The Role of Dirofilaria Immitis Antigen in the Pathogenesis of Pulmonary Arteritis in the Dog

Abstract

The aim of this study was to investigate the correlation between the Dirofilk immitis antigen and morphology response of pulmonary tissue. The pulmonary arteries of D.immitis naive dogs were infused with an antigenic extract of adult female D. immitis worms. Light and electron microscopy and an assessment of vascular permeability were performed to compare arterial pathology 1 h and 5 days after antigen infusion. Thrombus formation accompanied by perivascular edema was present initially, but it was not detectable after 5 days. 772TARISH and ATWELL D. immitis antigen extracts were infused into the pulmonary tissue of dogs to investigate the possible interaction between the presence of parasite antigen and associated local pathology. Material and Methods AnimalsSixteen healthy 5-6 month old dogs of mixed breed and of both sexes were obtained from a refuge and housed in a temperature and humidity controlled animal facility at the School of Veterinary Science, University of Queensland. Blood smear examinations for microfilariae of D. immitis were negative in all dogs. During the 3 week period of acclimatisation the dogs were treated with anthelmintic, Fenbendazole ("Panacur", Hoechst Australia Ltd., Melbourne, Vic.) and vaccinated against canine distemper, hepatitis and parvovirus ("Canine 3" Arthur Webster, Northead, N. S. W.).

Litomosoides sp. (Filarioidea: Onchocercidae) Infection in Frugivorous Bats (Artibeus spp.): Pathological Features, Molecular Evidence, and Prevalence

“…On the other hand, smooth-muscle hypertrophy of pulmonary arteries has not been previously associated with Litomosoides infection. This lesion could resemble a chronic process that has been reported in dogs parasitized with Dirofilaria immitis [25,26]. Unlike in our study where the most common vascular lesion was hypertrophy of the medial layer, in most studies in dogs with dirofilariosis, the most common were hyperplasia and hypertrophy of the capillary endothelium [25,26,27].…”

“…This lesion could resemble a chronic process that has been reported in dogs parasitized with Dirofilaria immitis [25,26]. Unlike in our study where the most common vascular lesion was hypertrophy of the medial layer, in most studies in dogs with dirofilariosis, the most common were hyperplasia and hypertrophy of the capillary endothelium [25,26,27]. In a murine model infected with L. sigmodontis , Mf presence inside blood vessels of the lungs was proposed as an anatomic reservoir site during the patency of the disease [21].…”

“…Lesions detected in bats were not clearly associated with filarial infection. Filarial antigens could activate different pathways of the immune response, as shown by the histological changes reported by Zahner et al (1987) [24] and Tarish and Atwell (1989) [26]. In these studies, tissue alterations were induced by the sole inoculation of the L. carinii -adult phase antigen in M. natalensis and of D. immitis in dogs, respectively.…”

2022 Update of the Consensus on the Rational Use of Antithrombotics and Thrombolytics in Veterinary Critical Care (CURATIVE) Domain 1‐ Defining populations at risk

“…In some dogs with preexisting dirofilariasis, pulmonary artery insertion of a large number (20‐50) of dead worms resulted in intimal proliferation of pulmonary arteries, dilation of main and lobar pulmonary arteries and obstruction of blood flow (LOE 3) 22 . The infusion of homogenized Dirofilaria antigen into the pulmonary arteries of dogs led to thrombosis within 1 hour of administration, but these thrombi were not detectable 5 days later, suggesting that Dirofilaria are thrombogenic but that actual worms are required for persistent thrombosis 23 . The transient nature of these thrombi confirms the antigenicity of the heartworm but suggests that solid worm fragments are necessary to support prolonged thrombus residence.…”

Levels of circulating plasma immune complexes after thiacetarsamide treatment in dogs naturally infected with Dirofilaria immitis

“…As the deposition of immune complexes in organs such as lung or kidney (Grauer and others 1989, Tarish and Atwell 1989) depends on immune complex concentrations in plasma, CIC determinations (especially when CIC‐SA and CIC‐ES are employed) could be useful to study the post‐treatment condition of infected animals in order to prevent complications after adulticidal treatment.…”