Search Results (121)

This study investigated the prevalence of 11 common pathogens in dogs and cats in Shenzhen, China, from January 2022 to March 2024, aiming to enhance the understanding of their epidemiological characteristics for improved disease control strategies. Diagnostic testing for the target pathogens was performed using polymerase chain reaction (PCR), colloidal gold test strips, or fluorescence immunoassay. Statistical analysis revealed that among 13,134 cats, Feline Panleukopenia Virus (FPV) showed the highest prevalence (35.83%), followed by Feline Calicivirus (FCV, 26.20%), Feline Infectious Peritonitis Virus (FIPV, 22.00%), and Feline Herpesvirus (FHV, 15.76%). Among 3626 dogs, Canine Parvovirus (CPV) and Canine Distemper Virus (CDV) were predominant, showing a prevalence of 54.55% and 42.83%, respectively. Risk factor analysis showed that most infections occurred in unvaccinated animals and young individuals (<1 year old), with higher incidences in winter and spring. Logistic regression indicated that sex, age, and season were significantly associated with FPV, FHV, and FIPV infections, while age and season were associated with FCV, CPV, and CDV infections (sex showed no association). This study contributes to the epidemiological knowledge of common infectious diseases in dogs and cats, providing a theoretical basis for disease prevention in dogs and cats. Full article

During their early life, puppies are protected against infectious agents with the presence of maternal derived antibodies (MDA). Vaccination is recommended to start as soon as the levels of MDA begin to wane to ensure that the puppy’s immune system can respond effectively to the vaccines and develop active immunity against diseases. Two studies were designed to assess the efficacy of the Canigen^TM DHPPi vaccine in puppies from 6 weeks of age. The studies comprised two parts: the efficacy assessment of the Canine Parainfluenza Virus (CPiV) vaccine component against a virulent challenge with CPiV (Experiment A) and an immunogenicity assessment of Canine Distemper Virus (CDV), Canine Adenovirus (CAV-2), and Canine Parvovirus (CPV-2) vaccine components (Experiment B). In Experiment A, twelve puppies were immunized with two injections of Canigen^TM DHPPi (at minimum titer) two weeks apart and twelve control puppies received the vaccine diluent. All animals were challenged with a virulent, heterologous CPiV strain two weeks after the second vaccination. Vaccinated puppies exhibited a significant reduction in nasal viral shedding compared to the control group. Clinical signs of respiratory disease were mild and transient in both groups. In Experiment B, six puppies were immunized with two injections of Canigen^TM DHPPi (at minimum titer) two weeks apart. A follow-up of the seroneutralizing antibodies titers against the CDV, CAV-2 and CPV-2 vaccine components was performed in order to assess the efficacy on the serological response basis. After the first vaccine injection, all the puppies seroconverted and presented seroneutralizing antibody titers reaching a protective thresholds against CDV (≥10^0.82), CAV-2 and CAV-1 (≥10^0.82), CPV-2 and CPV-2c (≥10^1.8). After the second vaccine injection, a more robust immune response was observed and the seroneutralizing antibody titers remained high until 4 weeks post vaccination for those three vaccine components. In both experiments (A and B), all vaccinated animals remained in good health, with no adverse reactions recorded during the vaccination phase. As a conclusion, the efficacy of the Canigen^TM DHPPi vaccine was demonstrated when administered in dogs from 6 weeks of age. These results fully support the interest of an early vaccination in such young puppies followed by the recommended vaccination scheme. Full article

Viral infections in humans and animals are increasing, and retrospective studies using formalin-fixed, paraffin-embedded (FFPE) samples reveal recurring outbreaks over past decades. However, the impact of pre-analytical factors like fixation and autolysis on immunohistochemistry (IHC) remains insufficiently understood. To examine how autolysis, fixation duration (6–72 h) and formalin concentration (2.5–25%) influence histology and IHC of canine distemper virus (CDV, Morbillivirus canis), interferon-β (IFN-β), and selected IFN-stimulated genes (ISGs), the study was conducted using an in vitro model based on persistently CDV-infected and non-infected DH82 cells (canine histiocytic sarcoma cell line). Autolysis led to a progressive loss of cell morphology, whereas formalin fixation had minimal impact. CDV nucleoprotein, ISG15, and myxovirus resistance protein (Mx) showed stable immunohistochemical signals across all fixation conditions and remained detectable after prolonged autolysis. CDV infection upregulated ISG15 and Mx. In contrast, IFN-β and phosphorylated protein kinase R (pPKR) exhibited variable staining and did not distinguish infected from non-infected samples. Overall, autolysis had a stronger negative impact on IHC signal quality than fixation parameters. Despite the limitations of the in vitro model, the robustness of CDV, ISG15, and Mx under suboptimal conditions highlights their potential utility as virus-sensing markers in FFPE material. Full article

