Non-infected Dogs Research Articles

Dog complement system is less effective against Leishmania infantum than human complement

Dogs are important reservoir hosts for Leishmania infantum, the causative agent of visceral leishmaniasis. The complement system, as part of the innate immune defense, is responsible for initiating the fight against pathogens that may invade an organism. A failure of the complement to combat L. infantum may explain, at least in part, why a mammal species is more or less susceptible to visceral leishmaniasis. The objective of this study was to compare the effectiveness of human and dog complement systems against L. infantum parasites. The results showed that dog serum was less effective than human serum at killing promastigote and amastigote-like forms. We also compared the efficiency of human and canine sera in classic and alternative hemolytic assays, as well as the serum efficiency of non-infected and Leishmania-infected dogs. Serum from dogs was less hemolytic than human serum in both pathways tested, but the efficiency of serum from infected dogs was higher than that of non-infected dogs. When testing C3b deposition assays on parasite surfaces, serum from infected dogs was more effective against amastigote-like forms than serum from non-infected dogs. However, both types of serum proved equally effective on promastigotes, while serum from infected dogs was more effective on amastigote-like forms. Considering the efficiency of the complement system, our results indicate that dogs are more susceptible to visceral leishmaniasis than humans are.

Clinical pathology and molecular examination of Babesia spp. infection in dogs; Mashhad, Northeast Iran

This study aimed to fill a crucial gap in our understanding of Babesia infection in dogs in Mashhad, northeast Iran. We not only investigated the prevalence of Babesia species among dogs but also undertook a comprehensive comparison of clinical, hematological, and clinicopathological findings between infected and non-infected cases, a unique aspect of our research. Materials and methodsOur research was conducted with meticulous attention to detail. We randomly collected blood specimens from a diverse population of 150 dogs, including owned pets (n = 47), stray dogs (n = 66), and shelter dogs (n = 37), to ensure the reliability and representativeness of our findings. We then used microscopy and PCR to investigate Babesia spp. infection and analyzed various biochemical and hematological variables. ResultsThe overall prevalence of babesiosis was 15.3 % (23/150) by PCR and 2 % (3/150) by microscopy. Upon microscopic examination, two cases of large Babesia and one case of small-sized Babesia were identified. The sequencing results confirmed that the two dogs testing positive for large-sized Babesia species in this study were both infected with B. vogeli, exhibiting 100 % sequence identity.There was no association between infection and gender, while housing status (k = 37.294, p = 0.000) and age (k = 6.897, p = 0.021) significantly related to infection rate. Among laboratory variables, infection with Babesia spp. showed a remarkable association with Hct (k = 4.749, p = 0.025) and RBC count (k = 14.669, p = 0.000), which were significantly lower in infected dogs compared to non-infected dogs (p < 0.05). Aside from severe non-regenerative anemia observed in all three clinically infected cases, the most clinicopathological changes were observed in one B. vogeli-infected dog, including pancytopenia, azotemia, hyperphosphatemia, hyperkalemia, hypoglycemia, hypocholesterolemia, hyponatremia. ConclusionThis study reveals a higher-than-expected prevalence of canine babesiosis in Northeastern Iran, necessitating further investigation of tick vectors and Babesia spp. distribution. Notably, many infected dogs were asymptomatic, raising concerns about silent spread via carriers. Moreover, the high prevalence of infection in shelters highlights the need for more effective control strategies in these centers.

Improved Antibody Detection for Canine Leptospirosis: ELISAs Modified Using Local Leptospiral Serovar Isolates from Asymptomatic Dogs.

