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The studies were carried on raccoons from Poland, Germany and the Czech Republic. Tissue samples from raccoon hearts, lungs and brains were used for molecular examination while meat juice was collected for immunological tests. Antibodies against T. gondii were detected in six out of 44 raccoons (13.6%), while T. gondii DNA was found in 18 (40.9%). Antibodies against N. caninum were found in seven raccoons (15.9%) but no parasite DNA was observed in any sample. DNA of T. gondii was observed in raccoons of both sexes (in 42.3% of females and 38.9% of males) from all three countries. The proportion of raccoons that tested positive for DNA of T. gondii was higher in the Czech Republic (47.1%) than in Germany (33.3%), however the difference was non-significant (p = 0.7032). It seems that the raccoons appear to have been exposed to both T. gondii and N. caninum, but only T. gondii infection was confirmed. The role of raccoons as reservoir, and as possibly contributing to spread of these parasites merits further studies.

The raccoon (Procyon lotor) is a species native to North America, but which is now spreading throughout Europe. Raccoons have been found to host various Trichinella species. The aim of the present study was to evaluate the effectiveness of using immunological testing of meat juice for determining the occurrence of Trichinella in raccoons. The studies were carried out on 139 animals from three European countries: the Czech Republic, Germany and Poland. Seven meat juice samples were found to be positive for antibodies to Trichinella by ELISA, and another seven were unclear. The ELISA results were confirmed by immunoblot: anti-Trichinella antibodies were identified in 9.35 % of the examined animals. Slight agreement (κ = 0.13) was found between the digestion method and the combined ELISA and immunoblot approach. From the results of our study, we concluded that meat juice may be used as a simple and convenient sample for detection of anti-Trichinella in racoons.

The raccoon (Procyon lotor) is a North American carnivore introduced to Europe in the 20th Century. Raccoons are believed to be the potential hosts of many parasites, or to be involved in their transmission to other animals. Nematodes of the genus Trichinella can infect many carnivorous and omnivorous animals worldwide. The aim of the present study was to determine the occurrence of Trichinella spp. infection in raccoons in Central Europe. Muscle samples were collected from various regions of Poland, the Czech Republic and Germany during the years 2012-2016. The larvae of Trichinella spp. were detected in 11 raccoons, and these were identified as T. spiralis and T. pseudospiralis by multiplex PCR (89.9% and 9.1%, respectively). No mixed infection was observed. This is the first report describing the occurrence of T. spiralis and T. pseudospiralis in P. lotor in Central Europe. Our findings also show that the raccoon population acts as a reservoir of Trichinella pseudospiralis.

Equine protozoal myeloencephalitis (EPM) is an important equine neurologic disorder, and treatments for the disease are often unrewarding. Prevention of the disease is the most important aspect for EPM, and a killed vaccine was previously developed for just that purpose. Evaluation of the vaccine had been hampered by lack of post vaccination challenge. The purpose of this study was to determine if the vaccine could prevent development of clinical signs after challenge with Sarcocystis neurona sporocysts in an equine challenge model. Seventy horses that were negative for antibodies to S. neurona and were neurologically normal were randomly assigned to vaccine or placebo groups and divided into short-term duration of immunity (study #1) and long-term duration of immunity (study #2) studies. S. neurona sporocysts used for the challenge were generated in the opossum/raccoon cycle isolate SN 37-R. Study #1 horses received an initial vaccination and a booster, and were challenged 34days post second vaccination. Study #2 horses received a vaccination and two boosters and were challenged 139days post third vaccination. All horses in study #1 developed neurologic signs (n=30) and there was no difference between the vaccinates and controls (P=0.7683). All but four horses in study #2 developed detectable neurologic deficits. The neurologic signs, although not statistically significant, were worse in the vaccinated horses (P=0.1559). In these two studies, vaccination with the S. neurona vaccine failed to prevent development of clinical neurologic deficits.

Equine protozoal myeloencephalitis (EPM) remains a significant central nervous system disease of horses in the American continents. Sarcocystis neurona is considered the primary causative agent and its intermediate life stages are carried by a wide host-range including raccoons (Procyon lotor) in North America. S. neurona sarcocysts mature in raccoon skeletal muscle and can produce central nervous system disease in raccoons, mirroring the clinical presentation in horses. The study aimed to develop laboratory tools whereby the life cycle and various life stages of S. neurona could be better studied and manipulated using in vitro and in vivo systems and compare the biology of two independent isolates. This study utilized culture-derived parasites from S. neurona strains derived from a raccoon or from a horse to initiate raccoon infections. Raccoon tissues, including fresh and cryopreserved tissues, were used to establish opossum (Didelphis virginiana) infections, which then shed sporocyts with retained biological activity to cause encephalitis in mice. These results demonstrate that sarcocysts can be generated using in vitro-derived S. neurona merozoites, including an isolate originally derived from a naturally infected horse with clinical EPM. This study indicates the life cycle can be significantly manipulated in the laboratory without affecting subsequent stage development, allowing further purification of strains and artificial maintenance of the life cycle.

