Do Animals Suffer Like People?

Imagine walking into a room filled with people crying. They are all wearing black; makeup running; tissues clutched hard in their hands. Instinctively, you too are overcome by the grief that is flowing through the room, knowing the cause of their misery and empathizing with their suffering. As humans, we are an intellectual and highly communicative species that uses emotion-laden words and body language to convey thoughts. It is fairly easy to understand, or at least see, the agony a fellow human being can be in because of the attributes we associate with it. With other animals, however, identifying suffering becomes much more complex. Animals more closely related to our species, such as chimpanzees, demonstrate similar emotional and intellectual qualities that often lead humans to more readily apply moral and ethical reasoning in regards to their welfare. Other animals, however, such as snakes or goldfish, may seem to be so distant from humans that it is hard to find the same concern for them (Mather, 2001). While our tests for emotion and intelligence may not reveal any substantial results for these types of animals, it is also fair to question if they are simply inadequate tests based on faulty human interpretation of non-translatable factors. How can we then determine which animals suffer, to what degree they suffer, and whether or not humans should take these factors into consideration in the treatment of those animals? While emotion is probably the most accessible indicator of an animal’s distress, not all animals were created to outwardly express those feelings (for example, perhaps because they lack comparable human facial muscles). We must also consider the dual definitions or interpretations of the word ‘feelings’; there is a qualitative difference between expressing a physiological reaction to something unpleasant (e.g., a reflex, a purely physical and instinctual response) and cognitively appraising the cause and implications of that pain (e.g., psychological suffering).

This brings to light the role of intelligence, as perhaps a decreased cognitive capacity limits an animal’s psychological suffering, even if indicators for physical pain are maintained. To make this distinction more salient, consider some examples: a researcher who was working with ants noticed that an ant recoiled when acetone was accidentally spilled on it, and attempted to wipe it off itself (Mather, 2001). Although the event clearly disturbed the ant, we cannot be one hundred percent sure if the ant’s reaction was a reflex response to an uncomfortable substance not normally on its body, or if it consciously interpreted pain the way we might. Similarly, a cat will cry out, jump, and run to hide after its tail is pulled, whether or not the animal reflects on why it was pulled or how it occurred. In this case though, the act is often more easily interpreted as cruel simply because the animal reacted in an indisputable negative fashion (Steinbock, 1978). Based on these narratives, I hope you have begun to see that the interpretation of suffering cannot be based solely on whether or not an animal outwardly shows emotion or seems to possess more cognitive capabilities than another species. Instead, what may be most helpful in discerning indicators of distress is to take into account a combination of the two, as well as the niche and range of normal behaviors of each animal. (A discussion of self-awareness within the context of emotion is also applicable here, but as it is outside the scope of this blog, I will instead direct you to an interesting article by Salzen (1998).)

Now, I am certainly not trying to persuade everyone to join the ranks of the reactionary and sensationalist PETA group by reviewing the suffering of animals. After all, many times we rightly justify that the benefit for humans outweighs possible injury to the animal. But I do think current society can benefit from a better understanding of animal sentience, or their potential capacity to perceive and respond emotionally. For one, it certainly plays a role in the connection between humans and animals, which has been particularly well-documented with dogs. Man’s best friend has been shown to have a wide range of health benefits for humans through their companionship (e.g., For example, the use of dogs in Animal-Assisted Therapy, or “a goal-directed intervention in which an animal that meets specific criteria is an integral part of the treatment process,” has been extensively documented to lower blood pressure and heart rate, reduce the risk factors for cardiovascular disease in males, and to help lessen anxiety and aggression in Alzheimer’s patients (for meta-analysis reviews, see Nimer & Lundahl, 2007 and Muñoz et al., 2011).

