don't think bites are a reason to condemn a dog to death. It does teach you to be careful!
Ghost32 on April 20, 2013:
Growing up, I was bitten by dogs twice. Reporting it (to law enforcement, anyway) was not even thought of. We lived on a Montana ranch and took care of our own business, at least back then. Eventually, my Dad ended up shooting both of the biters, but not because of the bites.
The first time, I was bitten by our own ranch dog. Served me right. I had it coming for being stupid at the age of 9 or so. Went running past his chain, which got him overly excited, and he nailed me.
Years later, when he was suffering greatly from old age and leftover pain from having been hit by cars on the highway more than once (one of the reasons he was seldom off the chain), Dad asked me one evening to shoot the dog. "He's your dog," I replied. "You do it!" And he did. The family knew I COULD do the hard things by that time (I was 16), but I did not feel like carrying that memory for my father, thank you very much.
Also when I was 16, Dad and I and a neighbor were heading into the neighbor's yard when his (the neighbor's) English sheepdog snuck up and bit me in the butt. I yelled, whirled, crouched, and snarled back at the snarling dog...until the owner managed to call his dog off, it looked like we might be going for a fight to the death.
That dog, the following winter, was caught running on our ranch--a death penalty offense in any ranching commuity--and caught a rifle bullet for his troubles.
Dr Mark (author) from The Atlantic Rain Forest, Brazil on April 20, 2013:
I like Chihuahuas, and think they are lashing out because everything around them is big and scary. It is unfortunate seeing all the videos on Youtubes where owners tease them to make a good video.
Bob, with that ASBTFAGG title you should be able to get a government grant. At the very least some NGO will latch onto you!!!
MAAN is no more. I think she got p.o.ed at me one day and just flew away. (One of my neighbors who raises ducks told me it was my fault since I do not like to clip their wings. Live and learn.)
Thanks for visiting and commenting!
Bob Bamberg on April 20, 2013:
The ASBTFAGG Study (Anecdotal Study By The Feed And Grain Guy) indicates that the chihuahua is the most aggressive...especially when being held by their owners.
When one's hand is offered for sniffing to a hand held chihuahua, the hand stands a 77.8% chance of being bitten. When the same hand is offered to the same chihuahua who is standing on the floor, the bite odds shrink to 44.4%.
Surprised to learn that JRTs can be aggressive, although I've heard more than one JRT owner refer to it as the Jack Russell Terrorist. I always considered them to be the calendar dogs for "a sugar high on steroids."
Fun hub...voted up and interesting.
Ashley from Colorado on April 19, 2013:
Chihuahuas freak me out, personally. I've seen chihuahuas be evil and would rather have a pitbull. Nobody ever thinks of the aggressive small dogs!
I mean, if were messing with animals anyway there's always a fear of getting bit by one.