Geriatric horses are older equines that typically exhibit age-related physiological changes impacting their health and management. As horses age, they may experience alterations in metabolism, immune function, and musculoskeletal integrity. These changes can increase their susceptibility to diseases and necessitate specialized care. Research on geriatric horses often focuses on understanding the aging process, identifying common health issues such as osteoarthritis and dental problems, and developing management strategies to enhance their quality of life. This page gathers peer-reviewed research studies and scholarly articles that explore the physiological changes, health challenges, and management practices associated with aging in horses.
van Proosdij R, Frietman S.Geriatric horses (>15 years) represent a substantial proportion of the equine population. The objective of this study was to (1) report on the cause of death in geriatric horses on a single retirement centre, (2) to evaluate the relationship between PPID status, and mortality rate. Data of 194 horses was collected over an eight-year period. This providing data for 80 geriatric cases of mortality. The average age of horses that died was 26.2 years (±4.8 years). The majority (95%) of mortalities were euthanised, most frequently due to colic (20%), old age (19%), and lameness (15%). Overall m...
Suagee-Bedore J, Shost N, Miller C, Grado L, Bechelli J.Older horses and those prone to obesity may be at a higher risk for inflammation than younger and leaner counterparts. Previous research indicated a postprandial elevation in plasma concentrations of interleukin-1β (IL-1β), a pro-inflammatory cytokine, after consuming 1.2 g of non-structural carbohydrates/kilogram of body weight. However, these studies utilized horses of mixed age and body condition. The current study evaluated post-prandial IL-1β concentrations in horses specifically comparing lean to over-conditioned and middle aged to older. Our results suggest that at least two weeks of...
Kelemen Z, Grimm H, Long M, Auer U, Jenner F.Recumbency is a prerequisite for horses achieving rapid eye movement (REM) sleep and completing a full sleep cycle. An inability to lie down due to environmental insecurities or pain results in REM sleep deficiency, which can cause substantial impairment of welfare and health. Therefore, the present study used wearable automated sensor technology on 83 horses housed in an animal sanctuary to measure and compare the recumbency, locomotion, and standing time budgets of geriatric horses with and without chronic lameness to younger adult sound and lame horses. Recumbency times ranged from 0 to 319...
Grenager NS.Endocrinopathic laminitis (EL) primarily occurs because of insulin dysregulation (ID) mediated through downstream effects of insulin on IGF-1R in lamellar tissues. There is likely contributing vascular and metabolic dysfunction within the lamellae, but EL is relatively non-inflammatory. EL is associated with lamellar stretching, proliferation, and failure, ultimately causing failure of the suspensory apparatus of the distal phalanx. Proper education regarding mitigating risk factors makes this a largely preventable cause of laminitis. Annual hoof evaluation plus screening geriatric horses for ...
Sage SE, Bedenice D, McKinney CA, Long AE, Pacheco A, Wagner B, Mazan MR, Paradis MR.To determine the impact of age on survival in horses with colitis and to elucidate whether a lower type-1/type-2 cytokine ratio or an exaggerated inflammatory state contribute to reduced survival in aged horses. Methods: Part 1: Retrospective cohort analysis. Part 2: Analytic observational study. Methods: Part 1: One hundred twenty-four adult horses with colitis. Part 2: Twenty-nine adult horses with new diarrhea onset while hospitalized. Results: Part 1: Patient signalment, select clinicopathological data, diagnoses, treatment, hospitalization length, and invoice were compared between survivo...
Vera L, Muylle S, Van Steenkiste G, Segers P, Decloedt A, Chiers K, van Loon G.Arterial rupture is a well-recognized cause of sudden death in horses, which mainly affects older horses. The arterial wall is known to stiffen with age, although the underlying age-related histological and biomechanical changes remain unclear. The purpose of this study was to investigate the effect of aging by histological analysis of the arterial wall and examination of the arterial wall biomechanical properties using an inflation-extension test. Entire circular samples of the proximal and distal aorta, cranial and caudal common carotid, external iliac, femoral and median artery were collect...