Baylisascaris procyonis is a zoonotic parasite that has been documented in raccoons throughout much of the United States; however, no published information on its occurrence is available for the transition zone from the Great Plains to the Rocky Mountains. Because this parasite can cause neural larva migrans and diffuse unilateral subacute neuroretinitis in humans (as well as other hosts), a more complete understanding of the distribution of this parasite seems warranted for public health reasons. The purpose of this study was to begin to fill in the gaps in our knowledge of the distribution of B. procyonis in an area of the US where there is, currently, no published information available. Fifty-three raccoons were collected throughout eastern Colorado during 2007-2010. Forty-six were examined by necropsy and seven by fecal flotation. Age (11 juveniles, 25 adults) and sex (16 males, 19 females) of the raccoons were recorded when intact carcasses were available. When available, feces were further processed for the detection of Giardia and Cryptosporidium using a direct fluorescent antibody detection method. B. procyonis was found in 31 of 53 raccoons (58.5%, 95% CI=44.1%, 71.9%). Mean intensity was 11.7 with a range of 1-49 worms per infected individual. There was no significant difference between age or sex, and the presence of ascarids or the number of ascarids. Cryptosporidium spp. oocysts and Giardia spp. cysts were detected in 11/44 (25%; 95% CI: 13.2, 40.3) and 3/44 (6.9%; 95% CI: 1.4, 18.7) raccoons, respectively. The genotype of the Giardia present could not be determined. The genotype of five of six cryptosporidial isolates was 100% homologous to the skunk genotype while the sixth was 100% homologous to Cryptosporidium parvum. Based on these results, both B. procyonis and Cryptosporidium spp. appear to be prevalent in raccoons of eastern Colorado.

Numbers of feral raccoon; the possible reservoir animal of Ehrlichia and Anaplasma, are increasing in Japan. Thus serological methods were utilized to examine Ehrlichia and Anaplasma infection in raccoons from Kanagawa Prefecture, Japan. By using an indirect immunofluorescence assay, among 187 feral raccoons examined, 1 (0.5%) serologically reacted with Ehrlichia canis, 3 (1.6%) with Ehrlichia chaffeensis and 1 (0.5%) with Anaplasma phagocytophilum with the titers of 1:40 or more. Although screening PCR for Ehrlichia and Anaplasma species failed to detect the presence of ehrlichial DNA in serum samples, results of the serological tests suggested that the feral raccoons might be infected with some species of Ehrlichia and Anaplasma.

Baylisascaris procyonis is a well-known ascaridoid nematode that causes larva migrans in humans and many other animal species. The North American raccoon (Procyon lotor) is the definitive host, which has been successfully introduced in the past decades to other geographical regions around the world. Two white-headed lemurs (Eulemuralbifrons) from a Zoological Park in Lugo, Spain, developed severe neurological signs within a brief period after being transferred from exhibit and placed in close contact with three captive raccoons from the same zoo. One lemur was euthanized due to the severity of disease progression and histopathology revealed granulomatous inflammation and ascaridoid larvae in kidneys, lung, spleen and brain. Larvae were identified as B. procyonis larvae by real time PCR. In light of the results, the cage mate with similar neurological signs was put on an albendazole treatment regimen adapted from a human pediatric protocol. The aggressive anthelmintic treatment likely contributed to the arrest of clinical signs and recovery of some motor skills. Importantly, Baylisascaris procyonis infection might occur in wild raccoon populations in Spain.

