Autism spectrum disorder (ASD) in humans has become more widely diagnosed over the past decade, with new resources dedicated to identifying and treating ASD in ever-younger children.
This increase in attention to ASD in the human world has led to questions about autism in the veterinary world: can dogs have autism, too? If so, how is it similar or different than the human expression of an autism spectrum disorder?
Let’s explore what this means and whether dogs can truly be diagnosed with autism.
What Is Autism?
Autism spectrum disorder is defined by the Centers for Disease Control and Prevention (CDC) as a developmental disability that can cause “significant social, communication, and behavioral challenges.”1
According to the CDC, 1 in 54 children in the United States are on the autism spectrum.2 Signs of ASD usually begin during early childhood, and a definitive diagnosis by age 2 is possible. For many people with ASD, however, diagnosis doesn’t occur until later in life, including into adulthood.
There are currently no blood or medical tests that can detect ASD. Instead, it’s diagnosed after careful behavioral screening by qualified medical professionals. Some of the behaviors associated with ASD in humans include:
Avoiding eye contact
Not pointing at objects of interest or following other people’s pointing cues
Difficulty relating to others or expressing interest in other people
An inability or difficulty to understand other people’s emotions
Avoiding physical contact
Not responding to verbal cues from other people or acknowledging their names
Not playing make-believe games
Repeating phrases or words
Getting easily upset with changes in the environment and routine
Obsessive and/or compulsive interests
Body rocking or spinning in circles
Playing the same way repeatedly
Delayed language, movement, cognitive/learning skills
Hyperactivity, impulsivity, and/or inattention
Unusual sleep or eating habits3
Can a Dog Have Autism?
While some of these behaviors are unique to humans, researchers have found that, in fact, ASD can occur in dogs, but it’s called canine dysfunctional behavior (CDB).
Researchers believe that canine dysfunctional behavior is an idiopathic condition, meaning that the cause is unknown. It appears to be congenital, so a dog is born with it. Studies suggest that dogs with this disorder lack certain neurons in their brain that are thought to help them learn social norms.
These neurons are called “mirror” neurons, as they help puppies and young dogs mirror the behaviors of older dogs in social situations. Without mirror neurons, a dog is unable to develop these social skills, similar to humans with ASD.
Research on Autism in Dogs
Veterinary research of autism-like symptoms in dogs began as early as the 1960s. More recently, in 2015, the American College of Veterinary Behaviorists (ACVB) presented their findings on a link between autism and tail-chasing in Bull Terriers.
The study found specific traits of 132 Bull Terriers in total; 77 of these dogs were the non-tail-chasing control group and 55 were the tail-chasers. They found that tail-chasing in this breed was:
More prevalent in males vs. females
Associated with trance-like behaviors
Associated with occasional aggressive behaviors
These behaviors—the repetitive behaviors as well as phobia tendencies—led them to conclude that this tail-chasing behavior could represent a form of autism spectrum disorder in dogs.4,5
Conditions in Dogs That Look Similar to Autism
Aside from canine behavioral disorder, there are other disorders in dogs that can produce similar clinical signs to autism in people. These include:
Canine anxiety: Dogs with this condition can exhibit compulsive behaviors such as compulsive chewing or spinning, hypersensitivity to sound and touch, and/or searching for familiar environments and avoiding play or eye contact.
Intracranial neurologic disease such as brain tumors or encephalitis: Dogs with these conditions can have abnormal episodes of staring off or circling behavior and have even been reported to have obsessive chewing behaviors.
Canine hypothyroidism: Dogs with this condition can have severe lethargy, which can make them seem aloof or lazy. Usually, this behavior is not paired with compulsive activities, though.
Discuss your dog’s behavior with your veterinarian if you are concerned that your dog may have canine dysfunctional behavior or any of the above disorders. Your veterinarian may recommend some behavioral testing, bloodwork, and possibly advanced imaging of the brain (such as MRI or CT scan).
Autism in Humans vs. Canine Dysfunctional Behavior
It can be difficult to diagnose autism in dogs due to the lack of evidence, but clinical signs can lead veterinarians to suspect canine dysfunctional behavior.
