Weight loss in horses refers to a reduction in body weight that can occur due to various factors such as inadequate nutrition, illness, parasitic infections, dental problems, or increased energy expenditure. It is a condition that can affect horses of all ages and breeds and may indicate underlying health issues. Monitoring weight changes is important for maintaining equine health and ensuring optimal performance. This topic includes research on the causes, diagnosis, and management of weight loss in horses. Studies often focus on nutritional assessments, veterinary evaluations, and the development of feeding strategies to address and prevent weight loss. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, implications, and treatment approaches for weight loss in horses.
Carter RA, McCutcheon LJ, Valle E, Meilahn EN, Geor RJ.To determine effects of exercise training without dietary restriction on adiposity, basal hormone and lipid concentrations and glucose and insulin dynamics in overweight or obese, insulin-resistant horses. Methods: 12 overweight or obese (body condition score > or = 7), insulin-resistant (insulin sensitivity < or = 1.2 x 10(-4) L/min/mU) geldings. Methods: 4 horses remained sedentary, and 8 horses were exercised for 4 weeks at low intensity and 4 weeks at higher intensity, followed by 2 weeks of detraining. Prior to and after each training period, frequently sampled IV glucose tolerance ...
Peel AJ, Bouts T, Flach E, Rivers S, Routh A.Pituitary pars intermedia dysfunction (PPID), also known as Equine Cushing's disease, is most often diagnosed in older horses and ponies. To the authors' knowledge, there have been no reports of its diagnosis in captive nondomestic equids. A 13-yr old onager (Equus hemionus onager) at the Zoological Society of London (ZSL) Whipsnade Zoo showed clinical signs suggestive of PPID, including hirsutism, fat redistribution, weight loss, laminitis, and chronic infections. A dexamethasone suppression test was performed to confirm PPID. Subsequently, adenomatous hyperplasia and microadenoma of the pars...
Pusterla N, Gebhart C.Equine proliferative enteropathy (EPE) is a disease of foals caused by the obligate intracellular organism Lawsonia intracellularis. This emerging disease affects mainly weanling foals and causes fever, lethargy, peripheral oedema, diarrhoea, colic and weight loss. The diagnosis of EPE may be challenging and relies on the presence of hypoproteinaemia, thickening of segments of the small intestinal wall observed on abdominal ultrasonography, positive serology and molecular detection of L. intracellularis in faeces. Although the clinical entity, diagnostic work-up and treatment of EPE are well e...
Tinworth KD, Harris PA, Sillence MN, Noble GK.Insulin resistance and hyperinsulinaemia increase the risk of laminitis and horse owners and veterinarians should attempt to enhance insulin sensitivity in at-risk groups. In obese animals this may be achieved, in part, by promoting weight loss and increasing exercise, but such intervention may not be appropriate in non-obese insulin-resistant animals, or where exercise is contra-indicated for clinical reasons. An alternative approach to controlling insulin sensitivity in obese and non-obese horses may be the use of certain herbal compounds that have shown promise in humans and laboratory anim...
Ryhner T, Wittenbrink M, Nitzl D, Zeller S, Gygax D, Wehrli Eser M.In this case report a 10 year old Freiberger mare with a Mycobacterium avium subsp. avium infection is presented. This infection leads to a tuberculosis like disease with granulomatous alterations particularly of the intestines and lungs and is only sporadically reported in horses of Central Europe. Diarrhoea, mastitis and neck stiffness as well as dyspnoea and chronic cough are more specific symptoms of the infection, while weight loss, weakness and lethargy are nonspecific signs. As these clinical signs can occur in many other diseases, the diagnosis of mycobacterial infection is difficult a...
Taylor SD, Haldorson GJ, Vaughan B, Pusterla N.Gastric neoplasia of horses is incompletely described. Objective: Provide history, clinical signs, and clinicopathological and pathological findings associated with gastric neoplasia in horses. Methods: Twenty-four horses with gastric neoplasia. Methods: Retrospective study. History, clinical signs, and clinicopathological and pathologic findings in horses diagnosed histologically with gastric neoplasia were reviewed. Results: Horses ranged in age from 9 to 25 years (median 18 years at presentation). There was no apparent breed or sex predisposition. The most common presenting complaints were ...
