Thoracic aortic aneurysm in a buck associated with caseous lymphadenitis

R.R Pinheiro,A.M.X Eloy,L.B Santiago,A Andrioli,F.S.F Alves

doi:10.1590/s0102-09352013000300012

Abstract

This paper reports the clinical, bacteriological and pathological findings of a thoracic aortic aneurysm in a four-year-old Anglo-Nubian goat buck, related to a framework of visceral caseous lymphadenitis. General clinical examination showed heart rate of 75 beats per minute, respiratory rate of 20 movements per minute and ruminal movements of four movements per minute. Superficial lymph nodes were normal upon palpation. Rectal temperature was slightly high (40.5°C). Blood test showed an intense leukocytosis (54,000/µL), characterized by strong neutrophil shift to the left. At necropsy, a large blood clot was detected in the thoracic cavity. The thickening of the myocardium and dilatation of the aorta in the thoracic portion, presenting a saculiform format was also observed. A large number of abscesses were disseminated in the media and intima layers of aorta. The aorta lumen obstruction by arterial plaques consisting of inflammatory infiltrate, predominantly neutrophilic was also detected. Abscesses were found spread in turbinate, rumen, reticulum, kidneys, liver, spleen, testicles and aorta wall. The microbiological exam of exudate confirmed Corynebacterium pseudotuberculosis as the causal agent.

Highlights

Caseous abscessation of lymph nodes and internal organs in goats and sheep, caused by Corynebacterium pseudotuberculosis, occurs worldwide and characterizes caseous lymphadenitis disease (CL)
Samples of exudate on abscesses found in aorta, kidneys, liver and testicles confirmed C. pseudotuberculosis as the causal agent of the disease, through bacteriological exam
C. pseudotuberculosis infection was disseminated into the animal organism

Summary

INTRODUCTION

Caseous abscessation of lymph nodes and internal organs in goats and sheep, caused by Corynebacterium pseudotuberculosis, occurs worldwide and characterizes caseous lymphadenitis disease (CL). Economic losses result primarily from condemnation of infected carcasses and devaluation of hides It is an important endemic infection in regions with large sheep and goats populations. CL is a cause of ill-thrift and sudden death in animals with internal abscesses. A complete blood count determined the following results: erythrocyte count of 10.5 million/mL, packed cell volume of 27%, hemoglobin of 9.2g/dL, mean corpuscle volume of 25.71 fL, mean corpuscle hemoglobin of 9.14 pg and mean corpuscle hemoglobin concentration of 35.5%. The necropsy showed a large blood clot formed inside the thoracic cavity, occupying approximately one third of the whole cavity (Figure 1). Samples of exudate on abscesses found in aorta, kidneys, liver and testicles confirmed C. pseudotuberculosis as the causal agent of the disease, through bacteriological exam

DISCUSSION

Findings

CONCLUSIONS