Selected cytokine expression in dogs with alergic conjunctivitis: Correlation with disease activity.

INTRODUCTION: Canine allergic conjunctivitis (cAC) is described as the most frequent ocular manifestation associated with canine atopic dermatitis (cAD). OBJECTIVES: Clinical and immunological characterization of cAD through IL-6, TNF-α and IL-12 mRNA expression quantification in canine conjunctivae. PROCEDURES: Twenty client-owned dogs with both cAC and cAD and twenty-one healthy controls were enrolled and clinician assessed CADESI-04 and grade of ocular signs were calculated. Conjunctival biopsies were performed on all animals and relative quantification of the interleukins mRNA expression performed by qRT-PCR. The correlation between cytokine gene expression and cAC score was evaluated, as well as CADESI-04 values. RESULTS: The qRT-PCR showed a significant gene upregulation of respectively 291.48 (p = 1.306e-09) and 4.85 (p = .00033) folds on IL-6 and IL-12 in dogs with allergic conjunctivitis compared to the control group. Regarding the average expression of TNF-α there were no statistical significant differences between both groups (p = .18). Higher cAC scores were associated with enhanced gene expression of TNF-α and IL-12. No correlation was found between the cytokine gene expression levels and the CADESI-04 values. CONCLUSION: An increase of IL6 and IL12 in cAC was found in the studied population. These two cytokines may be potential immunotherapy targets cAC classification.

Unveiling patterns of viral pathogen infection in free-ranging carnivores of northern Portugal using a complementary methodological approach.

Pathogen surveillance in free-ranging carnivores presents challenges due to their low densitie and secretive nature. We combined molecular and serological assays to investigate infections by viral pathogens (Canine parvovirus (CPV), Canine distemper virus (CDV) and Canine coronavirus (CCoV)) in Portuguese carnivores (Canis lupus, Vulpes vulpes, Lutra lutra, Martes foina, M. martes, Meles meles, and Genetta genetta) over a period of 16 years. Additionally we explored spatio-temporal patterns of virus occurrence in Canis lupus. Our study identified CPV DNA in all carnivore species with an overall prevalence of 91.9 %. CPV was detected in all sampled years and seasons in Canis lupus, supporting its enzootic nature. CDV RNA was mainly detected in the Canidae family, with viral nucleic acid recorded between 2005 and 2008 with a peak prevalence of 67 % among the wolf population, followed by a sharp decline, suggesting an epizootic behaviour of the virus. Antibodies show that mustelids and viverrids were often exposed to CDV. CCoV was first recorded by molecular methods in wolf samples in 2002, remaining in the wolf populations with marked fluctuations over time. The dual serological and molecular approach provided important epidemiological data on pathogens of wild carnivores in Portugal. These programmes should also include monitoring of other potential reservoir hosts such as domestic cats and dogs.

Granulomatous rhinitis secondary to feline leishmaniosis: report of an unusual presentation and therapeutic complications.

CASE SUMMARY: A 12-year-old male neutered domestic shorthair cat underwent rhinoscopy due to inspiratory dyspnoea and stertor. Rhinoscopy showed signs of chronic rhinitis and a multinodular nasopharyngeal mucosa. A marked infiltrate of macrophages that contained intracellular parasitic forms morphologically compatible with Leishmania amastigotes were observed on histopathological examination of nasal and nasopharyngeal biopsies. PCR from nasal tissue was positive for Leishmania infantum DNA, confirming the diagnosis of granulomatous rhinitis secondary to this parasite. Two eyelid nodules were identified 2 weeks later. Fine-needle aspiration revealed Leishmania amastigotes within macrophages and in the background. Allopurinol therapy was started, but 5 days later the cat developed dermatological signs compatible with a cutaneous adverse drug reaction. The drug was discontinued and meglumine antimoniate prescribed. Twenty-five days later, the cat presented with acute kidney injury and meglumine antimoniate was discontinued. Despite clinical improvement after fluid therapy, mild azotaemia persisted. The cat was subsequently treated with nucleotides and active hexose correlated compounds (N-AHCC). Four months later upper respiratory signs were exacerbated. A relapse of granulomatous rhinitis was suspected and miltefosine therapy started. Chronic kidney disease (CKD) worsened during miltefosine treatment, having improved under fluid therapy. Since then, the cat has been treated with N-AHCC and renal diet and at the time of writing shows stable CKD with no recurrence of respiratory signs. RELEVANCE AND NOVEL INFORMATION: This case describes Leishmania infantum as a cause of granulomatous rhinitis in a cat without cutaneous lesions, reporting the alternative use of N-AHCC and miltefosine when allopurinol seemed to have induced a cutaneous rash and there was acute kidney injury (AKI) after meglumine antimoniate therapy.

