title: Occurrence and clinical significance of Aelurostrongylus abstrusus and other endoparasites in Danish cats.
abstract: Feline endoparasites are highly prevalent worldwide and may cause a variety of clinical signs in infected cats. Prevalence rates are dynamic and there is limited knowledge of the current prevalence in Denmark and the clinical manifestation and significance of especially the lungworm Aelurostrongylus abstrusus. This study investigated the total and local prevalence of Aelurostrongylus abstrusus and other endoparasites in Danish cats. The clinical significance of feline aelurostrongylosis was also examined through identification of frequency and severity of selected clinical signs. Faecal samples (n=327) and clinical data (n=312) were collected from August to October 2015, primarily from outdoor cats located at shelters distributed across Denmark. A modified Baermann method and a concentration McMaster technique was used to diagnose A. abstrusus first stage larvae and eggs/oocysts of other endoparasites. The total A. abstrusus prevalence was 8.3% [95% CI: 5.6-11.9] but local prevalence rates varied from 0% [95% CI: 0.0-8.8] to 31.4% [95% CI: 16.9-49.3]. A rural habitat appeared to increase the risk of A. abstrusus and this accounted for most of the local variation. Furthermore, the risk of infection was lower in kittens younger than 11 weeks compared to older cats (p=0.002). The cats were also infected with Toxocara cati (44.4% [95% CI: 38.3-50.7]), taeniid species (8.9% [95% CI: 5.7-13.0]), Capillaria aerophila (3.1% [95% CI: 1.3-6.0]), Aonchotheca putorii (3.9% [95% CI: 1.9-7.0]), Cystoisospora felis (3.1% [95% CI: 1.3-6.0]) and Cystoisospora rivolta (2.3% [95% CI: 0.9-5.0]), but there was no difference in local distribution. Co-infection was common, as 66.7% of A. abstrusus infected cats were also infected with one or more other parasites, the most common being T. cati. However, none of these parasites were significantly associated with A. abstrusus. The vast majority of the A. abstrusus infected cats displayed mild to moderate clinical signs. The main symptoms associated with the infection were increased sound on auscultation of the lungs (p=0.002), increased respiratory rate (p=0.02), coughing (p=0.007) and enlarged mandibular lymph nodes (p=0.002). None of these symptoms were associated with T. cati or C. aerophila which may also affect the lungs. This supports that the symptoms may be related to A. abstrusus and that aelurostrongylosis should be considered an important differential diagnosis in any feline respiratory patient.
authors.affiliation: Department of Veterinary Animal Science, University of Copenhagen, Dyrlægevej 100, DK-1871 Frederiksberg C, Denmark. Electronic address: alice.puk@anis.au.dk.
authors.forename: Alice P
authors.initials: AP
authors.lastname: Hansen
authors.affiliation: Department of Veterinary Animal Science, University of Copenhagen, Dyrlægevej 100, DK-1871 Frederiksberg C, Denmark.
authors.forename: Line K
authors.initials: LK
authors.lastname: Skarbye
authors.affiliation: Department of Veterinary Animal Science, University of Copenhagen, Dyrlægevej 100, DK-1871 Frederiksberg C, Denmark.
authors.forename: Lene M
authors.initials: LM
authors.lastname: Vinther
authors.affiliation: Department of Veterinary Clinical Science, University of Copenhagen, Dyrlægevej 16, DK-1870 Frederiksberg, Denmark.
authors.forename: Jakob L
authors.initials: JL
authors.lastname: Willesen
authors.affiliation: Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 København N, Denmark.
authors.forename: Christian B
authors.initials: CB
authors.lastname: Pipper
authors.affiliation: Environmental Support, DFP, Ka, Novo Nordisk, Hallas Alle 1, DK-4400 Kalundborg, Denmark.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Olsen
authors.affiliation: Department of Veterinary Animal Science, University of Copenhagen, Dyrlægevej 100, DK-1871 Frederiksberg C, Denmark.
authors.forename: Helena
authors.initials: H
authors.lastname: Mejer
mesh_terms: D000367:Age Factors; D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology*; D002415:Cats; D060085:Coinfection / Q000453:epidemiology / Q000473:pathology; D003718:Denmark / Q000453:epidemiology; D005243:Feces / Q000469:parasitology; D008681:Metastrongyloidea / Q000502:physiology; D015995:Prevalence; D012307:Risk Factors; D017206:Strongylida Infections / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*
keywords: Aelurostrongylus abstrusus; Baermann; Cat; Clinical signs; Endoparasites; Prevalence