Infections in horses encompass a range of diseases caused by various pathogens, including bacteria, viruses, fungi, and parasites. These infections can affect different systems within the horse, such as the respiratory, gastrointestinal, and integumentary systems, leading to a variety of clinical signs depending on the pathogen and the severity of the infection. Common infectious diseases in horses include equine influenza, strangles, and equine herpesvirus. Diagnosis often involves clinical examination, laboratory testing, and sometimes imaging, to identify the causative agent and assess the extent of the disease. Treatment strategies may include antimicrobial therapy, supportive care, and preventive measures such as vaccination and biosecurity practices. This page aggregates peer-reviewed research studies and scholarly articles that explore the pathogenesis, diagnosis, treatment, and prevention of infectious diseases in equine populations.
Jacobsen K, Gintz T, Reed SM, Newbry J, Bayly WM, Perryman LE, Leid RW.Equine neutrophils (PMN) were isolated to greater than 99% purity by isopyknic sedimentation on coated colloidal silica particles. A cell recovery of 84.7 +/- 4.0%, with a viability of greater than 99%, was observed with this method. The isolated PMN were compared with mixed population of equine peripheral leukocytes with respect to functional integrity by chemiluminescence and bactericidal assays. There was no significant difference (P less than 0.01) observed in either assay between the isolated equine PMN and the mixed-cell populations. The methods used in both the isolation as well as the ...
MacMillan AP, Baskerville A, Hambleton P, Corbel MJ.Five mares, one stallion and a colt foal were inoculated intraconjunctivally with Brucella abortus strain 544. No clinical signs of disease developed except mild pyrexia. Intermittent bacteraemia was detected in the mares but not in the stallion or foal. Antibodies to B abortus became detectable from the second week after inoculation. Titres in the serum agglutination and complement fixation tests declined substantially after six to eight weeks but reactions to the Coombs antiglobulin, 2-mercaptoethanol and immunodiffusion tests were maintained. No consistent changes in biochemical or haematol...
Watts DM, LeDuc JW, Bailey CL, Dalrymple JM, Gargan TP.Serological data accumulated during the past decade indicated that a variety of feral and domestic animals of the Delaware-Maryland-Virginia (DelMarVa) Peninsula were infected with Jamestown Canyon (JC) and/or Keystone (KEY) viruses (Bunyaviridae, California serogroup). Neutralizing (N) antibody to JC virus was most prevalent in white-tailed deer, sika deer, cottontail rabbits and horses. KEY virus N antibody was detected most frequently in gray squirrels and domestic goats. N antibody indicative of past infection by one or both viruses also was found in raccoons, horses and humans. JC and/or ...
White G, Prior SD.A study was carried out on the bacteriological faecal flora of horses before and after oral doses of oxytetracycline or trimethoprim plus sulphadiazine. Administration of oxytetracycline was rapidly followed by large increases in counts of coliforms. Bacteroides and Streptococcus species, the disappearance of Veillonella species, the appearance of Clostridium perfringens type A in large numbers and the accumulation of watery fluid in the rectal contents. These changes were not seen following administration of trimethoprim-sulphadiazine and it was concluded that oral treatment of horses with th...
Fayer R, Dubey JP.Eight ponies and a horse were inoculated orally with sporocysts of Sarcocystis fayeri from dogs. They were examined for clinical signs of infection and killed 10, 15, 20, 25, 30, 50 (horse), 77, 101, and 156 days after inoculation (DAI). Elevated temperature was observed in three ponies 20 and 26 DAI and anemia was observed in three ponies and the horse 15 to 69 DAI. Schizonts were found in or near cells lining capillaries or arteries of the heart, brain, and kidney 10, 20, and 25 DAI. Immature cysts containing only metrocytes were first found in muscles 50 DAI. Mature intramuscular cysts cont...
Atherton JG, Pitt TL.Pseudomonas aeruginosa isolates from equine clinical material were categorised according to their serotype and phage type. Epidemiological evidence showed that serotypes 02a, 03, 04, 06, 09 and 010 were the cause of genital and non-genital infections; somatic type 03 accounted for 50 per cent of isolates. The laboratory tests used were of no value in predicting whether or not a particular isolate was likely to be a venereal pathogen, but all the serotypes encountered had the potential to be pathogenic, given a favourable environment in which to multiply.
