Lameness in a mare with signs of arteriovenous fistula.

This research study involves a case where a 5-year-old mare exhibited lameness and swelling in its right forelimb, and after various clinical tests, it was suspected to have an arteriovenous fistula. However, attempts to identify the fistula through angiography and surgical exploration were unsuccessful, potentially due to the closure of the shunt during anesthesia.

Background and Clinical Assessment

• The mare in the study started showing signs of lameness and swelling of the right forelimb which prompted the clinical examination. Lameness in horses can arise due to various causes, including injuries, infections, or systemic diseases.
• The clinical findings depicted several symptoms that pointed towards a potential arteriovenous fistula. Arteriovenous fistulas are abnormal connections or passageways between an artery and a vein. They are rare in horses, and can lead to diverse symptoms, including those observed in this case.

Detection failure of Arteriovenous Fistula

• The attempt to identify the fistula through angiography, a medical imaging technique used to visualize the inner structure of blood vessels and organs, did not succeed. The researchers linked this failure to the possible closure of the shunt (another name for the arteriovenous fistula) during the anesthesia process.
• Further, a surgical exploration to locate the shunt was also not successful. Thus, despite the strong initial indications of an arteriovenous fistula, the mare’s condition remained unconfirmed due to the inability to clearly identify the fistula.

Significance and Conclusion

• This case study is significant as it portrays the challenge in diagnosing and treating arteriovenous fistulas in horses, despite clear clinical signs. Further research may be beneficial to investigate effective techniques for the diagnosis and treatment of these fistulas in horses.
• Moreover, the research indicates the possibility for anesthesia to potentially close an existing shunt, making it undetectable during angiography or surgical exploration. This points to the need for alternative or supplementary approaches in cases with similar symptoms, to ensure a successful diagnosis and treatment plan.