Massive pulmonary thromboembolism in six horses

Area of Science:

• Veterinary Pathology
• Equine Medicine
• Cardiovascular Science

Background:

• Pulmonary thromboembolism (PTE) is a recognized condition in horses, but its association with generalized systemic illness in mature horses has not been well-documented.
• Previous literature has focused on PTE in younger horses or specific conditions, leaving a gap in understanding its occurrence in older, systemically ill horses.

Observation:

• This report details six cases of mature horses diagnosed with massive pulmonary thromboembolism (MPTE) post-mortem.
• Clinical data and pathological findings were reviewed for all cases, providing insights into the presentation and severity of MPTE.
• Notably, three cases were non-fatal, indicating potential survival and underdiagnosis of PTE in horses with systemic disorders.

Findings:

• Massive pulmonary thromboembolism (MPTE) is identified as an uncommon yet significant complication in mature horses suffering from medical or surgical disorders.
• The study suggests that MPTE may be more prevalent than previously assumed, particularly in systemically ill horses.
• The non-fatal outcomes in some cases imply that horses can survive PTE, leading to potential underrecognition of the condition.

Implications:

• Clinicians should consider MPTE as a differential diagnosis in mature horses with acute or severe systemic illnesses, especially those with respiratory or cardiovascular compromise.
• Further research is warranted to elucidate the true incidence and long-term outcomes of PTE in mature horses.
• Improved diagnostic strategies may be needed to identify subclinical or non-fatal cases of PTE in equine practice.