Canine dysfunctional behavior does not have a spectrum like human ASD, so veterinarians rely on comparison of normal versus abnormal behavioral prompts. Dogs that demonstrate repetitive and compulsive behaviors, along with impaired social interaction, can lead veterinarians to suspect this diagnosis, though they will rule out other medical and behavioral conditions prior to a final diagnosis.
Signs of CDB
Clinical signs of canine dysfunctional behavior include:
Antisocial behavior: If your dog does not pay attention to you on walks, playtime, or feeding time, or if your dog does not want to interact with other dogs, tell your veterinarian.
Obsessive-compulsive behaviors: These can include movements such as obsessive circling, tail-chasing, chewing, or teeth grinding. There are even reports of dogs lining up toys or other objects.
Communication issues: Dogs with suspected CDB may not be able to express their feelings or moods as easily as other dogs. For example, they may not wag their tails when they are happy or put their ears back when being reprimanded.
Non-reviewed research also describes a trance-like state where these dogs can “stare off into space” for a long time. They may be quieter than other dogs, seem to lack personality, or avoid eye contact with humans and other dogs.
Inappropriate reaction to stimuli: This could include yelping when being gently touched. They can be hypersensitive to stimuli as gentle as a head-petting, which can lead to pain, aggression, or fear. They can also be hypersensitive to noise, especially with sudden sounds.
Avoidance of new environments and situations: These dogs will often retreat to a familiar, safe space such as a closet or under a bed to avoid new stimuli.
Lethargy/decreased physical activity: These dogs may lack interest in and avoid high-energy activities such as playtime with humans and other dogs. They are often described as sedentary even if they are considered a high-energy dog breed.
Treatment of CDB
There is no single treatment for canine dysfunctional behavior. After ruling out other possible medical conditions, and a true diagnosis of canine dysfunctional behavior is made, your veterinarian may recommend some therapies such as:
Medication: Certain medications can provide relief for compulsive disorders. Fluoxetine (Prozac) and other behavior-modification medication can be helpful. Calming medications and sedatives can also help with aggressive behaviors.
Secure space: It is important to offer a safe, comfortable, low-stress space for these dogs, as they can be afraid of noises, sudden movement, and even touch. Also, avoiding stressful situations such as dog parks or busy city streets is best if your dog shows signs of anxiety in these situations. Do not force situations that can cause stress.
Regular exercise: Consistent, routine exercise can help reduce anxiety and stress while keeping your dog’s mind occupied. This can divert dogs from compulsive behaviors also.
Positive reinforcement: Working with your veterinarian, skilled trainers, and board-certified veterinary behaviorists can be helpful in managing canine dysfunctional behavior.
What to Do if You See Signs that Look Like Autism in Dogs
If you are concerned that your dog is showing signs of canine dysfunctional behavior, contact your veterinarian to schedule an appointment for a physical examination. Diagnostic testing may be discussed, as well as a referral to a board-certified veterinary behaviorist.
Your veterinarian will work with you to determine your dog’s triggers that can cause negative behavioral reactions. They may also discuss techniques such as pressure wraps (e.g., ThunderShirts) that provide reassuring pressure to a dog’s body, calming treats and pheromones, backpacks for carrying your dog to avoid stimuli during walks outside, putting notes on your front door to avoid people ringing your doorbell, and creating low-stress areas around your home with low sensory impact (low lighting, quiet area).
Centers for Disease Control and Prevention. What Is Autism Spectrum Disorder?
Ibid. What is ASD?
Moon-Fanelli AA, Dodman NH, Famula TR, Cottam N. Characteristics of compulsive tail chasing and associated risk factors in Bull Terriers. Journal of the American Veterinary Medical Association. 2011;238(7):883-889.
Tsilioni I, Dodman N, Petra AI, et al. Elevated serum neurotensin and CRH levels in children with autistic spectrum disorders and tail-chasing Bull Terriers with a phenotype similar to autism. Translational Psychiatry. 2014;4(10):e466-e466.
Featured image: iStock.com/tbradford