Lung health in horses encompasses the study of respiratory system function, disease, and maintenance in equine species. The equine respiratory system is vital for oxygen exchange and plays a significant role in overall health and athletic performance. Conditions affecting lung health include inflammatory airway disease (IAD), recurrent airway obstruction (RAO), and exercise-induced pulmonary hemorrhage (EIPH). These conditions can impact a horse's respiratory efficiency and performance capabilities. Research in this area often focuses on understanding the pathophysiology, diagnosis, and management of respiratory diseases, as well as the impact of environmental factors on lung function. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, diagnostic approaches, and therapeutic strategies related to lung health in horses.
Derksen FJ, Robinson NE, Slocombe RF.In awake sensitized ponies, we studied the effect of aerosol ovalbumin challenge on ventilation, pulmonary mechanics, lung volume, and gas exchange before and after vagal blockade. We also challenged the left lung and measured respiratory rate (f) and right and left respiratory system resistance (RrsR, RrsL) before and after both left and bilateral vagal section. Bilateral ovalbumin aerosol challenge increased f, minute ventilation (VE), total respiratory system resistance (Rrs), and minimal volume, decreased dynamic compliance, total lung capacity, and arterial oxygen tension, and was without...
O'Callaghan MW, Goulden BE.This paper describes the distinctive radiographic changes detected in the dorso-caudal lungfields of four racing thoroughbreds recently affected by exercise-induced epistaxis. A diffuse but localized increase in density was seen in all four cases, which demonstrated a variation from a predominantly alveolar density to an interstitial pattern and finally to increased bronchial markings. Evolution of the radiographic pattern of the pulmonary densities appeared to be related to the time that had elapsed since the bleeding incident. The implications of the changing pattern and site of the densitie...
Martens RJ, Fiske RA, Renshaw HW.Subacute pyogranulomatous pneumonia was experimentally induced in 3 neonatal foals following multiple challenge with aerosols containing Corynebacterium equi. On each of 7 consecutive days the foals were exposed to approximately 3.5 X 10(7) viable C equi in droplets small enough to reach the terminal airways. Clinical, pathological and bacteriological features of the induced syndrome were indistinguishable from those exhibited by cases with spontaneous subacute C equi foal pneumonia. Radiographic evidence of advanced pulmonary damage preceded the appearance of clinical signs and ante mortem cu...
McChesney SL, England JJ, McChesney AE.An agent lethal to embryonated chicken eggs was isolated from lung tissues of a quarter horse mare with a fatal respiratory disease. The lesions induced in embryonated chicken eggs, the tinctoral properties, the ultrastructural morphology, the resistance of the organism to sodium sulfadiazine, and the presence of a chlamydial complement fixing antigen, identify this isolate as a member of the family Chlamydiaceae and suggest the agent to be Chlamydia psittaci. Two Shetland ponies experimentally infected with the isolated agent developed subclinical infection as demonstrated by an increase in c...
Barnard K, Leadon DP, Silver IA.Collagen, elastin and structural glycoprotein content of the lungs of 38 fetal and neonatal foals, 8 of which were showing dysmaturity or convulsive syndrome, were measured by standard biochemical means. Glycoprotein content showed little or no change between 100 and 340 days of gestation; elastin remained constant from 100 to about 260 days when there was an exponential increase up to the time of birth, while collagen content rose linearly from 100 days to birth. In dysmature animals there was significantly less collagen in the lungs at birth but the difference in elastin content between the ...
Ford EJ, Adam SE.In the horse, 5'-nucleotidase (5'-NT) activity is found mainly in homogenates of lung, kidney, small intestine, mammary gland, liver and pancreas. Lower activities are present in brain and muscle. Activity can be demonstrated histochemically in the glomeruli and tubules of the kidney, in the sinusoidal borders of the hepatocytes and the bile duct epithelium as well as in the blood vessels of all organs. There is no significant difference between the 5'-NT activity in serum and plasma of normal horses and of horses suffering from a range of orthopaedic conditions. Previous findings that gamma g...