Molecular and serological surveillance of canine enteric viruses in stray dogs from Vila do Maio, Cape Verde.

BACKGROUND: Infections caused by canine parvovirus, canine distemper virus and canine coronavirus are an important cause of mortality and morbidity in dogs worldwide. Prior to this study, no information was available concerning the incidence and prevalence of these viruses in Cape Verde archipelago. RESULTS: To provide information regarding the health status of the canine population in Vila do Maio, Maio Island, Cape Verde, 53 rectal swabs were collected from 53 stray dogs during 2010 and 93 rectal swabs and 88 blood samples were collected from 125 stray dogs in 2011. All rectal swabs (2010 n = 53; 2011 n = 93) were analysed for the presence of canine parvovirus, canine distemper virus and canine coronavirus nucleic acids by quantitative PCR methods. Specific antibodies against canine distemper virus and canine parvovirus were also assessed (2011 n = 88).From the 2010 sampling, 43.3% (23/53) were positive for canine parvovirus DNA, 11.3% (6/53) for canine distemper virus RNA and 1.9% (1/53) for canine coronavirus RNA. In 2011, the prevalence values for canine parvovirus and canine coronavirus were quite similar to those from the previous year, respectively 44.1% (41/93), and 1.1% (1/93), but canine distemper virus was not detected in any of the samples analysed (0%, 0/93). Antibodies against canine parvovirus were detected in 71.6% (63/88) blood samples and the seroprevalence found for canine distemper virus was 51.1% (45/88). CONCLUSIONS: This study discloses the data obtained in a molecular and serological epidemiological surveillance carried out in urban populations of stray and domestic animals. Virus transmission and spreading occurs easily in large dog populations leading to high mortality rates particularly in unvaccinated susceptible animals. In addition, these animals can act as disease reservoirs for wild animal populations by occasional contact. Identification of susceptible wildlife of Maio Island is of upmost importance to evaluate the risk of pathogen spill over from domestic to wild animals in Cape Verde and to evaluate the associated threat to the wild susceptible species.

Relevance of feline interferon omega for clinical improvement and reduction of concurrent viral excretion in retrovirus infected cats from a rescue shelter.

Feline Immnunodeficiency (FIV) and Feline Leukemia (FeLV) viruses are common infectious agents in stray cats and shelter environments. Recombinant feline interferon-ω (rFeIFNω) has shown an antiviral action not only against FIV and FeLV but also against herpesvirus (FHV-1) and calicivirus (FCV). Sixteen naturally infected FIV/FeLV cats were followed during rFeIFNω therapy in order to monitor clinical signs and to correlate with excretion of concomitant viruses (FCV, FHV-1, feline coronavirus (FCoV) and parvovirus (FPV)). Cats were submitted to clinical evaluations and concomitant virus excretion assessement. Comparing D0-D65, 10/16 cats improved clinical scores. Of the 10 cats positive for FHV-1 on D0, 4 were negative and 6 reduced viral loads. Of the 11 FCoV positive cats, 9 reduced viral loads. The 13 FCV positive cats and the FPV positive cat were negative on D65. In conclusion, rFeIFNω improves clinical signs and reduces concurrent viral excretion in naturally infected retroviral cats.

Canine leishmaniosis. Modulation of macrophage/lymphocyte interactions by L. infantum.

