Cardio-Pulmonary Parasitic Nematodes Affecting Cats in Europe: Unraveling the Past, Depicting the Present, and Predicting the Future

Abstract

Various cardio-pulmonary parasitic nematodes infecting cats have recently been fascinating and stimulating the attention of the Academia, pharmaceutical companies, and veterinary practitioners. This is the case of the metastrongyloids: Aelurostrongylus abstrusus and Troglostrongylus brevior, the trichuroid: Capillaria aerophila (syn. Eucoleus aerophilus), and the filarioid: Dirofilaria immitis. Apparently, these parasites have been emerging in several European countries, thus, gaining an important role in feline parasitology and clinical practice. Under a practical standpoint, a sound knowledge of the biological, epidemiological, and clinical impact of cardio-respiratory parasitoses affecting cats, in addition to a potential risk of introduction, establishment, and spreading of “new” parasites in Europe is mandatory in order to understand the present and future impact for feline medicine and to address new strategies of control and treatment. The purpose of the present article is to review the current knowledge of heartworm and lungworm infections in cats, discussing and comparing past and present issues, and predicting possible future scenarios.

Diagnosis and management of lungworm infections in cats

“…5,7,43 L1s of T brevior have a pointed anterior extremity and a subterminal (dorsal) oral opening, while the tail gradually tapers towards the extremity, and possesses a deep dorsal incisure and a shallower ventral incisure near the tip (Figure 8 However, sampling from the respiratory tract requires sedation or anaesthesia and these procedures may fail to detect larvae due to absence of significant pulmonary tissue involvement, limited numbers of L1s, prepatent infection or poor sample recovery.…”

“…42 This mollusc is one of the most important intermediate hosts of A abstrusus and T brevior, and it is plausible that it has contributed (and is contributing) to the expansion of feline meta strongyloids in European countries. 43 Changes in geographic distribution influenced by global warming have been predicted for A vasorum via a climatic-based model. 44 No similar information is available for A abstrusus or T brevior; however, with similar biological cycles, the same factors involved in the expansion of canine angiostrongylosis would likely also affect feline lungworms.…”

“…11,43 An accurate morphological and morphometric appraisal of L1s is necessary to achieve a species-specific diagnosis but microscopic differentiation between A abstrusus and T brevior (Figure 7) 64 and genetic characterisation. 22 Thus, L1s of the two species should also be differentiated based on head and tail features.…”

PCR-based assay for the mitochondrial cox1 specific amplification of Eucoleus böhmi

“…In fact, being a neglected parasite, in routine clinical practice, E. böhmi is not taken into account as a cause of respiratory distress and trichuroid eggs are mostly accounted to T. vulpis, due to the common wrong misconception that T. vulpis is the only nematode shedding barrel-shaped eggs in dog faeces (De Liberato et al, 2009;Traversa et al, 2009Traversa et al, , 2010Di Cesare et al, 2012a,b;Traversa and Di Cesare, 2014). In addition, cases of mixed infections by respiratory E. böhmi and E. aerophilus may occur more frequently than expected, especially where these parasites are endemic.…”

First report of Angiostrongylus vasorum in red foxes (Vulpes vulpes) in Serbia

“…The finding of aelurostrongylosis in a cat, coupled with the finding of angiostrongylosis in red foxes, leads to the conclusion that gastropod-borne parasitoses are emerging in South Banat which seems to provide suitable conditions for the completion of the life cycle of both A. abstrusus and A. vasorum. The life cycle and the dynamics and activity of the population of gastropod intermediate hosts are mainly influenced by temperature, moisture and water availability (Traversa et al, 2010;Traversa and Di Cesare, 2014).…”