Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira spp. with small rodents serving as the main reservoir. In Croatia, the serogroup Pomona has been detected most frequently, but its genomic diversity remains insufficiently characterized. This study presents the first whole genome sequencing analysis of 48 Croatian Leptospira spp. isolates collected from small rodents over a 14-year period. Serological typing confirmed that all the isolates belonged to the serogroup Pomona. Genomic analysis assigned them to L. kirschneri based on high genomic similarity using average nucleotide identity (ANI). The isolates were assigned to ST-98 using traditional multilocus sequence typing (MLST), while cgMLST identified seven genotype clusters, many of which showed geographic structuring. Phylogenetic analyses based on single nucleotide polymorphisms (SNPs) supported this structure and revealed a monophyletic clade of Croatian isolates distinct from other global L. kirschneri strains. Serological typing, MLST, and phylogenetic clustering support classification of the isolates as L. kirschneri, serogroup Pomona, most likely serovar Mozdok, although serovar Tsaratsovo cannot be excluded. These results indicate the existence of a geographically restricted and potentially host-adapted lineage of L. kirschneri in Croatia. The integration of ecological, serological, and genomic data in this study emphasizes the value of whole genome sequencing for understanding the population biology of Leptospira spp. serogroup Pomona. Moreover, it supports targeted, country-specific surveillance and control strategies for leptospirosis through the identification of circulating serovars and species in reservoir hosts, in line with a One Health approach.

Leptospirosis is a re-emerging zoonosis of wide geographic distribution and high prevalence, significant in domestic and wild animals as well as humans. It may have a notable impact on reproductive health in dogs. The clinical spectrum ranges from mild subclinical infections to severe septicemic disease with renal failure and/or pulmonary hemorrhagic syndrome, often with a high mortality rate. Clinical expression depends on the host's susceptibility, immune status, infectious dose, and the virulence of the infecting serovar or strain. Certain serovars, for still unknown reasons, tend to cause more severe disease manifestations. Reproductive disorders-including embryonic resorption, abortion, and stillbirthare rarely described in the literature, although Leptospira spp. is known to cause transplacental infections. Individual cases of abortion associated with serovars Buenos Aires and Bratislava have been reported, but evidence remains limited and primarily anecdotal. Diagnostic approaches include serological testing (MAT), PCR, and histopathology, though interpretation may be hindered by cross-reactivity and post-vaccinal antibodies. Considering increasing indications of the reproductive impact of Leptospira spp., it should be routinely included in the differential diagnosis of abortion in bitches, especially in endemic areas and in late gestation. Prevention relies on vaccination, rodent control, and strict biosecurity measures, with special focus on breeding females.

Background: Free-roaming cats are a potential source of several infectious and parasitic diseases that can be easily transmitted to outdoor pet cats. Aim: The purpose of this study was to determine the prevalence and pattern of co-occurrence of causative agents of otitis externa and to identify associated risk factors in free-roaming cats living in the continental region of Croatia. In addition, we investigated the presence of Malassezia yeasts in the external ear canals of cats using mycology culture. Methods: Clinical assessment of otitis externa involved auricular and otoscopic examinations. Samples of cerumen and ear swabs were collected and analyzed via cytological examination and mycological culture. Results: The frequency of otitis externa in the population of free-roaming cats was 40.5% (30/74) based on the presence of Otodectes cynotis, Malassezia yeasts, cocci, rods, and/or neutrophils. Results revealed multiple diagnoses for the same ears and unevenly affected ears of the same cats. O. cynotis was detected in 25.7% (19/74) of the cats and was the primary cause of otitis in 63.3% (19/30) infected cats. Co-diagnosis of O. cynotis and Malassezia yeasts was common at both the ear (39.3%, 22/56 infected ears) and cat (40.0%, 12/30 infected cats) levels, while Malassezia was causing otitis in 30% (9/30) infected cats. Three or more diagnoses co-occurred in 15% of infected ears and 27% of infected cats. The clinical signs of otitis externa were absent in 8.9% (5/56) of infected ears, all affected by Malassezia alone or with O. cynotis. Malassezia yeasts were cultured in 83.3% (25/30) of the otitis cases, with heavy growth in 70% and M. pachydermatis as the predominant species in all cases. Conclusion: The high prevalence of otitis externa caused by O. cynotis and Malassezia yeasts in free-roaming cats in Croatia provides important insights into the health status of this cat population. Although otitis externa and its causative agents are frequently found in free-roaming cats, the actual prevalence of otitis externa and all associated risk factors have not been thoroughly assessed.