Raphel CF, Gunson DE.Percutaneous lung biopsies with a cutting needle (Vim Tru Cut) were obtained from 20 horses. The procedure was performed in standing horses under a local anesthesia without sedation. All lung tissue specimens were suitable for histologic examinations and contained both pulmonary parenchyma and large airways. The only complication was hemoptysis in 2 (10%) horses which required no therapy. All horses were subsequently killed, and no gross abnormalities were present at the biopsy site.
Malan FS, Reinecke RK, Scialdo RC.The entire gastro-intestinal tract and viscera of the abdomen and thorax, including the heart, aorta and its branches to the viscera, are removed from the carcass. All the branches of the aorta, with the exception of the A. gastrica sinistra, are dissected from the intestinal tract, and subsequently each branch is isolated from the mesentery, fat, pancreas, kidneys, etc. Usually, the A. ileocolica is grossly enlarged due to chronic arteritis with thrombus formation caused by 4th stage larvae, 4th moult and 5th stage Strongylus vulgaris. Descriptions of methods to examine the subperitoneal tiss...
Clayton HM, Trawford AF.A field study was designed to investigate the re-establishment of patent lungworm infections in donkeys following an anthelmintic treatment regime which was effective against Dictyocaulus arnfieldi. In April 1979 faecal samples from 259 donkeys were examined and each animal classified as a negative, low positive or high positive excretor of lungworm larvae. During the summer the control group of 126 donkeys showed an increase in the number of excretors from 80 per cent in April to 91 per cent in October. At the same time there was a rise in the faecal larval output of individual animals so tha...
Webb AI, Weaver BM.The solubilities of halothane at a concentration of 0.77% v/v in 5% carbon dioxide in air at 37 degrees C were determined for a variety of equine tissues. The mean values for the tissue/gas partition coefficients for visceral tissue taken from 36 horses were 5.42 for whole brain, 4.82 for grey matter, 7.41 for white matter, 4.18 for myocardium, 2.76 for lung, 8.51 for liver, 3.21 for kidneys, 2.66 for gastrointestinal tract, 1.77 for blood and 2.45 for spleen. The mean coefficients for eight different muscles taken from 23 horses ranged from 2.43 for extensor carpi radialis to 4.91 for psoas m...
Pascoe JR, Ferraro GL, Cannon JH, Arthur RM, Wheat JD.Of 235 Thoroughbred racehorses examined with a flexible fiberoptic endoscope within 2 hours of racing to determine the frequency of exercise-induced pulmonary hemorrhage (EIPH), 103 (43.8%) had various degrees of hemorrhage in the tracheal lumen. Two of these horses (0.8%) subsequently had blood flow from the nostrils. Blood seemed to originate from the lung. Statistical analysis of frequency data for 191 horses which finished in 1st, 2nd, and 3rd places did not show any relationship between EIPH and horse's age, sex, or finishing position. However, a trend toward an increased frequency of EIP...
Simpson CF, Buergelt CD.The alveoli of the lungs of 2 aborted foals contained elongated, dense bodies when examined histologically and by transmission and scanning electron microscopy. By light microscopy, the bodies (10 to 40 micrometers in size) stained intensely with the Gram stain, and up to 10 were present within an alveolus. Electron microscopy determined that such bodies were not cellular in origin but appeared to be a congealed fluid product composed of layers of fibrillar-like material. From the human literature, it was concluded that these intraalveolar bodies were probably congealed amniotic fluid.
Staddon GE, Weaver BM.The regional perfusion to the lungs of 14 ponies was studied using radioactively labelled microspheres injected intravenously. It was found that within half an hour of induction of anaesthesia the perfusion to the dependent lung had decreased significantly from the values in the standing animal. When anaesthesia was maintained for more than two and a half hours, however, the lung perfusions were not significantly different from the standing values when the animals were lying in lateral or supine recumbency.
Derksen FJ, Robinson NE.Pleural and esophageal pressures were compared in 6 standing sedated ponies. Pleural pressure was measured with blunt needles attached to transducers and inserted in the 10th intercostal space level with and 10 and 20 cm above the point of the shoulder. Two balloons (a condom and an esophageal balloon) attached to transducers measured esophageal pressure in the cranial, middle, and caudal portions of the thoracic part of the esophagus. Tidal volume was measured by integrating a flow signal derived from a pneumotachograph attached to an endotracheal tube inserted through a tracheostomy. Frequen...
