Maciej Klockiewicz

Environmental conditions have an impact on animals’ immune systems. Neutrophils, as key components of innate immunity, rapidly respond to bacterial stimuli through the activation of inflammatory and migratory pathways. This study evaluated the transcriptional and functional responses of neutrophils derived from dogs living under different housing environments following in vitro lipopolysaccharide (LPS) stimulation. Distinct transcriptional profiles were observed among groups in genes associated with leukocyte adhesion (CD11b), chemokine signaling (CXCR1, CXCR2, and CXCL8), and cytokines (TNF-α, IL-1β, and IL-6). Additional cytokine analyses confirmed neutrophil activation and revealed differences in the magnitude and duration of cytokine secretion between groups. These findings indicate that environmental background may be associated with differences in both transcriptional responsiveness and cytokine production in canine neutrophils. Dogs originating from different housing conditions exhibited distinct patterns of inflammatory activation. The combined assessment of gene expression and cytokine secretion provides valuable insight into innate immune adaptation and might represent a useful approach for monitoring immune status in dogs.

The immune status of dogs is shaped by continuous exposure to antigenic and various environmental stimuli, which together influence the development, regulation, and effectiveness of immune responses. Stress-related immune alterations may not be evident at the systemic level but can emerge at cellular and molecular scales. Therefore, this study aimed to comprehensively characterize the hematological and immunological profiles of dogs in different environments. We evaluated lymphocyte responses under basal conditions and following CD3/CD28-mediated in vitro activation, with subsequent long-term culture. Gene expression analyses targeted markers of early T cell activation, cytotoxic effector function, cytokine signaling, and inhibitory immune regulation. The memory phenotype of T lymphocytes was evaluated after blood collection and prolonged in vitro culture. In addition, hematological and biochemical profiles were assessed, including basic parameters, cortisol, and C-reactive protein. Our results revealed that client-owned dogs exhibited lower baseline expression of activation markers, especially in comparison with the short-term stay group, indicating an early immune activation state upon entry to the shelter environment. Furthermore, T lymphocytes from short- and long-term shelter dogs exhibited marked differences in the distribution of naïve and effector-memory subsets as well as different expansion capacity. These alterations persisted during prolonged in vitro culture, indicating that stress duration and environmental antigen exposure differentially shape immune responsiveness. In summary, chronic stress modulates canine immune status in a time-dependent manner, highlighting the importance of integrated cellular and molecular approaches in assessing the impact of environmental stressors on dogs’ health and welfare.

Environmental impact plays a pivotal role in forming the welfare of shelter dogs exposed to chronic stress. Standard methods of animal health monitoring, such as psychological evaluation or cortisol measurements, do not fully reflect modulation of the immune system. Functional cellular changes may be subtle and observed only at the molecular level. Therefore, the aim of this study was to characterize the immune function of shelter dogs kept on different timetables in comparison with client-owned dogs. We focused on potential alterations of antigen processing by neutrophils and monocytes in animals undergoing different durations of stress. Hematological and biochemical parameters were evaluated, and changes in TLR4 and MHC Class II expression on neutrophils and monocytes isolated from peripheral blood were determined. Additionally, we measured the percentage of apoptotic cells within these leukocyte populations. Our study revealed that stressful conditions can alter the molecular pattern of surface receptors on neutrophils and monocytes, as well as the leukocytes apoptosis rate. The obtained data also indicated that the dogs’ duration of stay in the shelter plays an important role in immunomodulation and triggering their adaptation mechanisms. These results bring a new perspective and will be crucial in developing improved guidelines for monitoring and promoting the welfare of shelter dogs.