Leptospirosis, a globally re-emerging zoonosis caused by pathogenic Leptospira spp., poses a significant threat to public health. Leptospirosis in cats is often neglected due to its high underdiagnosis. Therefore, the role of cats in disease transmission and bacterial maintenance in the environment remains unclear. For this study, 54 serum samples, 54 urine samples and 27 EDTA-anticoagulated blood samples from pet cats presenting to the Veterinary Teaching Hospital due to health problems were used. The serum samples were tested for antibodies against 12 pathogenic serovars of Leptospira spp. using the microscopic agglutination test (MAT). EDTA-anticoagulated blood and urine samples were tested for the lipL32 gene of pathogenic Leptospira spp. by conventional (PCR) and real-time (qPCR) polymerase chain reaction. Agglutinating antibodies were detected in 18.52% (10/54) of the sera with a titre range of 1:50 to 1:12800. The most common serogroup was Pomona, followed by Sejroe, Icterohaemorrhagiae, Australis and Javanica. Leptospira spp. DNA was found in 1.85% (1/54) of the urine samples, while all EDTA-anticoagulated blood samples were negative. A statistically significant difference in seropositivity regarding lifestyle was found between outdoor/indoor and indoor-only cats, while the presence of another cat in the household significantly increased the likelihood of seropositivity. Cats with immunocompromising conditions showed a significantly increased risk of seropositivity, especially those undergoing immunosuppressive treatment. In addition, respiratory signs and changes in lung structure associated with the presence of leptospiral antibodies, and these cats were more likely to be infected with the Pomona serogroup. Moreover, cats with anaemia, leucocytosis, and thrombocytopenia were significantly more likely to have antibodies against Leptospira spp., while seropositive cats had significantly lower urine-specific gravity compared to seronegative cats. The results underline the importance of raising awareness of feline leptospirosis in veterinary care and recognising pet cats as potential carriers of leptospires. Further research is needed to clarify the specific role of the Pomona serogroup as a potentially highly evolutionary drifting serogroup in terms of pathogenicity and to clarify the zoonotic potential of infected cats, which is crucial for the implementation of effective public health measures and veterinary interventions.

A 19 -month -old female common marmoset (Callithrix jacchus) was presented with a 4 -day history of anorexia and behavioral changes. At presentation, a combination of neurological signs, erosions, and ulcerations of the mucous membranes of the oral mucosa and mucocutaneous junction of the lips were observed, suggesting herpesvirus infection. Although etiological and symptomatic therapy was initiated immediately, the animal died the next day. A necropsy was performed, and gross pathology and pathohistology findings indicated a systemic viral infection. Definitive diagnosis was based on the results of molecular testing that demonstrated the presence of human herpes simplex virus type 1. In conclusion, marmosets are a highly susceptible host for human herpes simplex virus. To reduce the risk of infection and prevent this highly lethal disease in monkeys, contact with humans who have symptomatic or asymptomatic forms of HSV-1 should be limited and accompanied by appropriate hygiene measures.

Leptospirosis is a worldwide zoonosis caused by different pathogenic serovars of the genus Leptospira, with very complex aetiology and epidemiology. Recent publications suggest that wild boar (Sus scrofa) has an important role in the epizootiology of leptospirosis, representing a potential source of infection. Wild boar populations in urban environments are increasing, posing not only agricultural and ecosystem concerns, but also a public health concern. The aim of this study was to assess the prevalence, temporal patterns and risk factors of Pomona infection in wild boars from areas with pronounced human activity. A total of 159 wild boar serum samples were collected within a health monitoring project in Medvednica Nature Park over a period of six hunting seasons (2012–2016; 2018) and 25.2% samples tested positive. Seropositivity against seven different serogroups was observed, with the highest number of positive reactions to the serogroup Pomona. Annual variation in Pomona reactivity was also detected, and positive reactions were five times more common in females than in males. In most of studies, adults had a higher seroprevalence than younger categories; however, in this study,seroprevalence against Pomona was higher in piglets and subadults. The results indicate that wild boar has the potential of maintaining serovars from the serogroup Pomona in certain natural foci. Due to the expansion of wild boar populations and their intrusion into urban areas, they should be considered a potentially important source of infection for humans and domestic animals.