Leptospirosis is a zoonotic disease of significant concern for human and animal health, with domestic animals, including dogs, acting as reservoirs for human infection. Serology is widely used for leptospirosis diagnosis, even though the standard microscopic agglutination test (MAT) using a panel of serovars lacks specificity and can lead to detection limitations in certain regions. In this study, we aimed to develop an antibody detection tool for dogs using an indirect enzyme-linked immunosorbent assay (ELISA) with a set of local serovar isolates, including Paidjan, Dadas, and Mini, to enhance the accuracy of leptospirosis surveillance in our region. The specificity and sensitivity of various antigen preparations, namely leptospiral whole-cell protein (WCP), total membrane protein (TMP), and outer membrane protein (OMP), were assessed using sera from infected and non-infected dogs, as well as negative puppy sera. Leptospirosis diagnosis was supported using a genus-specific nested polymerase chain reaction test on all collected sera. Protein preparations were validated using SDS-PAGE and Western blotting analysis. In the results, the standard MAT failed to detect antibodies in any of the dogs confirmed as being infected using PCR and isolation, highlighting its limitations. In contrast, the OMP-based ELISAs using local isolates of Leptospira serovars gave positive results with sera from all infected dogs, and negative results with sera from all dogs from non-endemic areas. IgG titres of infected and unvaccinated dogs from endemically affected areas were significantly higher than those in non-endemic regions. Using the OMP-based IgG/ELISAs with the local serovar Dadas resulted in higher specificity and lower sensitivity than when using the WCP- and TMP-based IgG/ELISAs. Agreement analysis revealed fair and moderate concordance between OMP-based IgG/ELISAs and PCR results, whereas slight and fair agreement was observed between OMP-based ELISAs and the MAT. Overall, the modified OMP-based IgG/ELISAs, utilising relevant local serovar isolates from dogs, demonstrated improved accuracy in detecting leptospirosis in the study area, overcoming the limitations of the MAT. This study highlights the importance of identifying and incorporating these local circulating serovar isolates into serological techniques for leptospirosis diagnosis and surveillance.

Assessment of the diagnostic performance of serological tests in areas where Leishmania infantum and Leishmania tarentolae occur in sympatry

BackgroundVisceral leishmaniosis caused by infection with the zoonotic protozoan Leishmania infantum is a life-threatening disease affecting dogs and humans. The sympatric occurrence of L. infantum and Leishmania tarentolae in an area of southern Italy endemic for canine leishmaniosis, where dogs are also exposed to the latter species, suggests the persistence of herpetophilic L. tarentolae in a non-permissive host, therefore raising questions about the performance of serological diagnostic tests routinely employed.MethodsThe diagnostic performance of serological tests such as the immunofluorescence antibody test (IFAT), two commercial immunoenzymatic assays (i.e. NovaTec VetLine Leishmania ELISA® and rK39 ICT®) and an in-house enzyme-linked immunosorbent assay (ELISA) was evaluated in healthy dogs seropositive to L. infantum, whereas the only IFAT available was used to detect antibodies to L. tarentolae.ResultsWith the IFAT, out of a total of 104 dogs tested, 15 were seronegative for L. infantum of which three were L. tarentolae seropositive‚ and 89 were L. infantum seropositive. Of the latter 89 dogs, representing the highest proportion of seropositive animals (85.6%) detected by IFAT‚ 66 were also seropositive for L. tarentolae. Cohen's kappa (κ) agreement coefficient between the IFAT results and those of all the other tests was very low, and the IFAT results were significantly different from those of all the other serological tests as calculated by Cochran's Q-test. Analysis using the Bayesian latent class (Bayes-LCA) showed that the in-house ELISA and IFAT contributed the most towards identifying infected and non-infected dogs, respectively. The IFAT test showed low positive predictive value (59.5%), but high negative predictive value (100%).ConclusionsThese results demonstrate that the IFAT for L. infantum, although highly sensitive, may not be considered a useful diagnostic test due to its low specificity. Therefore, an accurate serological tool with high specificity is mandatory for avoiding cross-reaction in epidemiological contexts where the two species of Leishmania occur in sympatry.Graphical

Elimination of Dirofilaria immitis Infection in Dogs, Linosa Island, Italy, 2020-2022.

On Linosa Island, Italy, Dirofilaria immitis infection has been hyperendemic in dogs and seroprevalent among islanders. In 2020, we implemented a heartworm disease elimination program on Linosa Island. Of 54 dogs tested for D. immitis antigen and microfilariae, 28 had positive results and received treatment with oral doxycycline twice daily for 4 weeks plus topical imidacloprid/moxidectin monthly for 12 months. The 26 dogs with negative results received monthly topical imidacloprid/moxidectin as preventive. During month 1, the number of microfilaremic dogs was reduced by 76.5%. From month 2 on, all animals were microfilariae negative, and during months 3 to 9, the number of antigen-positive dogs decreased progressively. Treatment of positive dogs coupled with chemoprophylaxis for noninfected dogs was effective, protecting them from new infections. The elimination program reduced the risk for human infection, representing a One Health paradigm. Monitoring and chemoprophylaxis are advocated to maintain the status of heartworm disease-free area.

