Respiratory disease in horses encompasses a range of conditions affecting the respiratory system, including the upper and lower airways. These diseases can result from various etiologies such as infectious agents, environmental factors, or genetic predispositions. Common respiratory conditions in horses include equine asthma, equine influenza, and strangles. Clinical signs often associated with respiratory disease in horses include coughing, nasal discharge, and labored breathing. Diagnostic approaches may involve endoscopy, imaging, and laboratory tests to assess the function and health of the respiratory tract. This page compiles peer-reviewed research studies and scholarly articles that explore the pathophysiology, diagnosis, and management of respiratory diseases in equine populations.
McChesney AE.Since the advent of cell culture techniques, numerous viruses have been shown to be related to respiratory diseases in horses. Although the viruses differ in many ways, they cause disease with some common characteristics. This report is a summary of some of the available material from written sources and from personal observations. It is intended to help explain some of the changes observed in viral-induced respiratory disease.
McGuire TC, Poppie MJ, Banks KL.Measurement of serum immunoglobulins in 46 foals less than 2 weeks old revealed 9 foals with hypogammaglobulinemia. The hypogammaglobulinemia was attributed to failure in transfer of immunoglobulins from dam to foal via colostrum. Three of the affected foals did not nurse at all, or only slightly, and 2 of these died of infections within a few days after birth, whereas the 3rd foal did not grow as well as normal foals. Six of the affected foals nursed in an apparently normal manner, and 5 of these had nonfatal respiratory infections between 2 and 5 weeks of age. Analysis of serum samples from ...
Beech J.Tracheobronchial aspirates were obtained from 27 normal horses and from 57 horses with respiratory disease. Aspirates from normal horses contained mainly ciliated columnar epithelial cells, mononuclear cells, a few neutrophils and mucus. Aspirates from horses with acute suppurative bronchopneumonias or chronic bronchiolitis had predominantly neutrophils and usually large amounts of mucus; in severe suppurative inflammatory diseases, many of the cells were degenerated, and there were coils of fibrinous material resembling Curschmann's spirals. Eosinophils were rarely found, even from horses wit...
Weaver BM, Walley RV.Eleven out of 12 horses were underventilating while breathing spontaneously during halothane anaesthesia with high arterial carbon dioxide tensions. In addition, large alveolar to arterial oxygen tension gradients were found to be present. Mechanically, controlled ventilation with an intermittent positive pressure of 20-30 cm H2O reduced arterial carbon dioxide levels to normal. The alveolar to arterial oxygen gradients did not increase and in some cases decreased. These (A - a) Po2 gradients were due mainly to true shunt of the order of 30 per cent and not to ventilation perfusion inequality....
Ardans AA, Pritchett RF, Zee YC.A viral agent was isolated from lung tissue obtained upon necropsy of an Arabian foal which had exhibited clinical signs of pneumonia. The virus is 75 nm in diameter, cubic in symmetry, and resistant to chloroform and low pH (3.0). It contains deoxyribonucleic acid and has a buoyant density of 1.31 g/cm(3) in cesium chloride. These findings indicate that the virus is a member of the adenovirus group.
Aguilera-Tejero E, Pascoe JR, Smith BL, Woliner MJ.To investigate the influence of increased respiratory frequency on respiratory mechanics in the horse, measurements were made in two groups of seven tracheostomized horses before and after the administration of doxapram. The horses in group I had normal base line values for respiratory mechanics, whereas the horses in group II had significantly lower values of dynamic compliance (Cdyn), higher respiratory resistance (R), and a higher total change in pleural pressure (delta P). The administration of 0.3 mg kg-1 doxapram intravenously resulted in a significant increase in respiratory frequency (...
Escribano BM, Agüera EI, Vivo R, Santisteban R, Castejón FM, Rubio MD.The aim of this work was to assess whether progressive training caused an improvement in the nonspecific immune response of colts because several unusual infections are due to defects inherent in the neutrophilic function among which respiratory diseases are a major defect in the performance of athletes taking part in professional sports activities. A group of 7 Anglo-Arabian colts belonging to the Army was selected. These animals carry out training programmes for their participation in National Jumping Competitions. During a submaximal exercise test (heart rate 150 beats/min and lactate level...
