One Study or Many? Cohorts in the Dog Aging ProjectJanuary 8, 2021 - 11 minutes read
The Dog Aging Project is a long-term research project. We’re building a canine knowledge base using critical information provided by community scientists, who participate in what we call the Longitudinal Study of Companion Dogs. After dog owners nominate their dogs and complete the Health and Life Experience Survey, their dogs are members of the Dog Aging Project Pack—the largest and most important “cohort” in the project. All dogs, of all ages and with all kinds of health conditions, are welcome in the Pack!
What do we mean by cohort?
Generally speaking, a cohort is a group of individuals that share some common feature or features. In our project setting, different cohorts are groups of dogs with characteristics that allow us to ask specific scientific questions. For example, if we wanted to know how daily exercise affects health, we might want to compare dogs who engage in different daily physical activities such as leash walks, swimming, or playing fetch.
If this were our scientific question, the research cohort would include dogs who participate in the mentioned activities, but it would exclude dogs who do not participate in these activities. This doesn’t mean those dogs aren’t interesting to study; it just means they aren’t the right dogs for that particular question.
The cohort we call the Dog Aging Project Pack consists of tens of thousands of dogs, whom we will follow for the entirety of their lives. We will “observe” them through regular surveys completed by their owners without any Dog Aging Project team members intervening in their daily lives. A study design like this, where a cohort is followed over a time period, is called a “longitudinal” study. Putting it all together, this makes the Dog Aging Project Pack a longitudinal, observational study cohort. You can read more about this kind of research design here.
What comes next for Dog Aging Project Pack members?
Once a Pack member, always a Pack member!
Once a year, on the anniversary of becoming a Pack member, our research team will ask our participants to complete the Annual Follow-Up. This series of surveys is similar to the Health and Life Experience Survey and allows the dog owner to update information about their dog’s health history, behavior, and lifestyle changes.
In addition, there will be periodic opportunities to participate in additional surveys or join additional research cohorts. In fact, the first three of these additional studies will launch in early 2021! For these cohorts, known as Foundation, Precision, and TRIAD, our research team will be inviting dogs who are already members of the Pack and who meet specific research criteria.
What is involved with these additional studies?
To be eligible for Foundation, Precision, or TRIAD, participants must have submitted electronic veterinary medical records with the Health and Life Experience Survey (click here to read more about veterinary records). From that subset of Pack members, our veterinary team will review medical records and identify dogs who fit the age, sex, size, genetic background, geographic, and health parameters required for participation in these cohorts. The science we do will be the most powerful if we consider puppies and adults, males and females, intact and altered individuals, mixed breed and purebred dogs, and dogs who live all over the US.
As soon as a dog is invited to join Foundation or Precision, the participant will be able to read more about the study and will be asked to sign an informed consent form, stating that they know what is involved with participation and that they are willing to complete all study-related tasks. TRIAD has a more involved eligibility process (see below). If a participant declines to participate in an additional study, then their dog will continue to be a valuable member of the Dog Aging Project Pack as before.
If the participant joins the study, their personal research portal will guide them through all study-related tasks. If, at any point in the process, the participant chooses not to complete any of the tasks or is unable to complete tasks with the support of our team, they’ll be removed from the cohort but will continue to be part of the Pack as before.
The aim of the Foundation Cohort study is to provide a foundation (hence the name) of genetic information about a wide range of dogs. Once a participant consents to join the Foundation Cohort, they will go to their portal and request a free DNA Kit. They will use the kit to collect a saliva sample from their dog’s cheek and return it to our lab. Once we analyze this genetic material, participants will receive a personalized genomic report about their dog.
The aim of the Precision Cohort study is a more precise look at how canine biology and physiology are related to aging. Participants in this cohort will be invited to request a DNA Kit similar to that of Foundation Cohort members. After returning the saliva sample, the next step will be to request a Sample Kit for the collection of biological samples. Precision Cohort members will need to take their dogs to their primary care veterinarians for the collection of these samples using the Sample Kits we provide. (For safety, small dogs will need to have their samples collected in smaller quantities over the course of two visits.) In addition, we’ll ask participants to do other activities such as playing cognitive games with their dogs, taking body size measurements, and timing their dogs during mobility assessments.
The aim of the Test of Rapamycin in Aging Dogs (TRIAD) Cohort is to conduct a double-blind, placebo-controlled clinical trial of a drug called rapamycin (more about this in a future post). This cohort is smaller than either the Foundation or Precision Cohorts. The eligibility process is much more involved and will take several months. Dogs included in TRIAD must meet a series of specific eligibility requirements and attend a screening visit at a participating veterinary teaching hospital to ensure that they have no underlying health conditions which might prohibit their participation. Like Foundation and Precision members, those in the TRIAD eligibility process will receive DNA and Sample Kits. Pack members who are invited to begin the eligibility process will be given much more detailed information as the process unfolds and will be able to decline participation at any point.
All of the dogs in these three cohorts will continue to live and play at home with their owners. Participation is totally voluntary, and we strive to make the whole process fun, easy, and safe for all. Team science at its best!
What if you don’t want to participate in these additional studies?
As we mentioned before, once a Pack member, always a Pack member! All of these cohorts—Pack, Foundation, Precision, and TRIAD—are critical to the success of our research program. We want people to participate in ways that feel comfortable to them. If a dog isn’t invited this time around or if a dog owner decides not to accept an invitation to one of the cohorts, there will be other opportunities in the future to contribute.
So, is the Dog Aging Project one study or many?
If you consider these four cohorts, and the potential for other cohorts in the future, the Dog Aging Project is really a collection of complementary studies, each of which provides unique and valuable insights into the aging process. Taken together, the information we gather from each cohort will help us meet the primary aims of the Dog Aging Project: define aging, explain aging, and intervene in aging.
We are so thankful for all of the members of our Dog Aging Project family! We love having the opportunity to get to know all our participants, human and canine, better over the coming years!
Dog Aging Project Team