First published in Double Helix Network News, Summer 2004, Rev. May 2013
“I told them all about Blue, and offered to give them any kind of samples they want. How come they told me no?”
In three decades of providing genetic education and counseling for people with Australian Shepherds, I’ve heard this lament more than once. Rejection hurts and it smarts all the more when you have a dog that is sick or you’ve just discovered offspring of your top ranking stud dog have been diagnosed with a genetic disease. Even so, you shouldn’t take it personally nor view it as an unreasonable roadblock to returning a sick dog to health.
There are many reasons why researchers may not be able to use information or samples from your dog. Simply stated, the dog must fit the protocols for the study. Protocols are the rules that define how a project will be conducted and what constitutes appropriate data. To make an obvious example, if a study focused on hip dysplasia, researchers would not be looking for samples from dogs with cataracts. Few people would think of offering information or samples for a study when their dog has a different disease, but oftentimes the needs of a particular project may not be obvious to the concerned owner or breeder.
There are many different types of studies designed to investigate different aspects of canine hereditary disease. Clinical research aims at discovering how the disease presents or progresses or whether a particular treatment will be effective. Epidemiology studies focus on how illnesses arise in and are transmitted through populations. Cellular and molecular research investigate nano-scale disease processes, sometimes on the level of the DNA. Other DNA studies may try to locate responsible genes or things which change the function of genes.
All studies have particular needs when it comes to data. What works for one may not work for another, even if the studies seem similar in type or target the same disease. However, there are some things that will apply in most cases and understanding that will help you determine whether or not you may be able to provide useful data to a particular study.
A clinical study might focus on all breeds or only one, but the goal will be to improve diagnosis or treatment of the disease.
A hip dysplasia study investigating the value of a new surgical technique might accept dogs of any breed, including mixes. They wouldn’t want healthy dogs, even if a healthy individual had numerous affected relatives. The point is to see if treatment works. Even an affected dog might not be accepted for a study if the specifics of its condition didn’t meet study protocols or if it had other health issues that could cloud the result. Dogs with bad hearts, for example, are poor surgery candidates, and would likely be rejected for an investigation of a surgical technique. If the study was investigating a drug that could reduce degenerative joint disease in dysplastic dogs, researchers might want only dogs that had HD and degenerative joint disease.
A clinical study focused on prevention might be confined to a single breed or even a strain within a breed. Having a genetically consistent study population to draw from enables researchers to better evaluate environmental influences on the disease. Dogs who are already ill might or might not be needed.
Some diseases, like Progressive Retinal Atrophy, can be genetically different from breed to breed. It may be necessary to work only with a single breed to discover what screening and/or breeding practices will best reduce disease incidence. Results may or may not apply to other breeds with the disease.
Age of the dog may be a factor, if the research focuses on initiation and early development of the disease. Treatment studies may seek young individuals, looking to prevent or cure the disease, or at least mitigate its effects down the line. Other studies might focus on geriatric aspects of a disease.
Epidemiological studies aren’t just for infectious disease. Genetic diseases also arise and are transmitted through a population. The source of a disease may be a mutation in an individual or via the introduction of one or more carriers to the population. A study population might include an entire breed (Australian Shepherds), a single line or segment of the breed (show line Aussies), or a geographically isolated group (show line Aussies in Australia.)
Environmental influences on a genetic disease might limit what dogs will be acceptable study subjects. If sun exposure played a roll, researchers might want dogs only from the desert southwest or Alaska. Maybe even both, depending on what specific effect sunlight–or the lack of it—has. In a case like this, they might not be able to use samples from an Irish Setter in Iowa or a Newfoundland in New York even though both were diagnosed with the disease.
Pedigrees are vital to genetic epidemiology research. Because of this, rescues and other dogs of uncertain ancestry would not be eligible.
Cellular, Molecular and DNA Research
Cellular and molecular studies of disease processes, as with similar clinical studies, will need participation from affected dogs. However, the dog itself may never need to leave home. It might even have died.
Researchers use tissue samples or products derived from them. One study might require freshly drawn blood, where another can use blood that has been properly stored. “Proper” storage will be defined by the needs of the study, as will the specific tissue type. In addition to blood, biopsy samples of skin, internal organs, muscle or bone might be needed. Occasionally hair or nail samples or semen will do, but this is rare.
The only definitive way to diagnose some diseases is on necropsy. In such cases, appropriate tissue from deceased dogs needs to be submitted in the manner specified. Despite what you might think after a steady diet of TV forensic crime dramas, samples from interred or cremated remains generally are not useful for research. Samples usually need to have been removed from fresh corpses for immediate use or be properly chilled, dried or treated with a preservative agent for later use. No single study is likely to accept all of the above.
DNA research conducted to locate genes often requires blood samples or cheek swabs. Some studies, as with CEN (above,) will accept other tissues. DNA studies may require samples from individual affected dogs or from family groups. If a family is needed, what relatives do and don’t qualify as “family” will be defined. Pedigrees on sampled dogs must also be submitted so the researchers can develop genealogies, which serve as research tools and provide supporting documentation for their findings.
A longitudinal study follows a group of subjects, called a “cohort,” over a period of time. The period may range from months to decades depending on the focus of the study. These studies seek to find out what happens as time goes by…after diagnosis of a disease, after administration of a drug, or throughout a long-term course of medication. Some longitudinal studies are designed to follow an age group cohort of individuals, gathering data on their environment, genetics, and unfolding health or behavioral history.
Subjects for longitudinal studies must fall into a specific class: Dogs with hip dysplasia, survivors or a specific cancer, individuals who received a particular drug as juveniles, or Golden Retrievers aged 1-3 years. Length of the study will depend on the questions the researchers expect to ask of the data they gather.
Study subjects (or their owners, in the case of dogs) usually need to submit information on a regular basis, report to the research group or a cooperating local vet or clinic periodically for exams and/or testing, possibly conform to specific dietary or other personal practices, and agree to stay in the study for its expected duration. If your dog doesn’t meet the criteria for the study cohort or you aren’t willing to comply with study requirements, your dog will not be accepted into the study.
What to do
If you have a dog that you think might be suitable for a study, do some homework before you contact the lab or university involved. If outside animals are needed for the work, researchers will often have information posted on their institution’s website. Granting agencies, like Morris Animal Fund and the AKC Canine Health Foundation, routinely issue informational press releases and post supported studies on their websites. Read the information carefully to see whether your dog actually fits the needs of the study and whether you will be willing and able to do what is asked of you as owner. Follow directions for sample and data submission carefully and completely. If the study requires cases to be referred by a veterinarian, don’t bombard the researcher with calls and e-mails. Ask your vet to look into it for you.
Having an understanding of the needs of different types of studies, doing your homework on research projects of interest, and following directions is the best way to have your dog participate. If a particular researcher still tells you he doesn’t need samples from Blue, hank him and keep looking. You may find another with a project Blue can contribute to.