Page 306 - Feline Cardiology

314 Section H: Arterial Thromboembolism

appears that a large majority of cats suffering from ATE
have recurrent ATE, and a majority likely succumb to
this disorder. Published percentages of 20–75% may
reflect regional differences or underreported cases.
However, although the diagnosis of cardiogenic ATE
carries a poor prognosis, it is important to keep in mind
that treating these patients can still be fulfilling and may
result in good quality of life for an extended period of
time. In one report, when evaluating ATE cats that were
discharged from the hospital (19/49), the mean survival
time was 13.4 months (range of 3 days to 73 months).
Four cats were still alive at the time the report was pub-
lished, with the longest having survived 39.5 months at
that time (Schoeman 1999). In general, most studies Figure 20.9. A wound secondary to tissue necrosis in a hindlimb
have reported that 1/3 of affected cats survive to dis- following an episode of ATE in a cat. Photograph courtesy of Dr.
charge (Smith and Tobias 2004). However, as suggested Kristin MacDonald.
by Dr. Smith in her review, these results may reflect clini-
cian and owner bias in the face of a disease with a poor
prognosis. In general, in cases where the patient’s pain
Arterial Thromboembolism of catastrophic disease (for example, azotemia associ-
can be adequately controlled and there is not evidence

ated with renal artery embolization), the authors often
suggest initiating therapy to assess response over the first
few days. It is important to consider possible factors
suggestive of a worse prognosis in the individual patient
(hypothermia, etc.) when making these decisions.
Therapy directed at the underlying cause of thrombo-
embolism (most often cardiomyopathy) and CHF (when
present) is crucial for these patients. CHF also signifi-
cantly impacted long-term survival, suggesting that
the ability to control underlying heart disease is a
significant factor in survival of these cats. The mainstay Figure 20.10. A soft brace placed on a cat post-ATE to address
of CHF treatment in veterinary medicine is medical man- hock weakness and improve mobility. Photograph courtesy of Dr.
agement (see Chapter 19 for additional information Kristin MacDonald.
regarding case management of cats with congestive heart
failure). There are currently no survival data available to clearly
In most cats, motor and neurologic function of the define the superiority of one anticoagulant over another;
affected limb(s) returns over several days to weeks; however, one prospective trial evaluating clopidogrel is
however, in some cats post-ATE, limb function does not underway and it is possible this statement will become
completely return, due to neurologic dysfunction, outdated in the near future. Until that time comes, most
tendon contracture, or tissue necrosis. Wound manage- veterinary recommendations for anticoagulant therapy
ment is successful in many (Figure 20.9); however come from anecdotal experience and limited experimen-
amputation may be necessary in some patients. A tal and clinical trials (Lunsford and Mackin 2007). Of the
bandage may be useful in those patients with tendon available options, low-dose aspirin therapy is a low-risk
contracture (Figure 20.10). Rehabilitation therapy may and inexpensive option with theoretic benefit. Clopidogrel
be instituted after the first 2 days of ATE and includes is more costly but also appears to be low risk. At this time,
gentle passive range of motion, supporting the cat in a there are no nutraceuticals that have been proven to
standing position to retrain normal placement of the reduce the risk of ATE in cats. Dietary modification with
pelvic limbs and feet, and very gentle antegrade massage omega-3 fatty acids have been recommended by some.
from the feet to the hip. Owners can be trained how to However, one study which evaluated supplemented
administer rehabilitation therapy, which can be per- normal cats, found no alteration in bleeding time or
formed every 6 hours for the first 1–2 weeks of recovery, platelet function using up to 1.689 g EPA and 0.936 g
then tapered depending on neuromotor status. DHA with 60 IU vitamin E per cat (Bright et al. 1994).