Introduction: Dirofilaria repens is a zoonotic parasitic filarial nematode that infects carnivores and occasionally humans. Knowledge of the host–parasite molecular interactions enabling the parasite’s avoidance of the host immune response in subcutaneous dirofilariasis remains limited. Parasitic orthologues of host macrophage migration inhibitory factor (MIF) are molecules potentially involved in this process. Material and Methods: Complementary DNA encoding two D. repens MIF orthologues (rDre-MIF-1 and rDre-MIF-2) was cloned into a pET-28a expression vector. The recombinant proteins were produced in Escherichia coli and purified using affinity nickel chromatography. The reactivity of both recombinant proteins was analysed with infected dog and immunised mouse sera. Results: Stronger antibody production was induced by rDre-MIF-1 in mice, as evidenced by significantly higher levels of anti-rDre-MIF-1 total IgG, IgG2 and IgE antibodies than of anti-rDre-MIF-2 immunoglobulins. Additionally, a significantly different level of antibodies specific to both proteins was noted between the sera of infected dogs and those of uninfected dogs. Conclusion: This study is the first attempt to characterise MIF orthologues from the filarial parasite D. repens, which may affect the immune response during infection.

American mink (Neovison vison) is an invasive species in the sylvatic environment of Poland. Mink are exposed to different parasite infections as their preys serve as intermediate and/or paratenic hosts. The study aimed to discriminate the pattern of intestinal parasite infections in mink inhabiting Biebrza (BNP) and Narew (NNP) national parks. Gastrointestinal tract examinations revealed Coccidia, Echinostomatidae, Taenidae, and Capillariidae parasites. There was no significant difference in the parasite burden of mink, but patterns of infections varied between both localizations. Coccidia were found in 3.8% of BNP vs. 6.7% of NNP mink. Fluke prevalence was significantly higher in NNP 27.5% compared to 7.7% in BNP mink. Tapeworms were only found in 3.4% of NNP mink. Significantly more Aonchotheca eggs were found in BNP 34.6% vs. 11.4% in NNP mink. The intensity of coccidiosis and aonchothecosis was low in both parks. Fluke intensity varied between low to moderate (ranging from 1 to 16) in BNP and low to massive (ranging from 1 to 117) in NNP mink. Coinfections of various parasite species were noted in both areas. Morphological and DNA analysis revealed that flukes belonged to Isthiomorpha melis and tapeworms to Versteria mustelae. It was the first isolation of V. mustelae in mink of those localizations. In conclusion, our study showed that mink indwelling Biebrza and Narew national parks are moderately infested with parasites. Results suggest that mink play an important role as a reservoir for parasites endangering endemic mustelids, becoming also a potential risk factor in case of accidental transmissions to farm mink. That is why, more strict biosecurity measures are required to protect farm mink.

Introduction and Objective: The aim was to review available data concerning the occurrence of protozoan parasites affecting carnivorous fur farm animals, such as: American mink, blue and silver foxes, and raccoon dogs. Although, many protozoan pathogens have been isolated in wild fur animals,...

Dirofilariarepens is a parasitic nematode causing a vector-borne zoonotic infection (dirofilariosis), considered an emerging problem in human and veterinary medicine. Currently, diagnosis is based on the detection of the adult parasite and microfilariae in the host tissues. However, the efficacy of tests relying on microfilariae detection is limited by microfilariae periodic occurrence. Therefore, a new reliable and affordable serological diagnostic method is needed. Better characteristic of the parasite biology and its interaction with host immune system should help to achieve this goal. This study analyzes adult and microfilariae proteomes, and the use of one-dimensional electrophoresis (1-DE) and two-dimensional electrophoresis (2-DE) proteomics, immunoproteomics, and LC-MS/MS mass spectrometry allowed us to identify 316 potentially immunogenic proteins (75 belong to adult stage, 183 to microfilariae, and 58 are common for both). Classified by their ontology, the proteins showed important similarities and differences between both parasite stages. The most frequently identified proteins are structural, metabolic, and heat shock proteins. Additionally, real-time PCR analysis of some immunogenic targets revealed significant differences between microfilariae and adult life stages. We indicated molecules involved in parasite-host interactions and discussed their importance in parasite biology, which may help to reveal potential diagnostic antigens or select drug and vaccine targets.

