Topic:Pathology
Pathology in horses involves the study of diseases and abnormalities affecting equine health, encompassing a range of conditions that can impact various systems within the horse's body. This field examines the causes, mechanisms, and effects of diseases, as well as the structural and functional changes they induce in equine tissues and organs. Common pathological conditions in horses include laminitis, colic, equine infectious anemia, and respiratory disorders. Understanding these diseases involves evaluating clinical signs, diagnostic methods, and treatment options. This page compiles peer-reviewed research studies and scholarly articles that explore the etiology, pathogenesis, and clinical implications of pathological conditions in horses.
Venezuelan equine encephalitis virus: comparison of infectivity and virulence of strains V-38 and P676 in donkeys. Two strains of Venezuelan equine encephalitis (VEE) virus were examined for the ability to replicate in, as well as to produce death among donkeys. One, a low passage strain known as strain P676 was originally isolated from mosquitos in Venezuela. The other, strain V-38 was isolated from a horse brain in 1938 and had undergone an unknown number of laboratory passages; it is used extensively for the preparation of inactivated VEE vaccine. Both strains were found to be approximately equal in their ability to infect donkeys. However, a quantity as small as 50% hamster intraperitoneal infectious u...
Normal and abnormal xylose absorption in the horse. The D-xylose absorption test was applied to clinically normal horses and to horses with signs of gastrointestinal disease. A dosage of 0.5 grams of xylose per kilogram of bodyweight was useful in detecting horses that absorbed the pentose abnormally. The clinical findings were correlated with gross and microscopic findings by biopsy and at necropsy. Gastrointestinal lesions associated with abnormal xylose absorption were classified as: 1) villous atrophy; 2) edema of the lamina propria or 3) necrosis of the lamina propria.
[Dyspnoea due to intrathoracic haemorrhage and haemangiosarcoma in a horse (author’s transl)]. Post-morten examination of a fourteen-year-old mare of the Gelderland breed, which had been treated for severe dyspnoea and had subsequenlty died, revealed the presence of haemothorax, atelectasis of the lung and a metastasized haemangiosarcoma of the left ovary. The haemothorax could have resulted from rupture of one of the metastases.
Purification, characterization, and quantitation of the antigen employed in the immunodiffusion test for diagnosis of equine infectious anemia. Equine infectious anemia (EIA) antigen extracted from the spleen of horses infected with EIA virus was purified by pH treatment, (NH4)2SO4 fractionation and affinity chromatography. The homogeneity of the antigen was indicated by sedimentation rate and sedimentation equilibrium experiments. A S20,w of 0.51 was determined and a molecular weight of 7600 was calculated from sedimentation equilibrium analysis. The amino acid composition of the pure antigen indicated the antigen is an acidic protein. Employing radical immunodiffusion (RID) and pure antigen a method for quantitating antigen content ...
Cardiac monitoring during exercise tests in the horse. 3. Changes in the electrocardiogram during and after exercise. Changes that occur in the equine ECG during and after exercise have been described and compared with resting ECG's obtained from the same horses. When the speed of work equals or is greater than "three-quarter pace" (i.e. "even time" or 200 metres in 15 seconds) the high heart rates developed cause the loss of ECG waveforms that are readily discernible at rest. Although differences in the waveforms between horses with normal and abnormal resting ECG's have been observed, the more definitive useful information is the fact that abnormal horses showed significantly higher heart rates than normal ...
Squamous cell carcinoma in horses. In a review of neoplasm registry records at Kansas State University (1961 through 1971), 58 squamous cell carcinomas were reported in 10 breeds of horses. Mean age of the affected horses was 12.4 years. The head, eye and ocular adnexa accounted for 43.1%, the external male genitalia, 44.8%, and female perineal region, 12.0% of the squamous cell carcinomas, altogether representing 20.2% of 287 neoplasms recorded.
Condylomata acuminata. A 5-year-old Thoroughbred chestnut mare was presented because of multiple lesions noticed for approximately one year over the vulva and ther perianal areas. Clinically, there were moist warts that stood out because of their whitish color which contrasted strikingly with the surrounding, normally pigmented, uninvolved skin (Fig. 1). Repeated topical applications of 20% podophyllin in 95% ethyl alcohol produced rapid involution. Histopathologically, marked acanthosis, numerous mitoses, prominently vacuolated epidermal cells and a chronic dermal inflammatory infiltrate were seen (Figs. 2, 3, and ...
LDH and LDH isoenzymes of synovial fluid in the horse. LDH is an intracellular enzyme, which when cells degenerate is released to the extracellular spaces and body fluids. Cells and organs in the mammalian body differ from each other with respect to their LDH isoenzyme patterns. These circumstances have led to the use of LDH isoenzyme determinations in laboratory diagnostic work. In the present investigation total LDH activity and LDH isoenzyme distribution in equine synovial fluid from healthy joints, joints with serous arthritis, osteochondrosis dissecans and arthrosis, were determined. The fluids from the diseased joints differed from normal sy...
Meningoencephalomyelitis in horses associated with equine herpesvirus 1 infection. During an outbreak of abortion caused by equine herpesvirus 1, a neurologic disease characterized clinically by dullness and ataxia occurred in several mares. Equine herpesvirus 1 was isolated from brain and lung of two severely affected mares. Histologically, both mares had disseminated meningoencephalomyelitis characterized by necrotizing arteritis, focal malacia in grey and white matter of brain and spinal cord, and accumulation of lymphocytes and neutrophils in paravertebral ganglia. Eosinophilic intranuclear inclusion bodies occurred in foci of necrosis in thyroid adenomas of both mares.
