tvpjournal.com | November/December 2015 | ToDay's VeTeriNary PracTice
aHs HearTWorM HoTLiNe Peer reviewed
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according to the american Heartworm society,
over one million dogs in the United states
are currently infected with Diroflaria immitis
(heartworms). if diagnosed in a timely fashion,
most infections can be managed medically with
good results.
However, a small percentage of dogs harboring
heartworms develop caval syndrome (cs), an acute
phase, severe form of heartworm disease (HWD)
that is fatal without prompt surgical intervention.
Most commonly seen in dogs heavily infected
with heartworms, cs often presents acutely and
progresses rapidly (Figure 1).
cs is a life threatening condition; therefore, it is
extremely important that clinicians recognize and
understand this syndrome.
WHAT IS CAVAL SYNDROME?
cs is a specifc condition that develops when a
mass of heartworms becomes situated in the right
ventricle, right atrium, and often, the vena cava
(Figure 2). These worms partially obstruct the
canine caval syndrome series
Part 1: Understanding
develoPment of Caval
syndrome
Stephen L. Jones, DVM
Lakeside Animal Hospital, Moncks Corner, South Carolina
The Heartworm Hotline column is presented in partnership between Today's Veterinary
Practice and the american Heartworm society (heartwormsociety.org). The goal of the
column is to communicate practical and timely information on prevention, diagnosis, and
treatment of heartworm disease, as well as highlight current topics related to heartworm
research and fndings in veterinary medicine.
FIGURE 1. Classic caval syndrome in a dog with
a high worm burden.
FIGURE 2. Right view of the thorax depicting adult
heartworms in the anterior vena cava ( arrows).
FIGURE 3. A mass of adult heartworms lodged
within the tricuspid valve of a dog presented with
caval syndrome (view from the right ventricle).