Wylie CE, Proudman CJ.Equine grass sickness (EGS) is recognized as a debilitating and predominantly fatal neurodegenerative disease affecting grazing equids. The gastrointestinal tract is the most severely affected body system, resulting in the main clinical signs of colic (acute grass sickness), weight loss, or dysphagia (chronic grass sickness). EGS predominantly occurs within Great Britain, although it is also recognized in regions of mainland Europe, and mainly affects young horses with access to pasture in the springtime. There is strong evidence of an association between EGS and the type C toxins produced by ...
du Toit N, Burden FA, Dixon PM.Dental disease has been shown to be a risk factor for weight loss and colic in horses. No extensive clinical studies in donkeys have investigated the potential relationship between different dental disorders, or between dental disease and systemic disorders. Objective: To determine possible associations between dental disease and body condition score, weight loss, the need for supplemental feeding and prevalence of colic in donkeys of all ages, and to gain a better understanding of the pathogenesis of dental disease by the determination of associations between different dental disorders. Metho...
Jarvis NG.This article reviews current thoughts on nutrition of the older horse in health and disease. Common causes of weight loss and poor body condition in old horses include dental or oral cavity abnormalities, pituitary pars intermedia dysfunction, and reduced feed intake attributable to competition from herd mates or pain associated with osteoarthritis. Feed intake and body condition may improve after institution of management changes. Thin but otherwise healthy old horses can benefit from a diet that provides 12% to 16% crude protein and includes highly digestible feedstuffs. In horses with sever...
Geor RJ, Harris P.Insulin resistance (IR) and hyperinsulinemia increase risk for development of laminitis in horses and ponies. Obesity also has been associated with heightened risk for laminitis, likely by means of development of IR. Dietary factors, particularly the nonstructural carbohydrate (NSC) load, modulate risk for laminitis in these animals by means of exacerbation of IR or gastrointestinal disturbances that trigger the condition. Specific dietary management strategies to lessen risk for laminitis include caloric restriction to promote weight loss and improve insulin sensitivity in obese animals and s...
Hurcombe SD, Fox JG, Kohn CW.A 2-year-old quarterhorse was evaluated for chronic diarrhea and weight loss of 5 weeks duration after numerous diagnostic tests failed to identify an underlying cause. Historically, the horse was housed at pasture where human household waste vehicles were routinely cleaned and the effluent could run onto the field. Physical examination revealed poor body condition and frequent high-volume diarrhea. Diagnostic testing for Salmonella spp., endoparasites, Cryptosporidium spp., Clostridium spp., and diffuse infiltrative bowel disease were negative. Rectal tissue histopathology failed to identify ...
Hughes KJ, McGorum BC, Love S, Dixon PM.Six ponies and four horses with a mean (sd) age of 15.9 (6.0) years developed sudden-onset bilateral laryngeal paralysis (BLP) in association with hepatic dysfunction. Nine of them had been referred for the investigation of respiratory distress, and one pony had been referred for weight loss before BLP developed. Nine of the animals had clinicopathological evidence of liver disease, and nine had histological evidence of liver disease. All of the animals had one or more of the following: hepatic encephalopathy (in eight), hyperammonaemia (in six) and endoscopic evidence of BLP (in nine). Three ...
Ousey JC, Fowden AL, Wilsher S, Allen WR.Chronic and acute alterations in maternal nutrient intake during pregnancy alter pancreatic and hypothalamo-pituitary-adrenal (HPA) axis function in the offspring, before and after birth. Little is known about these effects. Objective: To determine whether maternal nutrient restriction caused by natural infection with Streptococcus equi altered endocrine function in neonatal foals born from mares fed a maintenance or high plane of nutrition throughout pregnancy. Methods: Ten primiparous mares received either a diet to maintain moderate body condition score (Moderate, n = 5) or a near ad libitu...
Saulez MN, Burton A, Steyl JC, Williams JH, Clift SJ.The medical records of four horses whose intestines had been perforated by metallic wires were reviewed. Three of the horses developed acute colic, and the other progressively lost weight and became inappetent and pyrexic. Metallic wires were detected either by exploratory laparotomy or postmortem examination. In three of the horses there were adhesions containing an encapsulated metallic wire in the small intestine, and in the other the wire was contained within an abscess with multiple adhesions involving the liver, spleen and mesentery.
Traversa D.Cyathostomes (Nematoda, Cyathostominae) cause colic, decreased performance and growth, peripheral edema, and dysorexia in equids. Also, the synchronous emergence of cyathostome larvae encysted in the colon and cecal wall causes larval cyathostominosis, which is characterized by protein-depriving enteropathy, chronic diarrhea, edema, weight loss, colitis, and may be fatal. In the past few decades, drug resistance in cyathostomes has become widespread, especially for benzimidazoles. Resistance to tetrahydropyrimidines is still confined to a few areas, and the recent reports of reduced efficacy i...