Subcutaneous dirofilariosis is a zoonotic disease emerging throughout Europe caused by the filarial nematode Dirofilaria repens. Despite its increasing prevalence, there is a large gap in knowledge of the impact of the parasite on the host. Currently classified as being non-pathogenic, recent evidence suggests that skin dirofilariosis is associated with dermatological conditions including concomitant pruritus, neoplastic processes, inflammation, and even blindness in dogs and humans. The aim of this study was to determine if natural canine D. repens infection leads to biological changes in the canine host. In a real-life veterinary clinic setting, animals are often presented to clinicians for unrelated issues, and D. repens is incidentally identified during inspection. As such, we compared hematological and biochemical parameters of 218 uninfected and 197 dogs naturally infected with D. repens. Interestingly, animals infected with D. repens had lower numbers of lymphocytes (p < 0.001), red blood cells (p < 0.001), and thrombocytes (p = 0.025), decreased hematocrit (p < 0.001), and increased alkaline phosphatase (p = 0.016) and creatinine activity (p = 0.023) compared to uninfected dogs. We further selected a subpopulation of 214 dogs having prima facie hematological and biochemical results within normal reference ranges to evaluate the effect of D. repens infections in seemingly healthy dogs. Among these patients, 93 dogs infected with D. repens had lower numbers of lymphocytes (p = 0.031), red blood cells (p = 0.025), and hematocrit (p = 0.002), higher glucose levels (p = 0.023), and border line elevated alkaline phosphatase levels (p = 0.054) compared to 121 uninfected animals. Despite being categorized as asymptomatic, we have observed hematological and biochemical changes associated with D. repens infections in dogs, and our data suggest that dirofilariosis may induce a state of chronic stress. These results link the presence of skin dirofilariosis to biological changes in the canine host, suggesting a mechanism for pathogenicity and shedding new light on the host–parasite relationship.

Introduction: Canine roundworm T. canis and T. leonina infections were investigated in experimentally infected farm mink ( Neovison vison ) to describe the pattern of pathological lesions in this paratenic host. Material and Methods: Infections in mink developed following ingestion of embryonated eggs of either parasite or mice tissue infected with both parasite species. Results: Comparative analysis of haematoxylin- and eosin-stained slides showed essential differences among the experimental groups. The lesions observed included eosinophil and mononuclear inflammatory infiltrates of the intestinal wall and local lymph nodes, inflammation and haemorrhages in liver tissues, and interstitial inflammation and mineralisation of the kidneys and lungs. Larvae migrating through the minks’ bodies also caused particularly salient enlargement of lymphoid follicles in the spleen and inflammatory infiltrates of mononuclear cells in skeletal and heart muscles. Conclusions: It is assumed that histopathological lesions appeared as a local and general host response to invasive L3 T. canis and T. leonina larvae migrating through the tissues of infected farm mink. Interestingly, mink infected with embryonated eggs had more pronounced lesions than animals infected with tissue larvae. Detailed histopathological examinations of parenchymal organs and striated muscles revealed lesions resembling those observed in other paratenic host species due to toxocarosis.

Introduction: Farm mink (Neovison vison) can be naturally exposed to T. canis and T. leonina pathogens on the farm. If mink were hosts, it would imply some veterinary public health as well as animal welfare issues. For this reason, the aim of the study was to determine whether mink might be definitive or paratenic hosts of these parasites. Material and Methods: Four groups of mink were infected with both parasite species using larvated eggs or feed containing mouse tissue previously infected with the parasites. Following inoculation, the infections were monitored in vivo by faecal examination for 14 weeks p.i., and then western blotting and ELISA were performed. Results: Coprology did not reveal any canine roundworm eggs, neither were nematodes found in mink intestines during post mortem examination. The specific IgG antibodies recognising excretory/secretory (ES) antigens of both parasite species were identified in mink sera. Single T. leonina tissue larvae were found in digested organs. Conclusions: Our results confirm that farm mink may contribute both T. canis and T. leonina infections. It was proved that farm mink were not their definitive hosts, and therefore mink faeces need not be considered a source of canine roundworm eggs in any soil it fertilises. Nonetheless, as farm mink may be a paratenic host for both parasite species, this may have some impact on the health and welfare of infected animals.