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses in the Americas and Sarcocystis neurona is the most common etiologic agent. The distribution of S. neurona infections follows the geographical distributions of its definitive hosts, opossums (Didelphis virginiana, Didelphis albiventris). Recently, cats and skunks were reported as experimental and armadillos as natural intermediate hosts of S. neurona. In the present report, raccoons (Procyon lotor) were identified as a natural intermediate host of S. neurona. Two laboratory-raised opossums were found to shed S. neurona-like sporocysts after ingesting tongues of naturally-infected raccoons. Interferon-gamma gene knockout (KO) mice fed raccoon-opossum-derived sporocysts developed neurologic signs. S. neurona was identified immunohistochemically in tissues of KO mice fed sporocysts and the parasite was isolated in cell cultures inoculated with infected KO mouse tissues. The DNA obtained from the tongue of a naturally-infected raccoon, brains of KO mice that had neurological signs, and from the organisms recovered in cell cultures inoculated with brains of neurologic KO mice, corresponded to that of S. neurona. Two raccoons fed mature S. neurona sarcocysts did not shed sporocysts in their feces, indicating raccoons are not likely to be its definitive host. Two raccoons fed sporocysts from opossum feces developed clinical illness and S. neurona-associated encephalomyelitis was found in raccoons killed 14 and 22 days after feeding sporocysts; schizonts and merozoites were seen in encephalitic lesions.

Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in the Americas. The protozoan most commonly associated with EPM is Sarcocystis neurona. The complete life cycle of S. neurona is unknown, including its natural intermediate host that harbors its sarcocyst. Opossums (Didelphis virginiana, Didelphis albiventris) are its definitive hosts. Horses are considered its aberrant hosts because only schizonts and merozoites (no sarcocysts) are found in horses. EPM-like disease occurs in a variety of mammals including cats, mink, raccoons, skunks, Pacific harbor seals, ponies, and Southern sea otters. Cats can act as an experimental intermediate host harboring the sarcocyst stage after ingesting sporocysts. This paper reviews information on the history, structure, life cycle, biology, pathogenesis, induction of disease in animals, clinical signs, diagnosis, pathology, epidemiology, and treatment of EPM caused by S. neurona.

Sarcocystis neurona associated granulomatous encephalitis was found in 2 of 84 adult raccoons. Both raccoons also had an extensive nonsuppurative myocarditis and one had S. neurona schizonts and merozoites in the myocardium. Only the asexual stages (schizonts and merozoites) of S. neurona are found in tissues of naturally infected animals (horse, mink, raccoons, cats, skunk, pony, seals, sea otters) and since these have not been reported outside the central nervous system, the presence of concurrent myocarditis in raccoons with the presence of S. neurona in the current study is of interest. Pathologists should consider the possible association of S. neurona with myocardial inflammation in other S. neurona susceptible animals.

The efficacy of six anthelmintics against natural infections of Baylisascaris procyonis in raccoons (n = 7 per drug) was determined in a series of critical tests. The drugs were given via moist cat food as a single dose or once daily for three consecutive days. Raccoons treated with pyrantel embonate (1 x 20 mg base kg-1 bodyweight (bwt.)), ivermectin (1 x 1 mg kg-1 bwt.), moxidectin (1 x 1 mg kg-1 bwt.), albendazole (3 x 50 mg kg-1 bwt.), fenbendazole (3 x 50 mg kg-1 bwt.) or flubendazole (3 x 22 mg kg-1 bwt.) expelled 1-198, 2-24, 2-14, 3-80, 2-70, or 2-35 B. procyonis stages, respectively, within the faeces. No roundworm was detected in any raccoon at post mortem examinations 7 days after the end of treatment. These results suggest that any of the six anthelmintics can be used at the dose rates tested in a deworming programme for captive raccoons.

Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

We recently reported that feral raccoons (Procyon lotor) with splenomegaly native to Japan were carriers of a Babesia microti-like parasite identical to that found in the United States, which was likely introduced to Japan from North America via raccoons imported as pets. Thus, we attempted extensive molecular survey for piroplasma infections of feral raccoon with normal spleen in Hokkaido, Japan using nested PCR that target broadly to 18S ribosomal RNA gene (SSU-rDNA) of all the parasites in the genus Babesia, Theileria, Cytauxzoon and B. microti group. Of the 348 raccoon samples analyzed, 9 gave positive signals. Cloning and phylogenetic analysis on SSU-rDNA sequences revealed that six of nine positives were found to be infected with Babesia and the remaining three with previously unreported Sarcocystis. Babesia sequences were further separated into two distantly related groups, those that reside in a novel phylogenetic group were consisted solely of four parasites found in this study, while those which included one identical sequence found in the three of our specimens were assembled together with both Babesia parasites of tick's in Japan and of raccoon's in U.S. These results may indicate that not only a B. microti-like parasite but also at least two yet undescribed Babesia species are being established in their new life cycles in the feral raccoon populations in Japan.

