ABSTRACT A Quarter Horse mare was presented with a history of imidocarb intoxication. During the initial evaluation, the patient presented an initial episode of syncope, in addition to a Grade III/IV diastolic murmur. On the basis of the observed condition, the animal underwent echocardiographic evaluation, in which artifacts were detected and subsequently characterized as air bubbles, restricted to the right cardiac chambers. A diagnosis of venous air embolism resulting from right jugular venocatheterization was made. This is the first reported case of venous air embolism secondary to jugular venocatheterization diagnosed by means of transthoracic echocardiography in a horse.