Tristeza Parasitária em bovinos na região de Botucatu – SP: estudo retrospectivo de 1986 – 2007

Abstract

ResumoFoi realizado um estudo retrospectivo dos casos de tristeza parasitária bovina (TPB) em bovinos com até um ano de idade ocorridos na região de Botucatu-SP, área de influência do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia de Botucatu -UNESP, entre os anos de 1986 e 2007. Ocorreram, nesse período, 232 casos da doença e 57 mortes. O principal agente etiológico causador da doença nesta região foi o Anaplasma marginale, identificado como um único agente em 31,5% dos episódios da doença. A maioria dos casos ocorreu no Outono, em animais mestiços e com dois a seis meses de idade. Os sinais clínicos predominantes foram: apatia, hiporexia ou anorexia, desidratação, perda de peso e palidez das mucosas. A elevada incidência e mortalidade observadas justificam ações profiláticas visando o equilíbrio entre hospedeiro, agente, vetor, e meio ambiente, evitando, assim, a forma clínica da doença e morte dos animais em rebanhos da região. Palavras-chave: Tristeza parasitária, hemoparasitas, bovinos AbstractA retrospective study of Cattle Tick Fever was made with animals up to one year old, which occurred from 1986-2007 in Botucatu-SP in the influence area of the Veterinary Hospital of the School of Veterinary Medicine and Animal Science -UNESP. There were 232 cases and 57 deaths. The main etiological agent causing the disease on this region is Anaplasma marginale identified as a single agent in 31.5% of the cases. Most of the cases occurred on autumn in mixed-blood animals two to six months old. Predominant clinical signs included apathy, hyporexia or anorexia, dehydration, weight loss and pale mucosa. The high incidence and mortality observed justify prophylactic actions to have the balance between host, agent, vector, and environment, thus avoiding the clinical form of disease and death of livestock herds in the region.

Effects and costs of a strategic selective treatment for controlling ecto - and hemoparasitosis in Holstein Friesian calves

“…However, calves between 180 and 365 days of age tended to exhibit lower positivity. This is in contrast to findings from Gonçalves et al (2011), indicating that calves between 60 and 180 days presented more tick-borne diseases, likely caused by a decrease in passive immunity and an insufficient establishment of active immunity.…”

“…Among CT calves, the situation was reversed, with animals from 91 to 180 days of age presenting a lower seropositivity index (75%) compared with other age groups. This pattern may be partially caused by a decrease in passive immunity, which occurs around three months of age (GONÇALVES et al, 2011).…”

Influencia de la infección subclínica por agentes de la fiebre por garrapatas en vacas lecheras

“…Las áreas de estabilidad enzoótica son aquellas en las que existe un balance entre la inmunidad y la enfermedad, es decir el 75% de los animales mayores de nueve meses son portadores de estos parásitos sanguíneos. Por lo tanto, podemos inferir que la mayoría de estos animales adquieren la infección cuando son jóvenes (2,3). Se incluye en el rebaño estudiado el área de Santa Catarina, en donde también se presenta dicha situación.…”

“…75% of the animals older than nine months are carriers of these blood parasites. Therefore, we can infer that most of these animals are acquiring the infection when young (2,3), this situation also in western Santa Catarina, area that is inserted the studied herd. This infection is asymptomatic in older animals since reinfections occur due to the maintenance of the tick Rhipicephalus microplus, responsible for transmission of tick fever agents (4), which causes infestations in cattle all old.…”

“…Thus, it results in a low mortality by blood parasites in adult animals. In endemic areas, where the vector population is high throughout the year, most young animals are infected, which leads to natural resistance to the disease (2,3).…”