Canine Kobuvirus (CaKoV) has been identified as an agent involved in gastrointestinal diseases among dogs worldwide, with a particular impact on young individuals. This study reports the first molecular detection of CaKoV in Ecuadorian dogs with gastroenteritis, using a sensitive SYBR Green-based RT-qPCR assay. The assay demonstrated high sensitivity, with detection limits approaching a single copy of genetic material (1 copy/μL), with a standard efficiency curve of 100.6% and a correlation coefficient of 0.997, facilitating accurate CaKoV detection even at a minimal number of gene copies; it was also highly specific for CaKoV genome amplification, as no amplification was shown for other canine enteric viruses [Canine Parvovirus (CPV-2), Canine Astrovirus (CaAstV), Canine Coronavirus (CCoV), and Canine Distemper Virus (CDV)], and demonstrated strong reproducibility across different runs. A total of 250 fecal samples were used to validate the assay and detect the presence of CaKoV, with 91 samples testing positive for CaKoV, confirming the virus’ presence across multiple provinces in Ecuador, with Pichincha reporting the highest number of positive samples. Phylogenetic analysis of the partial 3D gene sequence exhibited a nucleotide identity ≥ 90% with sequences of CaKoV strains from different countries around the world. Co-infections with other enteric viruses such as CPV-2, CCoV, and CaAstV were observed in 61.3% of CaKoV-positive samples from dogs with gastroenteritis, with triple co-infections (CPV-2, CaAstV, and CaKoV) being the most frequently detected combination in the study. The present study showed that CaKoV is circulating in domestic dogs affected with gastroenteric disease and in apparently healthy dogs. This work establishes CaKoV as a possible contributor to canine gastroenteritis in Ecuador, in addition to the typical viruses such as CPV-2 and CCoV; moreover, this study illustrates a molecular assay that is both rapid and reliable for the diagnosis of CaKoV. Full article

Canine distemper virus (CDV) is a serious and often fatal disease caused by Morbillivirus canis, which affects domestic dogs and wild carnivores, with case-fatality rates reaching up to 47%. The hemagglutinin (H) protein mediates viral adsorption and shows high genetic variability, making it a valuable molecular marker. This study aimed to detect and characterize the H gene of CDV strains from 14 dogs with fatal neurological disease in the Brazilian states of Mato Grosso and Rondônia. Brain tissue was tested via RT-PCR for the nucleocapsid gene, and positive samples were amplified for the H gene. Ten complete H-gene sequences were obtained. Phylogenetic analysis revealed two distinct clusters within the South America I/Europe lineage: one related to strains from Uruguay and Argentina (with residues 530G/549Y) and another related to Brazilian strains (530S/549Y). One sequence (MT8) showed an intermediate position in the haplotype network but clustered phylogenetically with Uruguay/Argentina-related strains. Most sequences carried 530S/549Y, a pattern linked to altered SLAM receptor usage in wildlife. These findings demonstrate the co-circulation of two CDV clusters in Central–Western Brazil, their regional and international genetic connectivity, and amino acid substitutions potentially influencing host adaptation and antigenicity. Full article

