Disease diagnosis in horses involves the identification and characterization of illnesses through various diagnostic methods and tools. This process is essential for effective veterinary care and management of equine health. Techniques used in diagnosing diseases in horses include clinical examinations, laboratory tests, imaging modalities such as ultrasonography and radiography, and molecular diagnostics. Blood tests are frequently utilized to assess parameters such as complete blood count and biochemical profiles, which can indicate underlying health issues. Additionally, advancements in genetic testing and biomarker identification have enhanced the ability to detect specific diseases early. This page aggregates peer-reviewed research studies and scholarly articles that explore diagnostic methodologies, their applications, and their impact on equine health management.
Paskin R.The equine influenza outbreak detected in August 2007 in New South Wales and Queensland did not enter Victoria, which was, however, considered at risk because of its sizable border with New South Wales. Accordingly, Victoria implemented a response plan to prevent disease entry and enable early detection of any disease. Horse movement restrictions, surveillance strategies and public awareness formed a large part of this response.
Scott-Orr H.The challenges faced in demonstrating Australia's freedom from equine influenza following the outbreak in 2007-08 and the responding strategy developed by the Proof of Freedom Working Group are presented.
Glanville RJ, Christie B.The equine influenza (EI) outbreak presented many challenges that required high-level coordination and decision making, as well as the development of new approaches for satisfactory and consistent resolution. This paper outlines the elements of the national coordination arrangements, preparatory arrangements in place prior to the outbreak that facilitated national coordination, and some of the issues faced and resolved in the response.
Watson J, Halpin K, Selleck P, Axell A, Bruce K, Hansson E, Hammond J, Daniels P, Jeggo M.Before 2007, equine influenza had never been diagnosed in Australia. On 22 August 2007, infection was confirmed in horses at Eastern Creek Animal Quarantine Station near Sydney. The virus subsequently isolated (A/equine/Sydney/2888-8/2007) was confirmed by sequence analysis of the haemagglutinin (HA) gene as an H3 virus of the variant American Florida lineage that is now referred to as Clade 1. The HA sequence of the virus was identical to that of a virus isolated from a contemporaneous outbreak in Japan and showed high homology to viruses circulating in North America.
Wong D.The clinical signs of horses diagnosed with equine influenza (EI) at Centennial Parklands Equestrian Centre (CPEC) and the events surrounding their diagnosis are described. This was the site of the first case of EI diagnosed outside of the Eastern Creek Animal Quarantine Station. The clinical data demonstrate the rapid spread of the disease after a sufficient viral load had developed from the initial cases within CPEC.
Sergeant ES, Cowled BD, Bingham P.This observational study was undertaken in order to evaluate the diagnostic specificity of the blocking enzyme-linked immunosorbent assay (bELISA) for serum antibodies to influenza A virus nucleoprotein during the equine influenza (EI) outbreak response in New South Wales, Australia, in 2007. Using data collected during the outbreak response, bELISA testing data were collated for assumed uninfected horses from areas where EI infection was never recorded. Diagnostic specificity of the bELISA used during the EI response was high, but varied significantly between some regions, although the reason...
Happold J, Rubira R.This study included 10 large Thoroughbred horse studs in the upper Hunter Valley of New South Wales and in southeast Queensland, Australia. The aims were to describe the EI epidemic in studs in the Special Restricted Area (Purple Zone) of NSW, to estimate seroprevalence among different groups of horses on these studs and to look for evidence of exposure to EI virus in horses on 'vaccinated' studs in southeast Queensland that were thought to have remained free of infection. As serology results from Queensland suggest that vaccination may have reduced the sensitivity of clinical surveillance to ...
Bell IG, Drury-Klein C.To analyse horse event and horse movement registration data collected between September 2007 and December 2008 during the outbreak of equine influenza in New South Wales, Australia. Results: A total of 9356 events were registered, involving 504,382 horses and 242,952 riders. Registered horse movements totalled 224,084, involving 349,327 horses (excluding mobs) travelling 34.4 million km with an average of 154 km per journey. The number of recorded events and movements were low while movement controls were most stringent, then increased from December 2007 as restrictions were eased, to peak in ...
