Angiostrongylus vasorum

Angiostrongylus vasorum

Angiostrongylus vasorum, also known as the French heartworm, is a parasitic nematode (roundworm) that infects the hearts and pulmonary arteries of its hosts. Primarily affecting dogs and wild canids, it has emerged as a significant cause of canine heart and lung diseases, particularly in parts of Europe, North America, and Africa. The life cycle of Angiostrongylus vasorum involves snails and slugs as intermediate hosts, making the disease difficult to control and prevent.

Life Cycle

The life cycle of Angiostrongylus vasorum is complex, involving both definitive hosts (dogs and wild canids) and intermediate hosts (snails and slugs). Adult worms reside in the right ventricle and pulmonary arteries of the definitive host, where they reproduce. Female worms release eggs that hatch into first-stage larvae (L1), which are then expelled through the host's feces. Once outside the body, these larvae are ingested by snails or slugs, where they develop into third-stage larvae (L3), the infectious stage for the definitive host. Dogs become infected by ingesting these intermediate hosts or by consuming water or food contaminated with the larvae.

Clinical Signs

Infection with Angiostrongylus vasorum can lead to a wide range of clinical signs, which may vary in severity. Common symptoms include coughing, difficulty breathing, lethargy, weight loss, and exercise intolerance. In severe cases, the infection can cause right-sided heart failure, coagulopathies (bleeding disorders), and neurological disorders. The wide range of symptoms can make diagnosis challenging without specific testing.

Diagnosis

Diagnosis of Angiostrongylus vasorum infection is typically achieved through fecal examination for the presence of larvae, serological tests to detect antibodies or antigens, and imaging techniques such as X-rays or ultrasound to observe any heart and lung changes. Early diagnosis is crucial for effective treatment and recovery.

Treatment and Prevention

Treatment for Angiostrongylus vasorum infection involves the administration of anthelmintic medications to eliminate the worms, along with supportive care to manage symptoms. Preventative measures include the use of prophylactic anthelmintic treatments and avoiding exposure to environments heavily populated by snails and slugs. Regular fecal examinations can also help in early detection and treatment of infections.

Epidemiology

The distribution of Angiostrongylus vasorum has expanded in recent years, with cases reported in various parts of Europe, including the UK and Denmark, as well as in Canada and parts of South America and Africa. The spread of the parasite is thought to be influenced by climate change, increasing movement of animals, and the presence of suitable intermediate hosts.