Canine leishmaniosis, caused by Leishmania infantum, is a systemic disease with variable clinical signs and a progressive evolution. This disease is characterized by impaired T cell-mediated immune response, which has been associated with disease chronicity and high mortality. Protective immunity against leishmaniosis is thought to be mediated by T cell and cytokine production. The T cell activation requires a primary signal delivered by the major histocompatibility complex (MHC) molecules present on the surface of antigen presenting cells, and a non-specific signal generated by co-stimulatory molecules. To characterize canine immune responses in the presence of L. infantum parasites or their antigens, in vitro cell cultures of canine macrophages and lymphocytes were established, and the macrophages presenting MHC class II molecules were evaluated as well as the expression of IL-12 and CD80-86 co-stimulatory molecules and nitric oxide production. The results showed for the first time the up-regulation of MHC class II molecules on the surface in canine peripheral blood monocyte-derived macrophages during L. infantum infection in the presence of lymphocytes. In addition, a lack of co-stimulatory expression and a reduced release of nitric oxide were observed, suggesting a loss of T cell function and consequently an inactivation of the macrophage oxidative burst which, in turn, favors the survival of Leishmania. These results constitute a new contribution for the understanding of the interactions between L. infantum and the canine immune system.

Kinetics of African swine fever virus infection in Ornithodoros erraticus ticks.

The kinetics of African swine fever virus (ASFV) infection in Ornithodoros erraticus ticks were investigated in specimens collected in the field at different times following an outbreak of the disease in Portugal in 1999 and in ticks infected experimentally with a virus isolated from a tick collected during this outbreak. In ticks collected from the field, initial screening for ASFV was carried out by PCR, followed by attempts to isolate the virus in macrophage cultures. Considering total numbers of ticks tested independently of developmental stages, ASFV DNA was detected in 42.3, 26.4 and 22.4% of specimens collected at weeks 0, 32 and 63 following the outbreak, respectively. Although virus was not isolated from most of these ticks, the proportion of isolations from large nymphs and adults increased between weeks 0 and 32 from 2 to 9 % and from 5 to 11.5%, respectively. These results, together with the higher virus titres at week 32, suggest that virus replication occurred. In contrast, virus isolations from small nymphs decreased over this period, from 5 to 1.3%. At week 63, infection rates decreased for all stages. Experimental infections showed the occurrence of virus replication within 4 weeks post-feeding and maintenance of high titres in almost 100% of ticks until 20 weeks post-infection. At weeks 41 and 61, a drop in virus titres and infection rates was observed. Relevant to the understanding of African swine fever epidemiology, our results show that ASFV replicates and persists in O. erraticus, but a viral clearance occurs at later times in both natural and experimental infections.

The non-haemadsorbing African swine fever virus isolate ASFV/NH/P68 provides a model for defining the protective anti-virus immune response.

African swine fever virus ASFV/NH/P68 is a naturally occurring, non-haemadsorbing and non-fatal isolate. Longitudinal clinical and immunological studies on 31 pigs inoculated oronasally or intramuscularly with this isolate defined two discrete groups of animals: those developing ASF chronic type lesions and those remaining asymptomatic. Animals developing lesions had viraemia and fever late after infection, NK activity levels close to that of control animals and high levels of anti-ASFV specific antibodies together with a marked hypergammaglobulinaemia involving IgG1, IgG2, IgM and IgA immunoglobulin isotypes. Pigs remaining asymptomatic after infection, on the other hand, did not have viraemia or fever after day 14 post-infection and had elevated NK cell activity, but normal plasma Ig concentrations and relatively low specific anti-virus antibody concentrations throughout the duration of the experiments. Importantly, the latter group of pigs virus were resistant to subsequent challenge with the highly virulent ASFV/L60 isolate and survived with no major changes in any of the parameters examined and referred to above. Finally, lymphoproliferative responses to the mitogens concanavalin A, phytohaemagglutinin and pokeweed mitogen were not depressed in either of the two clinically defined groups of pigs. Thus further studies with this infection model may provide new insights on mechanisms of protective immunity to ASFV.