Dogs with canine visceral leishmaniasis have a boost of extracellular vesicles and miR-21-5p up-expression.

This retrospective cohort study analysed extracellular vesicles (EVs) and microRNAs (miRNAs) excreted in canine sera from dogs with canine visceral leishmaniasis (CanVL). A total of 56 canine sera were divided into Group I (28, from healthy dogs) and Group II (28, from the same dogs, but already with CanVL). CanVL was determined by clinical and laboratory diagnoses. Canine sera were ultra-centrifuged to recover EVs (Can-EVs). Analyses by transmission electron microscopy, nanoparticle tracking analysis (NTA), sodium dodecyl sulfate-poli-acrylammide gel eletroforesis (SDS-PAGE) and, Immunoblot confirmed the presence of (i) microvesicles/exosomes and (ii) the tetraspanins CD63 and CD9. EVs secreted by Leishmania (Leishmania) infantum-EVs were reactive against sera from dogs with CanVL (performed by ELISA and Immunoblot). NTA analyses exhibited that concentrations of Can-EVs from dogs with CanVL (7.78 × 1010 Can-EVs/mL) were higher (p < .0001) than the non-infected dogs (mean: 1.47 × 1010 Can-EVs/mL). These results suggested that concentrations of Can-EVs were able to distinguish dogs with CanVL from healthy dogs. The relative expressions of 11 miRNAs species (miR-21-5p, miR-146a-5p, miR-125b-5p, miR-144-3p, miR-194-5p, miR-346, miR-29c-3p, miR-155-5p, miR-24-3p, miR-181a-5p, and miR-9-5p) were estimated in purified miRNAs of 30 canine sera. Dogs with CanVL up-expressed miR-21-5p and miR-146a-5p when compared with healthy dogs. The other miRNA species were poorly or not expressed in canine sera. In conclusion, this study suggests that CanVL induces changes in size and concentration of Can-EVs, as well as, the up-expression of miR-21-5p and miR-146a-5p in infected dogs.

Comparison of the quantity and antimicrobial activity of host defence peptides in ear canals between healthy and atopic dogs: A preliminary study.

Host defence peptides (HDPs) are involved in cutaneous immune defence. The secretion of HDPs in the ears of healthy normal and noninfected atopic dogs has not been measured. The aim of this study was to quantify the concentrations of β-defensins (cBD3)-like and cathelicidin (cCath) HDPs in ears of healthy and atopic dogs without infectious otitis, additionally to evaluate the antimicrobial effect of the HDPs obtained. Ten healthy and 20 atopic dogs with mild inflammatory, noninfectious otitis were included. Absence of infection was determined by cytological evaluation, and the severity of clinical signs, if present, was assessed by a previously validated score (Otitis Externa Scoring System for Clinical Study, OTIS-3). The left ear canal of each dog was rinsed with 2 mL of sodium phosphate buffer. The solution obtained was analysed by enzyme-linked immunosorbent assay to quantify HDPs. Additionally, aural secretions were incubated with two concentrations (5 × 105 and 5 × 104 colony-forming units/mL) of Staphylococcus pseudintermedius and the bacterial density measured after 24 h of incubation. Data were statistically analysed. Significance was set as p ≤ 0.05. There was a significantly lower concentration of HDPs from atopic ears when compared with those from normal healthy dogs (cBD3-like: p = 0.0007; cCath: p = 0.049). There was minimal to variable antimicrobial activity in the aural secretions of both groups. This study showed, for the first time, that the ear canals of atopic dogs with mild noninfectious otitis contain a lower concentration of cBD3-like and cCath HDPs than those of healthy dogs with normal ears. A consistent antimicrobial activity was not present in the aural secretions from either group.

Serodiagnosis of leishmaniasis in asymptomatic and symptomatic dogs by use of the recombinant dynamin-1-like protein from Leishmania infantum: A preliminary study

