Lifespan and Causes of Death in the Irish Wolfhound - Vetsuisse ...

3.8.1.3 Diagnosis
The diagnosis of epilepsy is essentially a diagnosis through the exclusion of any
other underlying disease. The owner should be asked about illnesses or trauma,
possibilities for intoxication, and vaccination history. A full neurological exam should
also be performed, but should be repeated if generalised abnormities are detected
soon after a seizure. Dogs with idiopathic epilepsy do not have inter-ictal neurological
deficits (Thomas 1994).
Differential diagnoses include seizures secondary to Portosystemic shunt (see
chapter 3.2), especially in younger animals; toxicity; structural brain disease including
tumours or scarring; and seizures second to other systemic disease processes. A full
laboratory workup is indicated to detect such possible changes. Further possibilities
include radiography, CT or MRI, and cerebrospinal fluid analysis, depending on what
other causes are suspected (Parent 2004).
3.8.1.4 Therapy
Treatment should be initiated after the second generalised seizure, if there are acute
cluster seizures or status epilepticus. The latter two states should be addressed early
and aggressively.
Phenobarbital is the drug of first choice in the treatment of canine epilepsy. The goal
is to reach a serum level of 100-120 μg/ml in the steady state, which takes between
12 and 15 days to reach.
In dogs with hepatic insufficiency or insufficient reaction to Phenobarbital alone,
potassium bromide (KBr) can also be used. Serum level in the steady state should be
between 1.2-1.6 mg/ml
3.8.1.5 Prognosis
The life expectancy of Irish Wolfhounds affected with epilepsy is reduced by about
two years (Casal, Munuve et al. 2006). This finding should be interpreted with
caution, however, since in the quoted study, the presented survival data of epileptic
Wolfhounds are likely tainted with right censored data (see 3.1.1.3) and then
compared to the Bernardi data (see 3.1.3.1), which has been shown to also be
subject to this bias in the present study.
In a population of n=126 epileptic Irish Wolfhounds, 76 (60.3%) died as a direct result
of the seizure disorder. These seizure-related deaths were classified as death during
seizure (16.1%), euthanasia due to uncontrolled seizures (65.8%), phenobarbital
hepatotoxicity (6.6%), aspiration during seizure and subsequent fatal pneumonia
(6.6%), and euthanasia due to non-recovery after a seizure (3.9%). The other 50
dogs (39.7%) died from unrelated causes. Median survival time after the first seizure
did not vary significantly between different ages at onset (Casal, Munuve et al. 2006)
as reproduced in figure 3.1 below. Again, these survival data are right censored and
thus likely too low.
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