Introduction
Canines just like any other mammalian species can run into multiple anatomical and physiological changes as they get older. The anatomy and physiology of the animal can go through multiple changes that slowly deteriorate the overall health status of the animal. These changes develop for a variety of reasons for the body to slowly break down and become less functional over time. Canine cognitive dysfunction (CCD) is a syndrome that develops in some aging geriatric dogs that suffer from neurodegenerative deficits resulting in behavioral changes that can be affiliated/ correlated to that of dementia and Alzheimer’s disease behaviors in humans. Aging over time involves degeneration of multiple tissues, cells, and organs which slowly become less functional on both a physical and practical standpoint. The purpose of this paper is to ensure the best quality of life for the patient when suffering with canine cognitive dysfunction. According to Landsberg (2012) The volume of the frontal lobe decreases while the ventricular size increases, meningeal calcification occurs, demyelination along with a decrease in neurons is noticed, increased lipofuscin and apoptic bodies, and finally neuroaxonal degeneration (pg.751). Common behavioral changes associated with CCD include decreased interactions, anxiety, disorientation, and unusual sleeping patterns (Fast et al., 2013). Multiple questionnaires have been developed over the years to help practitioners diagnose CCD based off of clinical signs noticed by both the owner and the practitioner’s assessment of the patient’s status.
The best and most useful diagnostic tool we can use to diagnose CCD is through client questionnaires. Client questionnaires are one of the only tests veterinarians can perform to evaluate the overall status of the patient. The complication of client questionnaires depends on which questionnaire is best to follow by in terms of criteria. Schütt (2015) stated that the degree of affected behavior is unified and if the questionnaire score can determine the level of cognitive dysfunction (pg.452). Multiple studies and other research relating to dementia and Alzheimer’s are being incorporated into these questionnaires to effectively narrow down to an ideal set of questions to diagnose CCD.
The brains ability to store once critical information and memory is slowly degenerating from the normal storage capacity due to neurodegenerative processes. Canine cognitive dysfunction has been linked to a variety of factors ranging from abnormal neurotransmitter behaviors, concentrations of platelet 2- adrenoreceptors and lymphocyte muscarinic receptors, and degeneration of tissues due to aging (Badino et al., 2012). According to Ozawa (2016) Major causes suggested of the syndrome include deposition of β-amyloid protein, senile plaque (SP) and cerebral amyloid angiopathy (CAA) (pg.1). β-amyloids are starch mimicking proteins that are one of the primary components of plaque associated with Alzheimer’s disease. Ozawa (2016) also said that Aβ is believed to be important in the neuronal death cascade that ultimately leads to decreased cognitive function and dementia (pg.1).
Cognitive aspects of the brain deteriorate over time and can affect the overall health and medical standpoint of the individual. With increasing age, can come deterioration of tissues and cells over time that can ultimately introduce other medical conditions. It is very important to rule out any other preexisting medical conditions that can potentially have similar effects on the status of the patient. Owners should seriously monitor the patient’s emotional and behavioral states along with paying close attention to the patient’s sleep schedule, house soiling, and appetite (Landsberg et al., 2012).
Canine cognitive dysfunction is an important topic to consider when evaluating and providing the best quality of life for the patient. The patient’s stress level should be fully maintained and monitored for ensuring the best quality of life for the patient. CCD can be stressful to both the patient and the owner due to the patient’s inability to comprehend certain interactions that at one point could have been a daily routine. The clinical signs of CCD worsen over time (Fast et al., 2013). CCD can often lead to confusion for the patient to a degree of abnormal and sudden aggressive behaviors towards others that were not previously exhibited.
Body
Behavioral changes in aging pets are often one of the first noticeable signs that the status of cognitive health along with overall health of the individual is declining. Canine and feline brain aging along with cognitive dysfunction can be comparable to what is known as Alzheimer disease in humans. Alzheimer disease can best be defined as a progressive disease resulting in the loss of higher cognitive function. When cognitive function is disrupted and altered, the overall health of the individual can be altered as well. The brain being the main control center of the individual controls and regulates everything that is going on with the rest of the body. The body therefore, typically suffers along with the brain when the brain is not functioning at its healthiest state.
