The Controversy Surrounding Animals & Trauma Treatment

The use of animals in therapeutic approaches for patients who have suffered a trauma is becoming increasingly common: we can all attest, anecdotally, to the increased popularity of this approach and the frequency with which we see animals employed in a helping role in our daily lives. However, despite the recent rise in popularity, this is not actually a terribly “new” concept. The earliest documented case involved the use of farm animals in a mental health institution in England in the 1790s, and the earliest recorded case in the United States was in 1919, where dogs were used as companions for psychiatric hospital patients (Jackson, 2012). There is also speculation that cases may have occurred even earlier, but were not meticulously documented, or that the documentation simply did not survive over the years.

But a century after the first U.S. case of animal-assisted therapy, the actual evidence for this treatment approach is still disappointingly murky. Molly Crossman, a psychological researcher at Yale, summarized the empirical evidence with the observation that “The clearest conclusion in the field is that we cannot yet draw clear conclusions” (Resnick, 2018). She further notes that within the already-limited dataset, the research is focused almost exclusively on dogs, and certainly would not generalize to peacocks, hamsters, a bear cub, or any other species that has already been used to relieve stress or provide support (Resnick, 2018). There is simply no evidence that cuddling a bear cub before final exams, or boarding a flight with a peacock, would provide any actual benefit to anyone.

Part of the confusion may stem from the distinction between an “emotional support animal” versus a “service animal.” The Americans with Disabilities Act, a civil rights law that was enacted in the 1990s, defines service animals as “dogs that are individually trained to do work or perform tasks for people with disabilities,” a definition that can occasionally be extended to include miniature horses rather than dogs (Maynard, 2019). ADA-compliance involves making public spaces available to anyone with a service animal that meets this definition. By contrast, emotional support animals are not entitled to the same rights as service animals under ADA, nor are their handlers (Brennan & Nguyen, 2014).

For example, when I was an undergrad at Brandeis University, I received permission to have an emotional support animal stay in my dorm, even though pets were not typically permitted in on-campus housing. I had been clinically diagnosed with PTSD, which came with a range of other complications, including clinically significant insomnia and depressive episodes. I was given permission to have a hamster. Hamsters are nocturnal, so she was a wonderful companion on the nights when I couldn’t sleep, but also could not take my prescription sleep-aid for various reasons (it would disrupt my ability to function in an early morning class the next day, for example). I found that interacting with her and caring for her brought me joy and gave me a sense of purpose to get out of bed on days when my depressive symptoms were particularly severe.

But my hamster certainly did not qualify as a service animal. While her status as an emotional support animal (and the documentation I provided from a psychiatrist and psychologist) allowed me to house her in my dorm room, I would not have been permitted to bring her into the dining hall, or to bring her to class with me, or anything along those lines. I did not “train” her. She did not support me with specific tasks. Any establishment that had a “No Pets” policy would absolutely have still applied to me as a handler, and I would not have been allowed to bring my hamster inside (nor would I have attempted to do so, since frankly, the hamster would not have appreciated it very much!).

However, many people do not understand this distinction, and they assume that if a mental health professional has signed off on their ownership of an emotional support animal, that this documentation entitles them to bring their animal- any species, with any level of training (including no training at all)- into any space that could be considered public. The owners of the establishment may be hesitant to enforce the rules in order to avoid a discrimination lawsuit, especially if the animal’s owner/handler pushes the issue and insists they are allowed to bring their animal inside (Maynard, 2019). This may occur because the owner/handler is intentionally exploiting the establishment maliciously while knowing that discrimination is such a sensitive issue. But they also may simply be lacking education about their own rights. The discrepancies between terminology (service animal, emotional support animal, pet, animal-assisted therapy, etc.) as well as the variations in state, local, and federal laws can lead to significant confusion.

One key distinction is that while an emotional support animal may provide ‘comfort’ in a very general sense of the term, a service animal has received highly specialized training to perform very specific tasks. The most well-known example of a service animal is a “seeing eye” dog, who has been trained to assist someone who is blind or visually impaired (Maynard, 2019). There are a number of tasks that a service animal can perform for someone with PTSD. Our online module lists the following examples: “although they are trained in universal tasks, they can be and are tailored for the handler that they will be in service of. The basic tasks that service dogs can provide are: guide a disoriented handler, find a person or place, conduct a room search, signal for certain sounds, interrupt and redirect, assist with balance, being help, bring medication in an emergency, clear an airway, and identify hallucinations” (Rousseau, 2019). Put more simply, service animals do not provide comfort in a vague sense but through specific actions, i.e. comforting a PTSD patient who suffers from hypervigilance by helping clear a room/apartment when the person returns home.

Thus, while the owner of a public establishment should not ask for specific details about a person’s disability, nor can they ask for documentation that “proves” a person is disabled, they should feel empowered to ask a) whether the animal is a service animal, and b) which tasks the animal is trained to perform (Brennan & Nguyen, 2014). They are well within their rights to make these basic inquiries.

