Robert P. Hunter PhD, Joel Ehrenzweig DVM, MRCVS, Atticus Hainsworth PhD, Abbe Crawford PhD, MRCVS, Asaf Dagan DVM, Jaime Sage DVM, MS, DACVR, and Joseph Araujo PhD.
DOI: https://doi.org/10.2460/ajvr.23.02.0032
AVMA Journals, 26 Sep 2023: Treatment options for human dementia remain limited, and additional research is needed to develop and validate translational models. Canine cognitive decline (CCD) is common in older dogs and a major source of morbidity.
The decline includes physiological and behavioral changes comparable to those in humans diagnosed with dementia. There are also corresponding changes in plasma neurodegenerative biomarkers and neuropathology. Biomarkers for both human and canine cognitive decline can be used to identify and quantify the onset of behavioral data suggestive of CCD.
Successful correlations would provide reference values for the early identification of neurodegeneration in canine patients. This could allow for the subsequent testing of interventions directed at ameliorating CCD and offer translational value leading to safe and effective treatment of dementia in people.
Research can help exploit, track, and provide benefits from the rapid progression of spontaneous naturally occurring CCD in a large heterogenous community of companion dogs. Research efforts should work to deliver information using blood biomarkers, comorbidities, and wearable technologies to track and evaluate biometric data associated with neurodegeneration and cognitive decline that can be used by both human and companion animal researchers.
The synergistic approach between human and veterinary medicine epitomized in one health underscores the interconnectedness of the well-being of both species. Leveraging the insights gained from studying CCD can not only lead to innovative interventions for pets but will also shed light on the complex mechanisms of human dementia.
Why the Dogs Overcoming Geriatric Memory and Aging Initiative?
The authors, as a group, support the Dogs Overcoming Geriatric Memory and Aging (DOGMA) Initiative as a reflection of the AVMA’s one-health goals, emphasizing the shared challenges of aging and cognitive decline across species. By fostering collaboration between veterinarians, medical doctors, and researchers from various fields, the proposed CCD study aims to enhance our understanding of these processes and to devise cross-species solutions. This alignment underscores the vital concept that improving the health and well-being of our pets may also pave the way for advancements in human health.
CCD highlights the shared health challenges faced by both humans and canines, particularly in the context of geriatric cognitive decline, and underscores the importance of interdisciplinary collaborations in addressing these challenges, which is a key tenet of the one-health approach.
CCD offers a clear and engaging introduction of the one-health approach to veterinarians, whether they are familiar with the concept or approaching interdisciplinary collaborations and communications in all aspects of health care for humans, animals, and the environment for the first time. The authors propose to reframe CCD from the perspective of the DOGMA acronym to put this condition into a broader framework of issues:
Dogs Overcoming Geriatric Memory and Aging (DOGMA) Initiative.
DOGMA
D – Dogs: Dogs share our homes and lifestyles, leading to shared health risks. Studying cognitive decline and aging in dogs can yield comparative insights into similar human conditions, benefiting both canine and human health.
O – Overcoming: This term encapsulates the proactive goal of the One Health Initiative to improve health and well-being across species. It underscores our shared aim of finding solutions to health issues affecting all living beings and their environments.
G – Geriatric: As life expectancies increase, age-related health issues are a growing concern in both human and veterinary medicine. By focusing on geriatric health, we address a significant challenge shared across species.
M – Memory: Cognitive decline, especially memory loss, significantly impacts aging in both humans and dogs. By studying and addressing memory impairment in dogs, we might uncover findings applicable to human medicine, particularly conditions like Alzheimer disease.
A – Aging: Aging is a universal biological process impacting all living organisms. Research into systemic changes that occur with aging can provide insights applicable across species, leading to potential interventions that can improve health and lifespan.
Behavior
The Canine Dementia Scale (CADES) questionnaire6 aims at identifying the onset, severity, and progression of behavioral and cognitive impairment in dogs with mild cognitive declines through observation of changes in social interaction and alterations of spatial orientation. Using CADES, dogs are classified as “mild,” “moderate,” or “severe” based on the level of behavioral change exhibited. Physical impairment, including visual and smell, has been linked to CCD progression.6
Innovative 24/7 wearable smart collars (ie, PetPace.com) can identify and track a number of physiological signs and behavioral changes that are consistent with CCD. The devices continuously monitor, collect, and report a dog’s vital signs using noninvasive sensors for body temperature, heart rate, respiration rate, degree of physical activity, body positioning, heart rate variability, and physical location as well as movement within the home. The activity sensor can identify, record, and report minute changes in activity patterns. Collected data are sent to a cloud-based monitoring platform that analyzes the information and issues an alert if deviations from routine exist.
The proprietary algorithms for these devices recognize the behavior, position, and biometric data representing an animal’s pattern of life, ie, that individual’s physiological values, behaviors, and routines. Data collection from individuals will continue to the end of life. If pattern of life findings are consistent with CCD onset diagnostics and one can rule out any concomitant issues, that individual could be viable for potential enrollment in a CCD research study.
In addition to biometric data, routine laboratory diagnostics would monitor for comorbidities that could result in CCD-like symptoms. Routine and specialized tests should include blood/serum analysis such as CBC, blood chemistry profile, C-reactive protein, amyloid-β proteins, phosphorylated τ proteins, neurofilament light chain protein, and glial fibrillary acidic protein. Additional evaluations should include routine ophthalmoscopic exams for hypertensive retinopathy and interstitial fluid evaluation. Samples could be cryobanked for later access and further CCD investigations.
Conclusion
The advances in science and medicine have enabled people and pets to live longer and healthier lives. This achievement has also resulted in an increased incidence of chronic conditions associated with advanced age and a dramatic surge in neurodegenerative diseases like Alzheimer’s disease and CCD. Treatments aimed at slowing or stopping the progression of neuropathic conditions have been hindered by the lack of suitable animal surrogates emulating the natural progression of people with the disease. The ability to recognize early behavioral manifestations of CCD and concurrent deviations in neurodegenerative biomarkers will allow for the identification of clinical study candidates for the treatment of CCD and comparative data that could ultimately lead to the diagnosis of early onset and the successful management of dementia.