Page 1027 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

1002 CHAPTER 8

VetBooks.ir 8.30 8.31

Fig. 8.30 Transrectal ultrasonogram of a horse Fig. 8.31 This horse had undergone recent colic
with aortoiliac thrombosis showing a large thrombus surgery and long-term placement of a jugular vein
attached to the ventral wall of the terminal aorta, catheter. It developed jugular vein thrombophlebitis,
which is causing interruption of the blood flow which clinically palpated as a hot, thready and fibrous
downstream of the mass (hyperechoic area on right vein proximal and distal to the skin puncture site, which
side of vessel). (Photo courtesy Graham Munroe) was moist and swollen. (Photo courtesy Graham Munroe)

administration, it often occurs in systemically ill Diagnosis
animals despite careful catheter management. In Clinical examination is often sufficient (Fig. 8.31).
these cases (e.g. horses with severe colitis), a hyper- Ultrasonography is beneficial for assessing the extent
coagulable state may predispose to the condition. of the thrombus and for determining if any pockets
In some cases, pulmonary thromboembolism or of fluid or gas are present (Figs. 8.32, 8.33). Partial
endocarditis may be a sequela to jugular throm- thrombosis may also be detected in a vein that emp-
bophlebitis. Thrombophlebitis may also occur ties slowly. Plasma fibrinogen assay and haematology
following a single i/v injection, particularly of an should be performed if thrombophlebitis is sus-
irritating substance. pected. If abnormalities are detected while a catheter
is in place, the catheter should be removed, and the
Clinical presentation tip submitted for bacterial culture.
In early cases, increased resistance to infusion
through the catheter may be the only sign. This Management
progresses to increased vessel distension distal to Removal of the indwelling catheter, if present, is
the thrombus. The thrombus may be palpable as a indicated. If the thrombus is very small, catheteri-
cylindrical firm structure within the vascular lumen. sation of the same vein lower down on the neck
Distension of the facial veins may be evident. Facial may be performed. If venous access is still required,
swelling is not often observed unless both jugular catheterisation of a remote vessel, such as the lateral
veins are involved, in which case the swelling may be thoracic, cephalic or saphenous vein is indicated.
severe. Respiratory distress can develop with severe Catheterisation of the other jugular vein is contrain-
pharyngeal oedema from bilateral thrombosis. Pain dicated due to the risk of thrombosis and the sequela
and heat on palpation are suggestive of thrombo- of severe head swelling. The jugular veins should
phlebitis. Discharge may become present at the skin also be avoided when venous sampling is required.
surface. Antimicrobial therapy is indicated if infection is