Many who oppose the use of service animals may also lack an understanding of their own rights as a member of the general public. For example, I have encountered the complaint that someone might be afraid of dogs, or have a dog allergy, meaning that an animal which makes one person more comfortable could cause distress for someone else. It is important to note that “allergies and fear of dogs are not valid reasons for denying access or refusing service to people using service animals” (Brennan & Nguyen, 2014). However, if a person is at risk of having a significant allergic reaction to an animal (even without contacting it), it is the responsibility of the business or government entity to find a way to accommodate both the individual using the service animal and the individual with the allergy (Brennan & Nguyen, 2014). This could be as simple as keeping the two parties further away from each other in a waiting room, or perhaps getting creative with barriers or changing the seating chart on a flight, such that the parties are as far away and physically separate as possible. The point is that the individual with allergies is not expected to suffer in order for the other person to benefit.

Similarly, the general public is protected against service animals that would disrupt their enjoyment of a public place. If the presence of an animal “would fundamentally alter the nature of the goods, services, facilities, privileges, advantages, or accommodations” provided by the business entity, they must be removed. A recent article gives a helpful example: “A consistently barking dog would fundamentally alter the services provided by a movie theater or concert hall. At that point, an employee may ask that the dog is removed. However, an employee may not preemptively bar entry to a service dog team based on the concern that the dog might bark. Service dogs may also be required to leave if they are not housebroken, or if they are out of control and the owner has not effectively regained control of the animal” (Maynard, 2019).

Airlines are afforded a bit more flexibility than the rules governing the general public. A 2014 report from Brennan and Nguyen summarizes their options:

“[Commercial airlines] are free to adopt any policy they choose regarding the carriage of pets and other animals (for example, search and rescue dogs) provided that they comply with other applicable requirements (for example, the Animal Welfare Act). Animals such as miniature horses, pigs, and monkeys may be considered service animals. A carrier must decide on a case-by-case basis according to factors such as the animal’s size and weight; state and foreign country restrictions; whether or not the animal would pose a direct threat to the health or safety of others; or cause a fundamental alteration in the cabin service. Individuals should contact the airlines ahead of travel to find out what is permitted. Airlines are never required to transport unusual animals such as snakes, other reptiles, ferrets, rodents, and spiders. Foreign carriers are not required to transport animals other than dogs.”

Essentially, the bottom line is that a letter from a medical professional is not a free ticket to do whatever you want, with any animal you choose, in any public space. There have been a number of unfortunate incidents in recent years which did not turn out well for other passengers or the animal itself: “A college student wanted to bring a hamster on a plane and then flushed it down an airport toilet after Spirit Airlines told her she wasn’t allowed to board with it. A United Airlines passenger attempted to get on a flight with a peacock. …Earlier this month, a Delta passenger complained that his seat was covered in dog feces” (Resnick, 2018). But these strange scenarios are not an unfortunate side-effect of ADA compliance, as some would suggest. These animals would not be considered service animals under ADA at all, including the dog, because any animal who is not controlled (i.e. house-broken) by the handler simply would not qualify.

Still, even though a deeper understanding of ADA and the various rights it protects could benefit all parties- and promote a more peaceful reception to service animals everywhere- it is important to also recognize that “there is little empirical research regarding service dogs for PTSD” (Rousseau, 2019). The data, or the studies proving a positive relationship, simply do not exist. As Crossman points out, “A lot of people have this impression that [the evidence] is very well established and we really know that [animals] are beneficial. But what is surprising is that we actually don’t know that at all” (Resnick, 2018). Many of the studies she examined lacked a control group, failed to analyze all the relevant variables, consisted of a small participant size, or failed to produce clinically significant results.

In one interview, Crossman was asked a compelling question: “Do we really need rigorous empirical evidence to know that pets bring comfort to people? Isn’t that kind of obvious? Many, many people have pets. It seems obvious that they bring joy” (Resnick, 2018). But as she convincingly argues, believing something based on anecdotal evidence or ‘knowing it in our hearts’ is not the same as having scientific evidence to support a claim. “I get that question a lot,” she notes, explaining that she has several different answers. “One is that there are different standards of evidence. So if you want to say that “my pet makes me feel good and it’s fun,” that’s great. You don’t really need lots of evidence for that. But with these emotional support animals, we’re talking about what is essentially a prescription from doctors to people with clinically significant symptoms. When we talk about that, there are very specific standards of evidence for psychiatric and psychological treatment, and these have not met that standard” (Resnick, 2018).

Clearly, the debate regarding the use of animals in treatment for patients with PTSD is just beginning, and more research is needed before scientifically valid conclusions can be drawn. In the meantime, we can rely on case studies and success stories to include service animals as an option for patients with PTSD, even though we cannot empirically argue that is the “best” or “safest” choice, or that positive benefits are the product of the animal alone, and not other combined influences.

For now, in cases where we can demonstrate that no harm will be done (to the patient or to the animal), seeing the joy on their face and the healing power of their relationship might be the only standard we need to meet.

Works Cited

Brennan, J. & Nguyen, V. (2014). Service animals and emotional support animals: Where are they allowed, and under what conditions? Southwest ADA Center. Retrieved from

Maynard, E. (2019). The problem with service dogs, the ADA, and PTSD. Very Well Mind. Retreived from

Resnick, B. (2018). The surprisingly weak scientific case for emotional support animals. Vox Science & Health. Retrieved from:

Rousseau, D. (2019). Module 4. Boston University. Retrieved from:

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