Light and electron microscopic investigation of equine synovial membrane. A comparison between healthy joints and joints with intraarticular fractures and osteochondrosis dissecans. Light and electron microscopic examination was made on equine synovial membrane from 23 healthy joints, nine joints with synovitis caused by intraarticular fracture and 10 joints with synovitis caused by osteochondrosis dissecans. Histologically as well as ultrastructurally the equine synovial membrane from healthy joints was of principally the same character as described in other species. Three types of synovial membrane — areolar, fibrous and adipose — and two types of lining cell were distinguished histologically. Ultrastructurally three types of lining cells were distinguished: A and Î...
Eimeria leuckarti infection in foals. This is the first report on Eimeria leuckarti infection in foals in Japan. Seven Thoroughbred or Angloarabian foals 2 to 7 months of age raised in the Hidaka district, Hokkaido, were infected with E. leuckarti. They died of severe alterations caused by the larval migration of Strongylus vulgaris, and were examined over a period from 1970 to 1973. Protozoa of this species were observed in the small intestine in all the foals. They were found mostly in vacuoles of the cytoplasm of monoclear cells in the lamina propria at or near the tip of villi. Various stages of gametocytes, oocysts, and micro...
Viscosity of equine synovial fluid. Synovial fluid samples from 51 light horses were examined with respect to their rhéologie properties. The analyses were made with a Rotovisco RV3 rotational viscosimeter. Samples from carpal, stifle and hock joints and from healthy joints, joints with synovitis and joints with infectious arthritis were studied. The analyses showed that synovial fluids from both healthy and diseased joints have complex rhéologie properties. In most samples the viscosity varied with the shear rates, the main exceptions being synovial fluids from joints with infectious arthritis. Flow curves (flow behaviour), r...
Hereditary multiple exostosis. A comparative genetic evaluation in man and horses. Comparative studies are being conducted on hereditary multiple exostosis in man and the horse. In both, there is an unquestionable inheritance pattern of a typical single, dominant, autosomal gene. Those who carry the gene have a one-half chance of transmitting it to each offspring, whereas, those who do not carry the gene do not transmit this abnormality to their progeny. The lesions are clinically and histologically similar; no persistent chromosomal irregularities have been associated with the abnormality in either man or the horse and no single evidence of malignancy in either man or anima...
Candida infection of the genital tract in thoroughbred mares. This paper describes sixteen cases of Candida infection of the genital tract in Thoroughbred mares. Clinical signs and histopathological lesions of the disease are described and the results of treatment with Lugol's solution and Nystatin are given.
Endometrial biopsy as a guide to diagnosis of endometrial pathology in the mare. A safe and simple technique of endometrial biopsy is described which the results suggest is a useful adjunct to the diagnosis of suspected pathological conditions of the uterus. In conjunction with other clinical data and a knowledge of the breeding history, histopathological findings form a basis for prognosis and treatment of the subfertile mare. A system of classification is presented as a basis for continuing work on the correlation of endometrial histopathology with fertility and breeding potential.
Preliminary observations on cranial cardiovascular changes during asphyxia in the newborn foal. This paper describes preliminary experiments designed to test the hypothesis that cerebral damage is caused by cardiovascular events involving explosive changes in cerebral blood flow during birth. These events may be responsible for the convulsive episodes of foals suffering from the neonatal maladjustment syndrome.
Selected pathological changes of the mare uterus and ovary. Focal enlargements of the uterus are palpable through the rectal wall and have various aetiology. Aspects of their diagnosis, possible pathogenesis, significance and treatment are presented. Lymphatic lacunae appear to be quite common in older mares and may occasionally give rise to large endometrial cyst, but more frequently cause widespread change throughout the uterine horns. Three unusual ovarian abnormalities are presented, a large, oestrogen-producing granulosa cell tumour, an oestrogen-producing large follicle in a 4-month-old filly, and an ectopic progesterone-producing adrenal structu...
Digitoxin metabolism by rat liver microsomes. The chest roentgenographic findings in Takayasu's arteritis include widening of the ascending aorta, contour irregularities of the descending aorta, arotic calcifications, pulmonary arterial changes, rib notching, and hilar lymphadenopathy. The single most important diagnostic sign is a segmental calcification outlining a localized or diffuse narrowing of the aorta. The other signs may be suspicious or suggestive, but the diagnostic accuracy increases when several findings are present simultaneously.
[Arterial repair after mechanical injury by migrating fourth-stage larvae of Strongylus vulgaris in the horse (a light and electron microscopic study) (author’s transl)]. Migrating fourth-stage larvae of Strongylus vulgaris, a parasite of equines, damage the intima of the anterior mesenteric artery and its larger branches and induce thrombus formation on the injured sites. As the time of larval passage through each of these branches has been exactly determined in earlier experiments, the aim of the present studies is to contribute to a more complete understanding of repair mechanisms in the process of time after thrombotic vascular injuries. Methods: five foals were separated individually to specially cleaned stables and given anthelmintic treatment till the ag...