Visceral leishmaniasis (VL) is a fatal manifestation of an infection caused by intracellular protozoa of the Leishmania genus. In New World countries, VL is classified as a zoonotic disease with domestic dogs acting as its main reservoir. Asymptomatic dogs are as competent to transmit Leishmania to the vectors as symptomatic dogs, however current diagnostic tests are limited and present low sensitivity for this important group. The development of accurate tests is fundamental to the early diagnosis, treatment, and control of canine leishmaniasis. In this study, we investigated the use of a recombinant protein (dynamin-1-like protein, Dyn-1) from L. infantum, as a potential target antigen for leishmaniasis serodiagnosis in both symptomatic and asymptomatic dogs. The antigenic performance of the protein was evaluated by means of ELISA assays using sera from symptomatic (n = 25), asymptomatic (n = 34) and non-infected dogs (n = 36) using ELISA. In addition, sera from dogs experimentally infected with Trypanosoma cruzi (n = 49) and naturally infected with Babesia sp. (n = 8) were tested to evaluate possible cross-reactivity. A crude soluble antigen (CSA) of Leishmania was used as an antigen control and K39 and K26 were used as reference antigens because they are already widely used in commercial tests. rDyn-1-based assay showed the highest sensitivity (97%) compared to the antigens K39 (88%), K26 (86%) and crude extract (95%). The highest specificity among the tests was also obtained with the protein rDyn-1 (94%), compared with the other antigens K39 (81%), K26 (87%), and crude extract (77%). This study showed that the rDyn-1 ELISA assay was able to identify 100% of asymptomatic dogs, establishing its potential as a target for the diagnosis of canine leishmaniasis.

Detection of Hepatozoon spp. in dogs in Shiraz, southern Iran and its effects on the hematological alterations.

Canine hepatozoonosis is a tick-transmitted apicomplexan infection caused by two species of Hepatozoon, H. canis, and H. americanum. The present research aimed at detection of Hepatozoon spp. in dogs and its effects on hematological alterations. Blood samples were taken from 108 dogs to assess Hepatozoon spp. Phylogenetic analysis was performed based on the 18S rDNA marker by PCR assay and Giemsa-stained blood smear examination. Of the 108 blood samples of dogs tested in the present study, eight (7.40%, 95% CI: 3.25-14.07%) were positive by the Hepatozoon-specific PCR assay. However, in the microscopic examination, only one sample (0.93%) was positive. All of the sequenced samples were H. canis. The Hepatozoon sequences obtained from PCR amplicons in the canine-positive cases exhibited 100% similarity to each other and 98.47-100% similarity to other relevant sequences in GenBank. These findings represent the first molecular evidence of H. canis in dog populations in South Iran. Furthermore, according to the hematological analysis, significantly higher average numbers of neutrophils and lymphocytes were found in the infected group compared to the non-infected dogs. In this study, no statistically significant connection (P<0.05) was observed between H. canis infection and the examined risk factors.

Study of ocular manifestations and humoral immune response in eyes of dogs with leishmaniasis.

Ocular manifestations in dogs with leishmaniasis are frequent and complications in affected tissues can lead to blindness. Immune processes play a very important role in the pathogenesis of ocular inflammation. Therefore, the immunology of ocular manifestations in dogs with leishmaniasis remains complex and poorly understood. Estimation and characterisation of ocular and periocular manifestations in dogs naturally infected with Leishmania infantum and investigation of the production site of specific anti-Leishmania infantum IgG. The present investigation used 53 confirmed dogs infected with Leishmania infantum, presenting ocular and periocular lesions, and 10 control non-infected dogs. Complete macroscopic ophthalmic examination of eyelids and globes was performed. Both total and anti-Leishmania infantum IgG antibodies were studied in sera and aqueous humour (AH) of all dogs by ELISA technique. A Goldmann-Witmer coefficient (C value) was calculated. The main ophthalmological findings were keratoconjunctivitis (71.7%; 38/53), hyperplasia of conjunctival lymphoid follicles (54.7%; 29/53), blepharitis (50.9%; 27/53) and uveitis (20.7%; 11/53). Ocular production of anti-Leishmania infantum IgG was detected in 73.6% (39/53) of infected dogs. There was no correlation between the antibody levels in AH and sera of the same dog. The mean anti-Leishmania infantum IgG in AH was higher in uveitis, followed by lesions affecting only the adnexa (p < 0.0001). The highest mean C values were observed for uveitis, conjunctivitis and keratitis. Our findings suggest that production of anti-Leishmania IgG in dogs infected with Leishmania infantum with ocular manifestations begin in situ and follows by a transfer of antibodies from the bloodstream to the AH.

Atypical Lesions in Canine Leishmaniosis: Description of New Cases.