Pandey VS.The lungs and livers of 429 adult donkeys from different parts of Morocco were examined for hydatid cysts; 4·2% of lungs were infected and 2·1% of livers. Most of the cysts were small and had very hard thick walls; 61% of the donkeys had only one hydatid cyst; 78·5% of them were sterile and 29% caseated or calcified.
Littlejohn A.Twenty cases of chronic cough originating in the lung and associated with loss of performance were clinically examined. The physical signs observed were compared with those observed in a control series of 38 clinically normal horses. Reduced work tolerance, coughing for more than 3 months and abnormal pulmonary sounds (râles) were primary signs of chronic obstructive pulmonary disease (COPD). Forced abdominal expiratory efforts and pumping of the anus were regarded as confirmatory signs. Neither nasal discharge nor increased marginal distance was found to be a reliable sign of COPD. The mean ...
Gehr P, Erni H.The lungs of two half-bred geldings were fixed in situ by instillation of a glutaraldehyde solution into the airways during deep anaesthesia. The body weight of both animals was 510 kg and their average lung volume about 38 l. Stratified random samples from 22 regions were morphometrically analysed from electron microscopic films. Eighty-six per cent of the total lung volume was gas exchange parenchyma. It contained 26.9 l air space and 5.6 l interalveolar septa which were composed of equal parts of capillaries and tissue. The average alveolar and capillary surface areas were 2457 m2 and 1663 ...
Nickels FA, Brown CM, Breeze RG.A unilateral pulmonary granular cell tumor occurred in a Thoroughbred mare with longstanding respiratory disease wrongly attributed to chronic obstructive pulmonary disease. The clinical features, radiology and endoscopic appearance permitted an accurate diagnosis, which was supported by subsequent necropsy and histologic examination. Obstructive pulmonary disease was ruled out after measurement of arterial blood gases and maximum intrathoracic pressure changes, and after microscopic examination of the lung.
Plopper CG, Mariassy AT, Hill LH.Two morphologic characteristics have been used to define the nonciliated bronchiolar epithelial cell: abundant agranular endoplasmic reticulum (AER) and membrane-bound avoid granules. To assess the ultrastructural homogeneity of this cell type in the lungs of large domestic mammals used as experimental models in pulmonary research, we evaluated lungs of horse, steer, sheep, dog, and cat. Bronchioles of known anatomic location were examined by electron microscopy following fixation by airway infusion at standard pressure and processing by selective embedding techniques. Nonciliated bronchiolar ...
Urch DL, Allen WR.The efficacy of orally administered fenbendazole on lung and intestinal parasitism in equids was investigated in a mixed herd of pony mares, jenny donkeys and foals. A single dose of 7.5 mg fenbendazole/kg body weight effectively removed intestinal parasites from the ponies, donkeys and foals, but higher doses and repeated treatments failed to eliminate lungworm infections in donkeys. The finding of eosinophilia proved useful in detecting lungworm infections in donkeys.
Sorenson PR, Robinson NE.Quasi-static pressure-volume curves and single-breath nitrogen washouts were performed simultaneously on eight anesthetized horses (average body wt = 485 kg) in left lateral, right lateral, prone, and supine postures (sequence randomized). The shift from prone to lateral or supine posture decreased expiratory reserve volume (ERV), vital capacity (VC), residual volume (RV), functional residual capacity (FRC), and total lung capacity (TLC); RV and FRC expressed as %TLC were unchanged, suggesting that in the lateral and supine postures a significant portion of the lung volume was not recruited by...
Sonea IM, Bowker RM, Robinson NE, Holland RE.The lungs of neonatal foals contain many nerves immunoreactive for substance P and calcitonin gene-related peptide. These nerves are closely associated with the epithelium, bronchial and pulmonary vessels and the airway smooth muscle of all intrathoracic airways, including non-cartilaginous bronchioles. Activation of sensory nerves in the respiratory epithelium could thus potentially affect, via local axon reflexes, vascular and respiratory smooth muscle in neonatal equine airways. Nerves immunoreactive for these peptides are much more widely distributed within the lung than in adult horses; t...
