Clinical Examination of Farm Animals - CYF MEDICAL DISTRIBUTION

CHAPTER 8
ception. Smears prepared from rectal mucosal
scrapes, and ileum and ileocaecal lymph node biopsies
using a right-sided laparotomy, may be useful
in confirming Mycobacterium avium subsp. panatuberculosis
infection.
Examination of the faeces
The presence of faeces in the rectum or voided onto
the floor indicates active gut motility. An absence of
faeces is abnormal. The volume, consistency, colour,
fibre length (comminution), mucous covering and
odour should be noted. The comminution of the
undigested fibre in the faeces is an indication of the
degree of mastication and rumen function. Poor
comminution indicates poor rumination or accelerated
passage through the forestomachs. The consistency
of the faeces is diet dependent. Animals on
fresh spring grass at turn out may have very watery
faeces, while dry cows on a straw-based diet may
have very stiff faeces that will support a stick if
placed vertically into a pat. Cattle faeces are usually
the consistency of a thick milk shake, although it is
always more meaningful to compare the faeces of a
sick animal with the other healthy cows in the group.
Slow passage through the gut or dehydration results
in the faeces becoming dry, dark brown and ball
shaped with a shiny surface due to the covering of
mucus. In haemolytic anaemia there is an increase in
the bile salts which produces faeces of a dark green
colour. Reduction in the bile content of the faeces
produces a paler olive green. A foetid smell may
be present in salmonellosis. Normal cattle fed on unprocessed
grain have undigested grains in their faeces.
Faeces may be absent, indicating gut stasis.
Dysenteric faeces occur in salmonellosis, mucosal
disease and winter dysentery, and are composed of
a mixture of undigested blood, mucus and watery
faeces, usually with an offensive smell. Fibrin may
appear as casts or as pieces of yellow-grey material,
sometimes with sheets of sloughed mucosa. Melanic
faeces are black on gross appearance. This type of
faeces is caused by the presence of digested blood.
Digestion of the blood occurs in the abomasum and
proximal intestinal tract. The source of the blood may
be direct from the gut (e.g. haemorrhagic abomasal
ulceration) or swallowed blood from the lungs (e.g.
posterior vena caval syndrome) or from the pharynx
(e.g. bracken and/or papilloma induced tumours).
Firm dry faeces covered in excessive mucus indicate
a slower than normal passage through the gastrointestinal
tract. Bleeding from the large intestine produces
fresh blood or clots of blood in the faeces;
coccidiosis and bleeding following rectal examination
are examples. Plentiful pasty faeces may be
observed in Johne’s disease. Scant and pasty faeces
usually indicate prolonged passage through the
forestomachs. Diarrhoea may indicate an enteritis or
an osmotic pathophysiology such as ruminal acidosis
following carbohydrate engorgement. Faecal
samples can be colleced for laboratory analysis
which may include bacteriology, virology and examination
for parasitic gastroenteritis, fascioliasis,
coccidiosis and Cryptosporidium.
CLINICIAN’S CHECKLIST – THE RECTAL
EXAMINATION
The quantity and composition of faeces should be noted
Palpate the dorsal sac of the rumen for size, content and
presence
Palpate the right side to check for
Dilated and distended loops of bowel (caecum, large and
small intestine)
A solid intussusception
A dilated abomasum
Abdominal masses
Gut tie
An enlarged liver
Fibrous adhesions or peritoneal roughness
Conditions occurring in the calf
Rumen – chronic recurrent ruminal bloat, putrefaction
of milk in rumen, chronic ruminal acidosis,
ruminal impaction with fibre (pot bellied calves),
ruminal hairballs (trichobezoars)
Abomasum – abomasal hairballs (trichobezoars),
abomasal ulceration, abomasal displacement,
abomasal bloat and/or dilatation
Small intestine – intussusception, torsion of the root of
the mesentery, atresia of small intestine
Large intestine – caecal torsion, atresia coli
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