Kirkland PD.During the 2007 equine influenza (EI) outbreak in Australia, diagnostic laboratories and the use of appropriate tests played a pivotal role in the response to the crisis. This role began with the detection of EI virus in New South Wales (NSW) on the evening of 24 August 2007 and culminated in providing the final 'proof of freedom' from EI in March 2008. The tests that were used during the EI response were able to provide results quickly, and with high sensitivity and specificity. This section of the supplement describes the roles and functions of the Australian laboratories; tests used and the...
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...
Brown L, Townsend W, Waltisbuhl D.The unique challenges that laboratories in Queensland and New South Wales faced during the response to the 2007 equine influenza outbreak and how these were managed are described.
Croft MG, Fraser GC, Gaul WN.A Laboratory Information Management System (LIMS) was used to manage the laboratory data and support planning and field activities as part of the response to the equine influenza outbreak in Australia in 2007. The database structure of the LIMS and the system configurations that were made to best handle the laboratory implications of the disease response are discussed. The operational aspects of the LIMS and the related procedures used at the laboratory to process the increased sample throughput are reviewed, as is the interaction of the LIMS with other corporate systems used in the management...
Webster WR.In August 2007 equine influenza (EI) was diagnosed in Australia's horse population following the failure to contain infection in quarantine after the importation of one or more infected horses. The response had many unique features, and addressed financial, social, economic, human and animal health, trade and recovery issues. The outbreak and the associated control measures had a vast impact on individual horse owners, the horse industry and associated sectors in both infected and uninfected states.
Morton JM, Dups JN, Anthony ND, Dwyer JF.The risk of individuals becoming infected during an epidemic of infectious disease can vary as the disease progresses. Monitoring this risk may provide information about the dynamics of transmission. This study describes the epidemic curve for an epidemic of equine influenza (EI) in a closed population of horses predominantly immunologically naïve to EI at a 3-day event at Morgan Park in southern Queensland, Australia. The hazard function suggested that a subset of horses were at reduced risk of becoming infected. This highlights the importance, when modelling infectious disease in population...
Moloney B, Sergeant ES, Taragel C, Buckley P.Equine influenza (EI) was first diagnosed in the Australian horse population on 24 August 2007 at Centennial Park Equestrian Centre (CPEC) in Sydney, New South Wales (NSW), Australia. By then, the virus had already spread to many properties in NSW and southern Queensland. The outbreak in NSW affected approximately 6000 premises populated by approximately 47,000 horses. Analyses undertaken by the epidemiology section, a distinct unit within the planning section of the State Disease Control Headquarters, included the attack risk on affected properties, the level of under-reporting of affected pr...
Mendoza FJ, Perez-Ecija RA, Monreal L, Estepa JC.Coagulation disorders are frequently diagnosed, especially in hospitalized equidae, and result in increased morbidity and mortality. However, hemostatic reference intervals have not been established for donkeys yet. Objective: To determine whether the most common coagulation parameters used in equine practice are different between healthy donkeys and horses. Methods: Thirty-eight healthy donkeys and 29 healthy horses. Methods: Blood samples were collected to assess both coagulation and fibrinolytic systems by determination of platelet count, fibrinogen concentration, clotting times (prothrombi...
Brault LS, Famula TR, Penedo MC.To determine the mode of inheritance for cerebellar abiotrophy (CA), a neurologic disease in Arabians. Methods: 804 Arabians, including 29 horses (15 males and 14 females) with CA. Methods: Most horses (n = 755) belonged to 1 of 4 paternal families. Among the 29 CA-affected horses, all had clinical signs consistent with the disease; the disease was confirmed histologically following euthanasia in 8 horses. From the pedigree information, inbreeding coefficients were calculated for 16 affected horses and compared with coefficients for a subgroup of 16 unaffected horses. Complex segregation analy...