Kelemen Z, Grimm H, Vogl C, Long M, Cavalleri JMV, Auer U, Jenner F.Housing and management conditions strongly influence the health, welfare and behaviour of horses. Consequently, objective and quantifiable comparisons between domestic environments and their influence on different equine demographics are needed to establish evidence-based criteria to assess and optimize horse welfare. Therefore, the present study aimed to measure and compare the time budgets (=percentage of time spent on specific activities) of horses with chronic orthopaedic disease and geriatric (≥20 years) horses living in different husbandry systems using an automated tracking device. Ho...
Smith R, Pinchbeck G, McGowan C, Ireland J, Perkins E.The number of aged horses in the UK has been growing over recent years, with many horses remaining active and being cared for into old age. However, increasing age is paralleled with a heightened risk of morbidity and mortality; therefore, owners of older horses must manage changes in their horse, making decisions about management and health care provision. In this paper, we discuss data collected from an open-access online discussion forum, where forum users sought advice arising from concerns about their older horse. Qualitative data analysis was performed using grounded theory methods. A co...
Miller AB, Loynachan AT, Barker VD, Adams AA.In order to better understand the influence of age on innate immune function in horses, blood was collected from twelve adult horses (aged 10-16 years; mean: 13 years) and ten geriatric horses (aged 18-26 years; mean: 21.7 years) for analysis of plasma myeloperoxidase, complete blood counts, and cytokine and receptor expression in response to in vitro stimulation with heat-inactivated Rhodococcus equi, heat-inactivated Escherichia coli, and PMA/ionomycin. Gene expression was measured using RT-PCR for IFNγ, IL-1β, IL-6, IL-8, IL-10, IL-12α, IL-13, IL-17α, TLR2, TLR4, and TNFα. Endocrine fu...
Tatum RC, McGowan CM, Dean RS, Ireland JL.Pituitary pars intermedia dysfunction (PPID) is the most prevalent endocrine disorder of older equids. To date, key research areas likely to have the greatest impact on equine health have not been identified. In human medicine, public and patient involvement is widely used to inform research agendas. This study aimed to engage with veterinary surgeons and horse owners to identify evidence gaps ('uncertainties') and prioritise these into a list of the 10 most important PPID research questions. The James Lind Alliance (JLA) Priority Setting Partnership (PSP) Framework was adapted. Questions abou...
Bagge J, MacLeod JN, Berg LC. Bone marrow (BM)- and adipose tissue (AT)-derived mesenchymal stem cells (MSCs) are used increasingly for autologous cell therapy in equine practice to treat musculoskeletal and other injuries. Current recommendations often call for 10-100 million MSCs per treatment, necessitating the expansion of primary cells in culture prior to therapeutic use. Of concern, human and rodent studies have shown a decline of both MSC recovery from sampled tissue and proliferative capacity with increasing donor age. This may be problematic for applications of autologous cell-based therapies in the important eq...
Christen G, Precht C, van der Kolk J, Fouché N, Gerber V.Endocrinopathic laminitis occurs as a consequence of hormonal derangements like pituitary pars intermedia dysfunction (PPID). The objective of the present study was to assess the occurrence of radiographic changes associated with chronic laminitis in elderly, clinically sound horses. Fifty-one horses were included in the study. Horses were assigned to different age groups, in groups according to their BCS and CNS as well as to groups with different ACTH concentrations in order to assess their risk of chronic laminitis (reported as odds ratios (OR) and confidence intervals (CI)). Horses assigne...
Tatum RC, McGowan CM, Ireland JL.Pergolide, a dopamine agonist, is commonly administered to manage pituitary pars intermedia dysfunction (PPID), a progressive neurodegenerative disease prevalent in aged horses. However, available evidence regarding pergolide's efficacy in improving clinical and endocrine parameters is limited. The aim of this systematic review was to assess published literature and evaluate evidence regarding whether pergolide treatment results in improvement of clinical signs and/or adrenocorticotrophic hormone (ACTH) concentration compared to no treatment or other unlicensed treatments. Systematic searches ...
