A history of canine parvovirus in Australia: what can we learn?

Molecular characterization of full-length VP2 gene of canine parvovirus type 2 strains circulating in Egypt 2019-2021

Canine parvovirus type 2 (CPV-2) is a major cause of fatal gastroenteritis and myocarditis in puppies of domestic and wild carnivores. CPV-2 has accumulated changes over time lead to the emergence of three antigenic variants CPV-2a, CPV-2b, and CPV-2c. VP2 is the major capsid protein that determines virus antigenicity, and host range. Although the three CPV-2 variants were previously identified in Egypt, most reports covered a restricted geographic region and/or time period, and only analyzed partial fragments of VP2 gene. Therefore, this study was designed to test 100 rectal swabs collected from 7 Egyptian governorates between 2019 and 2021 for CPV-2 using PCR. A total of 65 positive samples were identified, mostly in pure dog breeds of young age. The three variants co-circulated in 2019, while CPV-2b was not detected in 2020 and 2021. The frequency of CPV-2b and CPV-2c was higher in 2019 and 2021, respectively. Analysis of CPV-2 full-length VP2 gene sequence from 19/65 positive samples has identified four common amino acid substitutions F267Y, S297A, A300G, Y324I, which are characteristic for the new CPV-2 variants currently circulating worldwide. Unique substitutions including A5G, G36R, V38E, Q370R, and G392V were recognized in certain samples, and appears to have distinct effect on receptor binding, nuclear translocation, and inter-species transmission. Phylogenetic analysis showed separation of CPV-2 strains into two clades. All strains of this study were classified in clade I with Asian strains. In conclusion, this study provides updated comprehensive molecular analysis of CPV-2 variants in Egypt.

Exclusive circulation of canine parvovirus type 2c in the Guadalajara metropolitan area in western Mexico: a five-year study

Canine parvovirus type 2 (CPV-2) infection in dogs is associated with severe gastroenteritis, bloody diarrhea, and vomiting, resulting in high rates of death, especially in unvaccinated puppies within the first months of age. There are three variants, called CPV-2a, CPV-2b, and CPV-2c, co-circulating worldwide. Our group previously reported that the only circulating CPV-2 variant in the Guadalajara metropolitan area in western Mexico was type 2c. Now, a five-year study was performed in order to investigate the possible dominance of CPV-2c in our region. Rectal swabs were collected from 146 dogs with clinical gastroenteritis from May 2014 to August 2019 at the Veterinary Hospital of the University of Guadalajara. Of these, 90 dogs tested positive for canine parvovirus by PCR. Most of the infected dogs with CPV-2 had a partial or incomplete vaccination status (n = 88, 97.8%). Approximately 65% (n = 59) of them were mixed-breed dogs, 77.8% (n = 70) were under 6 months of age, and 37.8% (n = 34) of them died from clinical complications. RFLP analysis of amplicons derived from the vp2 gene showed that all 90 DNA samples corresponded to CPV-2c, with no evidence of the presence of CPV-2a or CPV-2b variants. Twenty-nine of the 90 DNA samples were selected for amplification of a portion of the vp2 gene, and sequencing of these amplicons showed that all of them had the sequence GAA at codon 426, encoding the amino acid glutamic acid, which is characteristic of CPV-2c. Phylogenetic analysis showed that the CPV-2c sequences were related to those of viruses from Europe and South America. The present study indicates that CPV-2c is still the only variant circulating in the dog population of the Guadalajara metropolitan area.

Emerging Parvoviruses in Domestic Cats

Parvovirus infections in cats have been well known for around 100 years. Recently, the use of molecular assays and metagenomic approaches for virus discovery and characterization has led to the detection of novel parvovirus lineages and/or species infecting the feline host. However, the involvement of emerging parvoviruses in the onset of gastroenteritis or other feline diseases is still uncertain.

Comparison of pathological changes in the study of dogs affected by parvoviral enteritis and intestinal yersiniosis

Aim of the study: to examine the pathological changes in dogs that died due to confirmed intestinal yersiniosis and parvoviral enteritis and establish trends for characteristic organ lesions for both diseases in comparison, then evaluate our findings with the existing published material of sufficient evidence quality regarding differential postmortem diagnosis of spontaneous intestinal yersiniosis and parvoviral enteritis in dogs. Materials and methods: the study examined the cases of 25 dogs from 2 month to 1.3 y.o. of various breed, gender that died due to either confirmed Canine parvoviral enteritis (CPV) infection or intestinal yersiniosis and subsequently divided into two groups based on their diagnosis. The definitive diagnosis has been confirmed by performing rapid ELISA diagnostics (SensPERT®, VetAll Laboratories, Kyunggi-Do, Korea) for CPV and serological tests for Y. enterocolitica sera AT were performed using yersiniosis antigens from the "Component set for serological diagnosis of animal yersiniosis" (Kharkiv, NSC IEKVM, TS 46.15.091-95) in accordance with the "Interim guidelines for the use of a set of components for serological diagnostics". A dilution of 1: 200 has been considered as the diagnostic titer. After the definitive diagnosis had been confirmed, the animals were divided into two groups, depending on diagnosis: CPV (n=14) or IY (n=11). The autopsies of twenty randomly (10 from each group) selected dog corpses have been conducted utilizing standard methodology. Results: according to the results of autopsy of dogs afflicted by CPV, the main pathological changes were found in the small intestine – catarrhal-desquamative inflammation (in 100 % of cases), serous-hemorrhagic mesenteric lymphadenitis (90 %) large intestine (70 %) in the stomach (60 %), in the liver (50 %), in other organs – less than 40 percent of cases and most notably caused lung damage (edema and local atelectasis) in 90 % of the animals in the study, which was not the case for intestinal yersiniosis with only 20 % incidence of lung damage. Conclusions: Spontaneous intestinal yersiniosis in dogs was pathologically manifested by pronounced catarrhal-desquamative processes mainly in the stomach and small intestine (70, 100 and 80 % of cases, respectively), inflammation of the mesenteric lymph nodes (90 %) and large intestine (80 %), dystrophy and congestive processes in the liver (80 %). Low incidence and type of lung damage (congestive hyperemia in 20 % of reviewed cases compared to 90 % of local atelectasis add edema in CPV group) was noteworthy. Cases of 25 animals that died due to either confirmed CPV or Y. enterocolitica infection were analyzed, and 20 animal corpses were autopsied during study. Dogs that died from intestinal yersiniosis had significantly higher frequency of pathological findings in kidney (200 %) and liver (60 %) in particular. Changes in stomach and large intestine were also more frequent. At the same time, we observed a lower frequency of pathological changes in spleen (33 % lower), heart (25 % lower) and the lowest frequency was in lungs (77 % lower) presented by edema and local atelectasis in animals afflicted by yersiniosis compared to CPV. Incidence and manifestation of pathological findings was mesenteric lymph nodes and abdominal cavity were similar, and could not be considered during posthumous diagnostics.