Chénier S, Macieira SM, Sylvestre D, Jean D.An 11-year-old Quarter horse mare was presented for recurrent episodes of colic. A chronic intestinal pseudo-obstruction was diagnosed. Medical treatment and surgical resection of the colon were performed but the condition did not improve and the horse was euthanized. Histopathological examination revealed a myenteric ganglionitis of the small intestine and ascending colon. Une jument Quarter Horse âgée de 11 ans a été présentée pour coliques récurrentes. Une pseudo-obstruction intestinale chronique a été diagnostiquée. Le traitement médical et la résection chirurgicale du côlon ...
Horohov DW, Loynachan AT, Page AE, Hughes K, Timoney JF, Fettinger M, Hatch T, Spaulding JG, McMichael J.Rhodococcus equi is a soil borne bacterium that causes severe morbidity and death in young foals. The economic costs of the disease include loss of life, treatment expenses, veterinary monitoring expenses and, perhaps most importantly, potential reduction in future athletic performance in horses that suffer severe lung abscessations caused by R. equi. Current standard of care for pneumonia caused by R. equi is treatment with a macrolide antimicrobial and rifampicin. However, the hallmark of pneumonia caused by R. equi is severe formation of pyogranulomas and a walling off effect that can preve...
Graham AS, Grosche A, Morton AJ, Polyak MM, Freeman DE.To induce ischemia and reperfusion injury in the large colon mucosa of horses in vivo and evaluate the recovery and effects of components of an organ transplant solution on mucosal recovery in vitro. Methods: 6 healthy horses. Methods: Horses were anesthetized, and ischemia was induced for 60 minutes in the pelvic flexure, which was followed by reperfusion for 240 minutes. Ischemic (n = 4 horses), reperfused (6), and adjacent control (6) colonic mucosae were isolated for in vitro testing and histologic examinations. Tissues were mounted in Ussing chambers with plain Krebs Ringer bicarbonate (K...
Delguste C, Doucet M, Gabriel A, Guyonnet J, Lepage OM, Amory H.This study assessed the feasibility of measuring tiludronate in horses using a minimally invasive bone biopsy technique. Eight horses were treated with intravenous (IV) tiludronate [1 mg/kg bodyweight (BW)], either once (n = 4) or twice, 28 d apart (n = 4). The horses that were treated once were euthanized on days 1, 43, 57, or 92 and those that were treated twice, were euthanized on days 112, 154, 194, or 364. Bone samples were taken bilaterally from each horse at 4 sites: the third metacarpal bone (MCIII), the 13th rib (R13), the tuber coxae (TC), and the cuboid bone (CB). Test samples were ...
Wilkołek P, Szczepanik M, Gołyński M, Adamek L, Pomorska A, Maj-Martyniuk M, Sitkowski W.The main aim of this study was to compare selected nonspecific immunity parameters in 14 allergic and 12 healthy horses. Each animal was assessed according to the following parameters: in vitro functional capacity of phagocytic cells using the nitro blue tetrazolium chloride reduction test, both spontaneous (NBT) and zymozan stimulated (NBTs), and ingestion capacity of phagocytic cells using a phagocytic index test (IF) and percentage of phagocytosing neutrophils activity (%KF). Differences were demonstrated between the group of allergic horses, especially with severe allergy symptoms, and hea...
