title: Dirofilaria immitis exposure status in client-owned cats with or without lower airway/lung-associated signs: case-control study in a canine heartworm-endemic area.
abstract: Objectives Heartworm-associated respiratory disease (HARD) is a recently recognised pathological manifestation in cats caused by Dirofilaria immitis exposure. This study aimed to estimate the percentage of cats at risk of developing HARD in a heartworm-endemic area (Taipei, Taiwan), and to test the correlation of heartworm exposure and the presence of lower airway/lung clinical signs (LA/L signs). Methods This was a prospective case-control study. The study design called for the enrolment of at least 80 cats with LA/L signs and at least 80 cats without such clinical signs in a 1 year period. The D immitis antibody seroprevalence of the two cohorts was compared. Results From February 2014 to January 2015, 187 client-owned cats were prospectively enrolled: 83 clinical cases with LA/L signs and 104 cats without such signs. Antibody seropositivity was approximately twice as frequent in cats with LA/L signs (13.3%) than in cats without signs (7.8%) (odds ratio [OR] 1.814); nevertheless, no statistically significant difference between the two cohorts ( P = 0.22) was found. We used 41 frozen samples from free-roaming cats to examine the possibility of different exposure rates to mosquito bites between client-owned cats and stray cats, finding the seroprevalence to be 7.5% in free-roaming cats - a result not statistically different to that in client-owned cats ( P = 0.60). Outdoor access was a significant risk factor for heartworm exposure in client-owned cats (OR 3.748; P = 0.03); however, living entirely indoors did not provide complete protection from exposure/infection. Conclusions and relevance Our results did not show statistically significant differences in antibody seroprevalence between cats with and without LA/L signs. LA/L signs were not always present under conditions of natural exposure. However, exposure to D immitis is not rare among client-owned cats, suggesting that heartworm prophylactics should be a part of routine care in all cats living in areas endemic for canine heartworm.
authors.affiliation: 1 Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan.|2 Section of Small Animal Internal Medicine, National Taiwan University Veterinary Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Chung-Hui
authors.initials: CH
authors.lastname: Lin
authors.affiliation: 2 Section of Small Animal Internal Medicine, National Taiwan University Veterinary Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Pei-Ying
authors.initials: PY
authors.lastname: Lo
authors.affiliation: 2 Section of Small Animal Internal Medicine, National Taiwan University Veterinary Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Han-Ju
authors.initials: HJ
authors.lastname: Tsai
authors.affiliation: 1 Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan.|2 Section of Small Animal Internal Medicine, National Taiwan University Veterinary Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Lih-Chiann
authors.initials: LC
authors.lastname: Wang
authors.affiliation: 3 Lifecare Animal Hospital, Taipei, Taiwan.
authors.forename: Bor-Song
authors.initials: BS
authors.lastname: Liaw
authors.affiliation: 2 Section of Small Animal Internal Medicine, National Taiwan University Veterinary Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Olivia F
authors.initials: OF
authors.lastname: Hsieh
authors.affiliation: 4 Pan-Asia Veterinary Clinic, Taipei, Taiwan.
authors.forename: Yeong-Shuenn
authors.initials: YS
authors.lastname: Chang
authors.affiliation: 5 In-Asia Animal Hospital, Taipei, Taiwan.
authors.forename: Yi-Chin
authors.initials: YC
authors.lastname: Tsai
authors.affiliation: 6 Dear Animal Hospital, Taipei, Taiwan.
authors.forename: Szu-Ching
authors.initials: SC
authors.lastname: Yu
authors.affiliation: 1 Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Ling-Ling
authors.initials: LL
authors.lastname: Chueh
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D016022:Case-Control Studies; D002371:Cat Diseases / Q000097:blood / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D002415:Cats; D004183:Dirofilaria immitis / Q000276:immunology / Q000302:isolation & purification*; D004184:Dirofilariasis / Q000097:blood / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D004285:Dogs; D005260:Female; D008297:Male; D010067:Ownership; D015995:Prevalence; D011446:Prospective Studies; D016036:Seroepidemiologic Studies; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000909:Antibodies, Helminth