Begin typing your search above and press return to search. Press Esc to cancel.

10 Things That Make a Dog Unsuitable For Service Dog Work

Everyone knows that Service Dogs are supposed to be calm, well trained dogs who work hard to help their human partners. However, too many people don’t know what makes a dog unsuitable for Service Dog work. An oft quipped saying in the Service Dog and Assistance Dog community is, “If you have to fix it, it isn’t a Service Dog.” So, without further ado, here are 10 things that should immediately disqualify a dog, puppy or candidate from beginning or completing Service Dog training.

1.) Structural Imbalances or Issues
Service Dogs work hard, and they have to keep up with their human partners in day to day life. Even dogs that don’t do physical tasks like bracing, pulling a wheelchair, opening heavy doors or carrying items often walk a lot, lay on hard floors for long periods of time, and must cope with the stress of frequent position changes. Dogs that do perform physically intensive work, especially any counter balance, bracing, mobility support or pulling based tasks, must be structurally sound and in great condition. Any structural imbalance, such as hip or elbow issues and dysplasia, back pain, malformed/deformed bones or past trauma that resulted in broken bones, means a dog shouldn’t begin Service Dog training. If a dog is found to have structural imbalance during training, they should be career changed. It’s usually best to ask your vet to x-ray any dog you’re considering as a Service Dog candidate and read the x-rays for joint and skeletal soundness.

2.) Genetic Illness
Few things hurt as badly as pouring your heart, soul, energy, effort, money and love into a dog, only to have it flunk out of training after 3 years because it develops a genetic disease. Dogs being considered for Service Dog work should have a series of tests done that determine whether or not the dog in question has the potential of developing a genetic illness that’s common in their breed. While you can’t test for everything, the peace of mind of knowing that the most common illnesses that run in your breed of choice aren’t present means a lot. Here’s a great resource from the Orthopedic Foundation for Animals that will help you find out which disorders and diseases your candidate or Service Dog in Training should be tested for.

3.) Vision or Hearing Problems
Service Dogs must be able to see and hear cues given by their partner, and they must be aware of the environment around them. Healthy eyes and ears are a must for any dog being considered for Service Dog work. Every year, the ACVO hosts an event to screen Service Dogs for eye (ocular) issues free of charge.

4.) Unsuitable Size
While it’s true that Service Dogs can be any breed, shape, size or color, it’s also true that their size must be appropriate for the task work they’ll be doing. A 40-pound dog cannot do brace or counterbalance work for a 230-pound man, and they cannot pull a wheelchair. If you need a dog to open drawers and doors, then a 12-pound terrier probably won’t cut it, simply because they can’t reach access buttons or any draw/door that’s not ground level. The dog being considered must be able to physically do the task work you need, and do it safely.

5.) Overweight or Obese
Overweight or obese dogs should not do Service Dog work. Being a working dog is taxing enough on a sound body, but additional weight means additional strain on joints, ligaments and their back. Service Dogs frequently change positions, squirm into small spaces under chairs and benches, raise up on their back legs and perform other tasks that could injure an overweight dog due to repetitive strain or a traumatic fall. Now, can a dog lose weight? Absolutely – but they should do so before beginning Service Dog training.

6.) Timidity 
Timidity is an huge flaw in a potential Service Dog. A Service Dog must be comfortable, settled and content in all environments and in all situations. “Oh, he’s just a little shy,” or “Oh, oops, sorry he growled; this is her first time,” are excuses. If a dog is panting excessively, drooling when there’s no food, showing the whites of their eyes, refusing to take treats, cringing away, growling or being avoidant, they are not comfortable, and they probably aren’t Service Dog material. That’s not to say that everyone doesn’t have “off” days, but if a dog is fearful by nature, then they’re unsuitable for Service Dog work.

7.) Reactivity 
Reactivity happens when a dog has an excessively strong reaction to a minor stimulus. For example, a dog may cringe and snarl when another dog passes them, or they may cower and hide when a person approaches. Reactivity can be minor or major, but regardless, it’s sign that there are situations the dog in question is very uncomfortable in, and it means they shouldn’t be a Service Dog.

8.) Aggression 
Aggression in its most extreme form looks like a dog attempting to attack, immediately upon sight, whatever they’re aggressive towards – cats, dogs, people, small animals, children, bicycles. It can also take the form of a dog snapping, snarling, growling, fixating on, going rigid and staring, etc. Whatever form it takes, it’s dangerous and utterly unacceptable for any dog who needs to be able to work safely and calmly in a public arena. “Oh, we don’t see children often” doesn’t matter – even if you can (MAYBE) control your dog, you cannot always control the environment, and you do not know when or if a trigger will appear. Any aggression whatsoever immediately disqualifies a dog as a Service Dog.

9.) Excessive Drive and/or Energy
Service Dogs work hard, and there are SO MANY THINGS they have to learn – basic obedience, advanced obedience, public access skills, task training. Some drive, particularly food and toy drive, and some energy, are necessary for them to succeed. That being said, if a dog is over the top about food to the point he can’t focus when it’s around, or has so much toy drive that if he sees a toy, he zeros in on it, or she has so much energy that she never seems to just “relax,” then that dog probably isn’t suitable as a Service Dog. Now, some types of Service Dogs, like hearing dogs, utilize high energy, higher drive dogs and channel all of it into monitoring the environment and reporting back in to the handler, but for most types of Service Dogs, too much drive or too much energy means a dog just won’t be able to work out properly. Service Dogs have to be calm, settled and relaxed while working – not vibrating with energy and passion and enthusiasm to the point they can never “wind down” and focus on the tasks at hand.

