Nematode dermatitis due to Angiostrongylus vasorum infection in a dog

Hematologic Abnormalities and Diseases Associated with Moderate-to-Marked Basophilia in a Large Cohort of Dogs

Basophilia is a rare hematologic finding in dogs. This research aimed to describe the hematologic and clinical characteristics of dogs with moderate-to-marked basophilia. CBC reports with blood smear examinations from dogs presented to the North Carolina State University Veterinary Teaching Hospital were retrospectively reviewed for basophilia (>193 cells/µL). We classified basophilia as moderate when counts were ≥500 cells/µL and marked when they reached ≥1000 cells/µL. We compared the hematologic and clinical profiles of dogs with moderate-to-marked basophilia (the basophilia group) to those without basophilia, serving as our control group. In addition, we investigated differences between dogs with marked basophilia versus those with moderate basophilia, as well as between dogs in the basophilia group with and without concurrent eosinophilia. Diseases associated with moderate-to-marked basophilia included eosinophilic lung disease (p < 0.0001), leukemia/myeloproliferative neoplasms (p = 0.004), parasitic infection (p = 0.004), mast cell tumor (p = 0.005), and inflammatory bowel disease (p = 0.02). Overall, dogs with marked basophilia had a lower frequency of inflammatory diseases (51% vs. 70%, p = 0.009) and a higher frequency of neoplastic diseases (48% vs. 26%, p = 0.003) compared to those with moderate basophilia. In the basophilia group, concurrent eosinophilia was only seen in 36% of dogs. Dogs with concurrent eosinophilia were more often diagnosed with inflammatory diseases (77% vs. 58%, p = 0.006), with fewer diagnoses of neoplasia (19% vs. 40%, p = 0.001), compared to dogs without concurrent eosinophilia. The findings of this study offer veterinary clinicians valuable guidance in determining diagnostic priorities for dogs with moderate-to-marked basophilia.

Comparative biology of parasitic nematodes in the genus Angiostrongylus and related genera

The rise to prominence of some Angiostrongylus species through associated emerging disease in humans and dogs has stimulated calls for a renewed focus on the biology of this genus and three related genera. Although significant research efforts have been made in recent years these have tended to focus on individual species and specific aspects such as diagnosis and treatment of disease or new records of occurrence and hosts. This comprehensive review takes a comparative approach, seeking commonalities and differences among species and asking such questions as: Which species belong to this and to closely related genera and how are they related? Why do only some species appear to be spreading geographically and what factors might underlie range expansion? Which animal species are involved in the life cycles as definitive, intermediate, paratenic and accidental hosts? How do parasite larvae find, infect and develop within these hosts? What are the consequences of infection for host health? How will climate change affect future spread and global health? Appreciating how species resemble and differ from each other shines a spotlight on knowledge gaps and provides provisional guidance on key species characteristics warranting detailed study. Similarities exist among species, including the basic life cycle and transmission processes, but important details such as host range, climatic requirements, migration patterns within hosts and disease mechanisms differ, with much more information available for A. cantonensis and A. vasorum than for other species. Nonetheless, comparison across Angiostrongylus reveals some common patterns. Historically narrow definitive host ranges are expanding with new knowledge, combining with very broad ranges of intermediate gastropod hosts and vertebrate and invertebrate paratenic and accidental hosts to provide the backdrop to complex interactions among climate, ecology and transmission that remain only partly understood, even for the species of dominant concern. Key outstanding questions concern larval dynamics and the potential for transmission outside trophic relations, relations between infection and disease severity in different hosts, and how global change is altering transmission beyond immediate impacts on development rate in gastropods. The concept of encounter and compatibility filters could help to explain differences in the relative importance of different gastropod species as intermediate hosts and determine the importance of host community composition and related environmental factors to transmission and range. Across the group, it remains unclear what, physiologically, immunologically or taxonomically, delimits definitive, accidental and paratenic hosts. Impacts of infection on definitive host fitness and consequences for population dynamics and transmission remain mostly unexplored across the genus. Continual updating and cross-referencing across species of Angiostrongylus and related genera is important to synthesise rapid advances in understanding of key traits and behaviours, especially in important Angiostrongylus species that are emerging causative agents of disease in humans and other animals.

