The nasal cavity in horses is a complex anatomical structure that plays a significant role in respiration and olfaction. It consists of a series of passages lined with mucous membranes and cilia that filter, humidify, and warm the air before it reaches the lungs. The nasal cavity is also involved in vocalization and serves as a conduit for pheromonal communication. Various conditions can affect the equine nasal cavity, including infections, allergies, and structural abnormalities, which can impact a horse's respiratory efficiency and overall health. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and pathologies associated with the nasal cavity in horses, as well as diagnostic and therapeutic approaches.
Roberts MC, Sutton RH, Lovell DK.A 13-year-old Standardbred stallion presented with a unilateral mucopurulent nasal discharge and airway obstruction was found to have an extensive cryptococcal nasal granuloma. Treatment was not attempted. The stallion was destroyed 26 months later having completed 2 successful breeding seasons. The granuloma had gradually increased in size and almost completely occupied the left nasal cavity and paranasal sinuses. It was characterised histologically by fibrous and myxomatous tissue and masses of yeasts. A cryptococcal granuloma found within the wall of the jejunum could represent evidence of ...
Mason TA.Two cases of bilateral atresia of the nasolacrimal orifice are described. The presenting sign was a persistent ocular discharge, clear in the one case and purulent in the other. Treatment by the creation of a fistula between the distal extremity of the blind ending duct and the nasal cavity was successful in both cases.
Valdez H, McMullan WC, Hobson HP, Hanselka DV.A 6-month-old Appaloosa colt had a deviation of the premaxilla and nasal septum as well as a dorsal hump of the nasal bone and maxillomandibular malocclusion. Two surgical procedures were performed 12 weeks apart to correct these anomalies. An intraoral approach and autogenous rib graft were used to correct the malocclusion and deviation of the premaxilla. Osteotomy of the nasal bone and removal of the nasal septum were performed to help correct the deviation and to facilitate free air passage through the nares.
Rawlinson RJ, Jones RT.The history and clinical findings of 1 horses with guttural pouch mycosis referred to us are described. The salient features of the history and clinical signs common to both cases were profuse spontaneous nasal haemorrhage, partial pharyngeal paralysis; subsequently bilateral nasal discharge containing food material, inability to drink and parotid pain became evident. One case made a gradual recovery with conservative medical treatment while the second case was destroyed and submitted for post-mortem, histopathological and microbiological examination. This examination failed to establish the i...
Moorthy AR, Spradbrow PB.Two strains of Chlamydia psittaci were isolated from the nasal tract of horses with acute respiratory disease. These 2 isolates (NS 121 and NS 172) were characterized as chlamydia on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacterial media and their possession of chlamydial common complement fixing group antigen. They were identified as C. psittaci on the basis of resistance to sodium sulphadiazine. The present strains were not pathogenic to mice and guinea pigs and non-toxigenic. They induced antibodies and caused latent infection in ...
Cook WR.Broken wind is a syndrome characterised by chronic bronchitis and alveolar emphysema. Clinical signs include nasal catarrh, persistent coughing, dyspnoea and poor exercise tolerance. In racehorses, lung haemorrhages may result in epistaxis. Broken wind is a disease of domestication ascribed to pollution of the stable air with fungal spores from hay and straw. Treatment and prevention are based on the provision of fresh air and, if housing is unavoidable, the adoption of a permanent regime of dust-free stable management. If an early diagnosis is made and appropriate treatment instituted, the pr...
Cannon JH, Grant BD, Sande RD.Development of cysts in the equine paranasal sinuses is probably a congenital disease; however, signs may not appear for several years. In 4 cases, clinical signs were observed when fluid accumulation within the cysts resulted in nasal discharge or facial swelling, or when secondary infection occurred. Treatment required surgical removal of the lining membrane and other involved tissues. Postoperative care included lavage of the sinuses and systemic antibiotic therapy.
