Bovine Trypanosomiasis: Retrospective Investigation and Clinical Signs

Abstract

Trypanosoma vivax is a protozoan that causes Bovine tripanosomiasys. Originally
from Africa, the disease has become common in other countries. Bovine trypanosomiasis is a
disease underdiagnosed in many parts of the world, including Brazil. The lack of knowledge
regarding this protozoan is a factor that contributes to the rapid spread of the disease. Many
losses are attributed to the disease, including death of animals. This study aimed to perform a
retrospective investigation of cattle with T. vivax that had blood samples forwarded to Veterinary
Hospital of Uberaba-Brazil by performing the Buffy coat technique. The collected data
showed that in 285 suspected animals, that had samples submitted to Hospital Veterinário de
Uberaba, 17.54% were positive. Separating in gender, females had 22.37% of positivity rate
and males 2.13%, which is explained by the handling of the animals where handlers are able
to see signs of the disease and decreased milk production, besides the use of the same needle
for oxytocin application before milking that spreads the disease for many animals in a short
period of time. The biggest prevalence among ages was seen in animals between 1 to 12 months
(35% of positivity) and 12 to 24 months of age (61.64% of positivity), possibly because of
the immune system development, younger animals do not have immunity to the disease. The
breed that most showed positivity was Holstein dairy breed (100%). The opportune diagnosis
of T. vivax is an important finding since the disease leads to large losses in cattle ranching and
prejudices the economic system.