Sonea IM, Bowker RM, Robinson NE.Autoradiography with [125I]-Bolton Hunter substance P ([I]-BHSP) was used to detect substance P binding sites in the equine lung. Specific [I]-BHSP binding sites were very dense over small bronchial vessels, tracheobronchial glands and airway epithelium in large and small airways. The density of [I]-BHSP binding sites over airway smooth muscle was much lower than in the preceding tissues. Competition with an excess of either a specific neurokinin 1 receptor agonist, or a specific neurokinin 2 receptor agonist indicated that most specific [I]-BHSP binding sites in the equine lung represent neur...
Aguilera-Tejero E, Pascoe JR, Smith BL, Tyler WS, Woliner MJ.The diffusing capacity for carbon monoxide (DLCO) and the functional residual capacity (FRC) of the lung were measured in 5 healthy Thoroughbreds before and after instillation of autologous blood into their lungs, in an attempt to develop a method to quantitate extravascular blood in the lungs of horses with exercise-induced pulmonary hemorrhage. Mean (+/- SD) baseline values of DLCO and FRC were 333.8 +/- 61.9 ml/min/mm of Hg and 21.464 +/- 4.156 L, respectively. Blood instillation resulted in decreases in DLCO and FRC. The paradoxic decrease in DLCO (we were expecting to find an increase owi...
Kelley LC, Hill JE, Hafner S, Wortham KJ.Spontaneous equine pulmonary granular cell tumors were diagnosed in six mature horses at slaughter. These tumors were grossly recognized as multiple (5/6) or single (1/6) creamy white, firm nodules. The tumors, located adjacent to bronchi and bronchioles, often invaded airways, resulting in partial to complete occlusion of the lumina. Neoplastic cells were rounded to polyhedral with numerous eosinophilic cytoplasmic granules that reacted uniformly positive with S-100 and neuron-specific enolase antibodies and multifocally with glial fibrillary acidic protein antibodies. These cells were negati...
Blunden AS, Gower SM.Lungs were obtained from 16 Thoroughbred horses, aged 1 day to 2 years, which had died or been humanely killed for reasons unrelated to disease of the lower respiratory tract. The lungs were then subjected to a histological and immunohistochemical examination of the humoral immune system. At birth there was no evidence of organized lymphoid tissue, and lymphocytes and plasma cells were virtually absent in all tissue compartments in the first week of life. However, by 12 weeks, foals exhibited well developed bronchus- and bronchiole-associated lymphoid tissue, but this had regressed progressive...
Johns I, McParland T, Mair T.Pleural effusion (PE) is reported to occur most commonly secondary to bacterial pneumonia or lung abscesses, with neoplastic effusions contributing the minority of cases. The majority of these reports originate from America and Australia, where long distance transport of horses, a recognised risk factor, appears to occur more frequently. Anecdotally, neoplastic PE is more commonly diagnosed in the UK. Objective: To describe the causes of PE in horses resident in the UK, and to identify potential markers that can help differentiate between infectious and neoplastic causes of PE. Methods: Retros...
Katayama Y, Kuwano A, Yoshihara T.A 4-year-old female thoroughbred race horse died of acute peritonitis caused by necrotizing granulomatous duodenitis. Yersinia enterocolitica was immunohistochemically demonstrated in macrophages in granulomas developed in the duodenum, lung, liver and abdominal lymph nodes. The yeast-like fungi were found in the cytoplasmic vacuoles of macrophages in the lung that infiltrated into the granulomas and surrounding alveoli with congestive edema. The yeast-like fungi were positively stained by Gomori-Grocott chromic acid methenamine silver stain and immuno-histochemically stained with anti-histopl...
Malek G, Leclere M, Masseau I, Zur Linden A, Beauchamp G, Finck C.Published studies describing the effects of bilateral radiographic projections on the detection of equine pulmonary lesions are currently lacking. The objectives of this retrospective, single center, observational study were to compare unilateral and bilateral thoracic radiographic projections for the detection of pulmonary lesions in a group of horses. Based on their clinical diagnosis, 167 adults and foals with bilateral thoracic radiographs were classified as having pneumonia (n = 88), inflammatory or diffuse pulmonary disease (n = 72), and pulmonary masses (n = 7). After an initial i...
