The prevalence of Dirofilaria repens in dogs in countries bordering Slovenia ranges from 1.5% to 47.3%. The aim of this study was to estimate its prevalence in Slovenian dogs and to present the cases of dirofilariasis diagnosed in humans from 2010 to 2020. Epidemiological data were collected and blood samples were taken from 465 dogs older than one year and born in Slovenia. A real-time PCR was performed on all samples to detect filarioid DNA, and a D. repens-and D. immitis-specific real-time PCR was performed on positive samples. Blood samples from 446 dogs were tested for Dirofilaria spp. using a modified Knott’s test. Human cases were diagnosed from histological sections of excised subcutaneous nodules. Descriptive statistics were used to characterise the samples. The one-sample nonparametric chi-squared test was used to assess whether categories of a variable were equally distributed. Three dogs’ samples tested positive for D. repens using the species-specific real-time PCR, while D. immitis DNA was not detected. The modified Knott’s test was positive in two of the three PCR-positive dogs, two of which had never travelled outside Slovenia’s borders. Four human patients with D. repens dirofilariasis were diagnosed. Since their travel history was unknown, autochthonous transmission could not be confirmed. Our study demonstrated a 0.64% prevalence of D. repens infection in dogs in Slovenia. Two cases could be autochthonous.

Leishmaniasis is a life-threatening zoonosis of which dogs are the major reservoir and sandflies are the vectors. Until now, the prevalence of canine leishmaniasis (CanL) in the Slovenian dog population was unknown. Epidemiological data, eye swabs and blood samples were taken from 465 dogs born in Slovenia and older than one year. Commercial ELISA kits and real-time PCR were used. For ELISA-positive samples, an immunofluorescence antibody test (IFAT) was performed. Descriptive statistics were used to characterise the samples. The one-sample nonparametric chi-square test was used to test whether the categories of a variable were equally distributed. A 59.9% proportion of the recruited dogs had travelled to endemic regions and 62.1% of them had not been protected by insect repellents. Skin symptoms that might be CanL-related were described in 109 of the dogs’ histories (23.4%), inappetence and/or weight loss in 25 (5.4%), and anaemia, intermittent fever, and/or lymphadenopathy in 19 (4.1%). At the time of recruitment, all dogs were asymptomatic. All samples were PCR negative, nine (1.9%) were ELISA positive, but none were IFAT positive. Five of the nine ELISA-positive dogs were non-travellers. We conclude that the seroprevalence of canine leishmaniasis of 1.9 % in the autochthonous Slovenian dog population may pose a risk of endemic spread of the disease.