Ferrets are highly susceptible to a wide range of mycobacteria, mainly M. bovis, M. avium, and M. triplex. Therefore, ferrets pose a risk of transmission of mycobacteriosis, especially zoonotically relevant tuberculosis. The aim of this study was to describe the findings of M. xenopi mycobacteriosis in a pet ferret and emphasize its zoonotic potential. A pet ferret had a history of weight loss, apathy, hyporexia, and hair loss. Abdominal ultrasound revealed splenomegaly with two solid masses and cystic lesions of the liver. Fine-needle aspiration cytology revealed numerous acid-fast bacilli in epithelioid cells, thus leading to the suspicion of mycobacterial infection. Because of its poor general condition, the ferret was euthanized. Necropsy examination revealed generalized granulomatous lymphadenitis, pneumonia, myocarditis, splenitis, and hepatitis. Histologically, in all organs, there were multifocal to coalescing areas of inflammatory infiltration composed of epithelioid macrophages, a low number of lymphocytes, and plasma cells, without necrosis nor multinucleated giant cells. Ziehl–Neelsen staining detected the presence of numerous (multibacillary) acid-fast bacteria, which were PCR-typed as M. xenopi. This is the first study showing the antimicrobial susceptibility testing of M. xenopi in veterinary medicine, describing the resistance to doxycycline. Overall, our results could facilitate further diagnosis and provide guidelines for the treatment protocols for such infections.

Leptospirosis is one of the most common zoonotic infections and a major problem in terms of both veterinary medicine and public health. However, the disease is under-recognised and under-diagnosed worldwide, particularly in horses. Clinical leptospirosis in horses is mainly associated with recurrent uveitis (ERU), which has recently been studied more intensively, and reproductive disorders, the epidemiology of which is still relatively poorly understood. To enhance our comprehension of abortions caused by leptospirosis in horses and to identify the causative strains, a serological study was carried out with subsequent molecular characterisation of the isolate obtained. Using the microscopic agglutination test (MAT), serum samples from mares that aborted and foetal fluids (when available) were tested for antibodies against Leptospira spp. Furthermore, bacteria isolation from kidney cultures was conducted. Of 97 mare serum samples, 21 (21.64%) tested positive, with Grippotyphosa and Pomona being the most frequently detected serogroups. A significantly higher seroprevalence was found in aborting mares compared to the healthy horse population from the same geographical area, as well as a pronounced seasonal variation. Leptospiral antibodies were not detected in any of the foetal fluids, but isolation was successful in 1 case out of 39 (2.56%). Genotyping by multilocus sequence typing (MLST) and core genome multilocus sequence typing (cgMLST) identified the obtained isolate as Leptospira kirschneri, serogroup Pomona, serovar Mozdok. Further surveillance and molecular typing of Leptospira strains causing abortion in horses would be invaluable in understanding the prevalence and impact of leptospirosis on equine reproductive health in Europe.

Canine respiratory coronavirus is a relatively new addition to the list of pathogens causing canine infectious disease complex. The virus is highly contagious, with a high prevalence in the dog population worldwide, especially in shelters. This study aimed to establish the presence and risk factors associated with infection in privately owned dogs and breeding colonies. This study was the first to demonstrate the presence of canine respiratory coronavirus in Croatia. Out of the 257 serum samples, 35.03% of dogs from breeding kennels and 43% of pet dogs tested enzyme-linked immunoassay positive, but the difference was not statistically significant. Sex was not an important risk factor, but the seropositivity rate increased with age. Mixing of dogs during hunting, training and dog shows was not associated with a higher seroprevalence in the breeding colonies. Daily cleaning and disinfection showed little effect on the infection spread. The study was done on a limited sample. However, it still provides evidence that the epizootiology of this disease is complex. There is no available vaccine for canine respiratory coronavirus, and further studies on environmental and risk factors will give the valuable data needed to prevent this disease.