Anderson IG, Hasslinger MA.The faeces of 34 horses of the "Bavarian main and state studfarm Schwaiganger" (Group I) and 10 ponies (Group II) from various regions of the Federal Republic of Germany, were examined and 4 834 small strongyles were identified. Three species Cyathostomum catinatum, Cylicostephanus longibursatus and Cylicocylus nassatus, were found to be widely distributed. Although various modern anthelmintics with different effective components were used over the past 20 years, no remarkable change has been brought about in the composition of the parasitic species of the horses in the Federal Republic of Ger...
Kunkle GA, Greiner EC.An episode of dermatitis in 12 horses and many animal handlers in the Veterinary Medical Teaching Hospital of the University of Florida was attributed to the straw itch mite, Pyemotes tritici. The mite was found in abundance alfalfa hay that recently had been delivered to the hospital. Papules were the most common cutaneous lesions, and these developed on areas of the body to which the mites had easiest access. The clinical course was self-limiting, remitting when the hay supply was depleted.
Suzuki T, Ueda S, Samejima T.An enzyme-linked immunosorbent assay (ELISA) was elaborated for the detection of specific antibody to equine infectious anemia (EIA) antigen. Sera from horses experimentally infected with EIA virus were assayed by ELISA, complement fixation (CF) and immunodiffusion (ID) tests for antibody to EIA antigen. The ELISA technique was found to be much more sensitive than CF and ID tests. In addition, EIA specific antibody could be detected by ELISA at an earlier stage of infection than by CF or ID techniques. The applicability of the technique to diagnosis of EIA is discussed.
Malan FS, De Vos V, Reinecke RK, Pletcher JM.Infective larvae were harvested from a culture of eggs collected from adult Strongylus asini recovered from a free-ranging Burchell's zebra, Equus burchelli, in the Kruger National Park. Worm-free zebra, horse and donkey foals were successfully infested, but infestation failed in a mule foal. At slaughter, 117-125 days post-infestation, S. asini in their 4th moult were recovered from the liver and portal veins. This is the first report of successful experimental infestation of these hosts with S. asini.
Drudge JH, Lyons ET, Tolliver SC.In 1973-1974, 4 controlled tests were performed in pony foals (n = 17) raised parasite-free and experimentally infected with Strongyloides westeri. Administration of infective larvae by stomach tube in 1 test resulted in low-grade infections and tended to invalidate the test. Intraoral and percutaneous (intra-aural) administration of larvae resulted in suitable test infections for 1 and 2 tests, respectively. A paste formulation of dichlorvos at 36.3 mg/kg of body weight removal from 4 ponies. Treatment of 4 the dosage rate of 44 mg/kg was consistently effective (greater than 99% to 100%) for ...
Orrego A, Issel CJ, Montelaro RC, Adams WV.Five serial passages of a cell-adapted strain of equine infectious anemia (EIA) virus were conducted in Shetland ponies. The 13 recipient ponies became agar-gel immunodiffusion test-positive by 25 days after they were inoculated. The virulence of the cell-adapted strain of EIA virus markedly increased through 3 serial passages, although individual variation within passages was high. The 1st serial-passage recipient remained afebrile through 200 days, whereas a febrile episode occurred about every 185, 44, 35, and 33 days in the 2nd, 3rd, 4th, and 5th serial-passage recipients, respectively. Se...
Yilma T, Perryman LE, McGuire TC.The results of a study on the induction of IFN-alpha, IFN-beta, and IFN-gamma in normal and SCID foals showed a deficiency of IFN-gamma but not IFN-beta in SCID foals. The ability of SCID mononuclear cells to produce IFN-alpha in response to poly I:C but not to NDV may indicate a partial deficiency of IFN-alpha in SCID foals. The deficiency of IFN-gamma and presence of IFN-beta in SCID foals supports the classification of IFN-gamma and IFN-beta as immune and nonimmune interferons, respectively. Furthermore, the deficiency of IFN-gamma in SCID foals may in part explain the high susceptibility t...
McAllister RA, Sack WO.A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crown-rump length (CRL) to 500-mm CRL (including a mule of 21-mm CRL). In saggital sections of the clitoris of a 480-mm CRL fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of ...