Simple SummaryCanine leishmaniosis is a zoonotic disease caused mainly by the protozoan Leishmania infantum that is endemic in the Mediterranean basin. The clinical signs and pathological characteristics have been extensively described; however, atypical lesions leading to clinical and pathological misdiagnosis have been sporadically reported. This study presents three cases of dogs experimentally infected with Leishmania infantum that showed gross lesions considered atypical of canine leishmaniosis and not previously reported. Macroscopic lesions were observed in the liver, spleen, and peritoneal cavity that corresponded to tan to whitish nodular lesions in all organs and multifocal irregular and linear whitish lesions in one of the livers that mimicked tumors. Microscopically, a marked granulomatous inflammation with a relative scarcity of parasites was observed in all the organs. In conclusion, microscopic and parasitological studies should be performed on atypical lesions observed in Leishmania-infected and non-infected dogs, especially in endemic regions. In addition, due to its zoonotic importance, leishmaniosis should be considered when atypical nodular lesions are observed in dogs from non-endemic regions with a history of travel to endemic regions.Pathological characteristics are well described in canine leishmaniosis (CanL). However, atypical lesions that can be confused with other pathologies or trigger unusual clinical signs are sporadically reported. Atypical lesions were observed during routine postmortem examination in three Leishmania-infected dogs and samples were taken for histopathological and immunohistochemical studies. Clinical signs, biochemical parameters, level of antibodies, and parasite detection by PCR were also evaluated. Atypical lesions were found in the peritoneal cavity, liver, and spleen. Splenomegalia and hepatomegalia were observed in all dogs. In addition, multifocal dark to white nodules of variable size were observed in the peritoneal cavity, liver, and spleen of one dog and in the spleen of the other two dogs. One dog presented diffuse irregular whitish lines with a threadlike appearance and another an intense fibrotic depression in the intermediate lobe. Microscopically, an intense granulomatous inflammation with abundant macrophages, a variable number of lymphocytes, and a low to moderate number of parasites was observed. This study represents the first description of granulomatous peritonitis associated with Leishmania in dogs. It also shows atypical macroscopic expression of hepatitis in CanL. In the absence of an adequate clinical history and laboratory analyses, certain lesions observed in CanL could admit alternative diagnoses.

The Relationship Between Antioxidant Trace Elements (Zn-Cu and Se) and Oxidative Stress in Dogs Affected with Dermatophytosis

Canine dermatologic problems are among the most common disorders seen in canine practice, caused by the fungus. The current study was planned to observe the relationship between antioxidant trace elements (Zn-Cu and Se) and oxidative stress in dogs affected with dermatophytosis. Briefly, this study comprised of 34 dogs. Compared different parameters including hematological, biochemical, histopathological, and the level of antioxidant trace elements in 14 infected dogs with 20 non-infected dogs (control group). Results showed a significantly higher level (P&lt;0.05) of TLC (16.33x103 U/L), MCHC (34.65g/dL), RDW (18.25%), and lymphocyte (47.9%) in the dermatophytosis-infected dogs as compared to the control group. Similarly, serum biochemical findings revealed a significant elevation in cortisol level (709.88nmol/L) in infected dogs while a significant decrease in free T4 (8.57pmol/L) in infected dogs compared to the control group. Furthermore, the level of selenium (0.02±0.00mg/dL), copper (59.725±3.01mg/dL) and zinc (60.99±2.76mg/dL) were significantly lower (P=0.00) in dogs infected with dermatophytosis. The study revealed that dermatophytes infection represents a stress factor affecting the level of antioxidant trace elements and the antioxidant defense system of the infected animal.