Le NPK, Gerdts V, Singh B.Integrin alpha-v/beta3 (αvβ3) recognizes arginine-glycine-aspartic acid (RGD) sequences and has important functions in cell adhesion, signaling, and survival. However, the expression of integrin αvβ3 in the equine lungs and jejunum is not well understood. The objective of this study was to explore the hitherto unknown expression of integrin αvβ3 in the lungs and jejuna of the horse using light and electron immunocytochemistry. Immunohistochemistry showed integrin αvβ3 on the epithelium, the immune cells in Peyer's patches, the smooth muscle, and the endothelium of equine jejuna. In equ...
Webb AI, Weaver BM.The solubilities of halothane at a concentration of 0.77% v/v in 5% carbon dioxide in air at 37 degrees C were determined for a variety of equine tissues. The mean values for the tissue/gas partition coefficients for visceral tissue taken from 36 horses were 5.42 for whole brain, 4.82 for grey matter, 7.41 for white matter, 4.18 for myocardium, 2.76 for lung, 8.51 for liver, 3.21 for kidneys, 2.66 for gastrointestinal tract, 1.77 for blood and 2.45 for spleen. The mean coefficients for eight different muscles taken from 23 horses ranged from 2.43 for extensor carpi radialis to 4.91 for psoas m...
Breuer D.In spite of regular vaccinations against equine influenza we are still observing a high rate of patients with respiratory problems in the equine practice. In our practice in Munich Riem, into which a horse clinic has been integrated, 4000 horses have been treated in 1985 alone. 874 of these showed some form of respiratory disease (= 22%). All of the 4000 horses have only been treated curatively, i.e. preventive forms of treatment such as vaccinations, deworming and examinations for insurance companies and prior to selling have not been taken into account. From 1983 until today in our clinic 25...
Laan TT, van Nieuwstadt RA, Sloet van Oldruitenborgh-Oosterbaan MM, Breukink HJ.Equine pulmonary disease and especially the terminology of lower airway disease have been subject to discussion. Besides established terms such as 'Chronic Obstructive Pulmonary Disease' (COPD) and Chronic bronchitis, the term 'small airway disease' (SAD) has been introduced, for respiratory disease with inflammation in the lower airways in combination with exercise intolerance. Bronchoalveolar lavage (BAL) enables the practitioner to diagnose SAD in an early stage when there are no other signs such as coughing or exudate in the trachea. The BAL fluid is microscopically examined after centrifu...
Gehlen H, Haubold A, Rohn K, Stadler P.In the present study we examined, if in Icelandic horses an increase in heart and/ or breathing rate is physiological and breed dependend or a sign of a pulmonary or cardiac disease. Therefore we examined 37 Icelandic horses with the prereport of being healthy. During clinical lung examination four horses showed symptoms of a pulmonary disease like increased breathing rate and enforced breathing at rest. These horses were excluded from the study. The other 33 horses were clinically normal. 17 of these horses were unridden (untrained) and 16 horses were regularly worked (trained). After clinica...
Polikepahad S, Haque M, Francis J, Moore RM, Venugopal CS.The purpose of the study was to determine and compare the expression of endothelin (ET) receptors in the peripheral lungs of healthy horses and those affected with recurrent airway obstruction (RAO) using reverse transcriptase polymerase chain reaction (RT-PCR), real-time PCR, Western blot analysis, and immunohistochemical techniques. Two groups of horses (7 healthy and 7 RAO-affected) were selected from a pool of horses destined for euthanasia. The grouping of horses was based on the history, clinical scoring, and pulmonary function testing. After euthanasia, gross postmortem evaluation of th...
Respiratory diseases are a major cause of morbidity and mortality in the horses of all ages including foals. There is limited understanding of the expression of immune molecules such as tetraspanins and surfactant proteins (SP) and the regulation of the immune responses in the lungs of the foals. Therefore, the expression of CD9, SP-A and SP-D in foal lungs was examined. Results: Lungs from one day old (n = 6) and 30 days old (n = 5) foals were examined for the expression of CD9, SP-A, and SP-D with immunohistology and Western blots. Western blot data showed significant increase in the...
Grünig G, Von Fellenberg R, Maier R, Corboz L.Seventeen out of 21 horses had pulmonary microbial organisms which reached considerable numbers in seven cases. Elastase-producing microorganisms from the environment (Streptomyces species and to a lesser extent Bacillus species) constituted 22 per cent to 99 per cent (mean 79 per cent) of the total growth. There was a considerable number of microorganisms with in vitro-produced elastases which were not or only slightly affected by horse serum. There was no correlation between numbers of organisms and pulmonary histopathological findings thus the significance of these microorganisms in the pat...