Leptospirosis is re-emerging zoonotic bacterial disease of global importance that affects domestic and wild animals and humans. Due to the public health importance, control of disease in Croatia is being implemented by monitoring the seroprevalence of equine leptospirosis and it is regulated by the law. In the period from 2012 to 2022, a total of 61,724 serum samples from apparently healthy horses were admitted to the Laboratory for leptospires, Faculty of Veterinary Medicine University of Zagreb. Serum samples were tested for Leptospira spp. antibodies using the microscopic agglutination test (MAT). Samples were considered seropositive with a cut-off titre 1:200 for Bratislava and 1:400 for other Leptospira spp. serovars. Out of 61,724 serum samples tested, 6,665 (10.80%) were found seropositive for at least one Leptospira serovar. In the studied period, seroprevalence varied between 5.00% and 15.94%. The highest seroprevalence was found for serovar Pomona (41.98%) and serovar Grippotyphosa (31.34%), followed by Sejroe (8.03%), Icterohaemorrhagiae (7.05%) and Bratislava (6.47%). Results indicated that horses in Croatia are particularly exposed to Leptospira spp. infections. The most prevalent presumed infective serovar was Pomona increasing each year. Investigated horses were randomly selected and healthy and most seropositive horses have anamnestic titre due to previous infection. This is the first study in Europe reporting such high seropositivity for the serovar Pomona in apparently healthy horses. According to the results of the present study, the question arises of the possible evolutionary adaptation of the pathogenic serovar Pomona as dominant for horses.

Objectives:Leptospira, the spirochaete causing leptospirosis, can be classified into >250 antigenically distinct serovars. Although knowledge of the animal host species and geographic distribution of Leptospira serovars is critical to understand the human and animal epidemiology of leptospirosis, currently data are fragmented. We aimed to systematically review the literature on animal host species and geographic distribution of Leptospira serovars to examine associations between serovars with animal host species and regions, and to identify geographic regions in need of study. Methods:Nine library databases were searched from inception through 9 March 2023 using keywords including Leptospira, animal, and a list of serovars. We sought reports of detection of Leptospira, from any animal, characterized by cross agglutinin absorption test, monoclonal antibody typing, serum factor analysis, or pulsed-field gel electrophoresis to identify the serovar. Results:We included 409 reports, published from 1927 through 2022, yielding data on 154 Leptospira serovars. The reports included data from 66 (26.5%) of 249 countries. Detections were from 144 animal host species including 135 (93.8%) from the class Mammalia, 5 (3.5%) from Amphibia, 3 (2.1%) from Reptilia, and 1 (0.7%) from Arachnida. Across the animal host species, Leptospira serovars that were detected in the largest number of animal species included Grippotyphosa (n=39), Icterohaemorrhagiae (n=29), Pomona (n=28), Australis (n=25), and Ballum (n=25). Of serovars, 76 were detected in a single animal host species. We created an online database to identify animal host species for each serovar by country. Conclusions:We found that many countries have few or no Leptospira serovars detected from animal host species and that many serovars were detected from a single animal species. Our study highlights the importance of efforts to identify animal host species of leptospirosis, especially in places with a high incidence of human leptospirosis. We provide an updated resource for leptospirosis researchers.

Altitudinal distributions, population structures and seasonal dynamics of tick fauna at three localities in Continental Croatia (Medvednica and Papuk) and an alpine biogeographic region (Gorski Kotar) were studied. Sampling of questing ticks was performed twice a year (spring and autumn, from 2019 to 2021) at different altitudes (200, 400, 600, 800 and 1000 m above sea level) using the flagging method. In total, 2942 ticks (53.9% larvae, 40.1% nymphs, 6.0% adults) were sampled and 2937 (99.83%) were determined as Ixodes ricinus, 4 (0.14%) as Haemaphysalis concinna and 1 (0.03%) as Ixodes frontalis. Ixodes ricinus was the only species found at all altitudes and sampling sites. The highest tick abundance was recorded at higher altitudes (800–1000 m asl.) on Medvednica and in Gorski Kotar within mixed forests of European beech and European silver fir, while on Papuk most of the ticks were sampled at lower altitudes (200 m asl.) in Sessile oak forest. From 27 pools containing 305 ticks, 1 (3.7%) was positive for Borrelia burgdorferi sensu lato infection. Borrelia burgdorferi s.l. was detected in 20% (1/5) of the pools containing nymphs and adults collected in Gorski Kotar (600 and 800 m asl.). Sequencing of the ospA gene and phylogenetic analysis revealed the presence of the Borrelia burgdorferi sensu stricto genotype.