Moorthy AR, Spradbrow PB.Mycoplasmas were isolated from two of 43 nasal swabs taken from live horses, and from one of 28 tracheal swabs taken from slaughtered horses. The slaughtered horse that yielded mycoplasmas had no gross pathological changes in the respiratory tract, but the nasal isolations were made from horses with rhinitis. The three mycoplasmas could be distinguished by cultural characteristics, and probably they represent three different species.
Mason BJ.A case of spindle cell sarcoma of the equine para-nasal sinuses is described and discussd in relation to similar tumours recorded in the literature.
Platt H.A series of 10 haemorrhagic polyps of the equine nasal cavity is described. The lesions show haematoma formation, abundant haemosiderin in macrophages and giant cells, and organising fibrous tissue. In one case, angiomatoid lesions were observed in the mucous membrane of the paranasal sinuses and it is suggested that some haemorrhagic nasal polyps may originate from pre-existing haemangiomatous areas in the respiratory mucosa.
Woolcock JB.Equine tonsillar tissue and the draining regional lymph nodes, as well as deep nasal swabs were examined bacteriologically. Group C streptococci, predominantly Streptococcus zooepidemicus, were shown to be present in all tissues. The most frequent site for isolation was the tonsil. Streptococcus equi was not located in any of the tissues sampled.
Oakey J, Hawkesford T, Smith C, Hewitson G, Tolosa X, Wright L, Moody N, Rodwell B, Corney B, Waltisbuhl D.Describe the in-house validation of a previously reported influenza virus type A 5'Taq nuclease assay for detecting equine influenza virus A RNA in nasal swab material. Methods: The validation compares the 5'Taq nuclease assay with a gel-based reverse transcription nested polymerase chain reaction (PCR) previously reported by the Irish Equine Centre for detection of H3N8 and H7N7 equine influenza viruses. This test was chosen because it targets a different region of the viral genome to the real-time test, so it is not merely a repeat of the same test in a different format. Moreover, nested PCR...
Perez JA, Hutton AE, Cudd SK, Brown JA.To describe a novel standing trans-nasal endoscopic guided CO2 laser fenestration approach to access the sphenopalatine sinus (SPS) in the horse. Methods: Case report. Methods: Cadaver study and client-owned 20-year-old Warmblood gelding. Methods: The rostral palatine bone within the nasopharynx was investigated as a possible site for fenestration to access the SPS in cadavers. The ability to fenestrate the SPS was tested in cadavers using a flexible endoscope and CO2 laser fiber inserted via biopsy channel. The fenestration procedure was then performed in a clinical case presented for unilate...
Hashikura S, Higuchi T, Taharaguchi S, Orita Y, Nanao Y, Takai S.The reliability of preparing bacteriological cultures from nasotracheal aspirates of foals routinely in order to diagnose R. equi pneumonia in foals was studied by isolating Rhodococcus equi from specimens obtained from 96 foals by nasotracheal aspiration with a silicon catheter. Results were compared with specimens obtained from 21 foals by transtracheal aspiration (percutaneous tracheal puncture). These 117 foals showed clinical signs of respiratory tract infection at sampling. R. equi was isolated from 14 of 21 (66.7%) specimens by transtracheal aspiration and from 59 of 96 (61.4%) specimen...
Rawlinson RJ, Jones RT.The history and clinical findings of 1 horses with guttural pouch mycosis referred to us are described. The salient features of the history and clinical signs common to both cases were profuse spontaneous nasal haemorrhage, partial pharyngeal paralysis; subsequently bilateral nasal discharge containing food material, inability to drink and parotid pain became evident. One case made a gradual recovery with conservative medical treatment while the second case was destroyed and submitted for post-mortem, histopathological and microbiological examination. This examination failed to establish the i...
Legere RM, Wooldridge AA, Sandey M, Hanson RR, Cole R.This case represents the first reported case of Bipolaris hawaiiensis infection in an equid, and its aggressive clinical course. This case provides important descriptive and prognostic information for horses diagnosed with phaeohyphomycotic rhinitis. A 19-year-old American Quarter Horse mare was presented for second opinion of stertor and exercise intolerance of four-month duration. Endoscopy revealed generalized, proximal nasal edema, and computed tomography identified a soft tissue mass eroded through the rostral nasal bone. Biopsy of the mass was identified as a fungal granuloma caused by B...