Newton TA, Rose SR.Phenylbutazone is a potent nonsteroidal, anti-inflammatory drug often used by veterinarians to treat racetrack animals. Its use in human beings is limited because of significant adverse effects and the availability of newer, safer drugs. We report the case of a 24-year-old man who ingested 17 g of equine phenylbutazone over a 24-hour period to treat the pain of a toothache. He developed grand mal seizures, coma, hypotension, respiratory and renal failure, and hepatic injury. Serum phenylbutazone concentration obtained approximately eight hours after presentation was 900 micrograms/mL. The pati...
Csellner H, Walker C, Love DN, Whalley JM.An equine herpesvirus 1 (EHV-1) mutant was constructed by inserting a lacZ expression cassette into the intergenic region upstream of gene 62 (glycoprotein L; gL) and downstream of gene 63 (a homologue of the herpes simplex virus transcriptional activator ICP0). The recombinant lacZ62/63-EHV-1 had similar growth kinetics in cell culture to those of the parental wild type (wt) virus, with indistinguishable cytopathic effects and plaque morphology. Reverse transcriptase PCR confirmed that the lacZ insertion did not interfere with transcription of gL and immunoblot analysis indicated there was no...
Bürki F, Nowotny N, Hofer A.The commercial vaccine "Resequin F Konz." devised against viral respiratory infections of horses contains the abortigenic Equine Herpesvirus-1 (EHV-1). Therefore we had used it in our protection project of the Austrian Lipizzaners+ primarily to prevent abortions. Taking into account the recent perception that for young horses the respiratory-pathogenic EHV-4 type is essential Behringwerke Marburg added this particular virus to their market product to produce a multicomponent experimental vaccine. We examined this vaccine for its antibody induction as well as their persistence against each of i...
Ryu SH, Koo HC, Lee YW, Park YH, Lee CW.Infectious upper respiratory disease (IURD) of Thoroughbred racehorses has been a frequent problem (29.6% of incidence) at the Seoul Race Park (Korea). Risk factors for IURD include the season with a high transfer rate (summer and fall), the stabling period (≤ 3 months), and age (2 to 3 years old), suggesting that the movement and new environment may have depressed the immune system of the horses and decreased their ability to respond properly to pathogens. The bacterial strains (n = 98) isolated from IURD horses included Pseudomonas spp., Escherichia coli, Staphylococcus spp., Streptococcus...
George LW, Tanner ML, Roberson EL, Burke TM.A 6-year-old Thoroughbred gelding was examined because of respiratory disease that developed after it was placed on pasture occupied by a donkey. Clinical signs in the gelding included a harsh, dry paroxysmal cough and increased expiratory effort. Eosinophils were seen in smears of mucus aspirated from the trachea and the bronchi. Immature, 5th-stage Dictyocaulus arnfieldi was identified in the tracheal mucus. The cough and other clinical signs were not diminished by corticosteroid therapy or by the administration of bronchodilators. Treatment with 10-fold therapeutic dosages of thiabendazole ...
Emmerich IU.In 2020, one novel pharmaceutical agent for horses or food-producing animals was released on the German market, rendering the inhaled glucocorticoid ciclesonide (Aservo EquiHaler) available for horses for the first time. The authorization of one established veterinary active ingredient was extended to an additional species: The anthelmintic fenbendazole (Gallifen) from the benzimidazole group is now also authorized for pheasants. Additionally, 3 veterinary drugs with a new combination of active ingredients (ketoprofen + tilmicosin, ketoprofen + tulathromycin, prednisolone + lidoc...
Baskerville A.For laboratory diagnosis of respiratory disease it is of overwhelming importance that the specimens taken are adequate, taken from the correct site and at the correct time. The lower regions of the respiratory tract are particularly difficult to sample but are more likely to yield the causative agent of a pneumonia. Infections involving the upper respiratory tract are much easier to sample and appropriate aspiration apparatus can be used. Consideration must be given to the timing of sample collection in relation to the life cycle of the causative micro-organism. Sampling of several animals is ...