According to Landsberg (2012) There are multiple cognitive domains that include learning, memory, management function, language, psychomotor ability, attention, and spatial abilities that all correlate into the term cognition. Clinicians and laboratories have special behaviors and protocols to look out for when also evaluating similar abilities/ functions in pets. Patients can go to animal behaviorists and neurologists and go through multiple tasks/ evaluations of the pet’s brain function and behavior. One test commonly used is the delayed nonmatching to position memory task (DNMP). According to Landsberg (2012) Older dogs can be broken up into three separate groups unimpaired, impaired, and severely impaired, which may be comparable to Alzheimer’s disease. Older dogs with DNMP impairments also show altered sleep –wake cycles, increased stereotypy, and decreased interactions with humans, which suggests linkage to cognitive dysfunction.
There are a countless number of clinical signs associated with cognitive dysfunction. The best way to evaluate cognitive dysfunction is to use the acronym DISHA (Landsberg et al, 2012). The acronym stands for evaluating disorientation, interaction with others (owners, other animals, surrounding environments), sleep – wake cycle, house soiling, and activity changes. Typically, owners with older pets report their recent changes/ increased behaviors of anxiety, fear, and phobias as their pets get older throughout the years. The easiest clinical sign to assess in a dog or cat is their memory. Memory is believed to be one of the first clinical signs that can be evaluated for cognitive dysfunction. An animal’s memory can be a visible clinical sign either from the owner evaluating behavior at home (staring at walls, lost in a room, forgets a daily routine) or practitioner evaluating similar behaviors when in the exam room.
Client questionnaires help significantly with evaluating/ diagnosing cognitive dysfunction in patients. These questionnaires are either asked by the clinician or sent home with the owner to further evaluate and report back to the clinician at a later date. Signs included DISHA observations along with countless others. Some other signs to look out for included: appetite behavior, bowel movement behaviors, drinking behaviors, perception, aimless behavior (circling, star gazing, stereotyped walking), and personality changes (Schütt et al, 2015). Other questions that were frequently asked were if the pet wanders, gets stuck behind objects and unable to get around, recognize familiar people, stare at walls, and walk into objects. These same questions would then be asked every 6 months proceeding to have a further diagnostically accurate results when trying to diagnose these certain behaviors with cognitive dysfunction.
Evaluating anatomical or physiological changes to the brain were through running other diagnostic tests that pertained more to actual physical changes versus behavioral changes. Blood work can be done to evaluate ongoing changes of certain characteristics of blood or notice any increase or decreasing levels of components. Cerebrospinal fluid may also be monitored for increasing or decreasing amounts associated with cognitive changes (Schütt et al, 2015). According to Badino (2012) A severe decrease in plasma levels of norepinephrine and dopamine was noticed in both older dogs and dogs with cognitive dysfunction as in relation to adult dogs that did not show signs of CCD. Necropsies and pathological studies of deceased animal’s brains can be performed to evaluate physical changes to the aging brain suspected as well with cognitive dysfunction. According to Badino (2012) Results suggest that decreased levels in HA muscarinic receptor-binding sites could be related to the physiological aging process, where the elevated levels in lymphocyte LA muscarinic receptors could potentially be related to cognitive decline. Other imaging techniques (radiographs, magnetic resonance imaging (MRI), positron emission tomography (PET) scan) as well can be performed to help evaluate more of the anatomical changes but as well as physiological changes to the brain to help gain more information.
Alzheimer’s disease in humans and canine cognitive dysfunction do share a lot of similar laboratory findings, clinical signs, and other similarities associated with one another. Both express a disruption in behavioral patterns, daily routines and other clinical signs that may worsen over time (Fast et al, 2013). Both diseases ultimately affect the health status and quality of life of the patient but for the most part tend to not be ultimately the reason for death. An enlarged ventricular system and noticeable cortical atrophy have been observed/ correlated with Alzheimer’s cognitive dysfunction (Fast et al, 2013). Both diseases if monitored especially over time, the patient can still live a normal life expectancy. Both diseases are also highly affected by an individual’s stress and anxiety. Typically stress and anxiety levels are increased with canine cognitive dysfunction due to the lack of mental security and increased confusion.