Berg LC, Thomsen PD, Andersen PH, Jensen HE, Jacobsen S.mRNA expression of the acute phase protein serum amyloid A (SAA) in histologically normal tissues derived from horses (n=13) and cattle (n=4) was investigated by quantitative reverse-transcriptase real-time polymerase-chain reaction. As expected, high constitutive SAA mRNA expression was demonstrated in hepatic tissue in both species. In horses, moderate (>1% of the hepatic expression) SAA mRNA expression was detected in the lung, mammary gland, pancreas, synovial membrane, thymus, thyroid gland and uterus. Other equine tissues and organs sampled included adipose tissue, adrenal gland, aort...
da Silva AC, Brass KE, da Silva Loreto E, Vinocur ME, Pozzobon R, da Silva Azevedo M.The aim was to detect the presence of polymorphisms at exons 1, 2, 3 and 4 of the Spi2 gene, and evaluate a possible association between them and recurrent airway obstruction (RAO) or inflammatory airway disease (IAD) in thoroughbred horses, through single-strand conformational-polymorphism (SSCP) screening. Although polymorphism was not detected in exons 1, 2 and 3, three alleles and six genotypes were identified in exon 4. The frequencies of allele A (0.6388) and genotype AA (0.3888) were higher in horses affected by RAO, although no association was found between polymorphism and horses with...
Tóth T, Broström H, Båverud V, Emanuelson U, Bagge E, Karlsson T, Bergvall K.Treatment and protection of wounds in horses can be challenging; protecting bandages may be difficult to apply on the proximal extremities and the body. Unprotected wounds carry an increased risk of bacterial contamination and subsequent infection which can lead to delayed wound healing. Topical treatment with antimicrobials is one possibility to prevent bacterial colonization or infection, but the frequent use of antimicrobials ultimately leads to development of bacterial resistance which is an increasing concern in both human and veterinary medicine. Methods: Standardized wounds were created...
Santos CE, Marques LC, Zanette RA, Jesus FP, Santurio JM.A cutaneous Pythium insidiosum reinfection was diagnosed in an equine in Brazil. Lesions with focal presentation appeared 2 years apart. The first infection and even immunotherapy were not likely to develop enough immune response to prevent reinfection. The use of adjuvants should be considered in the immunotherapy of pythiosis.
Gaschen L, LeRoux A, Trichel J, Riggs L, Bragulla HH, Rademacher N, Rodriguez D.The magnetic resonance (MR) imaging findings of foals with infectious and noninfectious arthritis are described. Six foals with infectious arthritis and three foals with noninfectious arthritis were grouped based on synovial fluid analysis results and examined with radiography and MR imaging. Four out of six foals with infectious arthritis had osseous lesions in MR images indicative of osteomyelitis and only 4/19 lesions were detected on digital radiographs. The three foals with noninfectious arthritis had no osseous lesions in MR images or radiographically. Of the six joints that had osseous ...
Herrera HD, Duchene AG, Croxatto JO, Burgués N, Amusquibar H.Vascular tumors of the conjunctiva in the horse are rare. We present a unique case of an intravascular papillary endothelial hyperplasia of the conjunctiva. Methods: Horse. Methods: Case report. A 6-year-old-mare presented with a red mass in the conjunctiva of the left eye. After complete ophthalmologic examination the lesion was excised. The tissue was processed for light microscopy and studied histopathologically. Results: Pathologic examination revealed a nonencapsulated vascular lesion composed of confluent vascular spaces filled by multiple papillary structures composed of a central colla...
Dart AJ, Dowling BA, Hodgson DR, Rose RJ.To evaluate high-speed treadmill videoendoscopy as a diagnostic technique and document the abnormalities found in Australian horses referred for poor performance associated with abnormal upper respiratory tract noise but where a definitive diagnosis could not be made at rest. Methods: A retrospective clinical study using client-owned horses. Methods: The clinical records and videorecordings of all horses referred to the University of Sydney for poor performance associated with abnormal upper respiratory tract noise during a 13-month period were examined. Only horses with a normal physical exam...
Misumi K, Tagami M, Kamimura T, Miyakoshi D, Helal IE, Arai K, Fujiki M.To quantify the urinary concentration of cartilage oligomeric matrix protein (COMP), and to evaluate the relationship between urinary COMP concentration and the catabolic activity of synovial fluid (SF) in diseased horses. Methods: COMP in horse urine was detected by immunoblotting with a monoclonal antibody (mAb; 14G4) raised against equine COMP from articular cartilage. Urine and serum samples were obtained from 83 Thoroughbred horses with aseptic joint diseases (AJD, 79 horses) or septic joint diseases (SJD, four horses) at the time of anesthesia induction, and samples of SF were obtained d...