Although most commonly used among people with disabilities, patients in hospitals, prison inmates, or with the elderly, Animal-Assisted Therapy has also been shown to help people who have difficulties developing relationships or nurturing skills, such as with Autistic children (Covert & Duncan, 2000). Importantly, research has suggested that the problem a patient presents with or its severity does not affect outcomes (Nimer & Lundahl, 2007). These and other positive effects have also been demonstrated by studies examining the use of service dogs with individuals who have other psychiatric disorders or physical disabilities, such as epilepsy, blindness, deafness, multiple sclerosis, cerebral palsy, or spinal cord/head injuries (e.g., Brown & Strong, 2001; Wells, 2007; Kwong & Bartholomew, 2011;

Yet the experience of the animal itself throughout these processes is also worthwhile to consider. In a study done on the relationship between pets and families, 4% of people noticed that their pet developed an illness when family tension was high, which suggests the emotional toll human distress can have on an animal (Sussman, 1985). Simple internet searches of Animal-Assisted Therapy can lead to anecdotes describing how a “vibrant, strong, and healthy therapy dog may lay around his/her home, uncharacteristically lethargic and inactive, sometimes for days after particularly stressful visits with extremely ill & very weak or depressed patients” ( While it is perfectly justifiable to question the scientific validity of such stories, there is unfortunately often little direct research investigating or discussing the effects some services have on the dog.

However, a recent article by the New York Times has put an important modern-day spin on this conversation ( It is nothing new to hear of dogs used within the police or security and military forces; they have long been employed to aid in drug or bomb/mine sniffing, patrolling, tracking, and helping to locate bodies in search and rescue efforts (e.g., Rouhi, 1997; Furton & Myers, 2001). The New York Times article, though, focuses on how more than 5% of the 650 military dogs deployed in Iraq and Afghanistan are “struggling with mental strains of combat nearly as much as their human counterparts.” Dr. Walter Burghardt, the chief of behavioral medicine at the Lackland's Daniel E. Holland Military Working Dog Hospital, has classified the cluster of symptoms he has seen in these animals as a form of canine post-traumatic stress disorder (PTSD). The legitimacy of this novel concept is still widely debated, but many behaviors seem to be somewhat analogous to those of the human counterpart, such as signs of hyper-vigilance, changes in temperament, and/or unusual, agitated reactions to once-tolerated noises or sights (for the current Diagnostic and Statistical Manual (DSM-IV-TR) criteria of human PTSD, see Correspondingly, the desensitization counterconditioning and medication treatments that are seemingly helpful for serious canine cases arguably pull from desensitization/cognitive therapies and pharmacological interventions that have been effective for human veterans with PTSD (for review see Sharpless & Barber, 2011).

While the applicability of this term to dogs will undoubtedly be deliberated for some time, it is not the first time dogs have been used as an animal model for human psychological or medical conditions (e.g., narcolepsy, Mason, 2006; aggression/anxiety neural biomarkers, Vermeire et al., 2011). True, these models are often simplified from the complex human versions, but they can still be widely informative. Above all, such relationships between human and animal conditions should inspire dialogue about our similarities, and hopefully encourage us to be cognizant of our treatment towards animals.


Brown, S.W., & Strong, V. (2001). The use of seizure-alert dogs. Seizure, 10, 39-41

Covert, M., & Duncan, C. (2000). School of nursing offers animal-assisted therapy. The News, 33(31). Retrieved from

Furton, K.G., & Myers, L.J. (2001). The scientific foundation and efficacy of the use of canines as chemical detectors for explosives. Talanta, 54(3), 487-500.

Mason, M. (2006). Man's best model. Howard Hughes Medical Institute Bulletin, 19(4), 26-31, 60.

Mather, J.A. (2001). Animal suffering: An invertebrate perspective. Journal of Applied Animal Welfare Science, 4, 151-157.

Nimer, J., & Lundahl, B. (2007). Animal-assisted therapy: a meta-analysis. Anthrozoos: A Multidisciplinary Journal of the Interactions of People & Animals, 20(3), 225-238.

Rouhi, A.M. (1997). Detecting illegal substances. Chemical and Engineering News, 75, 24-30.

Salzen, Eric A. (1998). Emotion and self-awareness. Applied Animal Behavior Science, 57, 299-313.

Steinbock, Bonnie. (1978). Speciesism and the idea of equality. Philosophy, 53, 247-256.

Sussman, M.B. (1985). Pets and the family. New York: Haworth Press, Inc.

Wells, D.L. (2007). Domestic dogs and human health: An overview. British Journal of Health Psychology, 12(1), 145-156.