New information on heartworm in dogs for small animal vets

The BSAVA has produced a new Scientific Information Document (SID) on heartworm that is intended to provide veterinary staff in small animal practice with relevant and easily accessible up-to-date information.

Although heartworm is not endemic in the UK, the number of heartworm infections diagnosed in dogs in the UK is increasing, with most cases found in dogs that have travelled to or been imported from areas where the disease is endemic, such as southern and eastern Europe.

Heartworm is caused by the nematode worm Dirofilaria immitis and is transmitted by mosquitoes. The worms predominantly live in the pulmonary arterial system, where it causes pulmonary pathology and can result in irreversible damage to the pulmonary arterial circulation.

Although average temperature conditions necessary for transmission of heartworm are currently rarely met in the UK, with increasing temperatures and the rise in imported dogs, there’s potentially an increasing risk of heartworm becoming endemic in the UK. Therefore, it is timely that veterinary surgeons remain alert and consider the possibility of heartworm as part of their differential diagnosis when seeing relevant dogs in practice.

The clinical manifestations of heartworm range from subclinical to life-threatening, with cough, exercise intolerance and abnormal lung sounds being frequent signs in moderate cases. Diagnosis of heartworm is recommended through antigen and microfilaria testing, while radiography and echocardiography are useful as additional methods for confirming the diagnosis and staging the severity of disease.

The Scientific Information Document provides key information on heartworm including transmission, diagnosis, treatment, and prevention. The document is available to all members of the profession in the BSAVA Library.