Leptospirosis, caused by pathogenic spirochaetes belonging to the genus Leptospira, is a globally distributed zoonosis that can affect many species of domestic and wild animals, and humans. The red fox (Vulpes vulpes) is a native species in Croatia and, due to constant food availability and lack of interspecies competition, is becoming more abundant in urban and suburban areas. Although antibodies for Leptospira spp have been detected in red foxes, lethal disease has not been reported. We necropsied a young, male red fox that had jaundice, multifocal haemorrhages in the heart, lungs and urinary bladder, hepatomegaly, non-congestive splenomegaly and slight yellow discolouration of the renal cortex and medulla. Histology revealed multifocal haemorrhages in parenchymal organs, thrombi within lung septal capillaries and other blood vessels, interstitial lymphocytic and plasmacytic nephritis and erosions of the gastric mucosa. A microscopic agglutination test on the post-mortem cardiac blood clot revealed a high titre to Leptospira interrogans serovar Icterohaemorrhagiae, which implies contact with rats, which are natural reservoirs of this serovar in Croatia. The gross and histological findings in this fox were similar to those in dogs with leptospirosis, indicating that fatal leptospirosis can occur in foxes and suggesting that this species can act as a source of infection for other animals and humans.

Staphylococcus pseudintermedius is a commensal bacterium residing on the mucosae and skin surfaces of dogs. Under favorable conditions, the organism may cause serious infections, primarily involving the skin, but it is also isolated in eye and ear infections. This report describes pathologic findings of pyometra associated with S pseudintermedius in two bitches.One bitch was a 6-year-old Pomeranian bitch who died after three days of diarrhea, vomiting, and depression. During necropsy, the uterus of the bitch was diffusely enlarged and filled with 30 mL of thick, yellow, creamy pus. Histology revealed acute to subacute, diffuse, severe, purulent endometritis with intralesional Gram-positive round cocci revealed as S pseudintermedius. The cause of death was pyometra with subsequent septic shock.The other bitch was a 2-year-old West Highland White Terrier who underwent diagnostic laparotomy due to suppurative peritonitis of unknown cause. During the procedure, about 100 mL of yellow, opaque exudate from the abdominal cavity was removed. The distended uterine horns noted during the procedure were removed and submitted for histopathology which revealed necrosis of endometrium with the accumulation of pus and numerous, intralesional S pseudintermedius in the uterine lumen. Focally, uterine wall necrosis was evident, with a spread of bacteria and purulent inflammation into the adjacent mesometrium causing purulent peritonitis.Although S pseudintermedius presents a common cause of skin and mucosal infection, it should be considered a possible etiological agent of canine pyometra.

Tetanus je akutna zarazna bolest u pasa koja nastaje uslijed djelovanja neurotoksina bakterije C. tetani. Ulazna vrata su najčešće ubodne rane ili ozljede na koži. Inkubacija može trajati u vremenskom rasponu od tri dana do tri tjedna. Razlikujemo dva klinička oblika bolesti: lokalizirani i generalizirani. Kod lokaliziranog oblika vidljiva je ukočenost ekstremiteta na kojem se nalazi ozljeda ili rana. Tipični klinički znaci generalizirang oblika bolesti su grč muskulature lica, a tijekom progresije bolesti dolazi do generalizirane ukočenosti svih ekstremiteta, intermitentnih toničkih grčeva dišne muskulature te spastične paralize. Bolest je popraćena brojnim komplikacijama, a letalan ishod posljedica je respiratornog ili srčanog zastoja. Dijagnostika se temelji na detaljnoj anamnezi i tipičnoj kliničkoj slici. Liječenje tetanusa uključuje kiruršku obradu rane, neutralizaciju slobodnog neurotoksina antitoksinom, sprječavanje daljnjeg umnažanja bakterije C. tetani antimikrobnim pripravcima te potpornu terapiju. Sam proces liječenja je dugotrajan, a prognoza i ishod bolesti ne ovise samo o obliku i tijeku bolesti već i o njezinom pravovremenom prepoznavanju te adekvatnom liječenju. Uz sve navedeno potrebno je naglasiti da još uvijek ne postoji jedinstveni pristup liječenju ove bolesti u pasa. Imunoprofilaksa tetanusa u pasa se ne provodi.