Germann SE, Richter M, Schwarzwald CC, Wimmershoff J, Spiess BM.A 6-year-old thoroughbred gelding was presented with a history of blepharospasm and opacity in the OS of 1 weeks' duration. Ophthalmic examination findings were consistent with acute uveitis in the OS, and traditional treatment was initiated with systemic antibiotics and anti-inflammatory drugs, topical mydriatics, and corticosteroids. During the total treatment period of 4 weeks response to treatment was weak and the horse developed further problems such as cellulitis of the right hind limb with fever and eventually weight loss and dependent edema. Blood work was indicative of liver disease. ...
Van Weyenberg S, Hesta M, Buyse J, Janssens GP.In nine initially obese ponies, a weekly weight loss according to 1% of their ideal body weight was evaluated for its impact on insulin sensitivity and metabolic profile. Weight loss was obtained solely through energy restriction, initially at 70% of maintenance energy requirements, but to maintain constant weight loss, feed amount had to be decreased to 50% and 35% of maintenance energy requirement during the course of the trial. An oral glucose tolerance test (OGTT) was performed at weeks 0, 10 and 17. Fasted blood samples were taken on weeks 0, 3, 10, 17 for analysis of triglycerides (TG), ...
Sugiyama A, Takeuchi T, Morita T, Matsuu A, Kanda T, Shimada A, Amaya T, Hikasa Y.A 15-year-old, neutered-male pony presented with a history of weight loss during 4 months. Clinical evaluation revealed severe bradycardia and complete atrioventricular block. At necropsy, a lobulated mass in the anterior mediastinum and moderate enlargement of the superficial cervical lymph nodes were observed. The vagus nerve and the brachiocephalic trunk were embedded in this anterior mediastinal tumor. Histologically, the mass was composed of sheets of neoplastic lymphoid cells expressing CD3, with a low mitotic rate. To the best of our knowledge, this is the first reported case of mediast...
Adams AA, Katepalli MP, Kohler K, Reedy SE, Stilz JP, Vick MM, Fitzgerald BP, Lawrence LM, Horohov DW.Advanced age is associated with a low-grade, systemic inflammatory response characterized by increased inflammatory cytokine production both in vitro and in vivo, termed inflamm-aging. It is also known that increased white adipose tissue, associated with obesity, leads to increased production of inflammatory cytokines. To date, it is unknown whether increased adiposity contributes to the age-related increased inflammatory status. Here we show that peripheral blood mononuclear cells (PBMC) from old horses compared to young horses have increased inflammatory cytokine production; moreover, fat ol...
Caulfield MJ, Karageorghis CI.We examined the psychological effects of rapid weight loss among a sample of 41 professional jockeys (mean age 30.9 years, s = 7.0). Participants completed the Brunel Mood Scale (BRUMS) and the Eating Attitudes Test-26 (EAT-26) to establish the relationships between rapid weight loss, mood, and attitudes towards eating. These instruments were administered on three occasions: at the jockeys' minimal weight (achieved through rapid weight loss), their optimal riding weight (when they were not excessively restricting their weight and felt healthy), and their relaxed weight (when there were no fort...
Rivero JL, van Breda E, Rogers CW, Lindner A, van Oldruitenborgh-Oosterbaan MM.When inadequate training stress is applied and recovery time is insufficient, performance reduction and chronic maladaptation occurs. Known as overtraining syndrome (OTS), this complex condition afflicts horses in top training. The name of the syndrome implies causation and it is necessary to differentiate it from over-reaching, a term used in horses that, after suffering a loss of performance without an obvious clinical reason, recover their performance within 1 or 2 weeks. The term OTS should be used for horses in heavy training losing performance without an obvious clinical reason and which...
Frank N, Elliott SB, Boston RC.To determine the effects of long-term oral administration of levothyroxine sodium (L-T(4)) on glucose dynamics in adult euthyroid horses. Methods: 6 healthy adult mares. Methods: Horses received L-T(4) (48 mg/d) orally for 48 weeks. Frequently sampled IV glucose tolerance test procedures were performed on 3 occasions (24-hour intervals) before and at 16, 32, and 48 weeks during the treatment period. Data were assessed via minimal model analysis. The repeatability of measurements was evaluated. Results: During treatment, body weight decreased significantly from the pretreatment value; mean +/- ...
Mitsui I, Jackson LP, Couëtil LL, Lin TL, Ramos-Vara JA.A 13-year-old Quarterhorse mare had a 6-month history of diarrhea, progressive weight loss, and lethargy. At presentation the mare was hirsute, had hyperhidrosis, and abnormal fat distribution in addition to severe diarrhea. A presumptive clinical diagnosis of protein-losing enteropathy and pituitary pars intermedia dysfunction was made. T-cell lymphoma was diagnosed in a rectal biopsy specimen. The owner elected to euthanize the mare because of poor prognosis and the severity of the disease. At necropsy, the mare had hypertrichosis and the pituitary gland was diffusely enlarged. Histologicall...