Dixon PM, Railton DI, McGorum BC.The majority of 270 adult horses with chronic pulmonary diseases had excessive volumes of respiratory secretions (RS) present in their trachea, elevated tracheal RS neutrophil ratios and lowered arterial oxygen partial pressures. Some control horses, had inexplicably elevated trachael RS neutrophil ratios. Only the chronic obstructive pulmonary disease (COPD) affected group had significantly elevated bronchoalveolar lavage fluid (BALF) neutrophil ratios. Maximal intrapleural pressure changes (max dPpl) were raised in 48% of COPD cases and rarely with other pulmonary disorders. Arterial pH or c...
Chesnel MA, Aprea F, Clutton RE.A traumatic pneumothorax and severe hemorrhage were present in a mare with a large thoracic wall defect, lung perforation, and multiple rib fractures. General anesthesia was induced to allow surgical exploration. We describe the anesthetic technique, and discuss the management of the ventilatory, hemodynamic, and metabolic disturbances encountered. Gestion de l’anesthésie générale d’un cheval avec un pneumothorax d’origine traumatique. Nous décrivons le cas d’une jument présentée avec un important déficit de la paroi thoracique d’origine traumatique, une perforation pulmonaire...
Clayton HM, Trawford AF.A field study was designed to investigate the re-establishment of patent lungworm infections in donkeys following an anthelmintic treatment regime which was effective against Dictyocaulus arnfieldi. In April 1979 faecal samples from 259 donkeys were examined and each animal classified as a negative, low positive or high positive excretor of lungworm larvae. During the summer the control group of 126 donkeys showed an increase in the number of excretors from 80 per cent in April to 91 per cent in October. At the same time there was a rise in the faecal larval output of individual animals so tha...
Bakos Z, Vörös K.The application of equine thoracic percussion has been ignored because of the availability of modern imaging techniques. Ultrasonography is a reliable tool in determining the caudal lung border of horses. The aim of the study was to compare percussion with ultrasonography to determine lung borders in horses. Objective: That thoracic percussion can detect the caudal lung border and that its accuracy is comparable with thoracic ultrasonography. Methods: Fifteen randomly chosen, healthy, Warmblood horses. Methods: The caudal lung border was detected by percussion and ultrasonography at the end of...
Anderson GF, Landsheft B.Performance horses should be thoroughly examined before sale to detect any defects that could render them unsuitable for the purchaser's intended use. With the horse in its stall, the eyes, nasolacrimal puncta, external ear canals and mouth are examined, the rectal temperature measured and the heart, lungs, trachea and sinuses auscultated. Moving the horse out of the stall, the head, parotid glands, mandibular lymph nodes, larynx, neck muscles, jugular veins and cervical vertebrae are inspected. The scapula, point of the shoulder, withers, tuber sacrale and point of the hip are palpated, after...
Harmegnies NF, Duvivier DH, Vandenput SN, Art T, Lekeux PM, Votion DM.This study aimed to compare exercise-induced pulmonary perfusion redistribution in healthy vs. 'heavey' horses using scintigraphy, a minimally invasive technique. Six healthy (A) and 5 'heavey' horses in remission (B(I)) and during clinical signs of disease (B(II)) were investigated. Dimensions of the exercising pulmonary perfusion (QE) images were expressed in percent of the resting perfusion (QR) images. Computed QE to QR ratios (QE/QR) images enabled the definition of the region more perfused at exercise than at rest (R1). In all groups, exercise induced a major enlargement of the Q image b...
Geisel O, von Sandersleben J.The chronic obstructive pulmonary disease (COPD) in horses is primarily based on a chronic bronchitis/bronchiolitis with constriction of the tubes in the lower respiratory tract. The outward appearance of the lung is characterized by a diffuse or marginal alveolar emphysema. The big bronchial tubes are usually not altered. Small bronchi and bronchioli can often be seen through the pulmonal pleura. On the sectional area they are visible as opaque grey-red nodules with a central lumen detectable under a magnifying glass. The histopathological picture of alterations in the bronchial tree can vary...
