By Becky Fogel
Fido, sit. Fido, fetch. Fido, detect cancer. These days, dogs are performing more than the usual tricks—they're helping improve our understanding of various human maladies and how we might treat them, from obsessive-compulsive disorder to drug addition. Here are a few examples:
Neural Tube Defects
As a veterinary student, Noa Safra got a bit of in-home training when her beloved Weimaraner gave birth. Of 10 pups, three were born with spinal dysraphism, or abnormalities of the spine. The breed is known for these neural tube defects, and Safra, now a postdoctoral fellow at the UC Davis School of Veterinary Medicine, thinks the German hunting dogs could give us insight into what causes spinal problems in humans. In a study appearing last summer in PLOS Genetics, she and other researchers mapped out the genomes of 100 Weimaraners. Of four dogs with spinal dysraphism, all had the same mutation in a certain gene called NKX2-8. Prompted by her findings, pediatricians at the University of Iowa investigated whether humans with spina bifida also had mutations in NKX2-8. Out of 149 patients studied, six did (the precise mutation varied, unlike in the dogs). At this stage, it’s unclear whether mutations in the NKX2-8 gene play a role in neural tube defects such as spina bifida in humans, but the team’s findings could pave the way for future studies.
Humans aren’t the only animals that engage in obsessive-compulsive behavior. Just as some people repetitively wash their hands or hoard old magazines in the garage, Doberman pinschers might suck on blankets, chase their tails, or, in rare instances, gather similar objects, such as teddy bears, into a geometric formation, says Nicholas Dodman, an animal behaviorist and clinical sciences professor at the Cummings School of Veterinary Medicine at Tufts University. Reporting last summer in Progress in Neuro-Psychopharmacology & Biological Psychiatry, Dodman and colleagues took MRI brain images of 16 Dobermans—half with canine compulsive disorder (CCD), and half without. They found that dogs with the disorder had structural changes that mirrored those previously seen in people with obsessive-compulsive disorder (OCD). Dodman says that studying dogs as opposed to another popular research subject—mice—may provide greater insight into what causes OCD in humans. Mice have to be conditioned to engage in compulsive behaviors, but because the disorder occurs naturally in dogs, they offer a better point of comparison with humans, he says.
Studies examining whether or not canines can smell various types of cancer date back to the late 1980s. Indeed, dog snouts are anywhere from 10,000 to 100,000 times more powerful than the human schnoz. A 2008 article published in Integrative Cancer Therapies found that ovarian cancer has a distinct scent that dogs can discern. As part of a new study, three dogs are being trained at the University of Pennsylvania’s Working Dog Center to identify the exact chemical compound that comprises ovarian cancer’s odor. If these molecules can be pinpointed, researchers at the Monell Chemical Senses Center will attempt to create a handheld device that can identify the specific smell in patients, says George Preti, an analytical organic chemist at Monell. Such a contraption could allow doctors to identify the disease in its early stages when it's most treatable. Only 20 percent of ovarian cancer cases are caught early, according to statistics from the Ovarian Cancer Research Fund.
In 2012, in search of a natural intervention method to improve the mental health of recovering substance abusers, Lindsay Ellsworth began bringing shelter dogs to a residential drug and alcohol treatment facility for teenage boys in Spokane, Washington. Once a week for about six months, Ellsworth, a doctoral candidate in animal science at Washington State University, instructed a control group to participate in a fun activity, such as playing videogames or pool, while an experimental group socialized with dogs from the Spokane Humane Society. The boys from each group then reported how they felt after their assigned activity. Ellsworth found that the kids who interacted with the shelter pups experienced less hostility and sadness compared to the control group (she plans to submit her findings for publication this spring). Time spent with the dogs might have increased the young men’s dopamine production, Ellsworth theorizes (she hasn’t experimentally proven it). If she’s right, hanging out with dogs could be a way to coax brains altered by drug and alcohol abuse into producing dopamine in a more natural way again.