Gehlen H, Jaburg N, Merle R, Winter J.The aim of the present study was to evaluate (i) the effects of different intensities and types of treated pain on the basal concentrations of adrenocorticotropic hormone (ACTH) and cortisol, and (ii) the thyrotropin-releasing hormone (TRH) stimulation test, to determine whether treated pain caused a marked increase of ACTH, which would lead to a false positive result in the diagnosis of pituitary pars intermedia dysfunction (PPID). Methods: Fifteen horses with treated low to moderate pain intensities were part of the study. They served as their own controls as soon as they were pain-free agai...
Carillon B, Jarzebowski W, Fulpin B, Miliotis A, Bernadac A, Saint-Georges Chaumet Y, Belmin J.Experienced in psychomotricity in two nursing homes, pony-assisted therapy shows first positive effects on psycho-behavioral symptoms. Recognized in the field of disability and psychiatry, this form of therapy is not developed in gerontology. To measure the effects of this therapy on the behavior of elderly people with neurocognitive disorders living in long-term care and especially on the involvement in this activity. Anxiety and apathy were chosen as the measurement criteria. An intervention study with an experimental cross-study design was conducted over two months for 23 subjects. An inter...
Żak A, Siwińska N, Chełmecka E, Bażanów B, Romuk E, Adams A, Niedźwiedź A, Stygar D.The study aims to assess the impact of age, pituitary pars intermedia dysfunction (PPID) and insulin dysregulation (ID) in horses on selected oxidative stress markers. The study includes 32 horses, divided into three groups: "young" adult group (aged 8-16 years old) "geriatric" group (aged 18-24 years old) and the "PPID" group (aged 15-31 years old). The PPID group was further divided into two subgroups: PPID ID+ and PPID ID- based on presence or absence of ID. We measured serum antioxidant stress markers in all horses: total oxidant status (TOS), total antioxidant capacity (TAC), ceruloplasmi...
Kędzierski W, Janczarek I, Kowalik S, Jamioł M, Wawak T, Borsuk G, Przetacznik M.In humans and animals, aging leads to a decrease in immune function and an increased susceptibility to infection. Decreased immunity and an increase in the incidence of infectious diseases are particularly notable during the autumn. Bee pollen supplementation improves immunity and antioxidant enzyme activity, as well as general performance. The aim of this study was to evaluate the effects of bee pollen supplementation during the autumn on blood parameters in aged horses. The study was performed on 16 warmblood horses aged 15-26 years. Half of this group received 60 g of bee pollen (soaked i...
Vera L, Van Steenkiste G, Decloedt A, Chiers K, van Loon G.Arterial rupture mainly affects older horses. The reason why older horses are more prone to arterial rupture and which underlying vascular changes predispose older horses to aortic rupture is still unclear. Objective: To investigate the effect of ageing on the equine arterial wall and blood pressure. Methods: Cohort study. Methods: Non-invasive blood pressure measurement using a tail cuff and vascular ultrasound from aorta, common carotid artery and external iliac artery was performed in 50 healthy young (3-7 years) and 50 healthy old Warmblood horses (>18 years). Arterial diameters and c...
Ballou ME, Mueller MK, Dowling-Guyer S.This study evaluated the experience of 1,448 people in the United States who currently care for or had previously cared for a geriatric horse and how that experience was qualified by the presence or absence of a chronic condition in the horse. An anonymous, online questionnaire was distributed to a cross-country sample to investigate the burden of caregivers from the perspective of owners of geriatric horses. Traumatic events and veterinary care decisions were also explored. Findings from the study supported the hypothesis that owners of geriatric horses with a chronic condition experienced hi...
McKinney CA, Oliveira BCM, Bedenice D, Paradis MR, Mazan M, Sage S, Sanchez A, Widmer G.Fecal microbial transplantation (FMT), a treatment for certain gastrointestinal conditions associated with dysbiosis in people, is also empirically employed in horses with colitis. This study used microbiota high-throughput sequencing to compare the fecal microbial profile of healthy horses to that of geriatric microbial transplant recipients experiencing diarrhea and tested whether FMT restores microbiota diversity. To evaluate the effect of environment and donor characteristics on the intestinal microbiota, fecal samples were collected per rectum from 15 healthy young-adult (2-12 years) and ...