Feary DJ, Gebhart CJ, Pusterla N.A weanling foal was diagnosed with proliferative enteropathy caused by Lawsonia intracellularis based on history, clinical findings of depression, anorexia, weight loss, colic, diarrhea, and ventral edema, and a combination of serology and fecal PCR. An epidemiological investigation on the premises revealed that many of the other foals and adult horses were seropositive for L. intracellularis, despite being clinically normal, and identified a dog as a potential carrier and source of infection for the foal. The foal was successfully treated with a combination of azithromycin and rifampin.
Zawadzkas XA, Sides RH, Bayly WM.Prerace administration of frusemide to horses has been linked with a significant improvement in racing performance, but the basis for this improvement is unclear. Objective: To test whether improved performance with prerace administration of frusemide is due to the drug's diuresis-induced weight loss rather than its apparent alleviation of exercise-induced pulmonary haemorrhage (EIPH). Methods: Eight thoroughbred horses underwent 3 trials in a random order, 2 or 3 weeks apart: control (C), frusemide/unburdened (FU), and frusemide/burdened (FB). None of the horses were known to have exhibited p...
Gordon ME, McKeever KH, Bokman S, Betros CL, Manso-Filho H, Liburt N, Streltsova J.Horses in training tend to become inappetant; however, the mechanism responsible for this training-induced inappetance is not known. Objective: Training and/or ulcers alter the feed intake (FI) and hormonal and/or biochemical (active ghrelin, leptin, glucose, insulin and cortisol) responses to acute high intensity exercise. Methods: Eight Standardbred mares underwent 3 interval exercise tests (IET) and 3 parallel control tests (CON) before (IET1) and after 8 weeks of training (IET2) and after treatment for gastric ulcers (IET3). Plasma samples were taken before (0 min), during (last 10 sec of ...
Taylor SD, Pusterla N, Vaughan B, Whitcomb MB, Wilson WD.Intestinal neoplasia of horses is inadequately described. Objective: Intestinal neoplasia of horses has characteristic clinicopathologic features. Methods: Thirty-four horses with intestinal neoplasia. Methods: Retrospective study. Results: Anamnesis, clinical signs, clinicopathologic and pathologic findings in 34 adult horses diagnosed histologically with intestinal neoplasia were reviewed. The horses ranged in age from 2 to 30 years (mean 16.6 years at presentation). The Arabian breed was most represented and there was no sex predisposition. The most common presenting complaints were weight ...
Wilsher S, Allen WR.There is a paucity of information on factors that influence placental development in the horse. Objective: Changes in nutrition, particularly around the time of proliferative placental growth, can affect development of the placenta and fetal growth. Objective: To investigate the effects of 2 planes of nutrition and an unforeseen infection-mediated nutritional insult on placental and fetal development in the mare. Methods: Twenty maiden Thoroughbred fillies, age 3 or 4 years, mated to one Thoroughbred stallion, were maintained on either High or Moderate food intake throughout pregnancy. In mid-...
Pusterla N, Pratt SM, Magdesian KG, Carlson GP.This paper describes the clinical, laboratory and histological findings in three horses with immune-mediated polysynovitis; they had lost weight, suffered intermittent fever, were lethargic and stiff, and had effusions in several joints. Laboratory abnormalities included anaemia, leucocytosis, hyperfibrinogenaemia and hyperglobulinaemia. The diagnosis was based on the presence of a suppurative, non-septic inflammation in at least two different joints in each of the horses and the presence of immunoglobulins in the synovial membrane of one of them. The horses were treated with a combination of ...
Steinbach T, Bauer C, Sasse H, Baumgärtner W, Rey-Moreno C, Hermosilla C, Damriyasa IM, Zahner H.The study was undertaken to evaluate adverse effects of larvicidal treatment in horses naturally infected with cyathostomins. Out of 24 ponies kept on pasture, four animals were housed in September and anthelmintically cured to serve as worm-free controls (group C-0). The others were housed in December. Eight animals each were treated 8 weeks later with 5 x 7.5mg/kg fenbendazole (FBZ) or 1 x 0.4 mg/kg moxidectin (MOX). Four animals remained untreated (group C-i). Two, 4, 6 and 14 days after the end of treatment two animals of each of the treated groups were necropsied together with group C-0 a...
