Deaf dogs: A Unique Communication
How can deaf dogs understand humans?
We all know that the process of domesticating dogs has made them develop a unique ability to read our gestures and body postures, to the point of making decisions and performing behaviors according to what we expect from them. A recent survey compared dogs’ responses to simple cues such as sitting, lying down, staying, and coming when called, and found that they respond better to gestures than verbal cues1. Deaf dogs, despite suffering from an important sensory deficit, have no difficulty understanding what we communicate to them. On the contrary, many trainers around the world with experience in training deaf dogs claim that these dogs have an even easier time reading our body posture when compared to hearing dogs2. This makes a lot of sense, especially for dogs that suffer from congenital sensorineural deafness, who, it is widely believed, tend to develop all other senses more acutely.3,4,5
There are also many authors who claim, even in an empirical way, that deaf dogs establish a much stronger bond with their owners and therefore are easier to train than hearing dogs.4,5,6 This can also be a consequence of this heightened ability to observe our gestures, body posture and, why not, our emotional state.
Communication with deaf dogs takes place, basically, through gestures. The gestures become cues that work not only for the dog to perform any behavior, but also as a signal associated with some object or someone, such as a car, ball, Mom, food. Most trainers and owners of deaf dogs end up using the same signals that are already used in basic training of hearing dogs, both for simple and advanced behavior. But there is still the possibility to use ASL (American Sign Language) or even invented gestures..
It is impossible to talk about deafness in dogs without talking about Dalmatians. It is the breed most affected by deafness, surpassing the second highest breed rate by 15 percentage points. In the latest survey done by the leading specialist in deafness, Dr. George M. Strain7, almost 30% of Dalmatians were diagnosed with deafness (between unilateral and bilateral). And, unfortunately, that number is not likely to decrease, as kennels do not tend to eliminate from breeding the strains that generated deaf dogs. Another way to reduce this number would be to change the pigmentation pattern of the breed, as it is already proven that more pigmented specimens (including those with patches, which are considered non-standard) reveal a significantly lower rate for deafness.
Me and the Dalmatians
My personal history is marked by the presence of Dalmatians. My first Dalmatian, Joaninha, came to my house in the year of my birth. She could hear (there are reports that she warned my parents when I cried in the crib), but she was the mother of a deaf (blue-eyed) dog. This deaf dog was donated to a family very close to us and I ended up growing up with both dogs. Unfortunately, no one was attuned to deafness in dogs at the time, and Jonas was a dog with many challenges. He attacked people when surprised while his back was turned, had some issues with touch, and was often quite agitated, considered by the family as “unpredictable” and with a “strong temper.”
After many years, when I decided as an adult to have my first dog, of course my spouse and I chose a Dalmatian. Even knowing the problem of the breed and choosing a good kennel, I discovered two weeks after the purchase, that Magali was profoundly deaf. As a result, I ended up becoming a professional dog trainer, as I fell in love with the profession after researching the best ways to communicate with her. When Magali died from pancreatitis at the age of 8, I was completing my post-graduate course in animal behavior, the culmination of which would be a study on our communication. The work ended up becoming just an analysis of what we had already built, but I could not go any further.
Two months after losing Magali, Milka appeared in my life. Milka is a 5-year-old male Dalmatian with congenital bilateral deafness. I adopted him at 56 days old from one of the few kennels here in Brazil who openly admitted to producing some deaf dogs. When I decided to adopt Milka, I felt much more prepared to deal with a deaf dog, not least because I already worked in dog training and specifically with the training of deaf dogs for 8 years. However, I did not imagine that he would develop compulsive behavior (he chases shadows and lights). The problem started when he was about 6 months old. Despite feeling quite powerless in the face of the situation, I tried to study more, to deepen and invest even more in our bond and our communication, as the main tool in all the behavioral modification work I did with him.
The sky is the limit
Based on some studies that demonstrate the unlimited learning capacity of a deaf dog, the strong bond that is established between them and humans, and my living with deaf dogs for almost 40 years, I decided to go beyond everything I knew in terms of communication with deaf dogs.