Zak A, Siwinska N, Elzinga S, Barker VD, Stefaniak T, Schanbacher BJ, Place NJ, Niedzwiedz A, Adams AA.Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concent...
Siard-Altman MH, Harris PA, Moffett-Krotky AD, Ireland JL, Betancourt A, Barker VD, McMurry KE, Reedy SE, Adams AA.Similarly to aged humans, senior horses (≥20 years) exhibit chronic low-grade inflammation systemically, known as inflamm-aging. Inflamm-aging in the senior horse has been characterized by increased circulating inflammatory cytokines as well as increased inflammatory cytokine production by lymphocytes and monocytes in response to a mitogen. Little is currently known regarding underlying causes of inflamm-aging. However, senior horses are also known to present with muscle wasting and often the endocrinopathy pituitary pars intermedia dysfunction (PPID). Despite the concurrence of these phenom...
Siwinska N, Zak A, Slowikowska M, Szczepankiewicz B, Niedzwiedz A, Paslawska U.The aim of this study was to establish the value of the renal resistive index (RI) of intrarenal arteries in healthy warmblood non-racing horses of different ages to assess the influence of physiologic factors and repeatability of measurement. The kidney ultrasonography examination was performed in three age groups: 15 foals, 15 adults and 15 elderly horses. The procedure was performed in unsedated standing animals. RI values were measured using pulsed-wave Doppler at the medial part of each kidney in the intrarenal arteries. To evaluate repeatability, all measurements were repeated two hours ...
Barrio E, Rickards KJ, Thiemann AK.Clinical evaluation and preventative care in donkeys should follow similar guidelines as for horses. There are species-specific differences due to the desert-adapted physiology of the donkey. Donkeys are mainly used as pack animals, companions and for production of meat or milk - they may be kept well into old age. Diseases often present late or may go unrecognized leading to poor welfare and quality of life. Basic knowledge of nutrition, blood values, pharmacology and common disease recognition will help veterinarians improve the health and welfare of donkeys.
Plasma clearance of iohexol is a reliable method to assess the glomerular filtration rate (GFR). The relationship between aging and GFR in horses is unclear. To compare GFR estimated by iohexol clearance in horses of different ages. Twenty-one clinically healthy horses were enrolled. Prospective study. Groups: (A) composed by 8 young horses (≤14 years old) with serum creatinine <1.5 mg/dL, (B) by 7 aged horses (≥20 years old) with serum creatinine <1.5 mg/dL, and (C) by 6 aged horses (≥20 years old) with serum creatinine ≥1.5 mg/dL. Iohexol was injected (75.5 mg/kg) through...
Mazzotti E, Teti G, Falconi M, Chiarini F, Barboni B, Mazzotti A, Muttini A.Osteoarthritis is a degenerative disease that strongly correlates with age and promotes the breakdown of joint cartilage and subchondral bone. There has been a surge of interest in developing cell-based therapies, focused particularly on the use of mesenchymal stromal cells (MSCs) isolated from adult tissues. It seems that MSCs derived from synovial joint tissues exhibit superior chondrogenic ability, but their unclear distribution and low frequency actually limit their clinical application. To date, the influence of aging on synovial joint derived MSCs' biological characteristics and differen...
White-Lewis S, Johnson R, Ye S, Russell C.To compare equine-assisted therapy to exercise education on pain, range of motion, and quality of life in adults and older adults with arthritis. Quality of life for adults and older adults is negatively impacted by arthritis pain, stiffness, and decreased function. Equine-assisted therapy provides unique movements to the rider's joints and muscles improving pain, range of motion, and quality of life and has improved outcomes in balance, gait, strength, functional mobility, and spasticity for older adults, stroke, spinal cord injury, and multiple sclerosis patients. No research has investigate...
