Avian Medicine in Malaysia

Blood parasites, leucocytes and plumage brightness in the Cirl Bunting,Emberiza cirlus

“…The age‐related differences in the proportions of different leucocyte cells reported in this study closely match those predicted by previous studies (see review in Campbell & Coles 1986). The reasons for these differences are not clear, although they apparently could be explained by a higher incidence of endoparasites in young individuals (see Fudge 1989), or a higher eosinophil activity in response to recently acquired infections in young.…”

“…In this case we have not examined the correlation of plumage brightness with the loads of any, usually randomly chosen, species of parasites, but have used a more general estimator of health status, in this case leucocyte counts. In birds, cellular immunity is usually mediated by heterophilic granulocites and lymphocytes, and the number and proportion of the different types of leucocytes reflect the levels of stress and health (Rose, Hesketh & Ogilvie 1979; Davis 1981; Hawkey et al 1983; Fudge 1989; Averbeck 1992; Ots, Murumägi & Hõrak 1998). Dramatic increases in the number of leucocytes (leucocytosis) is most commonly due to infectious disease, and leucocytes quickly react to a great variety of diseases including bacterial infections and blood parasites (Fudge 1989).…”

“…They enter the tissues during the inflammatory response and their lysis could be harmful to the host tissues (Parslow 1994). Relative increases in lymphocytes are usually associated with the presence of blood parasites, while relative heterophilias are commonly seen in bacterial infections moving from low‐grade towards clinical infections (see Fudge 1989). Relative increases in basophil number are characteristic of respiratory infections and relative increases in monocytes characterize granulomatous diseases (Fudge 1989).…”

“…Relative increases in lymphocytes are usually associated with the presence of blood parasites, while relative heterophilias are commonly seen in bacterial infections moving from low‐grade towards clinical infections (see Fudge 1989). Relative increases in basophil number are characteristic of respiratory infections and relative increases in monocytes characterize granulomatous diseases (Fudge 1989). Intestinal parasites usually produce increases in the relative frequency of eosinophils, although this response sometimes does not occur in birds (Dieterlen‐Liévre 1988; Fudge 1989).…”

“…Relative increases in basophil number are characteristic of respiratory infections and relative increases in monocytes characterize granulomatous diseases (Fudge 1989). Intestinal parasites usually produce increases in the relative frequency of eosinophils, although this response sometimes does not occur in birds (Dieterlen‐Liévre 1988; Fudge 1989).…”