The host micro-RNA cfa-miR-346 is induced in canine leishmaniasis

BackgroundLeishmaniases are a group of anthropo-zoonotic parasitic diseases caused by a protozoan of the Leishmania genus, affecting both humans and other vertebrates, including dogs. L. infantum is responsible for the visceral and occasionally cutaneous form of the disease in humans and canine leishmaniasis. Previously, we have shown that L. infantum induces a mild but significant increase in endoplasmic reticulum (ER) stress expression markers to promote parasites survival in human and murine infected macrophages. Moreover, we demonstrated that the miRNA hsa-miR-346, induced by the UPR-activated transcription factor sXBP1, was significantly upregulated in human macrophages infected with different L. infantum strains. However, the ER stress response in infected dogs, which represent an important reservoir for Leishmania parasite, was described once recently, whereas the miR-346 expression was not reported before. Therefore, this study aimed to investigate these pathways in the canine macrophage-like cell line DH82 infected by Leishmania spp. and to evaluate the presence of cfa-miR-346 in plasma of non-infected and infected dogs. The DH82 cells were infected with L. infantum and L. braziliensis parasites and the expression of cfa-mir-346 and several ER stress markers was evaluated by quantitative PCR (qPCR) at different time points. Furthermore, the cfa-miR-346 was monitored in plasma collected from non-infected dogs (n = 11) and dogs naturally infected by L. infantum (n = 18).ResultsThe results in DH82 cells showed that cfa-mir-346 was induced at both 24 h and 48 h post-infection with all Leishmania strains but not with tunicamycin, accounting for a mechanism of induction independent from sXBP1, unlike what was previously observed in human cell lines. Moreover, the cfa-miR-346 expression analysis on plasma revealed a significant increase in infected dogs compared to non-infected dogs.ConclusionsHere for the first time, we report the upregulation of cfa-miR-346 induced by Leishmania infection in canine macrophage-like cells and plasma samples of naturally infected dogs. According to our results, the cfa-miR-346 appears to be linked to infection, and understanding its role and identifying its target genes could contribute to elucidate the mechanisms underlying the host–pathogen interaction in leishmaniasis.

How does Dirofilaria immitis infection impact the health of dogs referred to cardiology care.

Dirofilaria immitis is a nematode that can cause a disease that may present clinical signs from severe to absent. When dogs are symptomatic, the clinical signs are cardiorespiratory and nonspecific, which may be misleading. This study aimed to demonstrate the clinical presentations to cardiac care by evaluating 26 dogs subjected to clinical examination, complete blood count (CBC), specific tests for D. immitis infection, chest radiography, and echocardiography. Among them, 11 (42.3%) dogs were infected and 15 (57.7%) were non-infected. Most dogs presented with coughing (65.4%) and abnormal lung sounds (81%) independent of infection. Murmur at the tricuspid focus was present in 26.9% of the dogs, of which 57.1% were infected. Echocardiography revealed tricuspid regurgitation in 30.8% of the dogs and pulmonary regurgitation in 46.1%, of which 37.5% and 50% were infected, respectively. Worms were detected by echocardiography in 45.5% of the infected dogs. The x-rays showed that the bronchial pattern was present in 45.5% of the infected dogs and in 46.7% of the non-infected dogs. The interstitial pattern was present in 18.2% of the infected animals, in contrast to 6.7% of the non-infected dogs. The CBC results for all dogs were within the reference range, except for platelets. Although similar, the percentage of dogs with thrombocytopenia was higher among infected dogs (36.4%) than among the non-infected (6.7%). These results reinforce that due to the non-specific signs of infection, it is mandatory to perform parasitological assays when evaluating dogs presenting with cardiopulmonary signs.

Detection of Trypanosoma cruzi infection by PCR in Canis lupus familiaris and their ectoparasites in Chile.

Chronic Chagas disease affects humans and animals, involving rural and urban inhabitants. Dogs participate in the maintenance and transmission of Trypanosoma cruzi. The objective of this study was to evaluate the presence of T. cruzi in dogs and their ticks and fleas, in a rural area of Central Chile. Trypanosoma cruzi was detected by PCR both in dogs and ectoparasites. From the blood samples obtained, 57% were infected by T. cruzi, 5.4% of the ticks detected were positive, and all fleas were negative. Additionally, we performed electrocardiograms and found supraventricular arrhythmia in 44% of T. cruzi-positive dogs. Nevertheless, their risk for supraventricular arrhythmias was not higher in infected versus noninfected dogs. Considering the detected infection levels, dogs act as T. cruzi hosts in Central Chile, and ticks could be used as an indicator of infection when blood samples are not available. However, at this point, there is no indication that these ticks could pass on the parasite to another host. Periodic ectoparasitic treatment of pets should reduce the chance of vectorial transmission of T. cruzi and improve canine health; however, this is an uncommon practice among rural communities, so governmental programs are encouraged to tackle this problem.

Vitamin d and leishmaniasis: Neither seasonal nor risk factor in canine host but potential adjuvant treatment through cbd103 expression.