Boorman S, Stefanovski D, Southwood LL.To determine risk factors, especially age, associated with postoperative reflux (POR; >2 L of reflux present upon intubation), high-volume POR (≥20 L in 24 hours), and short-term outcome after small intestinal (SI) surgery. Methods: Retrospective case-control study. Methods: Horses aged ≥16 years (geriatric; range, 16-30; n = 44) and <16 years (mature; range, 2-15; n = 39) with an SI surgical lesion that survived general anesthesia and did not have a second exploratory celiotomy during the same visit. Methods: Medical records (2009-2015) were reviewed; perioperative var...
McFarlane D, Hale GM, Johnson EM, Maxwell LK.To determine effects of pituitary pars intermedia dysfunction (Cushing's disease) and age on fecal egg count and time to egg reappearance after anthelmintic treatment in horses residing in similar environments. Methods: Cross-sectional study. Methods: 29 healthy horses (4 to 35 years old) and 13 horses with PPID (13 to 33 years old). Methods: Fecal egg counts were performed by use of a modified Wisconsin flotation method at 2-week intervals before and after ivermectin treatment. Results: Horses with PPID had higher fecal egg counts before and 8, 10, and 12 weeks after ivermectin treatment, com...
Borges de Araujo T, Martins WR, Freitas MP, Camargos E, Mota J, Safons MP.Alzheimer disease (AD) is a chronic, progressive dementia syndrome that features cognitive and behavioral symptoms, as well as physical and functional limitations that develop over the course of the disease. As an activity that involves physical and cognitive aspects, equine-assisted therapy (EAT) could be a useful therapeutic approach in conditions that involve physical and cognitive decline. However, to date, there are no reports of the use of this therapy in participants with AD. Within this context, the objective of this case series was to describe the effects of EAT on balance, functional...
Long M, Dürnberger C, Jenner F, Kelemen Z, Auer U, Grimm H.Equine Quality of Life (QoL) is an important concern in decision making in veterinary medicine and is especially relevant for chronically ill or geriatric horses towards the end of their lives. To our knowledge, there is no currently available QoL assessment tool for chronically ill or geriatric horses that assesses equine QoL defined as the horse's evaluation of their life. However, tools exist to assess equine welfare in different contexts. Hence, the aims of this study were to analyse how equine welfare, QoL, well-being and happiness assessment tools label, define and operationalise the con...
Homnick DN, Henning KM, Swain CV, Homnick TD.Falls are an important cause of morbidity in older adults. Equine-assisted activities including therapeutic riding (TR) benefit balance and neuromuscular control in patients with neurological disabilities but have not been systematically studied in older adults at greater risk for falls due to balance deficits. The effect of an 8-week TR program on measures of balance and quality of life in community-dwelling older adults with established balance deficits was evaluated. Methods: This was a pretest-post-test single-group trial of a TR program on measures of balance and quality of life. Methods:...
Freeman DE, Schaeffer DJ.To test the hypothesis that strangulation of the small intestine by a lipoma or in the epiploic foramen is more common in older horses. Methods: Retrospective study. Methods: 46 horses. Methods: Ages of horses with strangulation of the small intestine by a lipoma (n = 29) or in the epiploic foramen (17) were compared with ages of 79 horses with miscellaneous small intestinal lesions. Effects of increasing age on risk of the diseases of interest were examined by use of logistic regression and a 1-sided trend test for binomial proportions. Results: Mean age of the horses with strangulation in th...
Aleman M, Watson JL, Williams DC, LeCouteur RA, Nieto JE, Shelton GD.Fifteen horses with pituitary pars intermedia dysfunction were studied. The horses were of various breeds and between 15 and 28 years of age. Control horses matched for breed and age were studied for comparison. Evaluations included complete blood cell count and serum biochemical analysis, electromyography, and gluteus medius muscle biopsies for histochemical, morphometric, and ultrastructural analysis. No differences were found between groups of horses on routine laboratory analysis or electromyography. We demonstrated that muscle wasting in diseased horses was the result of atrophy of types ...
McGowan CM, Ireland JL.Duration of ownership strengthens the human-horse bond, affecting decision-making about the horse's welfare, quality of life (QoL), and euthanasia. Most owners consider their geriatric horses to have good or excellent QoL; however, increasing age is negatively associated with QoL. Management factors are important. The most common reasons for euthanasia include musculoskeletal disorders or lameness, colic, and nonspecific chronic diseases. The decision to euthanize is difficult, so the advice of the veterinarian and QoL are important. This article focuses on the human-horse bond, assessment of ...