Jordana M, Martens A, Duchateau L, Haspeslagh M, Vanderperren K, Oosterlinck M, Pille F.Controversy exists about the specificity of diagnostic analgesia of the digital flexor tendon sheath (DFTS) in horses. Objective: To evaluate the degree of diffusion of mepivacaine from the equine DFTS to adjacent synovial structures. Methods: Crossover experiment. Methods: Under general anaesthesia, the DFTS of one front and one hindlimb of 8 horses were injected simultaneously with mepivacaine. Synovial fluid samples of the injected DFTS, the adjacent metacarpo-/metatarsophalangeal (MCP/MTP) joint, proximal interphalangeal joint, distal interphalangeal joint, navicular bursa and contralatera...
Baratt RM.Radiography is an important imaging modality and is available to most equine veterinarians providing primary care. Diagnostic radiographic imaging of the equine skull and dentition requires careful positioning and technique. This article is aimed at providing the veterinarian with instructions and guidelines for obtaining diagnostic skull and dental radiographs and a discussion of the radiographic signs of dental disease with case-based examples. The limitations of radiography are discussed with regard to determining the need for adjunct diagnostic techniques and more advanced imaging techniqu...
Little D, Redding WR, Blikslager AT.To determine prevalence and risk factors for development of ileus of the large intestine after surgery in horses, identified by reduced postoperative fecal output (RPFO). Methods: Retrospective study. Methods: 37 horses that developed RPFO after undergoing general anesthesia for reasons unrelated to the gastrointestinal tract. Methods: Fecal output was obtained from medical records as number of defecations per 24-hour period after surgery; RPFO was defined as < or = 3 defecations per 24-hour period after surgery. The reference population included 48 horses that defecated > or = 4 times during ...
Rashmir-Raven A.Hereditary equine regional dermal asthenia is a form of Ehlers-Danlos syndrome, and has an autosomal recessive mode of inheritance. Affected horses are typically born normal and develop lesions within the first 2 years of life. The most common symptoms of the disease include stretchy, loose skin that feels doughy or mushy. More severely affected horses experience spontaneous skin sloughing and extensive lacerations, hematomas, and seromas from minor trauma. Affected horses have a higher than expected incidence of corneal ulcers. DNA testing can normal, establish carrier and affected status. Pa...
Dik KJ, Dyson SJ, Vail TB.The anatomy of the digital flexor tendon sheath and related tendons and ligaments is described. Diagnosis and management of acute tenosynovitis and long-term tenosynovitis and associated tendon injuries are discussed, as well as the syndrome of stenosis of the fetlock canal (or fetlock annular ligament constriction) and palmar annular ligament constriction. Desmitis of the palmar annular ligament is also described.
Johnston JK, Freeman DE.Displacements and intraluminal obstructions of the large colon carry a good to excellent prognosis for long-term recovery, and surgery for these diseases is rarely followed by short-term or long-term complications. Entrapment of the large colon over the renosplenic ligament is amenable to medical therapies so that surgery can be avoided in many cases. However, preoperative diagnosis of all nonstrangulating diseases of the large colon can be difficult. Vascular diseases of the large colon, such as thromboembolic diseases and large colon volvulus, are more difficult to treat and carry a poorer p...
Gudmundsdottir KB, Svansson V, Aalbaek B, Gunnarsson E, Sigurdarson S.Twenty isolates of Listeria monocytogenes associated with five confirmed and four suspected incidents of listeriosis in horses in Iceland were characterised by serotyping, pulsed-field gel electrophoresis and ribotyping. Semiquantitative estimates of the numbers of L monocytogenes were made on faeces from horses with clinical signs of listeriosis and on grass silage fed to them. Large numbers of L monocytogenes were often found in the faeces of horses with severe signs of disease. The 20 isolates could be divided into six genotypes, each incident involving only one genotype. One serovar 1/2a g...
