Topic:Allergies
Allergies in horses are immune-mediated responses to environmental antigens, such as pollen, dust, mold, food, or insect bites, that result in hypersensitivity reactions. These reactions can manifest as respiratory issues, skin conditions, or gastrointestinal disturbances, impacting the horse's overall health and performance. Common allergic conditions in horses include recurrent airway obstruction (RAO), urticaria, and insect bite hypersensitivity. Understanding the underlying mechanisms of equine allergies is crucial for developing effective management and treatment strategies. This page compiles peer-reviewed research studies and scholarly articles that explore the pathophysiology, diagnosis, and management of allergies in horses, as well as their impact on equine welfare and performance.
Demonstration isolation and identification of culturable microfungi and bacteria in horse hair and dandruff. Immunochemical comparison with allergic components. Horse hiar and dandruff have been investigated for their content of microfungi and bacteria. Inoculation and incubation on V-8 agar containing penicillin and streptomycin, with subsequent colony counting and identification, revealed more than nine and five different genera of microfungi and bacteria respectively, in horse hair and dandruff. Isolation and cultivation of the quantitatively dominating species, and preparation of an extract of these were performed, followed by immunochemical comparison with extract of the horse hair and dandruff using crossed-line immuno-electrophoresis. As no imm...
RAST in the diagnosis of hypersensitivity to horse allergens. A comparison with clinical history and in vivo tests. Case history, skin tests and RAST were compared in a group (n = 40) of children with a history suggesting allergy to horses and in a group (n = 43) in whom there was no suspicion of hypersensitivity to horses. There was an agreement of 91% between case history and prick test. The same magnitude of agreement was found between case history and RAST (89%), and the agreement between RAST and prick test was 90%. The results of this investigation are clearly in contrast to earlier earlier reports, in that there was a very good correlation between prick test, RAST and case history. The results sugges...
Chemical mediators of anaphylaxis (histamine, 5-HT, and SRS-A) released from horse lung and leukocytes in vitro. Horses were sensitized to bovine plasma in Freund's complete adjuvant. Leukocytes, separated from venous blood, yielded histamine upon incubation with bovine plasma. Ioslated lung fragments incubated with bovine plasma liberated histamine and 5-HT, but not SRS-A. Pulmonary veins obtained from the same animals contracted to histamine, 5-HT and to antigen (Schultz-Dale reaction). Histamine and 5-HT probably contribute to immediate-type hypersensitivity in horses whereas the role of SRS-A is not proved.
Isolation and partial characterization of three major allergens of horse hair and dandruff. Three major allergens of horse hair and dandruff have been isolated. The fractionation procedures involved various combinations, described in detail, of ethanol precipitation below --5degreesC, cation- and anion-exchange chromatography, and gel filtration. UV absorption, quantitative immunoelectrophoresis and RAST inhibition were used to monitor the separations. Protein impurities constituted less than 5% in all cases. The molecular weights of the isolated proteins were 1.9 X 10(4), 5.1 X 10(4) and 3.1 X 10(4) daltons, respectively. The pIs were determined as 4.1, 3.8 and 3.9, respectively. Th...
Identification of allergens in extract of horse hair and dandruff by means of crossed radioimmunoelectrophoresis. Sera from 26 patients and 4 normals were examined for specific IgE binding to antigens of extract of horse hair and dandruff by means of CRIE. 22 of the patients were RAST- and intracutaneous-positive to horse extract. 4 more of the patients were RAST-negative to horse allergens, but showed allergies to extract of allergens from sources other than horse. The remaining four sera from controls were RAST-negative to horse and had no history of allergy. Antigens of horse hair and dandruff showed a significantly higher degree of binding to specific IgE in the sera from the first group of patients t...
Treatment of horses with chronic diarrhea: immunologic status. All chronically diarrheal horses given (orally) 2 series of treatments with normal horse serum recovered in 2 to 4 weeks. However, mild diarrhea sometimes persisted several months in the group of horses with severe diarrhea. Weight gains were approximately 35% in horses with severe diarrhea and approximately 10% in horses with mild diarrhea. Serum specimens from 12 diarrheal and 20 normal horses were examined for immunoglobulins by single radial immunodiffusion technique. Concentration of immunoglobulin A in serum of diarrheal horses was approximately 50% lower than that in serum of normal hor...
Serum immunoglobulin, dermal response, and lymphocyte transformation studies in horses with chronic diarrhea. Serum specimens from 12 sick and 20 normal horses were examined for levels of different classes of immunoglobulin (Ig) by a single radial immunodiffusion. The level of IgA in the sera of sick horses was about 50% lower than in the sera of normal horses. By contrast, the level of serum IgG was higher in sick than in normal horses. Phytohemagglutinin (PHA) responsiveness of blood lymphocytes showed transient suppression during the stage of severe diarrhea. The regaining of PHA responsiveness of lymphocytes was observed simultaneously with the recovery process. However, the responsiveness of lymp...
Acute systemic anaphylaxis in the horse. 1. Histamine in small doses caused systemic depressor responses in horses, whereas greater doses caused biphasic effects. All doses of 5-hydroxytrypt-amine (5-HT) were pressor and all doses of bradykinin depressor. All three active substances raised pulmonary artery pressure and lowered central venous pressure. 5-HT reduced ventilation volume. Histamine caused brief apnoea followed by hyperpnoea only.2. Acute anaphylaxis in the horse was accompanied by a severe systemic arterial depressor response, a pressor response in the pulmonary artery and vena cava, and alternating phases of apnoea and d...