Mair TS, Stokes CR, Bourne FJ.Lavage procedures were used to obtain samples of respiratory secretions from the nasal cavity, trachea, bronchi and bronchoalveolar level of apparently normal conscious horses, and the cellular composition of the lavage fluids was assessed. There was a progressive increase in total cell count of the secretions obtained from the upper to the lower respiratory tracts. Nasal lavage fluid was composed chiefly of epithelial cells, whereas tracheal, bronchial and bronchoalveolar fluids contained higher proportions of macrophages, lymphocytes and neutrophils. Eosinophils and mast cells were identifie...
Nickels FA.Conditions of this portion of the respiratory tract are relatively uncommon. This article reviews these conditions and discusses the different modes of therapy. The conditions covered are redundant alar folds, diseases of the nasal septum, fungal infections, neoplasms, nasal polyps, and ethmoid hematomas. The different surgical approaches to the nasal cavity are reviewed, and surgery of removal of the nasal septum and the alar fold are described.
Lores M, Yarbrough T.A 9-year-old pony gelding was evaluated because it was suspected that a persistent oronasal fistula had developed after a fractured right maxillary second premolar tooth had been extracted via repulsion 6 months earlier. Results: Unilateral mucopurulent nasal discharge and malodorous breath were noted on clinical examination. Examination of the oral cavity revealed a 1 × 0.5-cm defect at the oral aspect of the right maxillary second premolar alveolus, from which feed material was extracted. Endoscopic examination revealed feed material in the rostral aspect of the right nasal cavity, confirmi...
Lane JG, Mair TS.The clinical records of 100 cases of headshaking in horses were reviewed. Possible causes of the abnormal behaviour were identified in 11 animals; these included ear mite infestation, otitis interna, cranial nerve dysfunction, cervical injury, ocular disease, guttural pouch mycosis, dental periapical osteitis and suspected vasomotor rhinitis. However, in only two of these could it be shown that correction of the abnormality led to elimination of the headshaking. The additional clinical signs exhibited by the other idiopathic cases of headshaking included evidence of nasal irritation, sneezing ...
Karakulska J, Fijałkowski K, Nawrotek P, Pobucewicz A, Poszumski F, Czernomysy-Furowicz D.The aim of this study was an analysis of the staphylococcal flora of the nasal cavity of 42 healthy horses from 4 farms, along with species identification of CoNS isolates and determination of resistance to 18 antimicrobial agents, particularly phenotypic and genotypic methicillin resistance. From the 81 swabs, 87 staphylococci were isolated. All isolates possessed the gap gene but the coa gene was not detected in any of these isolates. Using PCR-RFLP of the gap gene, 82.8% of CoNS were identified: S. equorum (14.9%), S. warneri (14.9%), S. sciuri (12.6%), S. vitulinus (12.6%), S. xylosus (11....
Boyle AG, Rankin SC, D￮ LA, Morris D.Methicillin-resistant Staphylococcus aureus (MRSA) is recognized as a cause of nosocomial infections in both human and veterinary medicine. Studies that examine the nasopharynx and guttural pouches of the horse as carriage sites for MRSA have not been reported. Objective: MRSA colonizes the nasopharynx and guttural pouch of horses. To determine the prevalence of MRSA in equine nasopharyngeal wash (NPW) and guttural pouch lavage (GPL) samples in a field population of horses. Methods: One hundred seventy-eight samples (123 NPW and 55 GPL) from 108 horses. Methods: Prospective study. Samples were...