Ablett JM, Fairbairn SM, Page CP, Lees P, Cunningham FM.A role for platelets in allergic airways disease has been postulated and changes in the responsiveness of circulating platelets have been demonstrated following antigen challenge of asthmatic human subjects. In this study agonist-induced aggregation of equine platelets in vitro has been compared before and after exposure of horses to a controlled hay and stray challenge. Prior to challenge the response of platelets, from horses with chronic obstructive pulmonary disease (COPD) and normal animals, to adenosine diphosphate (ADP) and platelet activating factor (PAF) did not differ. Five hours aft...
Votion DM, Vandenput SN, Duvivier DH, Lambert P, van Erck E, Art T, Lekeux PM.To assess sensitivity of scintigraphic alveolar clearance rate as an indicator of alveolar epithelium damage in horses. Methods: 5 healthy horses (group A) and 5 with chronic obstructive pulmonary disease (COPD; group B). Methods: Horses underwent clearance rate (k [%/min]) determination. Clearance rate of group-B horses was determined after remission of the disease following 2 months at pasture (remission 1), stabling in a controlled environment (remission 2), and during crisis induced by exposure to moldy hay and straw. Methacholine challenge test was performed at each investigation period t...
Broadstone RV, Robinson NE, Gray PR, Woods PS, Derksen FJ.The effect of aerosol and intravenous administrations of furosemide was examined in ponies with recurrent obstructive pulmonary disease, commonly called 'heaves'. This recurrent airway disease bears many similarities to human asthma. Six ponies with the disease (principal animals) were studied during clinical remission and during an acute attack of airway obstruction precipitated by stabling and feeding dusty hay. Six control animals were also studied. Furosemide (1.0 mg/kg) or vehicle was administered by aerosol in the first study, and intravenously in a second study. In principal ponies with...
To describe some cardiorespiratory effects of an inspiratory-to-expiratory (IE) ratio of 1:1 compared with 1:3 in ventilated horses in dorsal recumbency. Methods: Randomized crossover experimental study. Methods: A total of eight anesthetized horses, with 444 (330-485) kg body weight [median (range)]. Methods: Horses were ventilated in dorsal recumbency with a tidal volume of 15 mL kg and a respiratory rate of 8 breaths minute, and IE ratios of 1:1 (IE1:1) and 1:3 (IE1:3) in random order, each for 25 minutes after applying a recruitment maneuver. Spirometry, arterial blood gases and dobutamine...
Tatarov G, Dilovski M.An avirulent immunogenic virus strain mutant of the causative agent of rhinopneumonia was found to cause abortions and respiratory diseases in horses. The mutant was obtained with the use of a virulent strain that induced strongly manifested clinical symptoms of the disease, and was cultured in cell media containing 5-iodine-2-desoxiuridine as an antimetabolite, following a definite pattern. It was found that the mutant completely lost its virulence, however, it retained its immunogenicity. It likewise retained these newly acquired biologic properties with regard to its being stable and irreve...
BMC research notesJuly 12, 2014
Volume 7 448 doi: 10.1186/1756-0500-7-448
Boukharta M, Zakham F, Touil N, Elharrak M, Ennaji MM.The equine influenza (EI) is an infectious and contagious disease of the upper respiratory tract of horses. Two outbreaks were notified in Morocco during 1997 and 2004 respectively in Nador and Essaouira. The aims of the present study concern the amino acids sequences comparison with reference strain A/equine/Miami/1963(H3N8) of the HA2 subunit including the cleavage site of three equine influenza viruses (H3N8) isolated in Morocco: A/equine/Nador/1/1997(H3N8), A/equine/Essaouira/2/2004 (H3N8) and A/equine/Essaouira/3/2004 (H3N8). Results: The obtained results demonstrated that the substitutio...
Rangel JPP, de Oliveira APL, Baiotto GC, Junior OS, Figueiró GM, Araujo AL, Rossi Junior JL.Campylorrhinus lateralis, also known as "wry nose," is a congenital malformation that mainly affects Thoroughbreds. These horses have a unilateral deviation of the maxillae that may be to one side or the other side, and it causes airway obstruction and dental malocclusion. The choice of treatment is not necessarily operation; however, the treatment of choice, which aims to repair the maxillae deviation, is surgical to improve the horse's respiratory condition and correct the dental occlusion. There are currently no reports describing the first surgical technique for such deformity described by...