Navas De Solís C, Biscoe EW, Lund CM, Labbe K, Muñoz J, Farnsworth K.A 14-year-old Thoroughbred gelding was presented for chronic colic and weight loss. Transcutaneous and transrectal abdominal ultrasonography revealed distended, thickened small intestine with primary thickening of the muscularis and a focally more thickened loop with an echoic structure crossing the wall from the mucosa to the serosa. Visualization of diffuse thickening of the muscularis (muscular hypertrophy of the small intestine) and a focal lesion (pseudodiverticulum) helped clinicians make informed decisions. This case illustrates the importance of transabdominal and transrectal ultrasono...
Aleman MR, Kuesis B, Schott HC, Carlson GP.Renal tubular acidosis (RTA) is characterized by altered renal tubular function resulting in hyperchloremic metabolic acidosis. The purpose of the study was to describe RTA in 16 horses. No breed or sex predilection was found. The mean age at onset of the disease was 7 years of age. The type of diet had no apparent effect on development of RTA. The most common clinical signs were depression, poor performance, weight loss, and anorexia. Initial blood work revealed a marked hyperchloremic metabolic acidosis in all horses and a compensatory respiratory response in most horses. Sixty-three percent...
Ringger NC, Edens L, Bain P, Raskin RE, Larock R.A 5-year-old Thoroughbred mare presented with a 4 week history of weight loss, fever and leukopenia. Rectally, a large active foetus, thickened spleen and an abdominal mass were palpated. Leukopenia, mild anaemia, marked thrombocytopenia and hyperfibrinogenaemia were found. Cytology and cytochemical staining of a bone marrow aspirate supported a diagnosis of acute myelogenous leukaemia. The mare deteriorated despite medical therapy and was humanely euthanased.
Markel MD, Dorr TE.Multiple myeloma was diagnosed in a 22-year-old Arabian mare with a history of chronic weight loss. Quantitative immunoglobulin analysis revealed monoclonal gammopathy (IgG(T), 9,800 mg/dl). Due to progressive weight loss, the horse was euthanatized. Microscopy of tissues revealed plasma cell infiltrates in bone marrow, spleen, pituitary gland, adrenal cortex, muscle of the tongue, and bronchial, renal, and mesenteric lymph nodes.
Pellegrini-Masini A, Dolente BA, Habecker PL, Jesty SA.A 5-year-old Quarter Horse mare was referred for evaluation of oral ulcers, limb edema, weight loss, and weakness. There was marked diffuse swelling extending from the stifle region to the tarsal region of the left hind limb, and the horse had a left hind limb lameness. Firm swellings ranging from 2 to 15 cm in diameter and consisting of nodules, plaques, and discrete masses were palpated on both sides of the neck, over the right shoulder region, over the left elbow region, and over the left caudoventral aspect of the abdomen. Laboratory abnormalities included hypoproteinemia, neutrophilia, an...
Rumpler B, Riha A, Licka T, Kotschwar A, Peham C.Weight boots are commonly used for Icelandic horses to increase the height of the flight arc of the forelimbs in toelt. Objective: To show the influence of weights and toelting speed on the height of the swing phase. Methods: Eight Icelandic horses (mean ± s.d. 12 ± 3 years old, 369 ± 46 kg) were used. Reflecting makers were placed on the dorsal side of each hoof. The motion was collected with a kinematic system (10 cameras, 120 Hz sample rate, 1.3 Mpixels resolution). The horses were ridden in toelt by 2 experienced riders on a treadmill at 2 different speeds (2.96 m/s ± 0.30 and 4.10 m/s...
Greco-Otto P, Massie S, Shields E, Roy MF, Pajor E, Léguillette R.The Heavy Horse Pull is a competition where teams of two horses pull an increasingly heavy sled for a short distance. Similar to human wrestlers, some horses may undergo rapid weight change in order to enter a lower weight category. The objectives were to study the physiological effects of this practice as well as of the pulling competition in draft horses. Results: Fifty horses were divided into light-, middle- and heavyweight categories based on their arrival weights and competed 1-3 days after. Body weight was measured upon arrival and pre-competition. Blood was sampled for chemistry and h...
Medina-Torres CE, Underwood C, Pollitt CC, Castro-Olivera EM, Hodson MP, Richardson DW, van Eps AW.Lamellar perfusion is thought to be affected by weightbearing and limb load cycling; this may be critical in the development of supporting limb laminitis. Objective: To document the effects of unilateral weightbearing and altered limb load cycling on lamellar energy metabolism and perfusion. Methods: Randomised, controlled (within subject), experimental trial. Methods: Nine Standardbred horses were instrumented with microdialysis probes in the foot lamellar tissue and skin (over the tail base). Urea (20 mmol/l) was added to the perfusate. Samples were collected every 15 min for a 1 h con...