Oikawa M, Kaneko M, Yoshikawa T.To elucidate the pathomorphogenesis of extremely shortened small-intestinal villi, occurring spontaneously in neonatal foals, the morphology of the small intestine with stunted villi was studied in eight cases. All intestinal wall elements and the villi were poorly developed. Most villi were found to be extremely short throughout the entire length of the small intestine. The villous core consisted of undifferentiated, fibroblast-like cells held loosely together by ground substance which was rich in glycosaminoglycan. Development of the villous lamina propria was poor with respect to capillarie...
Elsinghorst TA.In this fourth article of a series of papers listing first case reports of animal diseases published since 2000, the following six cases of horse diseases are discussed: Disseminated metastatic intramedullary melanoma. Lipoma of the extensor tendon sheaths. Meningoencephalomyelitis in a neonatal foal due to Salmonella agona infection. Neuronal ceroid lipofuscinosis. Placentitis due to Rhodococcus equi infection. Right atrial diverticulum in a foal. After a short introduction, the bibliographical data, the abstract of the author(s), and some additional information derived from the article are g...
Warren A.A 5-year-old Hanoverian horse was presented for a palpable and visible mass over the frontal and maxillary sinuses. Following endoscopy and radiography surgical excision was attempted. The horse was euthanized during surgery and samples of the mass were identified as malignant anaplastic sarcoma, a seldom reported sinonasal tumor in equids. Sarcome anaplasique naso-sinusien équin infecté par Escherichia coli multirésistant aux antibiotiques. Un cheval Hanovrien âgé de 5 ans a été présenté pour une masse palpable et visible sur les sinus frontal et maxillaire. Après une endoscopie et ...
Medeiros LO, Medeiros LF, Barcelos SR, Ferri S, Reiner UR.
Summary:
The authors studied glycolytic and non-glycolytic erythrocytic enzyme activities in 8 thoroughbred horses with equine infectious anemia (EIA) and 16 normal controls. Biochemical lesions were indicated, the most outstanding being a deficiency of pyruvatekinase. Adenvlatekinase could be considered as a “salvage pathway” for the formation of ATP.
Zusammenfassung:
Infektiöse Anemie bei Pferden Mangel an Pirovatokinase in Erythrocyten der Englischen Vollblutpferde
Die Autoren untersuchten die Aktivität der glykolytischen und der nichtglykolytischen Enzyme der Erythrocyt...
Abigail McGlennon of the Animal Health Trust and Andrea Vilela of the Redwings Horse Sanctuary describe the creation and impact of a new initiative to tackle strangles in UK horses.
Moorthy AR, Spradbrow PB.
Summary:
During a survey in Queensland in 1974—77 four strains of rickettsia-like organisms were isolated from the respiratory tract of horses, of which two, NS7 and NS68 were isolated from nasal swabs of clinically normal horses and two, KSDH 91 and NSDH 100, from lung samples of slaughtered horses showing gross pathological lesions in the form of acute bronchiolitis and subacute interstitial pneumonia, respectively. The isolates are characterised as rickettsia-like organisms on the basis of their morphology, tinctorial property, growth in chicken embryos, inability to grow on bacteria...
Beadle RE, Short CR, Corstvet RE, Pawlusiow J, Nobles DD, McClure JR, Guthrie AJ, Clarke CR.A soft-tissue infection model was created in eight horses by infecting subcutaneous tissue chambers with Streptococcus zooepidemicus organisms. Responses of the horses to the infections were determined by monitoring changes in the complete blood count and body temperature and by following changes in the cytology and protein content of the tissue chambers. Systemic reactions to the infections included a mild neutrophilia, mild pyrexia and mild anemia. There was a marked influx of neutrophils and protein into the chambers after they were seeded with bacteria and chamber neutrophil viability decr...
Smith LH, Adams L, Derré M, Townsend WM.To describe the successful use of endoscopy to visualize and place a soft canine ureteral stent to relieve a chronic nasolacrimal duct (NLD) obstruction in a horse. Methods: A 7-year-old, Quarter horse gelding. Methods: Under general anesthesia, retrograde nasolacrimal endoscopy was performed using an 8.5 Fr Storz Flex XC ureteroscope through the nasal punctum (NP). An obstructive web of fibrous tissue was visualized approximately 20 cm proximal to the NP. A 0.035″/150 cm hydrophilic guidewire was passed normograde from the ventral lacrimal punctum and used to puncture the stenotic tissu...