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OBSERVATIONS ON THE EPIDEMIOLOGY OF PORCINE PARVOVIRUS 总被引:3,自引:0,他引:3
R. H. JOHNSON B.V.SC M.R.C.V.S. Ph.D. Dip. Bact M.R.C. Path. C. DONALDSON-WOOD B.V.SC. B.Sc. HAN Soo JOD D.V.M. U. ALLENDER B.Agr.Sc. 《Australian veterinary journal》1976,52(2):80-84
Evidence presented suggests that porcine parvovirus is highly stable and infective. Introduction of virus to susceptible herds results in 100% infection rate within the following 3 months. Active immunity is associated with high persistent levels of haemagglutination-inhibitating (HI) antibody (> 256), piglets suckling immune sows acquiring HI titres between 10,000 and 40,000. Loss of passive immunity, measured by HI, occurs in a majority of pigs between 14 and 26 weeks of age (mean 21 weeks), whilst an average of 25% (2–47%) of pigs lose HI titres between 26 and 36 weeks of age. Susceptibility to challenge with virus does not occur until 3–5 weeks following loss of HI titres. In endemically infected herds 98–100% of adult pigs show serological evidence of active immunity.
A significant proportion of gilts may not be actively immune to porcine parvovirus at the time of first service, and subsequent infection may occur while these gilts are pregnant. 相似文献
A significant proportion of gilts may not be actively immune to porcine parvovirus at the time of first service, and subsequent infection may occur while these gilts are pregnant. 相似文献
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A surgical treatment of ranula in the dog is described. The main features is the insertion of a stainless steel wire loop in a drainage incision. A permanent sinus or artificial puncta is hereby produced. The adaptability of this technique is illustrated in the two unusual cases presented. 相似文献
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Angeline Warner D. V. M. Ian G. Mayhew B.V. SC. Ph.D. 《Veterinary research communications》1983,6(1):249-264
Anhidrosis is loss of the ability to sweat. The problem is seen in horses kept in a hot humid climate, and it may cause severe impairment of thermoregulation in the equine athlete. British Thoroughbreds imported to her tropical colonies are the earliest recorded cases, and since then the syndrome has come to be described as one of Thoroughbreds, usually performance athletes, undergoing acclimatization to heat and humidity. A recent epidemiologic study of cases in Florida has shown, however, that many different breeds, and long time inhabitants of a hot climate, may be affected. Equine sweat glands are of the apocrine type, and sweating is stimulated by direct local release of epinephrine from adrenergic nerve endings and by circulating epinephrine. Lack of sweating could be due to a number of possible flaws in a sequence from central nervous stimulation through sweat stimulation and secretion to delivery of sweat to the skin surface. The most likely possibilities are inadequate sweat gland response due to habituation of receptors to a high circulating level of epinephrine and occlusion of the sweat ducts by keratin plugs. Hormonal or metabolic imbalance may play a role both in the onset and secondary signs associated with anhidrosis. 相似文献
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J. Francis D.SC. M.Sc. F.R.C.V.S. D. A. Little M.V.Sc. † 《Australian veterinary journal》1964,40(7):247-253
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