Studies of dogs that lose their hair from cancer treatments could benefit humans, too

May 10, 2017 by Genevieve Rajewski, Tufts University
Poodles are more apt to lose their hair during chemotherapy because their curly coats are similar to human hair. Credit: iStock

While it's rare for dogs undergoing chemotherapy to lose their hair, when they do, some owners will stop treatment for their pets because they assume the chemo has become toxic.

"When it's something an owner wasn't expecting, loss can be very frightening, even though in reality it has minimal negative effects on the pet," said Elizabeth Falk, V07.

To help veterinarians educate their clients about this side effect of cancer treatment, Falk and other researchers at Tufts took a closer look at the chemotherapy drug doxorubicin, which is used to treat many canine and human cancers. They studied 150 dogs that received the drug at Tufts between January 2012 and May 2014. They assessed the cases according to seven coat types and then tallied the number of patients from each group that had experienced hair loss, skin darkening or changes in their coats.

They found that dogs with two hair types—the curly or wiry hair seen in breeds like poodles and terriers—frequently experienced hair loss during chemo, most likely because their coats are more akin to human hair, said Falk, the study's lead researcher who was a dermatology resident at Cummings School at the time. The findings were published in the journal Veterinary Dermatology in December.

Longer term, the research could perhaps help patients avoid the hair loss brought on by chemotherapy.

In the Tufts study, 28 dogs, nearly one in five, experienced hair loss, and dogs with curly or wiry hair were significantly more likely to lose their hair than dogs with straight coats.

"Veterinary oncologists have recognized this as a phenomenon for many years, although it has not been studied systematically in veterinary medicine until now," said Lisa Barber, a veterinary oncologist at the Foster Hospital for Small Animals and co-investigator on the Cummings School study. "Loss of whiskers and eyebrows are the most predictable forms of hair loss related to chemotherapy," she said. "We often tell clients that dogs that need haircuts predictably lose hair and might even become close to naked, temporarily."

It's in the Hair Follicles

Like people, curly-coated and wire-haired breeds have a high percentage of hair follicles that are growing all the time, Falk said. "Chemotherapy is actively targeting rapidly dividing cells, and growing hair follicles are some of the most rapidly dividing cells in the body," she said. On the other hand, the majority of the hair follicles in dogs with straight coats—such as Rottweilers, Labrador retrievers, golden retrievers and German shepherds—are resting and inactive.

The researchers also discovered that dogs that received a higher cumulative dose of doxorubicin over the course of their treatment lost their hair more often.

Falk and Barber continue to collaborate with veterinary dermatologists Lluis Ferrer and Andrea Lam on the second phase of their research, studying more dogs receiving doxorubicin in an attempt to pinpoint the cellular mechanisms that cause hair loss. Owners of dogs at high risk for hair loss can consent to allow the Tufts vets to take hair samples and perform a skin biopsy at the start of chemotherapy and again once the animals have lost hair.

"Pictures from biopsies after the hair loss show that canine hair follicles are arrested. They look dilated and weird," said Falk. The researchers will compare gene expression in the samples before and after treatment to look for changes that might explain the molecular mechanism behind the hair loss and potentially serve as targets for therapy.

The veterinarians also are looking for the increased presence of the protein p53 in the affected ' hair follicles, because the protein exists in humans with chemotherapy-related . If it's there, what is learned from pets could, according to Falk's review of multiple studies, help oncologists develop a treatment for the side effect that about half of human cancer patients rank as the most devastating complication.

"Dogs could be a good model for understanding and preventing the condition in people," said Falk. While there have been some rodent models of this phenomenon, no therapies developed from these have proven safe and effective, she said. "Dogs are actually much more similar to people in the ways that their skin reacts to things."

Explore further: Scientists find skin cells at the root of balding, gray hair

More information: Elizabeth F. Falk et al. Clinical characteristics of doxorubicin-associated alopecia in 28 dogs, Veterinary Dermatology (2017). DOI: 10.1111/vde.12409

Related Stories

Scientists find skin cells at the root of balding, gray hair

May 8, 2017
UT Southwestern Medical Center researchers have identified the cells that directly give rise to hair as well as the mechanism that causes hair to turn gray – findings that could one day help identify possible treatments ...

Are cooling caps the solution to prevent hair loss during chemotherapy?

March 15, 2017
Hair loss—one of the most-feared side effects of cancer treatment—may have met its match. Scientists have known since the 80s that cooling a person's scalp can prevent significant hair loss during chemotherapy. A cooling ...

FDA clears cold cap to save hair during breast cancer chemo

December 8, 2015
Hair loss is one of the most despised side effects of chemotherapy, and now breast cancer patients are getting a new way to save their locks.

Blocking enzymes in hair follicles promotes hair growth

October 23, 2015
Inhibiting a family of enzymes inside hair follicles that are suspended in a resting state restores hair growth, a new study from researchers at Columbia University Medical Center has found. The research was published today ...

Hair loss in women with breast cancer can have major implications on their sense of identity

April 19, 2016
A new study from The University of Nottingham highlights the importance of hair loss to women with breast cancer.

Scalp cooling device may help reduce hair loss for women with breast cancer receiving chemotherapy

February 14, 2017
Two studies in the February 14 issue of JAMA examine hair loss among women with breast cancer who received scalp cooling before, during and after chemotherapy.

Recommended for you

Female biology – two X chromosomes and ovaries – extends life and protects mice from aging

December 18, 2018
Around the world, women outlive men. This is true in sickness and in health, in war and in peace, even during severe epidemics and famine. In most animal species, females live longer than males.

Get a warrant: Researchers demand better DNA protections

December 18, 2018
New laws are required to control access to medical genetic data by law enforcement agencies, an analysis by University of Queensland researchers has found.

Sugar targets gut microbe linked to lean and healthy people

December 18, 2018
Sugar can silence a key protein required for colonization by a gut bacterium associated with lean and healthy individuals, according to a new Yale study published the week of Dec. 17 in the journal Proceedings of the National ...

Wound care revolution: Put away your rulers and reach for your phone

December 18, 2018
Monitoring a wound is critical, especially in diabetic patients, whose lack of sensation due to nerve damage can lead to infection of a lesion and, ultimately, amputation. Clinicians and healthcare professionals at the McGill ...

Using light to stop itch

December 17, 2018
Itch is easily one of the most annoying sensations. For chronic skin diseases like eczema, it's a major symptom. Although it gives temporary relief, scratching only makes things worse because it can cause skin damage, additional ...

Law professor suggests a way to validate and integrate deep learning medical systems

December 13, 2018
University of Michigan professor W. Nicholson Price, who also has affiliations with Harvard Law School and the University of Copenhagen Faculty of Law, suggests in a Focus piece published in Science Translational Medicine, ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.