Camelidae and Cervidae Pericarditis and Epicarditis – NAVLE Study Guide

Overview and Clinical Importance

Pericarditis (inflammation of the pericardium) and epicarditis (inflammation of the epicardium/visceral pericardium) represent important cardiovascular conditions in camelids and cervids. While relatively uncommon compared to cattle, these conditions carry significant clinical importance for veterinary practitioners working with llamas, alpacas, deer, and elk. The pericardium consists of two layers: the fibrous pericardium (outer layer) and the serous pericardium, which is divided into the parietal layer (lining the fibrous pericardium) and the visceral layer (epicardium, covering the heart surface). Inflammation of these structures leads to fluid accumulation, fibrin deposition, and potentially life-threatening cardiac tamponade.

In camelids, pericarditis most commonly occurs as part of polyserositis associated with septicemic bacterial infections, particularly Streptococcus equi subspecies zooepidemicus (alpaca fever). In cervids, pericardial disease is less well documented but can occur secondary to systemic infections, trauma, or as part of multisystemic disease processes.

Anatomical Considerations

Camelid Cardiac Anatomy

The alpaca heart is located in the middle mediastinum with a craniocaudal extension from the third to the sixth rib. Unlike domestic ruminants, no ligament connects the fibrous pericardium to the sternum or diaphragm in alpacas, which may have implications for pericardial mobility and disease presentation. The Purkinje fiber network in camelids penetrates completely through the ventricular wall from endocardium to epicardium (similar to sheep), resulting in distinctive ECG patterns that differ from dogs and cats.