Sano Y, Okamoto M, Ootsuka Y, Matsuda K, Yusa S, Taniyama H.A 29-year-old stallion presented with bilateral blindness following the chronic purulent nasal drainage. The mass occupied the right caudal nasal cavity and right paranasal sinuses including maxillary, palatine and sphenoidal sinuses, and the right-side turbinal and paranasal septal bones, and cribriform plate of ethmoid bone were destructively replaced by the mass growth. The right optic nerve was invaded and involved by the mass, and the left optic nerve and optic chiasm were compressed by the mass which was extended and invaded the skull base. Histologically, the optic nerves and optic chia...
Holland M, Snyder JR, Steffey EP, Heath RB.Laryngotracheal damage following short-term nasotracheal intubation was studied in 7 healthy horses. A flexible fiberoptic endoscope was used to examine the upper respiratory tract of each horse before nasal intubation with a cuffed silicone endotracheal tube and again at 1 hour, 24 hours, and 48 hours after extubation. Any abnormalities still evident at 48 hours were evaluated at 7 days after extubation. Mucosal damage involved the nasal meatus (5 of 7 horses), the arytenoid cartilages (5 of 7 horses), the trachea (5 of 7 horses), the dorsal pharyngeal recess (4 of 7 horses), the vocal folds ...
Arun S, Neubauer H, Gürel A, Ayyildiz G, Kusçu B, Yesildere T, Meyer H, Hermanns W.In the course of an epidemiological study of glanders on a number of Turkish islands in the Sea of Marmara, 1128 horses were examined by using the intracutaneous mallein test. Thirty-five (3-1 per cent) developed an increase in rectal temperature and a swelling at the point of injection. Ten of these horses were killed and glanders was confirmed in five cases by the presence of lesions and by the immunohistological demonstration of the causative agent, Burkholderia mallei. Clinical and pathological findings indicated that in all cases the infection was restricted to the mucous membrane of the ...
Diaz-Méndez A, Hewson J, Shewen P, Nagy E, Viel L.To develop a method for experimental induction of equine rhinitis A virus (ERAV) infection in equids and to determine the clinical characteristics of such infection. Methods: 8 ponies (age, 8 to 12 months) seronegative for antibodies against ERAV. PROCEDURES-Nebulization was used to administer ERAV (strain ERAV/ON/05; n = 4 ponies) or cell culture medium (control ponies; 4) into airways of ponies; 4 previously ERAV-inoculated ponies were reinoculated 1 year later. Physical examinations and pulmonary function testing were performed at various times for 21 days after ERAV or mock inoculation. Va...
Gerard M, Pruitt A, Thrall DE.An aged pony with extensive paranasal sinus and nasal passage B-cell lymphoma was treated with palliative radiation therapy. Sixteen gray were administered in two fractions, 7 days apart. A lateral field was used for the first fraction and a dorsal field for the second. Because of tumor being present in the left frontal sinus, gross tumor was knowingly excluded from the treated volume in the lateral field. The tumor regressed within 2 months and the pony remained free of clinical disease for 2.5 years. Acute, temporary blindness developed shortly after the second radiation fraction, but a dire...
Angulo-Valadez CE, Scholl PJ, Cepeda-Palacios R, Jacquiet P, Dorchies P.Larvae causing obligatory myiasis are numerous and they may affect cutaneous and subcutaneous tissues, wounds, nasopharyngeal cavities (nasal bots), internal organs and the digestive tract (bots) of domestic and wild animals and humans as well. Nasal bots belong to the Family Oestridae, Subfamily Oestrinae, which includes several important genera: Oestrus, Kirkioestrus, and Gedoelstia infecting Artiodactyla (except Cervidae) in Africa and Eurasia, Cephenemyia and Pharyngomyia infecting Cervidae, Rhinoestrus infecting horses, Cephalopina infecting camels, Pharyngobolus infecting African elephan...