Villagrán CC, Vogt D, Gupta A, Fernández EA.A 3-year-old Quarter Horse gelding was evaluated for chronic weight loss, diarrhea, and pruritus. Physical examination revealed several ulcerative lesions on the skin and mucosal membranes. Diagnostic imaging findings were consistent with enteritis, typhlitis, and colitis. Multisystemic eosinophilic epitheliotropic disease (MEED) was diagnosed upon necropsy. This disease may be considered a form of equine inflammatory bowel disease complex which can be challenging to diagnose, requiring histological assessment, and in some cases, the use of immunohistochemical markers. Key clinical message: Mu...
Herraez P, Berridge B, Marsh P, Weeks B, Ramiro-Ibañez F.A 12-year-old Appaloosa gelding was referred to the Texas Veterinary Medical Center with a history of chronic diarrhea and weight loss. At necropsy, numerous oval, craterlike ulcers were observed throughout the small intestine. Histologically, these lesions were composed of a neoplastic proliferation of round cells with intracytoplasmic phosphotungstic acid-hematoxylin-positive granules. The tumor cells stained positively for the CD3 antigen and negatively for a B-cell marker. A diagnosis of large granular lymphoma was based on the morphologic and immunohistochemical characteristics of the neo...
Henderson B, Diaz M, Martins C, Kenney D, Baird JD, Arroyo LG.Medical records of 20 horses with a confirmed diagnosis of valvular endocarditis at the Ontario Veterinary College between January 1, 1993 and February 3, 2020 were reviewed. The diagnosis was based on physical examination findings, complete blood (cell) count (CBC), serum biochemistry, echocardiography, blood culture, and post-mortem findings. Common presenting signs included tachycardia, pyrexia, weight loss, lameness/joint distension, and a heart murmur. Clinicopathological findings included leukocytosis, anemia, hypoalbuminemia, hyperglobulinemia, and elevated inflammatory markers. Culture...
Sugiyama A, Takeuchi T, Morita T, Matsuu A, Kanda T, Shimada A, Amaya T, Hikasa Y.A 15-year-old, neutered-male pony presented with a history of weight loss during 4 months. Clinical evaluation revealed severe bradycardia and complete atrioventricular block. At necropsy, a lobulated mass in the anterior mediastinum and moderate enlargement of the superficial cervical lymph nodes were observed. The vagus nerve and the brachiocephalic trunk were embedded in this anterior mediastinal tumor. Histologically, the mass was composed of sheets of neoplastic lymphoid cells expressing CD3, with a low mitotic rate. To the best of our knowledge, this is the first reported case of mediast...
Saied AA, Bryan LK, Bolin DC. infection in horses is common and is characterized by pyogranulomatous pneumonia and ulcerative enterocolitis. clinical disease in cattle, however, is rare and typically manifests as granulomatous lymphadenitis discovered in the abattoir. A 19-mo-old female Santa Gertrudis had a history of intermittent inappetence and weight loss for a 3-mo period before euthanasia. Gross and histologic examination revealed severe, chronic, ulcerative, and granulomatous inflammation in the tongue, pharynx, and small intestine. Also, the heifer had severe, granulomatous pharyngeal and mesenteric lymphadenitis...
Bayly WM, Slocombe RF, Schott HC, Hodgson DR.To determine whether i.v. administration of furosemide (250 mg) to horses before maximal exercise affected maximal oxygen consumption (VO2max), breathing mechanics, or gas exchange during exercise. Methods: 7 healthy, well-conditioned Thoroughbred horses. Methods: 5 horses initially performed an incremental treadmill exercise test to determine VO2max 4 hours after i.v. administration of furosemide (250 mg i.v.) or placebo (saline [0.9% NaCl] solution). Time to fatigue and distance run were recorded. All 7 horses were then used to determine the effects of furosemide on gas exchange and breathin...
Feary DJ, Gebhart CJ, Pusterla N.A weanling foal was diagnosed with proliferative enteropathy caused by Lawsonia intracellularis based on history, clinical findings of depression, anorexia, weight loss, colic, diarrhea, and ventral edema, and a combination of serology and fecal PCR. An epidemiological investigation on the premises revealed that many of the other foals and adult horses were seropositive for L. intracellularis, despite being clinically normal, and identified a dog as a potential carrier and source of infection for the foal. The foal was successfully treated with a combination of azithromycin and rifampin.
Begg LM, Hughes KJ, Kessell A, Krockenberger MB, Wigney DI, Malik R.A 20-year-old Welsh Mountain Pony (212 kg) mare was initially presented for a chronic cough, fever, weight loss and low grade abdominal pain. She later developed dyspnoea, tachypnoea and exercise intolerance. The presence of multiple masses (up to 17 cm diameter) in the pulmonary parenchyma was established using lateral thoracic radiography and transthoracic ultrasonography. Encapsulated, budding yeasts were observed in smears made from transtracheal washings and needle aspirates of the pulmonary lesions. Cryptococcus gattii (synonym: Cryptococcus neoformans variety gattii; Cryptococcus bacill...