Verhaar N, Hermans H, van Rooij E, van Oldruitenborgh-Oosterbaan MS, Ensink J.In tropical and subtropical climates, infection of periocular tissue by Habronema larvae is a recognised cause of conjunctivitis or blepharitis. To the authors' knowledge, only a few cases of habronemiasis have been described in Western Europe, and it has not been documented previously in the Netherlands. The objective of this report is to describe the occurrence of five cases of (peri)ocular habronemiasis in the Netherlands, of which four date from the past few years. The diagnosis was based on the history, clinical signs and histopathologic examination of biopsy specimens. A granulomatous co...
Pepe M, Angelone M, Gialletti R, Nannarone S, Beccati F.Although arthropathy of the cervical articular process joints (APJs) is common, descriptions of the arthroscopic technique of the cervical APJ have not been reported previously. Objective: To develop an arthroscopic approach to the APJ and to describe the arthroscopic anatomy of the APJ. Methods: Descriptive cadaver study and clinical case report. Methods: The regional anatomy was reviewed and the technique developed on fresh cadaver necks. A series of cadaveric APJ arthroscopies from C2-C3 to C6-C7 were performed to evaluate the procedure, which was then used in 3 clinical cases. A descriptio...
Couëtil LL, Hoffman AM.A 3-day-old female Pinto was admitted with profuse watery diarrhea and severe hypovolemic shock. After 1 week of intensive care, the foal developed seizures associated with profound serum electrolyte abnormalities suggestive of hypoadrenocorticism. Treatment with prednisone and isotonic saline (0.9% NaCl) solution led to prompt clinical response. Premature withdrawal of prednisone resulted in relapse of clinical signs. A diagnosis of adrenal insufficiency was made on the basis of clinical signs, electrolyte abnormalities, low baseline cortisol concentration, and lack of response to administrat...
Galvin P, Gildea S, Nelly M, Quinlivan M, Arkins S, Walsh C, Cullinane A.Equine influenza (EI) is a highly contagious respiratory disease of horses. Objective: The aim of this study was to evaluate two rapid antigen detection kits (Directigen or DFA, and Espline) and a commercial ELISA for the detection of EI nucleoprotein in nasal swabs. Methods: Nasal swab samples from naturally and experimentally infected horses were used to compare the sensitivity and specificity of these assays to virus isolation (VI) and real-time RT-PCR. Results: If real-time RT-PCR was considered as the gold standard, the sensitivity of the other tests in field samples was 68% (DFA), 35% (E...
Chen Y, Cai S, Zhang Y, Lai Z, Zhong L, Sun X, Li S, Lu G.Equine hepacivirus (EqHV) is a newly discovered hepatitis C virus-like virus that can infect equines. EqHV strains circulating worldwide have been classified into subtypes 1-3. In previous studies, we detected the presence of EqHV strains of subtype 1 and 3 in China. To determine whether EqHV strains of subtype 2 are prevalent in China, serum samples were collected from 133 racehorses in Guangdong province in 2021 and were tested for EqHV RNA by RT-PCR, and the positive rate was 9% (12/133). Sequencing of the NS3 gene revealed that one field strain (GD2021) had a high degree of genetic similar...
Milner PI, Sidwell S, Talbot AM, Clegg PD.Primary lesions of the deep digital flexor tendon (DDFT) within the digit are an important cause of lameness diagnosed using magnetic resonance imaging (MRI) but appearance of these lesions over time has not been documented. Objective: To determine whether the magnetic resonance (MR) appearance of different primary DDFT lesions alter over a 6 month period and whether lesion type is a determinant of these changes. Methods: Cases included had lameness attributable to a primary lesion involving the DDFT in the digit diagnosed on MRI. Lesions were typed into parasagittal, dorsal border and core le...