Ohnesorge B, Deegen E.From 1995 to 1997 11 racehorses, one Hanoverian and one Pony were presented to the clinic with a sudden appearing, very loudly gurgling expiratory respiratory noise. Considering the preliminary report and the clinical and endoscopical findings, as exercise induced dorsal displacement of the soft palate (DDSP) was found to be the cause of the respiratory noise. The 13 horses were treated in general anaesthesia by transendoscopic coagulation of the caudal margin of the soft palate with a Neodym-YAG-Laser. This surgical intervention had to be repeated on four horses with unchanged signs. Eight of...
Olson LE, Perkowski SZ, Mason DE, Muir WW.Strips of trachealis muscle were dissected from the midcervical portion of the trachea of horses that were free of respiratory tract disease, and the overlying epithelium and mucosa were removed. Muscle strips were suspended in tissue baths that were filled with Krebs-bicarbonate solution, aerated with 5% CO2 in oxygen and maintained at 37 C. Isometric tension was continuously recorded. The increase in active isometric tension was concentration dependent when acetylcholine (10(-9) to 10(-4) M) or histamine (10(-9) to 10(-4) M) was added to the tissue baths in 0.5-logarithmic increments. When t...
Raulo SM, Maisi P.To determine whether gelatinolytic activity in tracheal epithelial lining fluid (TELF), blood neutrophils, and blood lymphocytes from horses was metalloprotease activity, and to compare, for healthy horses and horses with chronic obstructive pulmonary disease, gelatinolytic activity in neutrophils, lymphocytes, and serum with activity in TELF. Methods: 7 horses with chronic obstructive pulmonary disease (COPD) and 4 healthy control horses. Methods: Neutrophils and lymphocytes were obtained by means of Percoll separation. Zymography was used to detect gelatinolytic activity; EDTA inhibition and...
Gislason D, Asmundsson T, Gislason T.Diseases connected with work in hay have been known in Iceland for a long time. In 1981 scientific studies of these diseases were started in Iceland at the request of the Farmers Union. The results of these studies are summarized in this article. In studies of hay a great amount of storage mites, moulds and thermophilic actinomycetes (microlyspora faeni) were found in addition to allergens from mice and pollen. Symptoms caused by hay dust were mainly from nose and eyes in people with positive skin tests, but cough, dyspnea and fever were equally common in those with negative skin tests. The mo...
Schellenberg LM, Bonicelli J, Hochheim I, Regenthal R, Abraham G.The β-adrenergic receptor (β-AR) plays an important role in regulating a variety of cell and organ functions in different animal species and is an important target in asthma pathogenesis and therapy. The β-AR expression and function in equine bronchial epithelial cells (EBEC) were not known but innervation and significant decrease in receptor level were reported in the equine bronchial tissues from asthmatic horses. I-iodocyanopindolol (ICYP) binding studies were undertaken in primary freshly isolated and cultured EBEC to identify the presence of the β-ARs. The receptor distribution was as...
Tatarov G, Martinov S, Panova M.It was established that the complement binding reaction (CBR) is a suitable and very fast method for horse rhino-pneumonitis diagnostics. Cell cultural virus produced in cell cultures of pig kidneys was used as antigen. The antigen lots tested have no anticomplementary properties. Highest complement binding activity was evident in the non-diluted antigen, which discovered specific antibodies in immune serums. The CBR specificity was tested by the aid of homologous and heterologous serums and antigens. The titers of complement binding antibodies in the serums of 255 horses recovered from the di...
Christensen H, Hommez J, Olsen JE, Bisgaard M.To investigate if taxon 42 of Bisgaard isolated from pigs represents genuine [Pasteurella] caballi, which was previously only isolated from horses. Results: A total of 15 field isolates from horses and pigs from five different countries representing three continents were subjected to extended phenotypical characterization. Although minor differences were observed between taxon 42 and [P.] caballi, these differences did not allow phenotypic separation. Ribotyping based on HindIII digestion showed five profiles based on nine band positions. One [P.] caballi strain and two taxon 42 strains shared...