Milka’s response to our daily training has always been above my expectations. He learned everything very quickly and his ability to focus and connect with me has always been the subject of comments among all the trainers and dog owners who follow my work. A trainer I was talking to about Milka asked if I had already tried using a verbal marker with him. I thought the idea was bold, but I decided to try it out. In less than four days of training, pairing the previous marker (a thumbs up sign) with the new marker (“yes”), Milka started to anticipate and respond with a clear positive conditioned emotional response (CER+) with only “yes.” Throughout the process, I took care to remove all prompts to ensure that the only SD present would be my facial expression.
“Yes” as a liberation marker
“Yes” as a positive marker
From there, a world of possibilities opened up within the scope of our communication. I thought: Since we have achieved this, why not try with behaviors that he already consistently performed with very subtle gestures? We started with the verbal cue “senta” (which means “sit”). Milka was already responding to the gesture to sit in a very subtle way. He learned to sit by luring, but, little by little, I decreased the intensity of the gesture, so that he ultimately responded with just a small movement of my hand, even from a distance.
“Sit” with a gesture at a distance
So, I started to do the pairing using classical conditioning, making only the movement with my mouth to say “senta” and then making the old cue (the gesture). It took a few sessions for Milka to start anticipating the gesture to sit and to do the behavior right after the verbal cue. I consider this to be a great milestone in our communication, as I didn’t think we would succeed. I was extremely touched and, after that, I started to test all the possibilities of stimulus control, to make sure that the behavior was happening only due to the reading of the movements of my lips.
- Test 1: Ask for other behaviors in the same session, to ensure that the dog is not responding automatically because he already knows the behavior that is being asked for.
- Test 2: Removal of all prompts, such as movement of the head, changing the direction in which I look by moving my eyes or moving my body, putting hands on the treat pouch, having treats in my hands.
- Test 3: Generalize different places and people to perform the same exercise.
- Test 4: Cue the dog in different postures (standing, lying down, on a place like a mat) as another way of generalizing the exercise.
“Sit” with lip reading (“senta”)
“Sit” with lip reading (“senta”) with another person, in a different location
“Sit” with lip reading (“senta”) with distance, with another person, on a place
We then started with the behavior “deita” (which means “lie down”), which I decided to do with a more pronounced difference on the lips, because it would be almost impossible to differentiate it from “senta” if I didn’t (in Portuguese, the lip movement for the words “senta” and “deita” are very similar). So, I started the same pairing process and, after he was anticipating the response, I did all the stimulus control tests. Milka’s understanding and response was very quick, and I realized that differentiating the movement of the lips was fundamental for this.
“Down” with lip reading (“deita”), with initial standing position
“Down” with lip reading (“deita”), with another person, in another location
“Down” with lip reading (“deita”), with distance, on a place
The next step was quite challenging. I wanted to test the cue “vem” (which means “come”). This verbal cue, in my experience as a trainer of clients’ dogs and other professional trainers, is one of the most difficult to guarantee a good stimulus control, because everything can be considered a discriminative stimulus (distance, body movements, gestures with the head). I ended up being extra careful to ensure that he came only because of my lip movements.
“Come” with lip reading (“vem”)
“Come” with lip reading (“vem”), with another person
We are currently building the “spin,” and pairing it with the blink of an eye. Previously, I tried to do it with a more pronounced movement of the mouth and head, as if it were a sneeze, but in the tests of stimulus control, it was clear that there was a lot of trial and error. For the time being, I got only three anticipations of response in different training sessions. I imagine that the conditioning of the two cues has not yet happened. But we are on the way!
“Spin” with the blink of both eyes and the gesture
Made-up gestures: Our signs
Another way of communication that I really like to practice with Milka, and even with other dogs (deaf and hearing), is to create signs that are not lures and that, paired with the previous cue (inductive in the case of deaf dogs), come to mean an action for the dog. I notice that when we are able to practice this level of communication with deaf dogs, the connection, the bond, the attention, and the dog’s own response rise in a very special way. Just as I work on advanced communication with my hearing students, through verbal cues and withdrawal of prompts, the idea is the same when we insert gestures that don’t function as lures with deaf dogs.
“Between” with a specific gesture
Place” and “paws up” with specific gestures
Circling around an object with a specific gesture
Another process I started with some of my clients was to work on communication through lip reading and non-luring gestures, as another way to generalize and test the effectiveness of this communication. One of them is Bella, a bilaterally deaf Dalmatian, who has already learned “yes” as a marker, the “sit” cue, and some gestures, such as circling around an object, going to the crate, and going to her place. The other one is Rebeca, a hearing Border collie, who already performs a lot of behaviors only with verbal cues, and is learning to respond by lip reading too.