Koterba AM, Kosch PC.Breathing pattern, respiratory muscle activation pattern, lung volumes and volume-pressure characteristics of the respiratory system of normal, term, neonatal foals on Days 2 and 7 of age were determined to test the hypothesis that the foal actively maintains end-expiratory lung volume (EEV) greater than the relaxation volume of the respiratory system (Vrx) because of a highly compliant chest wall. Breathing pattern was measured in the awake, unsedated foal during quiet breathing in lateral and standing positions. The typical neonatal foal breathing pattern was characterized by a monophasic in...
Art T, Tack S, Kirschvinck N, Busoni V, Votion D, Freeman K, Lekeux P.This study aimed at measuring the functional consequences and the pulmonary cytology changes following a simulation of pulmonary haemorrhage. Pulmonary function tests including lobeline-induced hyperventilation, cytology of tracheo-bronchial wash (TBW) and thoracic radiographs were performed before, as well as 1, 7, 14 and 28 days after, the instillation of 300 ml of blood into the lungs of 4 horses deemed free of exercise-induced pulmonary haemorrhage (Group 1). Control data (Group 2) were obtained by instilling the same volume of saline into the lungs of the same horses in a crossover design...
Staddon GE, Weaver BM.The regional perfusion to the lungs of 14 ponies was studied using radioactively labelled microspheres injected intravenously. It was found that within half an hour of induction of anaesthesia the perfusion to the dependent lung had decreased significantly from the values in the standing animal. When anaesthesia was maintained for more than two and a half hours, however, the lung perfusions were not significantly different from the standing values when the animals were lying in lateral or supine recumbency.
Lyons ET, Tolliver SC, Drudge JH, Swerczek TW, Crowe MW.A total of 89 Thoroughbreds, 14 to 333 days old (born in 1982), were examined at necropsy for certain internal parasites during a 1-year-period, Mar 1, 1982, to Feb 28, 1983. The eyes of 73 of the horses and the cranial mesenteric arteries of 71 were examined. Specific interest was on prevalence of parasites according to month of the year and age of the horses at necropsy. Parasites recovered (first month-last month infected horse found) were as follows: Thelazia lacrymalis (eyes) immature and mature (June - February); Habronema/Draschia (lungs) immature (May - September); Habronema muscae (st...
Erickson BK, Forster HV, Lowry TF, Pan LG, Korducki MJ, Forster AL, Forster MA.The objective of the present study was to determine whether lung and diaphragm afferents contribute to the changes in respiratory muscle activity when end-expiratory lung volume (EELV) is changed in ponies. We studied the responses of the diaphragm and the transversus abdominis (TA) muscles to passive increases in EELV in awake intact (I), diaphragm-deafferented (DD), pulmonary vagal- (hilar nerve) denervated (HND), and DD + HND ponies. Negative pressure of -10 or -20 cmH2O applied around the ponies' torsos [positive transrespiratory (TR) pressure] increased (P < 0.05) EELV in all ponies; t...
Becker-Birck M, Schmidt A, Wulf M, Aurich J, von der Wense A, Möstl E, Berz R, Aurich C.Bringing the head and neck of ridden horses into a position of hyperflexion is widely used in equestrian sports. In our study, the hypothesis was tested that hyperflexion is an acute stressor for horses. Salivary cortisol concentrations, heart rate, heart rate variability (HRV) and superficial body temperature were determined in horses (n = 16) lunged on two subsequent days. The head and neck of the horse was fixed with side reins in a position allowing forward extension on day A and fixed in hyperflexion on day B. The order of treatments alternated between horses. In response to lunging, ...
Bakos Z, Vörös K, Kellokoski H, Reiczigel J.The aim of the study was to evaluate the diagnostic value of thoracic percussion and ultrasonography with the help of distance measurements and statistical methods in the determination of the caudal lung border in horses with recurrent airway obstruction (RAO). Examinations were performed on 11 healthy, warm-blooded horses of different breeds, age and grade of disease. First, the caudal lung border was determined by the traditional indirect percussion method in the 10th, 12th, 14th and 16th intercostal spaces at the end of inspiration and expiration on both sides of the thorax. To apply standa...
