Cystic echinococcosis due to Echinococcus equinus in a horse from southern Germany.

The research presents the first recorded case of Echinococcus equinus infection, a parasitic disease, in a horse born and raised in Germany. The study further confirms the diagnosis through molecular analysis.

Echinococcus equinus Infection

• The research focuses on a particular infection in a 19-year-old mare from Germany. It suffered from symptoms such as loss of appetite, weakness, and respiratory difficulties.
• The disease is identified as cystic echinococcosis, which is caused by various Echinococcus species. However, this specific case was due to Echinococcus equinus.
• Responsible for equine cystic echinococcosis, Echinococcus equinus, sometimes referred to as the “horse strain” of the parasite, is known to produce fertile cysts.

Occurrence of E. equinus Infection

• This parasitic infection is considered rare in horses in Europe and is usually diagnosed either during slaughter or post-mortem examination.
• E. equinus is endemic in certain regions such as Great Britain, Ireland, Spain, and Italy, with sporadic reporting in Belgium and Switzerland. However, this is the first confirmed case in Germany.

Disease Detection and Diagnosis

• The diagnosis procedure started with x-ray radiographs of the thorax which identified two well-defined masses in the rear lung field, each about 10 cm in diameter resembling tumors.
• Due to the rapid deterioration of the horse’s health, it was euthanized. A necropsy found two hydatid cysts, each of 7-8 cm in diameter, in the lungs.
• Microscopic investigation of the cysts revealed a multilayered structure while the interior contained a clear amber liquid with hydatid sand and free protoscoleces.

Molecular Confirmation of E. equinus

• For thorough confirmation, samples of protoscoleces, the infective larvae of the echinococcus parasite, were subjected to molecular characterization.
• The infection was finally proven to be E. equinus through methods of restriction fragment length polymorphism-polymerase chain reaction and sequence analysis of the mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene.