Neonatal neosporosis in a 2-week-old Bernese mountain dog infected with multiple Neospora caninum strains based on MS10 microsatellite analysis

Nutrition and Theriogenology: A Glimpse Into Nutrition and Nutritional Supplementation During Gestation, Lactation, Weaning and Breeding Dogs and Cats

Feeding during normal reproduction is often not thought of until there is a problem with conception or gestational losses. Energy demands of lactation and early puppy/kitten are of concern, particularly in large and giant breed dogs where mineral balance is crucial to normal development. There is a paucity of information around optimizing feeding during conception and gestation with many myths around ingredients which will be explored in this article along with supplements that may be able to support spermatogenesis and conception which primarily comes from the human literature and may have validity in times of difficult conception.

The Causes of Canine Myocarditis and Myocardial Fibrosis Are Elusive by Targeted Molecular Testing: Retrospective Analysis and Literature Review

Myocarditis can cause death or permanent heart damage. As epidemiologic and etiopathologic data for canine myocarditis are lacking, we performed a retrospective study using nucleic acid extracted from archived (2007 to 2015) tissues from myocarditis cases and control dogs without myocardial lesions. Heart tissue from pediatric/juvenile and adult dogs was tested with a comprehensive panel of conventional and real-time polymerase chain reaction (PCR) assays targeting recognized agents of canine myocarditis based on a literature review and informed by the comparative epidemiology of human myocarditis. The PCR screen, which included canine parvovirus 2 (CPV-2), canine distemper virus, canine herpesvirus, Borrelia spp, West Nile virus, adenovirus, parainfluenza virus, pneumovirus, respiratory coronavirus, influenza virus, Bartonella spp, Rickettsia spp, Mycoplasma spp, and Neospora caninum, did not detect agents in 35 of 66 cases (53%; 95% confidence interval [CI], 41%-65%) and was frequently negative in adults (21/26); by comparison, agents were not detected in 27 of 57 controls (47%; 95% CI, 35%-60%). Canine distemper virus, herpesvirus, adenovirus, coronavirus, parainfluenza virus, Mycoplasma haemocanis, and N. caninum were occasionally detected in both cases and controls; thus, PCR detection was not considered to indicate causation. We previously reported that CPV-2 continues to be associated with myocarditis in young dogs despite widespread vaccination; in adults, CPV-2 was detected in 2 of 26 cases and 4 of 22 controls. As several agents were similarly detected in cases and controls, it is unclear if these are cardiopathogenic, incidental, or latent. West Nile virus was detected at the analytic limit in 1 adult case. We did not detect Borrelia spp, Bartonella spp, Rickettsia spp, or influenza A virus in the myocarditis cases. These data demonstrate the limitations of current targeted diagnostic tests and the need for additional research to identify unknown agents and develop testing strategies for canine myocarditis.

Microsatellite Analysis of Geographically Close Isolates of Cystoisospora suis

Microsatellites are short repetitive DNA sequences of 2–6 repeats interspersed in the genome that display a rapid mutation rate and consequently show high variation between individuals or populations. They have been used to characterize population diversity and structure and the level of variation between different isolates of a number of different organisms, including apicomplexan protozoa. Currently nothing is known about the genetic variability and population structure of Cystoisospora suis (Apicomplexa: Coccidia), the causative agent of piglet coccidiosis, and we made use of the recently available genome of C. suis (strain Wien-I) to amplify microsatellite regions (ca. 300–550 bp) and evaluate the applicability of fluorescence-labeled primers to investigate amplicon length variation at high resolution using capillary electrophoresis (CE). Two phenotypically characterized isolates (Wien-I, toltrazuril susceptible; Holl 1 toltrazuril resistant) and six field isolates from Europe were compared by conventional PCR followed by agar-gel electrophoresis, Sanger sequencing, and CE (fluorescence labeling and fragment length analysis) to evaluate the applicability of the method. Four primer pairs could be identified that amplified bands of the expected size and were labeled for CE analysis. High resolution CE for size determination of PCR amplicons proved to be a reliable and simple method. It revealed high diversity of the analyzed strains, with marked differences even between two strains from neighboring swine farms. In follow-up studies, adaptation of the PCR assay to multiplexing and amplification of small DNA quantities will provide a cost-effective tool to analyse field strains to reveal geographic diversity that could be mapped to phenotypic traits.

Clinical Toxoplasmosis in Dogs and Cats: An Update

Toxoplasmosis is caused by the globally distributed protozoan parasite Toxoplasma gondii (phylum Apicomplexa); the disease can be clinically important for almost all homeothermic animals, including birds and humans. Toxoplasmosis course involves general clinical signs, such as fever, anorexia, or dyspnea, and more specific signs with neural, respiratory, cutaneous, or ocular involvement. Because of the wide range of clinical signs, the diagnosis in domestic and pet animals can be complicated. Hence, this review aims to provide a comprehensive analysis of some scarcely discussed aspects of toxoplasmosis, such as ocular and cutaneous manifestations, congenital infections, influence of T. gondii genotype on clinical toxoplasmosis, and recent findings regarding differential diagnosis. This review could be of special interest to clinicians and researchers.

Presumptive vertical transmission of Neospora caninum in related Bernese Mountain dogs

Neospora caninum is a tissue cyst-forming coccidium capable of causing spinal cord or skeletal muscle disease in dogs. Infected bitches can transmit the parasite to their pups in utero. Seroprevalence of N. caninum was studied in naturally-infected, privately owned Bernese Mountain dogs, using antibody detection via an indirect fluorescent antibody test (IFAT) to identify infected individuals. A retrospective study was undertaken on available dogs from 14 litters. Five of eight dams tested seropositive. The index case was a bitch with a titre of 1:3200 by IFAT. Only one offspring from her first litter was seropositive. The frequency of putative congenital transmission in the breeding kennel was variable. Our results reiterate the importance of serological testing of all dams and littermates in a breeding kennel when clinical neosporosis is suspected in neonatal puppies.

Neospora caninum bioassay in gerbils using placental tissues from naturally infected goats

Neospora caninum is one of the main agents that causes abortions in cattle worldwide. However, little is known about the pathogenesis of neosporosis in small ruminants, especially goats. Gerbils (Meriones unguiculatus) have been used as a model for neosporosis, and this species is highly susceptible to infection by bovine N. caninum strains. The present study aimed to evaluate the susceptibility of gerbils to a N. caninum isolate from goats. The placentas were obtained from naturally infected goats, that presented with mild to severe lymphoplasmacytic and histiocytic infiltrate, foci of necrosis, calcification and protozoan-like structures. Immunosuppressed gerbils bioassayed with N. caninum-infected placental tissues showed severe neurological signs. Microscopic lesions in these gerbils were characterized by encephalitis, myocarditis, myositis and pancreatitis. These lesions were often associated with a small to moderate number of N. caninum tachyzoites, confirmed by immunohistochemistry and PCR. This is the first report showing that goat N. caninum strains could infect immunocompetent gerbils and cause severe lesions and clinical signs in immunosuppressed gerbils.

High seroprevalance of Neospora caninum in dogs in Victoria, Australia, compared to 20 years ago

BACKGROUND

Canids are definitive hosts of the apicomplexan parasite Neospora caninum, the leading cause of abortion in cattle worldwide. For horizontal transmission from canids to occur, oocysts of N. caninum must be shed by the definitive host into the environment of susceptible intermediate hosts such as cattle. The purpose of this study was to determine the prevalence of N. caninum in canids in Victoria, Australia's leading dairy producing state.

RESULTS

Neospora-like oocysts were observed in 8% (18/234) of faecal samples from wild dogs, domestic dogs and red foxes from Victoria, Australia. However, none tested positive for N. caninum DNA using a quantitative PCR. In a separate sample population, blood sera from 483 domestic dogs were tested for anti-N. caninum antibodies using competitive ELISA. A subset of cELISA samples were re-tested using indirect fluorescence antibody test (IFAT). A seroprevalence of 29.8% (144/483; 95% CI: 11.7-47.8%) was calculated when using cELISA; whereas it was 32.9% (27/80; 95% CI: 15.8-51.8%) using IFAT. Potential risk factors were evaluated using univariable analyses and then assessed in separate multivariable models. Using 'aged' dogs as a reference, the seroprevalence of 'adolescent' and 'adult' dogs was 88% (P = 0.05) and 91% (P = 0.08), respectively, indicating seroprevalence increases with age. There was a 19% higher likelihood of infection in rural locations (P = 0.10) relative to urban areas. Jack Russell Terriers had a 22% higher risk of a cELISA-positive result (P = 0.05) regardless of geographical location, age or sex.

CONCLUSION

These results demonstrate that exposure to N. caninum in domestic dogs is widespread in Victoria, although faecal oocyst shedding is infrequent. Our results indicate increased N. caninum seroprevalance status in dogs over the past two decades. The results imply that dogs get either exposed to the infected meat more frequently or that vertical dam to foetus transmission is more frequent than previously thought. Our study calls for re-evaluation of historical N. caninum seroprevalance studies, because the attitude to dog diet changes.

Serological study of Neospora caninum infection in dogs in central China

Neospora caninum is a protozoan parasite that causes abortion in cattle as well as reproduction problems and neurological disorders in dogs. Dogs are important in the epidemiology of N. caninum because they act as definitive hosts, shedding oocysts in the environment. To investigate the seroprevalence of N. caninum infection in dogs in central China, 1176 serum samples were collected from domestic dogs in Henan province, central China between March 2015 and February 2016 and tested for IgG antibody against N. caninum, using the indirect fluorescent antibody test (IFAT). The overall seroprevalence of N. caninum was nearly 15% (172/1176). No significant difference was observed between this seroprevalence according to sex and breed of dogs (p > 0.05). The infection rate in rural dogs (18%) was higher (p < 0.05) than in urban dogs (11%). The prevalence of N. caninum infection in dogs increased (p < 0.05) with age. The results of the present study indicate the high prevalence of N. caninum antibodies in dogs in Henan province, central China. Sanitary conditions and animal health must be improved to prevent the transmission risk of N. caninum by dogs.