Avaliação clínica e laboratorial em bezerros holandês primoinfestados experimentalmente com Rhipicephalus (Boophilus) microplus

• Ano de defesa: 2013
• Autor(a) principal: Gustavo Henrique Ferreira Abreu Moreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: carrapato; resposta inflamatória; bovinos; anemia; Anemia; Bezerro Parasito; Boophilus microplus; Carrapato; Bezerro Doenças
• Link de acesso: http://hdl.handle.net/1843/SMOC-9WRPMS

The aim of the present study was to evaluate the behavioral and hematological changes and the inflammatory response of Holstein calves undergoing experimental primary Rhipicephalus (Boophilus) microplus infestation. Five males Holstein calves, five months old, were experimentally infested at three different times. A total of 4500 larvae were placed on each calf. The larvae were distributed into two points in the dorsal-caudal base of the neck and two parallel points near the tail base. Clinical examination and measurements of the skin thickness and the left and right superficial cervical and subiliac lymph nodes were daily performed. Skin biopsies were made for histological evaluation of the local inflammatory response. In addition, blood samples for hematological, biochemical and serum proteinogram analyzes were collected. Statistical differences were found in the average count of females 4.5 mm as well as in the behavior pattern of the calves and mucosal score during the experimental period. There was significant variation (p<0.05) of heart and respiratory rates, rectal temperature and serum biochemistry, however, these variations could not be associated with the time of infestation. There were no statistical differences in red blood cell counts and average mast cell counts during this period, although values had varied according to the infestation time for both variables (p>0.05). In contrast, this trend could not be observed in leukogram, even in monocyte counts, which showed a significant variation among some days (p<0.05). In serum proteinogram, statistical differences were observed only for alfa-globulins, more specifically at day 21 post-infestation. A trend of increasing skin thickness and lymph nodes size was observed during the experimental period, with the highest values obtained at the end of the infestation (p<0.05). On histological analysis of the skin, there was a slight increase in mononuclear inflammatory infiltrate after the third peak of infestation. Low R. microplus infestation of calves can stimulate local and systemic host response without causing significant changes in clinical and laboratory parameters