Studies spanning decades provide important information about the epidemiology and occurrence of a broad range of diseases that affect the central nervous system (CNS) of dogs. This study analyzed records and formalin-fixed paraffin-embedded (FFPE) CNS tissue samples from necropsied dogs with neuropathologic changes between 1962 and 2022. A total of 134,854 animals, including 20,117 dogs, were submitted for necropsy during this time span. Of these dogs, 2646 displayed alterations of the CNS. Degenerative and non-suppurative inflammatory lesions were the most common changes, accounting for 35.6% and 28.6%, respectively. Vascular diseases, neoplasms, congenital malformations, and suppurative inflammation represented 13.8%, 8.6%, 7.2%, and 5.4% of cases, respectively. Morbillivirus canis, the agent of canine distemper, was the most commonly diagnosed. The second most commonly detected virus, varicellovirus suidalpha1, the agent of pseudorabies, occurred almost exclusively between the mid-1970s and 1990s. Other pathogens, including Lyssavirus rabies, canine herpes virus, tick-borne encephalitis virus, apicomplexan parasites, such as Neospora caninum and Toxoplasma gondii, as well as fungal and other parasitic infections, were less frequently diagnosed. Interestingly, 47.6% of cases with non-suppurative inflammation remained etiologically undetermined. This study provides insights into the epidemiology of canine neurotropic infections and shows the value of FFPE material for investigations of past disease outbreaks. Full article

Canine distemper virus (CDV) is a multi-host morbillivirus whose evolution and host-switching capacity are largely determined by its hemagglutinin (H) gene. To reconsider the molecular evolution of this critical gene, we performed comprehensive phylogenetic, selection, and structural analyses on a curated dataset of 68 representative global H gene sequences. Our phylogenetic reconstruction confirmed the segregation of sequences into distinct, geographically associated lineages. To provide stronger evidence for viral adaptation, we performed a site-specific selection analysis, which identified 15 amino acid sites in the H protein undergoing significant episodic positive selection. Crucially, the majority of the known SLAM and Nectin-4 receptor-binding residues were found to be among these positively selected sites. We further contextualized these findings by mapping the sites onto a 3D homology model of the H protein, which confirmed their location on the exposed surfaces of the receptor-binding domain. This compilation provides quantitative evidence that the key functional regions of the H protein are direct targets for adaptive evolution, which has significant implications for understanding host tropism and the ongoing challenge of vaccine mismatch. Full article

Antibody titer testing can be useful in controlling successful puppy immunization and can reduce unnecessary vaccinations in adult dogs. We evaluated three commercially available point-of-care tests (POCTs) for detecting antibodies against canine parvovirus (CPV-2), canine distemper virus (CDV) and canine adenovirus (CAV-1 and/or -2), comparing them to the reference virus neutralization (VN) assay. Sera from 200 client-owned dogs (13 healthy, 63 chronically diseased, 124 acute) and 60 specific pathogen-free (SPF) dogs, including 20 sera with maternally derived antibodies (MDA), were tested. All three POCTs demonstrated high sensitivity (79.0–100%) and specificity (97.8–100%) for CPV-2. In contrast, specificity for CDV and CAV was lower with POCT-1 (43.5% and 55.3%) and POCT-2 (42.4% and 79.2%), despite high sensitivity (CDV in both POCTs 98.7%; CAV POCT-1: 99.4%, POCT-2: 90.8%). POCT-3, by comparison, showed high specificity (CDV: 94.1%; CAV: 84.4%) but very low sensitivity (CDV: 17.4%; CAV: 33.1%). Only POCT-1 for CPV-2 detected MDA reliably, whereas the other two POCTs, and POCT-1 for CDV and CAV, did not. When compared to VN, the agreement in vaccination recommendations was 82% for POCT-1 and POCT-2, and 62% for POCT-3. In conclusion, all three POCTs reliably detected antibodies against CPV-2, including MDA with POCT-1. However, the lower specificity for CDV and CAV antibody detection in POCT-1 and POCT-2 raises concerns about misclassifying unprotected dogs as immune, while false-negatives with POCT-3 could lead to unnecessary vaccinations. Further optimization of all three POCTs for CDV and CAV is recommended. Full article