Horohov DW, Dimock A, Guirnalda P, Folsom RW, McKeever KH, Malinowski K.To compare exercise-induced immune modulation in young and older horses. Methods: 6 young and 6 aged horses that were vaccinated against equine influenza virus. Methods: Venous blood samples were collected for immunologic assessment before and immediately after exercise at targeted heart rates and after exercise for determination of plasma lactate and cortisol concentrations. Mononuclear cells were assayed for lymphoproliferative responses and incubated with interleukin-2 (IL-2) to induce lymphokine-activated killer (LAK) cells. Antibodies to equine influenza virus were measured. Results: Olde...
Forrer R, Gautschi K, Lutz H.It was the goal of this paper to establish total selenium reference values for Switzerland in different animal species and in humans. To this purpose, a flameless atomic absorption method with deuterium background compensation utilizing a graphite furnace atomization system with a pyrolytic platform inside and palladium solution as matrix modifier was developed for the measurement of selenium in serum. The method was characterized by rapid performability, small sample requirement, acceptable detection limit (0.04 mumol/L) and precision and a linear range of measurement up to 4 mumol/L. The met...
Smith R, Pinchbeck G, McGowan C, Ireland J, Perkins E.The number of aged horses in the UK has been growing over recent years, with many horses remaining active and being cared for into old age. However, increasing age is paralleled with a heightened risk of morbidity and mortality; therefore, owners of older horses must manage changes in their horse, making decisions about management and health care provision. In this paper, we discuss data collected from an open-access online discussion forum, where forum users sought advice arising from concerns about their older horse. Qualitative data analysis was performed using grounded theory methods. A co...
Hofberger S, Gauff F, Licka T.In older horses, pituitary pars intermedia dysfunction (PPID) and suspensory ligament (SL) degeneration are common. The aim of the present study was to identify histopathological changes in the SL in horses with PPID. SLs of four horses with clinical signs of PPID (17-26 years of age) were compared with SLs from four old horses (18-31 years of age) and three young horses (4-9 years of age). In horses with PPID, there was reduced longitudinal arrangement of collagen fibres in SLs, along with inclusions of cartilage, extracellular matrix and haemorrhage, as well as significant proteoglycan accum...
Stevens KB, Marr CM, Horn JN, Pfeiffer DU, Perkins JD, Bowen IM, Allan EJ, Campbell J, Elliott J.The effect of left-sided valvular regurgitation (LSVR) on the mortality of middle-aged and older horses was investigated in a prospective cohort study involving 19 yards and 1153 horses. The horses were examined to determine whether they had a cardiac murmur and its type, and their age, sex, breed type and occupation were recorded. They were followed up at intervals of two years by postal questionnaire, and after four years information on 773 horses was available. There was no significant difference in the mortality of the horses with and without LSVR, but small horses had a significantly high...
Spelta CW, Axon JE.The clinical manifestations of equine pituitary pars intermedia dysfunction (PPID) in temperate climates are well described. The classic presentation is that of an older animal with hirsutism, laminitis, poor muscle tone, pendulous abdomen and weight loss. This case series highlights the additional clinical signs of anhidrosis and heat stress with secondary exercise intolerance that were seen as primary presenting problems in equids with PPID in the hot, humid conditions of a tropical climate. The clinical signs resolved with medical treatment for PPID.
Ralston SL, Nockels CF, Squires EL.Hematologic data and results of diagnostic tests were compared between aged (greater than or equal to 20 years old) and young (less than or equal to 5 years old) horses to identify hematologic and metabolic changes associated with aging. Initial data were obtained from 8 aged and 6 young mares (group 1). Similar data were collected from a second group of aged (3 mares and 3 geldings) and young (1 mare and 5 geldings) horses (group 2). Dexamethasone suppression tests (DST) and necropsies were performed on 6 additional mares and mare 8 from group 1 (group 3). Complete blood counts and serum bioc...