Travers CW, van den Berg JS.This paper describes the case histories of two Thoroughbred horses, a 2-year-old colt in training and a 7-year-old broodmare, that were presented with histories of weight loss, exercise intolerance, intermittent fever, limb oedema and anaemia. Vegetative endocarditis of the mitral and tricuspid valves was diagnosed in the colt by means of echocardiography. Pseudomonas sp. endocarditis of the mitral valve was diagnosed in the mare using echocardiography and bacterial culture. The colt had secondary congestive heart failure and was euthanased on humane grounds. Pseudomonas cepacia was isolated f...
van den Wollenberg L, Butler CM, Houwers DJ, de Grootv MW, Panhuijzen H, van Maanen C, van Oldruitenborgh-Oosterbaan MM.Equine proliferative enteropathy (EPE) is an emerging infectious enteric disease caused by the obligate intracellular gram-negative bacterium Lawsonia intracellularis. EPE was tentatively diagnosed in six weanling foals, aged between 5 and 7 months. Clinical signs included depression, anorexia, ventral oedema, and weight loss. Plasma biochemistry consistently revealed severe hypoproteinaemia. The ante-mortem diagnosis of EPE was based on clinical signs, hypoproteinaemia (6/6), the detection of moderate-to-high titres of L. intracellularis antibody (6/6), and severe thickening of the small inte...
Nolen-Walston RD, Norton JL, Navas de Solis C, Underwood C, Boston R, Slack J, Dallap BL.Central venous pressure (CVP) is used in many species to monitor right-sided intravascular volume status, especially in critical care medicine. Objective: That hypohydration in adult horses is associated with a proportional reduction in CVP. Methods: Ten healthy adult horses from the university teaching herd. Methods: In this experimental study, horses underwent central venous catheter placement and CVP readings were obtained by water manometry. The horses were then deprived of water and administered furosemide (1 mg/kg IV q6h) for up to 36 hours. Weight, CVP, vital signs, PCV, total protein (...
Golland LC, Hodgson DR, Hodgson JL, Brownlow MA, Hutchins DR, Rawlinson RJ, Collins MB, McClintock SA, Raisis AL.Peritonitis attributable to Actinobacillus equuli was diagnosed in 15 horses examined at the veterinary center between 1982 and 1992. In 13 horses, historical findings included acute onset of mild to severe signs of abdominal pain, lethargy, and inappetence. Two other horses had a history of weight loss for 3 to 6 weeks prior to examination. Diagnosis was based on the physical signs and laboratory findings, including results of peritoneal fluid analysis (gross characteristics, total protein, total and differential nucleated cell counts, and morphologic findings) and culture of A equuli. Actino...
Jarvis N, McKenzie HC.Weight loss occurs when the supply of energy is insufficient to meet the energy needs of an individual. The energy supply may be reduced by inadequate provision of feed, inadequate consumption, reduced digestion and absorption, or disruption in metabolic processing. Increased energy expenditure occurs with exercise and during cold temperatures, pregnancy, and lactation. Underlying clinical disease, particularly chronic inflammation, neoplasia, and protein-losing conditions, can cause weight loss or exacerbate existing weight loss. A methodical approach to weight-loss investigation and treatmen...
Naylor JM, Nickel DD, Trimino G, Card C, Lightfoot K, Adams G.Historical, clinical and experimental data were collected from 9 horses homozygous for HYPP (H/H). All showed episodes of respiratory stertor, described as a rattling or honking sound, usually within the first week post partum. Five horses had one or more episodes of dysphagia, in 3 horses this was accompanied by drooling and in 3 by weight loss. In comparison, only one of 35 contemporaneous half siblings (of which approximately half would be expected to be of the H/N genotype and half N/N) was observed to have respiratory stertor prior to weaning and none had problems with dysphagia. One matu...
Wilson G, Lucas D, Hambly C, Speakman JR, Morton JP, Close GL.To formulate individualized dietary strategies for jockeys, it is vital that energy requirements are quantified. We measured total energy expenditure (TEE) over two separate weeks in spring and summer using doubly labelled water in a group of male flat jockeys (n = 8, 36.9 ± 5.7 years, 164 ± 8 cm, 54.6 ± 2.5 kg). Total energy intake (TEI) was self-recorded, as were all riding and structured exercise activity. Mean daily TEE was 10.83 (±2.3) and 10.66 (±1.76) MJ, (p = .61) respectively. Self-reported TEI were 6.03 (±1.7) and 5.37 (±1.1) MJ (p = .40), respectiv...
