Irreversible Ocular Lesions in a Dog With Angiostrongylus Vasorum Infection

Ultrasonography of Parasitic Diseases in Domestic Animals: A Systematic Review

Simple Summary

The aim of this literature review was to summarize the current knowledge on the application of ultrasonography in diagnosis, staging and monitoring of helminthic diseases in domestic animals. We selected and analyzed 122 papers about the application of ultrasonography in parasitic disease in ruminants, equids, swine, and companion animals. Helminths can be recognized in ultrasound images by their morphology, size, and location. In some cases, the parasites are not directly seen by ultrasound, but the lesions caused by them can be easily visualized. Ultrasound imaging is taking on an increasingly important role in veterinary parasitology.

Abstract

The aim of this review was to summarize the current knowledge on the application of ultrasonography in diagnosis, staging and monitoring of helminthic diseases in domestic animals. Only peer reviewed papers written in English language were included in this systematic review. All papers concerning unicellular parasites, wild animals, non-domestic experimental animals, or ex vivo or in vitro applications of ultrasonography were excluded from the review. A total of 122 papers met the inclusion criteria. Among them 47% concerned nematodes, 37% cestodes, and 16% trematodes with the genus Dirofilaria, Echinococcus, and Fasciola the most represented, respectively. Helminths can be recognized in ultrasound images by their morphology, size, and location. In some cases, the parasite stages are not directly seen by ultrasound, but the lesions caused by them can be easily visualized. Ultrasound imaging is taking on an increasingly important role in the diagnosis, staging, monitoring, and control of parasitic diseases in veterinary medicine. However, it cannot replace the clinical approach and the diagnostic tests commonly used in veterinary parasitology.

Pneumothorax in a persistent canine Angiostrongylus vasorum infection

Canine angiostrongylosis is a gastropod-borne parasitosis caused by the cosmopolitan nematode Angiostrongylus vasorum. It is associated with cardiorespiratory disorders and eventually fatal coagulopathies. A 6-months-old female dog previously diagnosed with bronchopneumonia and pneumothorax, treated accordingly without success, was hospitalized for further treatment. Complementary diagnostics confirmed previous findings plus pneumomediastinum, thoracic exudate, leucocytosis, thrombocytosis, hypercoagulability, and hyperglobulinemia. Coprological analysis showed a severe patent A. vasorum infection. After the third daily fenbendazole administration, all A. vasorum larvae were found dead in follow-up coprological analyses while in intensive care. Upon release, the dog was monitored until full clinical recovery 3 months later. Up to date, A. vasorum infection-related pneumothorax was rarely described, particularly with full recovery of such a young patient. Thus, a parasitological aetiology should be considered for dogs with severe bronchopneumonia or pneumothorax, especially in Europe and South America where increasing numbers of canine angiostrongylosis cases call for enhanced awareness of veterinary practitioners.

The current situation of Angiostrongylus vasorum in Romania: a national questionnaire-based survey

Background

Angiostrongylus vasorum (Nematoda, Metastrongyloidea) is a vascular nematode that resides in the pulmonary arteries and the right side of the heart of a wide variety of carnivores, with an indirect life cycle using coprophagic gastropods as intermediate hosts. For domestic dogs, the infection with A. vasorum can be asymptomatic, but more frequently, it is associated with a wide range of clinical manifestations like cardio-respiratory signs, bleedings, neurological signs, and ocular problems which can lead to death when not treated accordingly. Angiostrongylosis was confirmed for the first time in Romania in red foxes (Vulpes vulpes) in 2017 and two years later a seroepidemiologic study was conducted among domestic dogs. However, to this date, no clinical canine angiostrongylosis cases were published in Romania. The aim of the present paper was to evaluate the knowledge about canine angiostrongylosis among veterinarians in Romania and to update the distribution of this disease using a national wide anonymous questionnaire.

Results

Overall, 147 unique responses were submitted, from 31 out of 42 counties. Twelve veterinarians (8%) from 8 counties (26%) acknowledged diagnosing a case of angiostrongylosis including 5 from the Bucharest and 1 from each of the remaining seven counties. All affected dogs had respiratory distress, 75% suffered cardiopathy, 16% coagulopathies and 8% neurological signs. Case diagnosis was based mostly on larval detection by coprology (67%) and serological antigen detection test (42%).

Conclusions

Romanian veterinarians are aware of canine angiostrongylosis and a significant number have clinical experience with the disease. Epidemiological studies are now needed to assess its distribution in the country, and further efforts are required to improve understanding of the disease, its diagnostic and treatment methods among veterinarians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03034-1.