Siard-Altman MH, Harris PA, Moffett-Krotky AD, Ireland JL, Betancourt A, Barker VD, McMurry KE, Reedy SE, Adams AA.Similarly to aged humans, senior horses (≥20 years) exhibit chronic low-grade inflammation systemically, known as inflamm-aging. Inflamm-aging in the senior horse has been characterized by increased circulating inflammatory cytokines as well as increased inflammatory cytokine production by lymphocytes and monocytes in response to a mitogen. Little is currently known regarding underlying causes of inflamm-aging. However, senior horses are also known to present with muscle wasting and often the endocrinopathy pituitary pars intermedia dysfunction (PPID). Despite the concurrence of these phenom...
Patterson-Kane JC, Sanchez LC, Uhl EW, Edens LM.A 12-year-old grey Warmblood stallion presented with fever of unknown origin, and anaemia. Five days later it had developed ataxia and become recumbent, and was humanely killed. At necropsy, malignant melanomas were identified in the perineal subcutis, spleen, and thoracic vertebral canal (T10-11). Populations of malignant melanoma cells were scattered throughout medullary cavities of the axial and appendicular skeleton, and were identified grossly as irregular areas of black to grey discoloration. To the authors' knowledge, this is the first report of disseminated intramedullary melanoma in a...
McFarlane D, Hill K, Anton J.Immunosuppression leading to opportunist bacterial infection is a well-recognized sequela of equine pituitary pars intermedia dysfunction (PPID). The mechanisms responsible for immune dysfunction in PPID however, are as of yet poorly characterized. Horses with PPID have high concentrations of hormones known to impact immune function including α-melanocyte stimulating hormone (α-MSH) and insulin. α-MSH and related melanocortins have been shown in rodents and people to impair neutrophil function by decreasing superoxide production (known as oxidative burst activity), migration and adhesion. T...
Kim MJ, Kim T, Oh S, Yoon B.Horseback riding is an effective exercise for improving postural control and balance. To reduce costs and improve accessibility, simulated horseback riding has been developed; but no differential effects of simulated and real horseback riding on muscle activation patterns in older adults have been studied. Thus, we compared muscle activation patterns for older and younger adults engaged in real and simulated horseback riding exercises, using surface electromyography recordings of the erector spinae, rectus abdominis, internal oblique abdominis, and rectus femoris muscles. We recorded muscle ac...
Badin L, Alibran É, Pothier K, Bailly N.Equine-assisted interventions (EAI) can improve a variety of health problems in older adults and thus promote their well-being. This systematic review aimed to synthesize studies on EAI to understand better their effects on the health of older adults. Unassigned: A systematic search guided by the PRISMA 2020 approach was performed on specific databases: Medline (PubMed), EMBASE, PsycINFO, and Cochrane Library. Peer-reviewed articles published in the English language from inception to June 2022 were retrieved. Methodological quality was established using the modified version of the Downs and Bl...
Muirhead TL, McClure JT, Wichtel JJ, Stryhn H, Markham RJ, McFarlane D, Lunn DP.Few studies have investigated immunosenescence in the horse, but it is accepted that the primary and secondary (anamnestic) immune responses may differ between aged and younger horses. The aim of the present study was to determine whether aged horses have a protective immune response post-vaccination. Thirty-four aged healthy horses (> or =20 years) and 29 younger adult horses (4-12 years) of various breeds were vaccinated with commercially produced killed rabies and influenza vaccines. Rabies serum neutralizing antibody titres and equine influenza virus specific antibody subclasses (immunoglo...
Zak A, Siwinska N, Elzinga S, Barker VD, Stefaniak T, Schanbacher BJ, Place NJ, Niedzwiedz A, Adams AA.Age, neurodegenerative disorders, and dysfunction of insulin secretion may be correlated with increased systemic concentrations of acute phase markers. Thus, the study aimed to determine the effect of age, pituitary pars intermedia dysfunction (PPID), and insulin dysregulation (ID) associated with PPID, on markers of the acute phase reaction. Twenty-nine mix-breed horses of both sexes were classified into groups: (1) healthy adult controls, (2) healthy non-PPID geriatric horses, (3) PPID ID+ horses, and (4) PPID ID- horses. Whole blood proinflammatory cytokine gene expression and serum concent...