Staniar WB, Kronfeld DS, Hoffman RM, Wilson JA, Harris PA.Monitoring weight of foals is a useful management practice to aid in maximising athletic potential while minimising risks associated with deviations from normal growth. Objective: To develop predictive equations for weight, based on linear measurements of growing Thoroughbreds (TBs). Methods: Morphometric equations predicting weight from measurements of the trunk and legs were developed from data of 153 foals. The accuracy, precision and bias of the best fitting equation were compared to published equations using a naive data set of 22 foals. Results: Accuracy and precision were maximised with...
Edens LM, Taylor DD, Murray MJ, Spurlock GH, Anver MR.A large fibrotic mass originating from the cecal base was discovered upon surgical exploration of the abdomen in a Thoroughbred mare with a history of chronic colic and weight loss. The mass protruded intraluminally resulting in partial obstruction. Surgical excision was not feasible due to the location of the mass and the inability to exteriorize it adequately from the abdominal cavity. The mass was fibrous with a shiny, gelatinous material present throughout the neoplasm. Histologically, large confluent spaces filled with mucopolysaccharides were identified by staining with Alcian blue. The ...
Gross DK, Hinchcliff KW, French PS, Goclan SA, Lahmers KK, Lauderdale M, Ellis JA, Haines DM, Slemons RD, Morley PS.The purpose of this experiment was to determine if exercising horses, infected with influenza virus, exacerbates the severity of clinical disease. Eight horses were trained on a treadmill for 42 days and then challenged with aerosolised influenza A/equine/Kentucky/91 (H3N8). Following challenge, 4 horses (exercise group) continued training for 28 days, while the other 4 horses (nonexercise group) were confined to their stalls. All horses developed clinical signs within 36 h of challenge (fever, coughing, and mucopurulent nasal discharge) and clinical scores were greater in the exercise group. ...
Jago RC, Handel I, Hahn CN, Pirie RS, Keen JA, Waggett BE, McGorum BC.Objective criteria for predicting survival of chronic grass sickness cases are currently lacking. Objective: To determine whether the rate and/or magnitude of bodyweight change during hospitalisation of chronic grass sickness cases can provide an objective predictor of survival to discharge from hospital. Clinicians' recorded indication(s) for euthanasia were also reviewed. Methods: Single centre retrospective observational study. Methods: Case records of all horses admitted for management of chronic grass sickness to The Dick Vet Equine Hospital between 1998 and 2013 were analysed. Case backg...
van Eps AW, Belknap JK, Schneider X, Stefanovski D, Engiles JB, Richardson DW, Zedler ST, Medina-Torres CE, Watts MR.Supporting limb laminitis (SLL) is suspected to be caused by lamellar ischaemia as a consequence of increased mechanical load. Objective: Examine the effects of prolonged preferential weight bearing (PWB) on lamellar perfusion and metabolism. Methods: In vivo experiment. Methods: Microdialysis probes were inserted in the lamellar and sublamellar dermis of one forelimb in 13 Standardbred horses. In six horses, a platform shoe (contralateral forelimb) was used to induce increased load on the microdialysis-instrumented forelimb (PWB). The remaining seven horses were controls (CON). All horses wer...
Lennox TJ, Wilson JH, Hayden DW, Bouljihad M, Sage AM, Walser MM, Manivel JC.A 2.5-year-old female Thoroughbred was examined because of lethargy, anorexia, and weight loss. Analysis of a CBC revealed erythrocytosis and an increase in PCV. Serum biochemical analysis revealed increases in activities of several hepatic enzymes. Ultrasonography revealed hepatomegaly and a heterogeneous appearance of the hepatic parenchyma. The horse did not improve despite supportive care, and it was euthanatized. Necropsy revealed numerous raised white to gray foci in the liver. Histologically, these foci consisted of neoplastic cells that resembled fetal hepatocytes, embryonal-type cells...
Dascanio JJ, Zhang CH, Antczak DF, Blue JT, Simmons TR.Chronic lymphocytic leukemia (CLL) was diagnosed in two horses: an 18-year-old Quarter Horse gelding that was examined because of edema of the prepuce and ventral abdomen; and a 20-year-old mixed breed gelding that was referred because of lymphocytosis, ventral edema, and weight loss. The first horse had enlarged peripheral lymph nodes and cool nonpainful pitting edema of the ventral abdomen and prepuce. The second horse had enlarged peripheral lymph nodes, cool nonpainful pitting edema of the ventral thorax and cranial ventral abdomen, and a 3/5 holosystolic heart murmur. The diagnosis of CLL...