Vitamin D (VitD) deficiency has been shown to be a risk factor for a plethora of disorders. We have shown that dogs with clinical leishmaniasis presented lower VitD serum levels than non-infected dogs, and even lower than those with asymptomatic infection. However, if VitD deficiency is a risk factor to develop clinical leishmaniasis remains to be answered. It is also unknown if VitD participates in Leishmania control. First, we retrospectively analysed VitD concentration in serum samples from 36 healthy dogs collected in different periods of the year concluding that there isn’t a seasonal variation of this vitamin in dogs. We also included 9 dogs with clinical leishmaniasis and 10 non-infected healthy dogs, in which we measured VitD levels at the beginning of the study, when all dogs were negative for serology and qPCR, and 1 year later. Whereas non-infected dogs showed no change in VitD levels along the study, those developing clinical leishmaniasis showed a significant VitD reduction at the end of the study (35%). When we compared VitD concentration between the two groups at the beginning of the study, no differences were detected (43.6 (38–59) ng/mL, P = 0.962). Furthermore, an in vitro model using a canine macrophage cell line proved that adding active VitD leads to a significant reduction in L. infantum load (31.4%). Analyzing expression of genes related to VitD pathway on primary canine monocytes, we showed that CBD103 expression was significantly enhanced after 1,25(OH)2D addition. Our results show that VitD concentration is neither seasonal nor a risk factor for developing canine leishmaniasis, but it diminishes with the onset of clinical disease suggesting a role in parasitic control. Our in vitro results corroborate this hypothesis and point out that VitD regulates infection through CBD103 expression. These results open the possibility for studies testing VitD as an adjuvant in leishmaniasis therapy.

Vector-borne haemoparasitic and rickettsial diseases of dogs in South west, Nigeria: An eleven years retrospective study

Adequate knowledge of the occurrence and seasonal variation in the distribution of parasitic and rickettsial diseases affecting dogs is required for formulation of effective disease control measures. Hence, this study assessed the prevalence of vector borne haemoparasites and rickettsial of dogs between 2009 and 2019. Clinical records of dogs presented for clinical examination and confirmed by microscopic screening of their blood were assessed and analysed statistically. Overall, 1483 dogs were presented to the Veterinary Teaching Hospital (VTH). This included 641 (43.2%) male, 842 (56.8%) female, 967 (65.2%) young and 516 (34.8%) adult dogs. 33 (2.2%) and 1450 (97.8%) were mongrel and exotic breeds, respectively. 511 (34.5%) were infected with either haemoparasites or rickettsial. This comprised 34.0% (218/641) and 34.8% (293/842) male and female, 317 (32.8%) and 194 (37.6%) young and adult dogs, respectively. There was no significant (p =0.05) difference in the prevalence among sexes and age groups. Seasonal prevalence was 35.88% (315/878) and 32.40% (196/605) in wet and dry seasons, respectively. Six haemoparasites/rickettsials were reported from 511 dogs, these included single infections of Babesia species 477 (93.5%), Ehrlichia species 8 (1.6%), Hepatozoon canis 2(0.39%), Mycoplasma haemocanis 7 (1.4%), Trypanosoma species 16 (3.1%) and mixed infection of Babesia and Hepatozoon canis 1 (0.2%). The mean PCV values were significantly (t = 2.45; P = 0.014) different between infected and non-infected dogs. This study suggests that Babesia spp. isthe most prevalentin the dogs presented to the VTH in the study area and the detection of Trypanosoma spp. in some dogssuggeststhat dogs could be reservoir of trypanosomesfor both animals and human.&#x0D; Keywords: Dogs, haemoparasites, prevalence, retrospective-study

Immunoprophylactic Potential of a New Recombinant Leishmania infantum Antigen for Canine Visceral Leishmaniasis: An In Vitro Finding.