Bella demonstrating understanding of non-luring cues and lip reading
Rebeca demonstrating understanding of lip reading (word “senta” which means sit)
Self-awareness? Or consciousness of me?
This has always been a topic that has interested me in the study of scientific articles. After all, does the mirror test prove that dogs are not self-aware? The subject, even in the scientific community, is controversial since, unlike chimpanzees and other species that passed the test, a mark on a part of the body for dogs may simply not be relevant, due to a lack of connection of that mark with any adaptive need for the species. Due to the relevance of the theme to me and because I closely observed our relationship, I started to realize that Milka noticed me in the mirror. He looked at my reflection in the mirror and, without me doing anything, he looked at me. That was the cue I needed to start testing whether our advanced communication could happen through the mirror.
I took the same precautions to control the environment in order to ensure that his behavioral response was happening only through the movements of my lips, seen through the mirror. And it’s working! He already knows that when I stop in front of the mirror, he must look at my reflection. So, I started testing the positive marker “yes” for his look and it was very clear that he only looks at me after he sees me in the reflection moving my lips with the “yes.” We started off with the behaviors “deita” and “senta,” and the response was incredible! He only looks at me directly after he sees me in the reflection doing the movement of the lips that signifies one of the behaviors. I confess that the result was quite surprising.
Lip reading of the marker “yes” through the mirror
Lip reading of the word “deita” through the mirror
Lip reading of the word “senta” through the mirror
A new perspective
My goal with this article is to show, on one hand, the immense learning capacity of deaf dogs, when training is based on positive reinforcements and consistent, clear, and clean communication. And, on the other hand, I hope to show breeders, veterinarians, dog owners, and professionals who work with these dogs the importance of knowing the specifics and issues related to this sensory deficit so that we can improve the quality of life of deaf dogs, who are often abandoned, isolated, or even euthanized.8
This happens simply because people do not know how to deal with them. Many handlers end up relying on widely propagated myths about deaf dogs being aggressive, unpredictable, stubborn, or irritable. This lack of skill and knowledge on the part of the people who deal with these dogs leads them to fail to prevent scares that end up resulting in aggression. People also fail to create a routine appropriate to a deaf dog’s basic needs and to understand possible tendencies toward behavioral problems resulting from deafness (such as separation anxiety and compulsive disorders). This results in a huge number of misunderstood dogs. And everything can be quite different, completely different! I hope our story is an example that reminds everyone that humans’ relationship with deaf dogs can be one of the most special things that has ever happened to us. Mine, for sure, is.
A summary of our communication
- D’Aniello, B. et al (2016) . The importance of gestural communication: a study of human–dog communication using incongruent information. Animal Cognition 19:6, :1231-1235.
- Klein, P. (2012) What’s Different, And What’s Not, About Training Deaf Dogs. Deaf Dogs Rock.
- Hayward, T. (2015) A Deaf Dog Joins the Family. CreateSpace Independent Publishing Platform.
- Willms, J. (2011) My Dog is Deaf — But Lives Life to the Full. Dorchester: Hubble & Hattie.
- Ross, P. (2012) Training a Deaf Dog: The Ultimate Guide to Living with a Deaf Dog. LuluCom.
- Cope Becker, S. (2017) Living With a Deaf Dog: A Book of Advice, Facts and Experiences About Canine Deafness. Vonore, TN: Self-published.
- Strain, G. M. (2015) Breed-specific deafness prevalence in dogs (percent). In: Deafness in Dogs and Cats, Louisiana State University School of Veterinary Medicine.
- Savel, S. & Sombé, P. (2020) Are dogs with congenital hearing and/or vision impairments so different from sensory normal dogs? A survey of demographics, morphology, health, behaviour, communication, and activities. BioRxiv 2020.03.06.980482.
Carolina Jardim is a Brazilian psychologist with a postgraduate degree in animal behavior and has been working with dog training since 2009. Currently she coordinates a team of trainers, offers training for professional trainers and provides behavioral consultancy for owners of deaf dogs.