10.) Aloof, No Desire to Interact or No Focus
Some dogs have no desire to interact with people, and that’s ok. That’s just their core personality and it takes all kinds. That being said, a dog that is very aloof, too independent, or who wants to get away from people and go exploring and sniffing at the first available opportunity probably will never be happy working as a Service Dog, nor would it be emotionally fulfilling for the handler or training to try to force this dog to change who they were. Additionally, many of these dogs have no focus – they zip from one stimulus to the next and could care less that there’s a person around. Those dogs won’t make it through Service Dog training and should not be considered for the job.

So there you have it – 10 things that disqualify a dog from being a Service Dog. This list is by no means exhaustive, and there are, of course, some exceptions, but they are very few and far between. Do you have anything you’d add? Share in the comments!


Learn more about voluntary, community-defined training and behavior standards for handlers and their Service Dogs at



  • Terry McCormack January 22, 2016


    As a professional in the service dog field, I compliment you on this article. Very well done.

    Terry McCormack
    Saint Francis German Shepherd Service Dogs Inc.

    • Joshua Franks August 2, 2022

      I agree with the list, my question is what to do if a dog has went thru all the training and has been a service dog for a year when something comes up, particularly reactive.

  • Heather Houlahan January 23, 2016

    People need to understand that structural defects can include attributes that “fanciers” like to define as “normal for the breed.”

    Just because the lady with all the ribbons on her walls tells you that a basset hound is “supposed to be” an achondroplastic dwarf, or that stenotic nares and brachycephalic syndrome are “normal” for this pug doesn’t mean that those are functional structures or okay for any dog — any quadruped.

  • Patti Goettler January 24, 2016

    You left out a big one….stupidity…I have seen many “Service Dogs” who are dumb as a rock and will never be able to work with out being told to take every single step. Their Handlers are thrilled because they are “obedient” but there comes a time when a dog should be able to do common Tasks without being ordered to. All the Hounds I train as PTSD SDs work pretty much automatically, watching their Handlers and supplying the appropriate Task, (blocking, bracing, etc.) This frees their person up to use their limited spoons dealing with life.

    • Katy Prinzi March 2, 2016

      Thank you for your comment. I quite agree. I am in the early process, as in I have almost no idea where to start, of finding someone to help me train my dog as my Psychiatric Service dog for PTSD. I would never consider it if he wasn’t as smart and in-tune w me as he is. It takes a very intelligent dog to handle situations where a handler may be too stressed to give commands, such as fear paralysis.

    • Adrian March 14, 2016

      Just need to compliment you on your statement. Have adopted a Labador/hound mix from the local shelter for the purpose to train her for my PSTD, anxiety etc. even though she is 14 months old she already does brace & is starting with the blocking, she’ll whins when she senses my anxiety which is a distraction from feelings. So therefore her assistance does give me the opportunity to do activities otherwise I would avoid. Although she is still a work in progress she does have the basics. One last comment, her progress makes me proud to get out and continue working with her and to have people comment on her behavior and response to me.

  • landsharkinnc January 24, 2016

    Shelter dogs, in particular, seem to be a ‘target’ for potential placement in the ‘Service dog’ field – especially as ’emotional support’ dogs — most Shelter workers don’t have the luxury of developing a working knowledge of dogs in their care that could/would be prospects for such work, and persons wanting a dog for this purpose usually have no real ‘dog savvy’ or ‘training’ knowledge or experience. Too many have been placed only to have both dog/owner ‘fail’ in the endeavor, for one or more of the reasons listed above.

  • Barb Pierce January 30, 2016

    I have been registering my dogs with USSDR for years. I can’t believe I missed this amazing resource. Thank you for the well written, informative articles. I will be passing this on to my clients as well.

  • Cindy Sanford January 31, 2016

    Kea, I love your articles! They are easy-to-read and very informative. I teach public access classes at the community college, may I use some of your articles as handouts for the students that don’t have access to computers/printers? I cover most of the topics you do in some form or another, written or spoken, but yours are much more succinct than what I have so far.

      • Jose November 1, 2017


  • Helen Harris February 6, 2016

    This information was very helpful. It put my worries to rest about my partner. Thank you so very much.

  • Mdezarsha Fernan March 11, 2016

    Just discovered this web site. It is just what I need. Thank you so much for your help in learning so many things in regard to service dogs. For over 50 years I’ve dreamed of training service dogs for others. Now my husbands failing health and cancer related complications is making it obvious that he could benefit greatly, in so many ways with a service dog/companion. Thank you. I look forward to reading many more articles.

  • Marsha Fernandez March 11, 2016

    correction to above comment name…my computer is failing in oh so many ways! Sorry.

  • Dayna M Barney March 12, 2016

    I need help getting started on getting my seizure alert dog, I also have scoliosis and can’t lift or bend. Don’t know where to start with this. I live in phoenix Az I am planning on getting a letter from neurologist, but what next. And whatever comes next I need someone with me sitting next to me doing it with me. Please help

    • Cindy Sanford March 14, 2016

      Top Dog USA is in Tuscon. It is an owner-trainer company whose founder wrote “Teamwork” and “Teamwork Two” on training your own service dog.

  • Albina Mackey March 31, 2017

    Lady move above me has a huge German shepard banging to much like thousand legs running she lied and calls it a severe dog its not a its a wild dog how did she move in like that the law past any dogs in apartment should be under 25 lbs

  • Annie January 11, 2018

    There is only one here I can’t completely agree with. Which is reactivity. Chester is a self trained service dog and mid into his training he started barking at certain dogs. I thought well that’s great he won’t work out. It took time to figure out what it was for. (It was a friendly hello kind of bark) but in the course of 2 days I worked around dogs with him using a reward/correction system. He doesn’t bark at dogs anymore in fact he doesn’t find a need to look at them either. Maybe he’s just a super story but he always was to begin with.


Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.