Aging can lead to multiple deteriorations of the body and one of them that can occur over time and affect cognitive dysfunction is brain lesions. Amyloid protein (A) is suspected to be one of the leading proteins that can deposit in the brain as senile plaque along with cerebral amyloid angiopathy (CAA) to be associated with cognitive dysfunction syndrome and Alzheimer’s disease (Ozawa et al, 2016). Ozawa (2016) also stated that (A) is believed to have a critical role in the neuronal death cascade that ultimately suggests cognitive decline and dementia. The severity of the (A) depositions and (CAA) directly affect the level of loss of cognitive dysfunction in older animals. These physiological abnormalities along with general aging both correlate with neurodegenerative properties that can either further enhance cognitive dysfunction in dogs and Alzheimer’s disease in humans.
Older animals and humans also need to be examined for any preexisting medical conditions or diseases that may alter their cognitive abilities in the process due to aging or genetics. Ruling out any prior complications, conditions, and diseases is critical to the diagnosing process of cognitive dysfunction and Alzheimer’s. Drug therapy may also play a role in misdiagnosing cognitive dysfunction or Alzheimer’s disease due to the residual affects of the drug inside the body. Side effects from some drugs can even lead to some neurodegenerative properties of the brain and thus result in a potential misdiagnosis.
Canine and Feline patients with cognitive dysfunction have also been used to experiment with neurological drugs and experiments in hopes to treat for cognitive dysfunction in animals as well as Alzheimer’s disease in humans in the future. Cognitive dysfunction is not curable during this present time period, but there are drugs out there that can slow down deterioration and clinical signs associated with it. According to Landsberg (2012) Selegiline (Anipryl) is a irreversible inhibitor of monoamine oxidase B that has the capability to enhance dopamine and other catecholamines in the cortex and hippocampus. It has been shown both in the laboratory and clinic to improve signs consistent with cognitive dysfunction in dogs. There are also multiple attempts at neurology care based off of food nutrition.
Reference Page
Badino, P., Odore, R., Bergamasco, L., Barbero, R., Osella, M., D’Angelo, A., . . . Girardi, C. (2012, November 26). Concentrations of platelet α2-adrenoceptors, lymphocyte muscarinic receptors, and blood monoamines in dogs (Canis familiaris) affected by canine cognitive dysfunction syndrome. Journal of Veterinary Behavior: Clinical Applications and Research, Retrieved February 01, 2017, from http://www.sciencedirect.com.mtiproxy.minlib.net/science/article/pii/S1558787812000998?np=y&npKey=b740e5721ff90eaf0760839f7f1ad32446f30b259c0a4867d06b0839b26515f5
Fast, R., Schütt, T., Toft, N., Møller, A., Berendt, M. (2013). An observational study with long-term follow up of canine cognitive dysfunction: Clinical characteristics, survival, and risk factors. Journal of Veterinary Internal Medicine, Retrieved February 01, 2017, from http://onlinelibrary.wiley.com.mtiproxy.minlib.net/store/10.1111/jvim.12109/asset/jvim12109.pdf?v=1&t=iyo97skc&s=0bb24ab5ebd2566f057b5d8bae00f603c45124e1
Landsberg, G.M., Nichol, J., Araujo, J.A. (2012). Cognitive dysfunction syndrome a disease of canine and feline brain aging. Vet.Clin. North Am.:Small Anim. Pract., Retrieved February 01, 2017, from http://webinars.veteducation.com.au/wp-content/images/Cognitive-Dysfunction-Syndrome.pdf
Ozawa, M., Chambers, J. K., Uchida, K., & Nakayama, H. (2016, June). The Relation between canine cognitive dysfunction and age-related brain lesions. Journal of Veterinary Medical Science, Retrieved February 01, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4937160/