Espíndola JP, Machado G, Diehl GN, Dos Santos LC, de Vargas AC, Gressler LT.Microbiological diagnosis of equine respiratory infections is essential for disease management. However, reliable diagnosis can be a challenge due to colonization of the upper respiratory tract (URT) by a diverse microbial population, and because there is a lack of studies with samples from healthy animals. Aiming to guide adequate URT culture, this work reports culturable microbial population from the URT of 1,010 apparently healthy horses from 341 farms in Southern Brazil and identifies the putative presence of pathogenic microorganisms. Nasal swabs were cultured in 5% blood agar, and the is...
Vuerich M, Nannarone S.The aim of this study was to retrospectively report outcomes resulting from the approach to the maxillary nerve block (MNB) through the infraorbital canal, in terms of needles selection, drawbacks or side effects during or after block execution, and analgesic efficacy leading to clinical and cardiovascular stability during surgery. Anesthetic records of 15 horses undergoing orofacial surgery in standing analgo-sedation (STA, n = 6) and in general anesthesia (GEN, n = 9) were retrieved and analyzed. Horses in group STA required surgery for dental extraction, nasal polyp resection and maxillary/...
Boyle AG, Stefanovski D, Rankin SC.Streptococcus equi subsp equi (S. equi) is the cause of "equine strangles" which is a highly infectious upper respiratory disease. Detection of S. equi is influenced by site of specimen collection, method of sampling, and type of diagnostic test that is performed. We hypothesized i) that a loop-mediated isothermal amplification (LAMP) assay that targets the S. equi-specific eqbE gene would be more sensitive than a realtime PCR assay that targets the S. equi-specific seeI gene and ii) that LAMP of specimens obtained by guttural pouch lavage (GPL) would be more sensitive than LAMP of nasopharyng...
Zetterström S, Groover E, Lascola K, Cole R, Velloso A, Boone L.A five-year-old Thoroughbred mare was evaluated because of chronic, malodorous, unilateral nasal discharge, and suspected maxillary cheek tooth root abscess. Skull radiographs revealed bilateral sinusitis suspected secondary to tooth root abscessation of 109 and 210. Following oral extraction of 109, bilateral conchofrontal sinus trephination and lavage; fever, tachycardia, and cervical stiffness developed. A lumbosacral cerebrospinal fluid tap was performed, and a presumptive diagnosis of bacterial meningitis was made. Targeted therapy consisted of antibiotic treatment with penicillin, enrofl...
Wilcox A, Barnum S, Wademan C, Corbin R, Escobar E, Hodzic E, Schumacher S, Pusterla N.Actively shedding healthy horses have been indicated as a possible source of respiratory pathogen outbreak, transmission, and spread. Using nasal swabs from clinically healthy sport horses submitted for qPCR testing after an outbreak of equine herpesvirus-1 (EHV-1) myeloencephalopathy (EHM) in the spring of 2022, this study aimed to identify the rate of clinically healthy horses shedding common and less characterized respiratory pathogens within the sport horse population to better understand their role in outbreaks. Swabs were collected during a required quarantine and testing period, accordi...
Bailey CJ, Reid SW, Hodgson DR, Rose RJ.A prospective study of injuries and disease in a cohort of Australian thoroughbreds in training was conducted with the participation of 24 trainers. From the horses catalogued at a major yearling sale in 1995, 169 were enrolled in the study and followed through their two- and three-year-old racing seasons. The principal aim was to quantify the time lost in training as a result of the various categories of injuries and disease, recorded as either days of modified training, or weeks rested at pasture. Shin soreness was the most common condition in two-year-olds (affecting 42 per cent of the hors...
Puff C, Ohnesorge B, Wagels R, Baumgärtner W.A 4-month-old Warm-blooded colt presented with facial distorsion and an abnormal respiratory noise of 2 weeks' duration. A proliferative mass was found endoscopically and by computer tomography. Clinical differential diagnosis included cyst formation of the concha, malformation and neoplasia. Euthanasia was followed by post-mortem examination, which revealed a well-circumscribed, semi-solid, jelly like structure, measuring 14.5 x 9.0 x 12.0 cm, in the left posterior nasal cavity extending into the left frontal and maxillary sinus. Histologically, the mass consisted of trabeculae of woven bone,...
