Contributed Papers: Posters Pathology |
Experimental
production of necrotic enteritis and its use for studies
on the relationships between necrotic enteritis and
coccidiosis in chickens.
Ralph. N. Marshall a,
Ray. B. Williams.b, Roberto. M. La Ragione.a, Jacqueline.
A. Marshalla, aVeterinary Laboratories Agency (Weybridge),
New Haw, Addlestone, Surrey, KT15 3NB; bSchering-Plough
Animal Health, Breakspear Road South, Harefield, Uxbridge,
Middlesex UB9 6LS.Corresponding Author: r.n.marshall@vla.defra.gsi.gov.uk
Necrotic enteritis
is a potentially fatal disease of poultry, and is
both a welfare and economic problem. The disease is
an enterotoxaemia caused by Clostridium perfringens
types A and C, and manifests itself when the presence
of high numbers of bacteria coincides with significant
damage to the gut epithelium. Gut damage caused by
various species of the coccidian genus Eimeria has
been implicated. A new method for the experimental
production of necrotic enteritis in chickens is described,
and this was used to examine the relationship between
clostridial and coccidial infections. Groups consisted
of an uninfected control, a group which received Cl.
perfringens only, another which received Eimeria maxima
only, and a fourth which received E. maxima followed
by Cl. perfringens. In all cases the Cl. perfringens
was administered directly to the intestine using a
catheter, and the disease monitored. Parameters measured
were clinical symptoms, lesions and weight gain. Results:
Coccidiosis caused by virulent E. maxima exacerbated
lesions of necrotic enteritis and other clinical effects
caused by a subsequent challenge of virulent Cl. perfringens
type A. This group had the highest lesion score, and
also a highly significant weight difference when compared
to all other groups.