Is Pulmonary Hypertension a Rare Condition Associated to Angiostrongylosis in Naturally Infected Dogs?

Canine angiostrongylosis due to Angiostrongylus vasorum is one of the cardiopulmonary parasitic diseases in dogs and it can manifest with very different clinical pictures, which often make diagnosis very difficult. Based on the nature of the vascular and parenchymal lesions induced by the infection (thrombo-arteritis and fibrosis), it is not surprising that cases of pulmonary arterial hypertension (PAH) associated with angiostrongylosis have been reported in the literature, although it seems to represent a rare condition. The aim of the present work is to describe the clinical and instrumental aspects referred to cases of canine angiostrongylosis before and after treatment then to evaluate even mild conditions of PAH using echocardiography. PAH was not only conventionally investigated based on characteristic cardiac changes that occur secondary to PAH and by estimating pulmonary pressure from spectral Doppler tracings, but also by using a combination of further selected echocardiographic parameters (AT/ET, PA/Ao, Pulmonary flow profile pattern) able also to reveal PAH in the absence of tricuspid or pulmonary regurgitation. Clinical and instrumental aspects of 17 cases of angiostrongylosis, divided into respiratory cases (n = 6), nonrespiratory (n = 5), and asymptomatic (n = 6), are here described. Radiographic alterations were recorded in 90% of patients despite the reason for clinical presentation. A state of mild to severe PAH was diagnosed in 58.8% of cases. Although the return to a normal clinical condition was achieved 2 months after treatment in almost all patients, radiographic and echocardiographic alterations were persistent for longer. The cases presented reinforce the evidence on the complexity of the clinical picture of angiostrongylosis. PAH associated with canine angiostrongylosis could be a more common condition than previously reported in naturally infected dogs. In some cases, echocardiographic findings suggestive of PAH could be the starting point to address the clinical diagnosis toward angiostrongylosis. PAH may be responsible for worsening of the clinical picture of patients; thus, a careful evaluation is suggested before and after anthelmintic treatment in order to optimize the therapeutic management of each case.

Efficacy of orally administered combination of moxidectin, sarolaner and pyrantel (Simparica Trio™) for the prevention of experimental Angiostrongylus vasorum infection in dogs

BACKGROUND

Infection with Angiostrongylus vasorum may cause severe clinical disease, even death in dogs, however, due to the often non-specific clinical signs, diagnosis is not always straightforward. Regular prophylactic treatment may offer a safe means to protect dogs against infection. The efficacy of a novel oral endectocide containing moxidectin, sarolaner and pyrantel was investigated for the prevention of angiostrongylosis in dogs in three placebo-controlled, randomized, masked studies. The initial study (Study 1) determined the efficacious dosage of moxidectin in the combination product by evaluating three different dose levels, and two follow-up studies (Studies 2 and 3) confirmed the efficacy of the selected moxidectin dose.

METHODS

Animals were infected orally with 200 infective third-stage larvae (L3) of A. vasorum and were treated 28 days later with the combination product or with placebo. Timing of dosing relative to infection allowed for efficacy to be evaluated against the immature adult (L5) stage. Dogs in Study 1 received treatments with oral tablets to deliver 3, 12 or 24 µg/kg moxidectin in combination with 2 mg/kg sarolaner and 5.0 mg/kg pyrantel (as pamoate salt) or placebo. In Studies 2 and 3, Simparica Trio™ tablets were administered to provide minimum dosages of 1.2 mg/kg sarolaner, 24 µg/kg moxidectin and 5.0 mg/kg pyrantel (as pamoate salt). Efficacy of the combination product was calculated as the percent reduction in adult worm counts at necropsy relative to placebo.

RESULTS

In Study 1, the 3, 12 and 24 µg/kg moxidectin dosage in the combination product provided 7.2%, 54.5% and 94.7% efficacy against the immature adult stages of A. vasorum, respectively. Studies 2 and 3 confirmed that the efficacy of 24 µg/kg moxidectin combined with 1.2 mg/kg sarolaner and 5 mg/kg pyrantel in Simparica Trio™ was ≥ 92.9%. All three studies established that a single oral administration of 24 µg/kg moxidectin in the combination product provided effective prophylactic treatment for angiostrongylosis, reduced L1 production and fecal excretion and minimized the tissue damage to the lungs.

CONCLUSIONS

A single oral treatment of dogs with Simparica Trio™ providing moxidectin at a minimum dose of 24 µg/kg was efficacious in the prevention of angiostrongylosis.