Highly Variable Clinical Pictures in Dogs Naturally Infected with Angiostrongylus vasorum

Canine angiostrongylosis by Angiostrongylus vasorum is increasingly reported in both enzootic and previously free areas. The complex pathogenesis of the disease makes the clinical workup challenging. Infected dogs show highly variable clinical pictures, characterized by subclinical to life-threatening general, cardio-respiratory, neurological and/or gastrointestinal signs. The present study reports the high variability of clinical pictures from 36 dogs across central and southern Italy that were naturally infected by A. vasorum. Of them, 23 (63.9%) presented at least one clinical sign, while 13 (36.1%) were subclinically infected and apparently healthy. Overall, 19 dogs (52.8%) showed cardiorespiratory signs, 14 (38.9%) had non-specific abnormalities, 2 (5.6%) presented coagulation disorders and 1 (2.8%) had a severe neurological condition. Importantly, four dogs presenting with clinical signs had neither cough nor dyspnea. These results underline that angiostrongylosis should be included in the differential diagnosis, even when dogs display only non-specific clinical signs. The proportion of apparently healthy dogs highlights the relevance of routine copromicroscopic and/or antigenic tests in enzootic areas to avoid the sudden onset of potentially life-threatening signs.

Angiostrongylus vasorum in foxes (Vulpes vulpes) and wolves (Canis lupus italicus) from Abruzzo region, Italy

In Europe wildlife animals such as the red fox (Vulpes vulpes) are considered the main reservoir for Angiostrongylus vasorum as well as a potential threat for domestic dog infection. Though this parasite is endemic in fox populations, data on A. vasorum infection in wolves (Canis lupus italicus) are still scant, having only recently been described in Northwestern Spain, in Italy, in Croatia and in Slovakia. Based on the rising number of cases of canine lungworm infection in Central Italy (Abruzzo region), the aim of the present study was to investigate the infection by A. vasorum in fox and wolf populations sharing the same geographical area of dogs. From October 2008 to November 2019, A. vasorum specimens were collected, through routine post-mortem examination, from 56 carcasses (44 foxes and 12 wolves). Adult parasites were searched for in the right side of the heart and in pulmonary artery of all carcasses. First stage of larvae (L1) was searched in faeces using the Baermann technique and in lungs by tissue impressions. Overall, 230 adult specimens were collected and identified on a morphological basis. To confirm the morphological identification, 4 adult specimens (n = 3 from fox, n = 1 from wolf) were molecularly identified as A. vasorum by amplification of partial fragment of nuclear 18S rRNA (~1700 bp) genes. The anatomo-pathological and parasitological examinations indicated the presence of A. vasorum in 33 foxes (75%) and in 8 wolves (66.7%). The level of prevalence of infested wolves was higher than the previous one reported in other European countries. Interestingly, the prevalence of infection in foxes herein recorded was higher than that described in dogs (8.9%) living in the same geographical area. This result may confirm the hypothesis that the spread of canine angiostrongylosis is linked to fox populations infection.

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.

Irreversible Ocular Lesions in a Dog With Angiostrongylus Vasorum Infection

This report describes a 10-month-old dog with a sudden loss of vision and severe dyspnoea. The ocular examination revealed bilateral panuveitis, lens subluxation, secondary glaucoma, and retinal detachment. In addition, the ocular ultrasound showed in the vitreous body of the right eye, a small doubled-lined foreign body compatible with an intraocular parasite. Radiographs of the thorax revealed an increased opacity with mixed lung pattern (alveolar and bronchial) and thoracic ultrasonography showed several subpleural nodules. The presence of Angiostrongylus vasorum first stage larvae was confirmed with 324 larvae per gram of feces and an antigen test for the parasite (AngioDetect, IDEXX) also yielded a positive result. The severe and irreversible ocular lesions described in this case enhanced the complexity of the clinical picture of canine angiostrongylosis. Infection with the parasite should be included in the list of differential diagnoses for ocular uveitis to avoid potentially serious complications related to a missed or delayed diagnosis.