Equine protozoal myeloencephalitis (EPM) is the most important protozoal disease of horses in North America and it is caused by Sarcocystis neurona. Natural cases of encephalitis due to S. neurona have been reported in raccoons, Procyon lotor. We examined 99 raccoons for agglutinating antibodies to S. neurona using the S. neurona agglutination test (SAT) employing formalin-fixed merozoites as antigen. Raccoons originated in Florida (N=24, collected in 1996), New Jersey (N=25, collected in 1993), Pennsylvania (N=25, collected in 1999), and Massachusetts (N=25, collected in 1993 and 1994). We found that 58 (58.6%) of the 99 raccoons were positive for antibodies to S. neurona using the SAT; 44 of 99 raccoons (44%) had titers of > or =1:500. This prevalence is similar to the reported seroprevalence of 33-60% for S. neurona antibodies in horses from the United States using the Western blot test.

Captive-bred raccoons ( Procyon lotor ) developed immune resistance to infestation by the larval stage of the ixodid tick, Ixodes scapularis , the vector of Borrelia burgdorferi , following repeated applications of both nymphs and larvae. Resistance was expressed as a significant decrease in the proportion of engorged larvae recovered from each cohort. Resistance to nymphs was not noted, but, only two such cohorts were applied. Utilizing an enzyme-linked immunosorbent assay (ELISA) developed to detect raccoon serum antibodies to tick salivary gland antigens, raccoons evidenced a two to ten-fold increase in anti-tick salivary extract antibody titer following the application of two cohorts of nymphs and eights cohorts of larvae. The tick saliva antigens recognized by both pre- and post-exposure raccoon sera were evaluated by Western blotting. The production of antibodies correlated with the development of resistance to infestation, suggesting that the resistance was immune-mediated and could be measured by anti-tick salivary extract antibody titers. Resistance in exposed raccoons prevents nearly 90% of larvae from prolonged feeding. Prolonged feeding is required for engorgement and the transmission of various infectious agents, such as B. burgdorferi .

Multiparous sows from 19 central Iowa swine farms were tested for antibodies against Toxoplasma gondii by the modified direct agglutination test. Antibody titers of 1:32 or greater were considered positive. Rodents, domestic cats, opossums (Didelphis virginiana), raccoons (Procyon lotor) and striped skunks (Mephitis mephitis) were live-trapped on each farm and similarly tested for antibodies. The overall prevalence of T. gondii antibodies in the species tested was 39/273 (14.3%) swine, 31/74 (41.9%) cats, 2/588 (0.3%) house mice (Mus musculus), 0/21 mice of the genus Peromyscus, 0/9 Norway rats (Rattus norvegicus), 1/34 (2.9%) opossums, 4/14 (28.6%) raccoons and 2/7 (28.6%) striped skunks. The overall prevalence was significantly greater in adult cats versus juvenile cats, adult male cats versus adult female cats, and adult raccoons versus juvenile raccoons. The prevalence of T. gondii antibodies in sows was compared with the prevalence in each non-swine species on a farm basis in order to identify existing associations. The prevalence in sows (and each of the non-swine species) was also analyzed on a farm basis for association with farm characteristics or swine management practices, including the degree of confinement of swine, population size and average parity of breeding female swine, estimated cat population size, and estimated mouse and rat abundance. Average titers of seropositive animals were compared on a species basis. The prevalence in sows which were totally and continuously confined was lower than that in sows which were not totally and continuously confined. The prevalence in sows from farms with an average parity of less than 2.0 was significantly lower than that in sows from farms with an average parity of 2.0 or greater. These results suggested that the prevalence of T. gondii antibodies in swine increased with age and that prevalence in swine could be reduced through total confinement. No associations could be established between prevalence in sows and prevalence in non-swine species or other farm characteristics/swine management practices. However, the high prevalence of T. gondii antibodies in cats suggested that fecal contamination of the environment by cats may be the most significant source of toxoplasmosis for swine. The extremely low prevalence of T. gondii antibodies in house mice suggested that this species was not an important source of T. gondii for swine in Iowa.

Nine dogs were fed Hepatozoon canis -exposed Rhipicephalus sanguineus thicks; 6 showed clinical signs suggestive of canine hepatozoonosis, and the parasite was found in sections of muscle tissue from 2 of the dogs. Schizont-like cysts were found in the skeletal muscle of both infected dogs as were gametocytes in the circulating leucocytes. Periosteal new-bone lesions were seen in 1 dog. Attempts to infect a raccoon, 3 cats, 6 laboratory mice, and tick- or canine-cells in vitro, failed.