The development and application of safe and effective immunoprophylactic/immunotherapeutic agents against canine visceral leishmaniasis (CanL) have been pointed out as the only means for the real control of the disease. Thus, this study aimed to evaluate the in vitro cellular immune response of dogs, elicited by the new recombinant proteins of Leishmania infantum, Lci10 and Lci13, in order to investigate their potential for vaccinology. Twenty-four dogs were submitted to clinical, parasitological, serological and molecular tests, and then separated into two study groups: 12 infected (InD) and 12 non-infected dogs (NInD), and six of each group were directed for Lci10 and Lci13 evaluation. Peripheral blood mononuclear cells (PBMC) were cultured and stimulated with Lci10 (10 μg/ml) or Lci13 (5 μg/ml), and with L. infantum soluble antigen (LSA) (25 μg/ml) or no stimulus (NS) as controls. Afterwards, the mRNA levels of different cytokines were quantified through qPCR, and Nitric Oxide (NO) production was assessed in the culture supernatants. Significant differences were considered when p ≤ 0.05. The comparative analysis revealed that, in the NInD group, Lci13 promoted a significant increase in the expression of IFN-γ in relation to LSA (p = 0.0362), and the expression of this cytokine in NInD was significantly higher than that presented in the InD (p = 0.0028). A negative expression for TGF-β was obtained in both groups. Lci13 also induced a greater production of NO in relation to the NS sample in the NInD group. No significant differences were observed after stimulation with Lci10. In conclusion, the results suggest a protective role of Lci13 for uninfected animals, thus with a potential for immunoprophylaxis. The results will help to direct the antigen Lci13 for further studies (pre-clinical trials), in order to determine its immunogenicity and reactogenicity effects, as a way to consolidate its real applicability for vaccinology against CanL.

Evaluation of the cutaneous inflammatory cells in dogs with leishmaniosis and in dogs without the disease that were naturally infected by Leishmania infantum (syn. L. chagasi).

Canine leishmaniosis (CanL) is associated with an aberrant cutaneous immune response. Few studies have compared cutaneous immune cells among dogs with leishmaniosis or infected without leishmaniosis, and noninfected dogs. Evaluate the number of neutrophils, histiocytes, T lymphocytes, T-bet-positive, GATA3-positive, FoxP3-positive and interleukin (IL)-17-positive cells, in lesional (Group A) and normal-looking (Group B) skin of nine dogs with stage II/III leishmaniosis; in normal-looking PCR-positive (Group C; n=6) or PCR-negative (Group D; n=6) skin of infected dogs; and in the normal-looking skin of 12 noninfected dogs (Group E). Diagnosis of CanL considered clinical signs, clinicopathological abnormalities, detection of Leishmania amastigotes in lymph nodes, and/or bone marrow and positive serological results. Paraffin-embedded skin biopsies were processed for routine immunofluorescence and positive cells were identified using commercially available anti-canine antibodies. In Group A, there was a significantly higher number of neutrophils (P<0.001), histiocytes (P=0.012), T lymphocytes (P=0.011), GATA3-positive (P=0.02) and IL-17A-positive (P=0.002) cells compared to Group E. In Group B, there was a significantly higher number of histiocytes (P=0.02), T lymphocytes (P=0.004), GATA3-positive (P=0.006) and FoxP3-positive (P=0.028) cells compared to Group E. There was no difference in between groups A and B and between groups C or D and E. In the lesional and/or normal-looking skin of dogs with moderate/severe CanL there is an infiltration of neutrophils, histiocytes, T lymphocytes, GATA3-, FoxP3- and IL17A-positive cells. By contrast, the number of these cells is not increased in the normal-looking skin of infected dogs without CanL compared to the skin of noninfected dogs.

Investigation of Variables Associated with Surgical Site Infection following the Management of Canine Cranial Cruciate Ligament Rupture with a Lateral Fabellotibial Suture.

This study investigated variables associated with surgical site infection (SSI) in dogs with cranial cruciate ligament rupture managed with stifle joint examination and lateral fabellotibial suture stabilization. A retrospective study of dogs that had stifle arthroscopy, stifle arthrotomy, or a combination of both, followed by lateral fabellotibial suture stabilization for cranial cruciate ligament rupture. All cases had a minimum follow-up of 90 days. Lameness grades were recorded preoperatively, and at 6-week and final follow-up. One hundred fifty procedures in 130 dogs met the inclusion criteria. Overall, SSI rate was 17.3% and removal of the lateral fabellotibial suture was performed in 53% of SSI. Multivariable analysis showed significant association between SSI and bodyweight (p = 0.013), and induction using propofol (p = 0.029). Multilevel ordinal logistic regression analysis showed a greater proportion of dogs had a higher lameness grade at 6-week (p = 0.021) and final follow-up (p = 0.002) assessments in the infected compared with non-infected dogs. Our study demonstrated a higher SSI incidence than previously reported in dogs undergoing a lateral fabellotibial suture for cranial cruciate ligament rupture. Bodyweight and induction with propofol were identified as significant risk factors for postoperative SSI. Owners could be advised of an increased SSI risk in larger dogs and consideration should be given to selection of induction agent. Dogs that develop an SSI have a worse lameness grade at 6-week and final follow-up.