Page 860 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Gastrointestinal system: 4.2 The lower gastrointestinal tr act 835

VetBooks.ir 4.159 Table 4.9 Protocol for caecal trocharisation

• A tympanic area over the right paralumbar fossa should
be clipped, surgically prepared and blocked with 2%
lidocaine
• A 14G catheter or trochar set should be used. The catheter
or trochar should be inserted perpendicular to the skin
surface, until gas escapes. Suction can be used to expedite
decompression
• It might be beneficial to inject 10 ml of sterile saline
through the catheter prior to removal to lessen
contamination of the body wall as the catheter is removed.
Some degree of local peritonitis is expected, and severe
peritonitis may develop secondary to laceration of a viscus
or leakage from the site of intestinal puncture, although
this is rare
• A single dose of broad-spectrum antimicrobial prophylaxis
(e.g. sodium/potassium penicillin 20,000–40,000 IU/kg i/v
Fig. 4.159 Caecal trocharisation in a horse with and gentamicin 6.6–8.8 mg/kg i/v q24 h) is indicated
progressive abdominal distension and pain.

Prognosis 4.160
The prognosis for primary caecal tympany is very
good. Recurrence is most often the result of ongo-
ing management issues rather than a primary cae-
cal abnormality. The prognosis for secondary caecal
tympany depends on the primary cause.

TAPEWORM INFECTION

Definition/overview
Infestation with tapeworms is common world-
wide. While typically benign, infestation with
Anoplocephala perfoliata can be associated with colic,
particularly if large numbers are present. Fig. 4.160 Ileocaecal intussusception. Note the
numerous tapeworms.
Aetiology/pathophysiology
A. perfoliata, A. magna and Paranoplocephala mamillana Mucosal congestion, focal ulceration and muco-
are tapeworms that can be found in horses; however, sal thickening may develop at the site of A. perfoliata
A. magna and P. mamillana are not typically consid- attachment. In most cases, no clinical signs result;
ered to be pathogenic. In some areas the prevalence however, inflammation at the site is thought to pre-
of tapeworm infestation can be very high (up to dispose to the development of ileocaecal intussus-
80%). This is usually in temperate climates as com- ception (Fig. 4.160). Studies have also associated
pared with hot and arid areas. A. perfoliata infestation with spasmodic colic and
Tapeworms have an indirect life cycle. Horses are ileal impaction, and they may be associated with an
infected by ingestion of Oribatid mites, the intermedi- increased incidence of colic overall. The risk appears
ate host. Adult tapeworms can be found in the intesti- to be proportional to the tapeworm burden, and
nal tract 1–2 months following ingestion. A. perfoliata is tapeworm-associated colic appears to be more com-
most commonly found around the ileocaecal junction. mon in horses 5 years of age or younger.