Canine morbillivirus (CDV), the cause of canine distemper, is a pathogen affecting many hosts. While modified live virus (MLV) vaccines are crucial for controlling the disease in dogs, cases of vaccine-related infections have been found in both domestic and wild animals. Specifically, the America-1 and Rockborn-like vaccine genotypes are concerning due to their spread and ability to transmit between different species. This study conducted a review and analysis of molecular detections of these strains in various carnivores (domestic, captive, synanthropic, and wild species). This study used a conceptual model considering host ecology and the domestic–wild interface to evaluate plausible transmission connections over time using Linear Directional Mean (LDM) and Weighted Mean Centre (WMC) methods. Statistical analyses examined the relationship between how likely a strain is to spread and factors like host type and vaccination status. The findings showed that the America-1 genotype spread in a more organised way, with domestic dogs being the main source and recipient, bridging different environments. Synanthropic mesocarnivores also played this same role, with less intensity. America-1 was most concentrated in the North Atlantic and Western Europe. In contrast, the Rockborn-like strain showed a more unpredictable and restricted spread, residual circulation from past use rather than ongoing spread. Species involved in vaccine-related infections often share characteristics like generalist behaviour, social living, and a preference for areas where domestic animals and wildlife interact. We did not find a general link between a host vaccination status and the likelihood of the strain spreading. The study emphasised the ongoing risk of vaccine-derived strains moving from domestic and synanthropic animals to vulnerable wild species, supporting the need for improved vaccination approaches. Mapping these plausible transmission routes can serve as a basis for targeted surveillance, not only of vaccine-derived strains, but of any other circulating genotype. Full article

Canine distemper, a fatal and highly transmissible disease caused by the canine distemper virus (CDV), poses a major threat to the companion animal industry. An urgent need exists for a rapid, specific, and simple method for the detection of this disease in order to improve its prevention and control. In this research, two monoclonal antibodies (mAbs), 1D3E9 and 1H9B7, were prepared, both of which specifically recognize the nucleoprotein (N protein) of CDV, and an immunochromatographic assay for CDV detection was subsequently developed using these mAbs. The results showed that both mAbs belong to the IgG1 subclass with kappa light chains. 1D3E9 was found to recognize the linear epitope ⁴¹⁰AGPKQSQITFLH⁴²¹, while 1H9B7 targeted the epitope ⁴⁵⁰HFNDERFPGH⁴⁵⁹. The test strips exhibited high specificity and good stability for up to two months when stored at 4, 25, and 37 °C. The assay exhibited a sensitivity of 10^2.39 TCID₅₀/0.1 mL. When compared with RT-PCR for detecting CDV in clinical samples, the concordance rate was 91.67%. Thus, this method shows great potential for facilitating rapid on-site detection of CDV and could be highly beneficial from the viewpoint of disease surveillance and control. Full article

Free-ranging dogs (Canis lupus familiaris) pose a significant but often overlooked threat to wildlife populations and global conservation efforts while also having the potential to contribute positively to conservation initiatives. As generalist predators and scavengers, these adaptable animals can lead to biodiversity loss through predation, disease transmission, competition, and behavioral disruption of native species. This review synthesizes global studies on their ecological impact, highlighting notable cases of predation on endangered species, such as the markhor (Capra falconeri cashmiriensis) in Pakistan and elephant seals (Mirounga angustirostris) in Mexico, as well as the spread of zoonotic diseases like Echinococcus spp. and canine distemper. A growing concern is hybridization between free-ranging dogs and wild canids. Such genetic mixing can erode local adaptations, reduce genetic purity, and undermine conservation efforts for wild canid populations. Current management strategies—including lethal control, trap–neuter–release, and vaccination—have produced mixed results and face challenges related to data limitations, regional variability, and cultural barriers. This review advocates for integrated, context-specific management approaches that consider ecological, social, and economic dimensions. Future research should prioritize standardized definitions and data collection, long-term evaluation of intervention effectiveness, and the socio-economic drivers of dog–wildlife interactions to develop sustainable solutions for mitigating the multifaceted threats imposed by free-ranging dogs to global diversity. Full article