Velloso Alvarez A, Jose-Cunilleras E, Dorrego-Rodriguez A, Santiago-Llorente I, de la Cuesta-Torrado M, Troya-Portillo L, Rivera B, Vitale V....Real-time PCR is the diagnostic technique of choice for the diagnosis and control of equine herpesvirus-1 (EHV-1) in an outbreak setting. The presence of EHV-1 in nasal swabs (NS), whole blood, brain and spinal cord samples has been extensively described; however, there are no reports on the excretion of EHV-1 in urine, its DNA detection patterns, and the role of urine in viral spread during an outbreak. Objective: To determine the presence of EHV-1 DNA in urine during natural infection and to compare the DNA detection patterns of EHV-1 in urine, buffy coat (BC) and NS. Methods: Descriptive st...
Rasheed H, Ijaz M, Ahmed A, Javed MU, Shah SFA, Anwaar F.Antimicrobial resistance is a global issue that limits therapeutic options for infections. S. aureus being a member of the ESKAPE group is capable of "escaping" the biocidal action of antimicrobial agents. There are phenotypic and genotypic methods used for the identification of antibiotic resistant genes harboring S. aureus but these methods do not always show concordant results. To address these discrepancies, a total of 335 equine nasal swab samples from four districts of Punjab were collected using a convenient sampling technique. These samples were first subjected to common microbial tech...
Mitlehner A, Mitlehner C, Reißmann M, Stoll P, Swoboda I, Mitlehner W.American Bashkir Curly Horses are claimed to be hypoallergenic, but this has not been clinically proven. In the present study, the effect of exposure to Curly Horses was investigated in 141 patients allergic to horses by measuring their lung function and nasal patency during Curly Horse contact. Continuous contact with Curly Horses, including riding and brushing, decreased the allergic riders' reactivity as measured by FEV1, PEF, and PNIF. Subsequent visits (up to 40 or more hours of riding) further reduced reactivity to the Curly Horses. Allergic events to horses occurred only in 72 out of 13...
Osterrieder K, Dorman DC, Burgess BA, Goehring LS, Gross P, Neinast C, Pusterla N, Hussey GS, Lunn DP.Equine herpes virus type 1 (EHV-1) infection in horses is associated with respiratory and neurologic disease, abortion, and neonatal death. Objective: Vaccines decrease the occurrence of clinical disease in EHV-1-infected horses. Methods: A systematic review was performed searching multiple databases to identify relevant studies. Selection criteria were original peer-reviewed research reports that investigated the in vivo use of vaccines for the prevention of disease caused by EHV-1 in domesticated horses. Main outcomes of interest included pyrexia, abortion, neurologic disease, viremia, and n...
Lee DF, Everest DJ, Cooley W, Chambers MA.Equine asthma, previously known as Recurrent Airway Obstruction (RAO) or Inflammatory Airway Disease (IAD), is an often-debilitating condition that may severely affect both performance and quality of life. Research is hindered by the low sample numbers of subjects recruited to studies, a consequence in part of the invasive nature of the sampling methods of bronchial brushing and biopsy. We present an alternative method of sampling equine airway epithelial cells, the 'nasal brush method' (NBM). Obtained by light brushing of the ventral meatus whilst the horse is under standing sedation, these c...
Pusterla N, Dorman DC, Burgess BA, Goehring L, Gross M, Osterrieder K, Soboll Hussey G, Lunn DP.Equine herpesvirus type 1 (EHV-1) infection is associated with upper respiratory disease, EHM, abortions, and neonatal death. Objective: Are nasal secretions a more sensitive biological sample compared to blood for the detection of EHV-1 infection? How long is EHV-1 detectable after primary infection by PCR? Methods: MedLine and Web of Science searches identified original peer-reviewed reports evaluating nasal shedding and viremia using virus isolation methods or PCR published in English before October 9, 2023. Results: Sixty experimental and 20 observational studies met inclusion criteria. EH...
