Intestinal parasites and lungworms in stray, shelter and privately owned cats of Switzerland.

Endoparasitic infections represent relevant causes of respiratory and gastrointestinal diseases in cats. The aim of the study was to investigate the occurrence of endoparasites in Swiss cats in order to evaluate the risk of onset of parasitic diseases and potential correlated zoonoses. Therefore 664 faecal samples from privately owned (n = 299), shelter (n = 197) and stray (n = 168) cats were investigated by sedimentation-flotation and 468 samples additionally by the Baermann technique. Overall, 77.4% (n = 130), 21.8% (n = 43) and 11.7% (n = 35) of stray, shelter and privately owned cats, respectively, were positive, with significant differences between the groups. Among infected cats, 58.7% (n = 122) harboured a single, 30.8% (n = 64) two and 10.6% (n = 22) more than two parasite species. Toxocara cati, with an infection rate of 18.5% (n = 123), was the most frequently detected parasite. The rates for other intestinal parasites were: Taenia sp. 11.1% (n = 74), Isospora sp. 8.1% (n = 54), Capillaria sp. 4.7% (n = 31), hookworms 1.1% (n = 7), Giardia duodenalis 0.8% (n = 5), Dipylidium caninum 0.6% (n = 4), Toxoplasma gondii 0.6% (n = 4), Hammondia hammondi 0.5% (n = 3), Sarcocystis sp. 0.2% (n = 1) and Diphyllobothrium latum 0.2% (n = 1). First-stage larvae of the lungworm Aelurostrongylus abstrusus were found in 2.3% (n = 15) of all samples. The morphological identification of Taenia sp., T. gondii, H. hammondi and A. abstrusus was confirmed by molecular techniques. Overall, cats younger than one year and intact animals were more frequently infected with parasites than older and neutered animals. The observed infection rates were comparable to those from other European studies, except for Taenia sp. showing a significantly higher occurrence. This implicates that there is a persistent risk of environmental contamination with parasitic stages especially by stray cats, and a risk of infection for cat owners with potential zoonotic pathogens, emphasizing the need for appropriate parasite control measures.

Detection of specific antibodies in cats infected with the lung nematode Aelurostrongylus abstrusus.

Feline aelurostrongylosis, caused by the metastrongylid nematode Aelurostrongylus abstrusus, is an underestimated respiratory parasitosis. Its diagnosis currently mainly relies on the isolation of first stage larvae from fresh faecal samples. The aim of our study was to develop a serological test for the detection of specific antibodies against A. abstrusus by ELISA. We used recombinant major sperm protein (MSP) of the bovine lungworm Dictyocaulus viviparus as detection antigen and evaluated two different ELISA plates (Maxisorp and Immobilizer™ Amino-plate, Nunc Roskilde, Denmark) with two different enzyme systems [alkaline phosphatase (AP) and horseradish peroxidase (HRP)]. Sera from cats experimentally (n=54) and naturally (n=17) infected with A. abstrusus and from randomly selected cats with different medical issues (n=160) were used to determine sensitivity and specificity. Furthermore, cross-reactions were evaluated using sera from cats naturally (n=71) and experimentally (n=8) infected with different nematodes. A sensitivity of 100% was obtained with sera from experimentally infected cats at 10 weeks post infection using MSP on the Immobilizer™ Amino-plate with HRP, while it ranged between 90.5 and 95.2% in the other ELISA set-ups. Using sera from naturally infected cats, a sensitivity of 88.2% (95% confidence interval: 63.6-98.5%) was achieved in all four set-ups. The specificity was 85.2-94.4% in sera from uninfected cats prior to experimental infection and 68.1-90% in randomly selected cats depending on the plate and enzyme system. The number of seropositive cats increased over time post infection. Serological follow-up showed a decrease of antibody levels within 30days after anthelmintic treatment. Seropositive reactions were observed with sera from stray cats naturally infected with Toxocara cati, Capillaria sp., hookworms and Taeniidae; however, coproscopic false negative A. abstrusus findings cannot be excluded. The serological detection of specific antibodies against A. abstrusus using ELISA requires a single serum sample and therefore represents a valid alternative for reliable individual diagnosis of A. abstrusus in cats and facilitates mass screening, overcoming the usually difficult collection of cat faeces.