Background: canine distemper (CD) is a highly contagious and fatal disease caused by canine distemper virus (CDV), posing a significant threat to carnivores. New CDV strain circulation and multi-species infection may lead to the potential dilemma of safety concern and insufficient efficacy of the commercial modified live vaccines. Safe and effective vaccines for canine and wildlife prevention of CD need to be continuously updated and developed. Methods: we developed two DNA vaccines, p17F-LNP and p17H-LNP, encoding the fusion protein (F) or hemagglutinin protein (H) of a field CDV strain (HLJ17) and encapsulated in lipid nanoparticles (LNPs). Serum neutralizing antibody (NAb) was evaluated via neutralization tests, and mouse serum cytokine detection were evaluated via ELISA. Results: immunization of p17F-LNP and p17H-LNP monovalent or bivalent were safe, and induced robust CDV NAb and cytokine responses in mice. LNP encapsulation improved immune responses compared to naked DNA formulation, and the bivalent formulation of p17F-LNP and p17H-LNP (p17F/H-LNP) exhibited synergistic effects with a high level of immune responses. Moreover, two doses of p17F/H-LNP induced long-lasting CDV NAb for over 300 days in dogs, and prime and boost NAb responses in foxes and raccoon dogs. Conclusions: the preliminary findings provided here warrant further development of the p17F/H-LNP vaccine for animal targets against CDV infection. Full article

Canine distemper virus (CDV) is a highly contagious disease with high morbidity and mortality rates in veterinary medicine. This retrospective study aimed to identify epidemiological characteristics and potential risk factors associated with CDV infection in dogs exhibiting neurological manifestations. The diagnosis was confirmed through immunochromatographic antigen testing, RT-PCR, or Lentz corpuscles identification. Dogs diagnosed with central nervous system (CNS) disorders unrelated to CDV served as the control group. Age, breed, weight, sex, and neuter status were compared between groups using logistic regression (p < 0.05), the log-likelihood method, and log odds ratio (LOR) calculations. Clinical signs, seasonality, and vaccination protocols were documented. Prevalence, mortality, lethality, and survival rates were determined. Younger dogs (p = 0.00690; LOR = −0.01438) and Shih Tzu (p = 0.00007; LOR = 1.53774) and Lhasa Apso (p = 0.000264; LOR = 1.76084) showed a significantly increased likelihood of developing neurological signs due to CDV infection. Most CDV-infected dogs exhibited multifocal CNS involvement and accompanying extra-neural signs. The highest occurrence of CDV-related neurological signs was recorded in autumn. Many infected dogs had an updated vaccination protocol. The prevalence of dogs with CDV was 4.72%. Mortality and lethality rates were 1.94% and 47.06%, respectively. The median survival time was 754 days. The identified epidemiological characteristics and risk factors provide essential insights for improving preventive strategies against CDV infection. Full article

Canine distemper is caused by a morbillivirus similar to others that affect livestock and humans. The increase in host range and its persistence in wildlife reservoirs complicate eradication considerably. Canine distemper virus has been reported in wildlife in Mexico since 2007. Dogs were previously considered the main reservoirs, but high vaccination coverage in the USA has helped control the disease, and racoons (Procyon lotor) are now recognized as the main reservoirs of the agent in the USA, since they live in high densities in urban environments (peridomestic), where contact with domestic and wildlife species is common. Racoons are now considered to spread CDV in wildlife species and zoo animals. Mexico is home to at least two wildlife species that have been reported as carriers of the CDV infection in studies in the USA. Raccoons and Coyotes are distributed in several Mexican states and could play the same reservoir role as for the US. In addition, the increase in non-traditional pets expands the availability of susceptible individuals to preserve CDV in domiciliary and peri-domiciliary environments, contributing to the spread of the disease. Combined with incomplete vaccination coverage in domestic canids, this could contribute to maintaining subclinical infections. Infected pets with incomplete vaccination schedules could also spread CDV to other canines or wildlife coexisting species. In controlled habitats, such as flora and fauna sanctuaries, protected habitats, zoo collections, etc., populations of wildlife species and stray dogs facilitate the spread of CDV infection, causing the spilling over of this infectious agent. Restricting domestic pets from wildlife habitats reduces the chance of spreading the infection. Regular epidemiological surveillance and specific wildlife conservation practices can contribute to managing threatened species susceptible to diseases like CDV. This may also facilitate timely interventions in companion animals which eventually minimize the impact of this disease in both scenarios. Aim: The review discusses the circulation of CDV in wildlife populations, and highlights the need for epidemiological surveillance in wildlife, particularly in endangered wildlife species from Mexico. Through an extensive review of recent scientific literature about CDV disease in wildlife that has been published in local and international databases, the findings were connected with the current needs of information from a local to global perspective, and conclusions were made to broaden the context of Mexican epidemiological scenarios as closely related to the neighboring regions. Full article