Agriculture Reference
In-Depth Information
(b)
(a)
Figure 9.16
(a) Chronic pneumonia in apical and part cardiac lobes. (b) Bovine suppurative pneumonia.
to strip the pleura, the diaphragm should be removed
(Fig. 9.16).
The possibility of
antimicrobial residues
being present
must be considered.
Endocarditis
Endocarditis
(inflammation of the endothelial lining of the
heart) is bacterial, parasitic or mycotic in origin, most often
affecting the valves. The most common lesion is
verrucose
or
vegetative endocarditis
of pigs, a valuable diagnostic lesion of
chronic swine erysipelas. The mitral valve is the main part
involved, varying degrees of rough yellowish or greyish
yellow adhering to the valve, sometimes large enough to
occlude the atrioventricular orifice. The chordae tendineae
may also show vegetations. Streptococci, especially
Str. suis
type 2, are common causes of acute endocarditis in pigs.
An extensive analysis of the results of bacteriological
investigations and judgements of samples obtained from
117 pigs and cattle diagnosed at post-mortem with endo-
carditis, between 1977 and 1989 in Hungary, was carried
out by Szazados (1991). In pigs,
Erysipelothrix rhusi-
opathiae
, a beta-haemolytic streptococci, streptococci
belonging to the viridans group,
Arcanobacterium pyo-
genes
(formally Corynebacterium pyrogenes) and
Staphylococcus aureus
, were isolated in decreasing order
of frequency. In cattle,
A. pyogenes
was isolated most
frequently.
Ulcerative valvular endocarditis due to streptococci or
Corynebacterium (A.) pyogenes
is occasionally met with
in the bovine, appearing as rough valvular plaques.
Figure 9.17
Endocarditis - classic vegetative lesion right side of
heart (Courtesy of Hal Thompson).
In sheep, verrucose endocarditis, when caused by
Streptoccus faecalis
, is usually seen on the bicuspid
valve.
Bacteria were present in the spleen, liver and kidney of
over 60% of the samples examined, and muscle and
lymph nodes were positive in over 30% of samples.
Of the 117 cases, 79 cases (67.5%) were condemned
for septicaemia. Without this type of detailed bacterio-
logical examination, however, given these statistics,
condemnation of the carcase is justified in all cases of
endocarditis (Fig. 9.17).