Kingston JK, Bayly WM, Sides RH.Exercise-induced pulmonary haemorrhage has been associated with reduced performance in racing horses. However, it is unclear what volume of blood loss into the lungs impairs performance. The purpose of the present study was to determine the minimal volume of autologous Horses blood instilled into the airways that significantly affects performance and pulmonary function in exercising horses. Six Thoroughbred horses performed 2 exercise bouts on each of 4 treatment test days. Each exercise bout consisted of a 2 min warm-up at 4 m/s followed by running at a speed equivalent to 115% VO2max, until ...
Barakzai SZ, Wells J, Parkin TDH, Cramp P.Unilateral ventriculocordectomy (VeC) is frequently performed, yet objective studies in horses with naturally occurring recurrent laryngeal neuropathy (RLN) are few. Objective: To evaluate respiratory noise and exercising overground endoscopy in horses with grade B and C laryngeal function, before and after unilateral laser VeC. Methods: Prospective study in clinically affected client-owned horses. Methods: Exercising endoscopy was performed and concurrent respiratory noise was recorded. A left-sided laser VeC was performed under standing sedation. Owners were asked to present the horse for re...
Auckburally A, Nyman G, Wiklund MK, Straube AK, Perchiazzi G, Beda A, Ley CJ, Lord PF.To develop a method based on CT angiography and the maximum slope model (MSM) to measure regional lung perfusion in anesthetized ponies. Methods: 6 ponies. Methods: Anesthetized ponies were positioned in dorsal recumbency in the CT gantry. Contrast was injected, and the lungs were imaged while ponies were breathing spontaneously and while they were mechanically ventilated. Two observers delineated regions of interest in aerated and atelectatic lung, and perfusion in those regions was calculated with the MSM. Measurements obtained with a computerized method were compared with manual measurement...
Vyslouzil L, Seidl K, Svarcová J, Landsmannová V.A case history of mass foal disease which affected ten of the total stock of 50 foals and killed eight is described. The disease was characterized by respiratory disorders and extensive pneumonias with abscess formation, metastatic abscesses in mesenterial lymph nodes and in other organs. As a result of the examination of two dead foals and three nasal smears from diseased animals, gram-positive bacteria were isolated from the lungs, pulmonary and abdominal abscesses and the nasal smears of the affected foals; with their cultivation, morphological and biochemical characteristics these bacteria...
Rodzyń I, Karpińska K, Bis-Wencel H, Wlazło Ł, Ossowski M, Strzelec K, Jaguszewski S, Nowakowicz-Dębek B.Due to the increasing prevalence of equine non-infectious respiratory disease, the air contamination in equine housing (Stables A-C) and training facilities (indoor riding arenas A - C) was investigated. The aim of the study was to monitor gaseous pollutants, bioaerosols, and dust concentrations at three different sites (stables and riding halls), where different floor materials were used in the riding halls. Methods: Air quality was monitored in housing for horses and in riding halls in terms of dust concentration, the presence of gaseous chemical pollutants, and concentrations of biological ...
Oliveira BE, Canola PA.Ultrasonographic imaging of the diaphragm is a non-invasive alternative for respiratory function evaluation in horses. This study aimed to measure diaphragm thickness, thickening (change in thickness with contraction) and thickening fraction in healthy adult horses during tidal breathing and forced vital capacity. Correlation between body weight (≤400 kg and >400 kg) and diaphragm thickness was investigated. To that purpose, 20 adult horses, weight 409±50 kg, height 1.47±0.05 m, and age 16±6 years were included in the study. Diaphragm thickness was measured at end-inspiration and end-e...
Rasmussen N, Karlsen P, Otten ND, Fjeldborg J, Hansen S.Bronchoalveolar lavage (BAL) cytology results from 1 lung might not be representative of both lungs. Objective: To determine whether the lung site sampled would influence the horse's BAL cytology profile, and if a pooled BAL sample would be superior with regard to BAL cytology diagnosis in a cohort of healthy and subclinical asthmatic warmblood horses. Methods: Fifty-nine horses in 2021 and 70 horses in 2022, the follow-up included 53 of the same in each year. Methods: A cross-sectional study with follow-up included BAL cytology samples from individual lungs and from pooled BAL samples. The BA...