Boorman S, Stefanovski D, Southwood LL.To determine risk factors, especially age, associated with postoperative reflux (POR; >2 L of reflux present upon intubation), high-volume POR (≥20 L in 24 hours), and short-term outcome after small intestinal (SI) surgery. Methods: Retrospective case-control study. Methods: Horses aged ≥16 years (geriatric; range, 16-30; n = 44) and <16 years (mature; range, 2-15; n = 39) with an SI surgical lesion that survived general anesthesia and did not have a second exploratory celiotomy during the same visit. Methods: Medical records (2009-2015) were reviewed; perioperative var...
Pease AP, Schott HC, Howey EB, Patterson JS.Pituitary pars intermedia dysfunction (PPID) is the most common endocrinologic disorder of aged horses. Objective: Pituitary glands of PPID-affected horses are larger than those of aged horses without signs of PPID, and the size difference can be detected using computed tomography (CT) imaging. Methods: Eight horses with clinical signs of PPID and supportive endocrinologic test results and 3 aged control (PPID-negative) horses. Methods: Computed tomography examination of the brain and pituitary gland was performed twice in 10 of the 11 horses, approximately 6 months apart. Six PPID-affected ho...
Ballou ME, Mueller MK, Dowling-Guyer S.This study evaluated the experience of 1,448 people in the United States who currently care for or had previously cared for a geriatric horse and how that experience was qualified by the presence or absence of a chronic condition in the horse. An anonymous, online questionnaire was distributed to a cross-country sample to investigate the burden of caregivers from the perspective of owners of geriatric horses. Traumatic events and veterinary care decisions were also explored. Findings from the study supported the hypothesis that owners of geriatric horses with a chronic condition experienced hi...
Bollwein A, Hänichen T.The cervical vertebral column of 103 horses of different age (42 weeks old fetus to 23 years) were examined with respect to age-related changes of the intervertebral disks. On gross examination the cervical intervertebral disks in the horse miss a pulpy nucleus but consist of a fibrocartilaginous tissue only, which is in contrast to literature. Age-related degenerative lesions as disintegration of connective tissue fibers leading to partial or complete loss of connection between the disks were found. In the more severe cases a yellow discoloration of the separated disks could be seen. Incidenc...
Wilson WJ, Mills PC, Dzulkarnain AA.To use the brainstem auditory evoked response (BAER) to test the hypothesis that auditory function could be worse in older horses than in younger horses. Methods: BAER waveforms in response to click stimuli were measured in five younger horses (5-8 years) and four older horses (17-22 years). Results: Compared with the younger horses, the older horses showed significantly (P < 0.02) worse BAER thresholds and significantly (P < 0.02) worse BAER wave V amplitudes to the 90 decibels above normal hearing level stimulus. These results were consistent with partial deafness in the older horse gr...
Reed SA, LaVigne EK, Jones AK, Patterson DF, Schauer AL.With improvements in care, the equine population is living longer, remaining active, and competing at increasingly older ages. Both advancing age and exercise result in increased concentrations of circulating and local cytokines, including IL-1β, IL-6, and tumor necrosis factor-α. Athletic endeavors in the aged horse may further increase the proinflammatory environment in muscle, decreasing the ability to react appropriately to exercise. Poor response to exercise limits the athletic ability of geriatric horses, thus reducing their useful life span and potentially increasing the risk of injur...
Mastro LM, Adams AA, Urschel KL.Equine pituitary pars intermedia dysfunction (PPID) has been associated with reduced insulin sensitivity in comparison with younger adult horses; however, the difference in insulin sensitivity between horses with PPID and aged-matched controls has not been well characterized. The objective of the study was to determine if aged horses with PPID had reduced insulin sensitivity and alterations in the insulin-mediated signaling pathways in the skeletal muscle when compared with healthy aged horses. Isoglycemic hyperinsulinemic clamp procedures were conducted in 12 horses that were classified as ei...
