I know of a daugther and grand son of Pakrus that both dropped dead in the same kennel with no previous symptoms and nothing found on postmortum (3 and 4 years old). Has anyone heard of this from this line before?

I'm not sure about the Pakrus line, but Sudden Death Syndrome runs in all lines of GSD. It appears more frequent in certain lines than others. You can read this article for more info:

Inherited ventricular arrhythmias and sudden death in German shepherd dogs.

Moise NS, Meyers-Wallen V, Flahive WJ, Valentine BA, Scarlett JM, Brown CA, Chavkin MJ, Dugger DA, Renaud-Farrell S,Kornreich B, et al.

Source

Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853.

Abstract

OBJECTIVES:

This report describes a unique group of German shepherd dogs with inherited ventricular arrhythmias and sudden death. Before death, these dogs have no evidence of cardiovascular failure.

BACKGROUND:

There are few spontaneous animal models of sudden death that permit intensive investigation.

METHODS:

To determine the temporal evolution of ventricular arrhythmias and to characterize the syndrome of sudden cardiac death in these dogs, 24-h ambulatory electrocardiographic (ECG) monitoring, echocardiograms, electrophysiologic testing and breeding studies were conducted.

RESULTS:

The 24-h ambulatory ECGs from dogs that died showed frequent ventricular arrhythmias with rapid polymorphic ventricular tachycardia (rates > 480 beats/min). Affected dogs had a window of vulnerability for arrhythmias, with the highest incidence and severity of arrhythmias between 20 to 30 and 40 to 50 weeks of age. Affected dogs that died did not have prolongation of the QT interval over a spectrum of heart rates compared with unaffected dogs. The clinical arrhythmia was not induced in dogs during programmed electrical stimulation. Severely affected dogs monitored > 5 years did not develop any evidence of heart failure or cardiomyopathy, and no histopathologic abnormalities existed. Seventeen dogs died suddenly (age 4 to 30 months) and were either 1) found dead at first observation in the morning (n = 8), 2) observed to die during sleep (n = 4), 3) observed to die while resting after exercise (n = 3), or 4) observed to die during exercise (n = 2). All sudden deaths occurred between the end of September and April, with most (n = 11) during January and February.

CONCLUSIONS:

The cause of the inherited severe ventricular arrhythmias and sudden death in these young German shepherd dogs is still undetermined. A purely arrhythmic disorder is supported by the lack of cardiac pathology. Moreover, the window of vulnerability to ventricular arrhythmias and the age and circumstances of death invite speculation about the role of the autonomic nervous system.

Thanks, I'll pass it along. Neither dog had any hsitory of 'heart problems' and the last dog was hooked to an ekg and showed normal heart rhythms even as it was dying. Strange.