Comparison of fluorescent antibody and microscopic agglutination testing for Leptospira in pregnant and nonpregnant cows.

Serum and urine samples from 30 cows (15 pregnant and 15 nonpregnant) from each of 10 Georgia dairy herds (total cows = 300) were examined by microscopic agglutination testing (MAT) and direct fluorescent antibody testing (FAT), respectively. Seven of the 10 herds had at least 1 cow with a positive FAT, and all of the herds had at least 1 cow with a reciprocal MAT titer > or =100 for 1 or more serovars. Serological testing was not helpful in identifying the infecting serovar for cows with a positive FAT result. The MAT titers for all 7 of the serovars evaluated were significantly correlated with one another, with 17 (81%) of the 21 Spearman rank correlation coefficients > or =0.4 in magnitude. Twenty (56%) of 36 FAT-positive cows did not have a titer that was highest for any particular serovar. Four of the 7 herds that reported using a Leptospira borgpetersenii serovar Hardjo-bovis vaccine had one or more FAT-positive cows compared with 3 out of 3 herds that reported they were not using this type of vaccine, although this difference was not statistically significant.

Efficacy of select disinfectants at inactivating Ranavirus.

Ranavirus can cause disease in reptiles and amphibians. Because survival time outside of a host remains uncertain, equipment must be disinfected to prevent transmission of ranaviruses. However, disinfectant efficacy against amphibian ranaviruses has not been investigated for chlorhexidine (Nolvasan), sodium hypochlorite (bleach), or potassium compounds. Our goal was to determine the efficacy of Nolvasan (0.25, 0.75 and 2.0%), bleach (0.2, 1.0, 3.0 and 5.0%), and Virkon S (1.0%) at inactivating Ranavirus at 1 and 5 min contact durations. Potassium permanganate (KMnO4) (2.0 and 5.0 ppm) was also tested with a 60 min contact time. Nolvasan at 0.75 and 2.0% and bleach at 3.0 and 5.0% concentration were effective for both contact durations. Virkon S was effective for both durations, but KMnO4 was not effective at either concentration. Concentrations of Nolvasan, bleach and Virkon S that are at least 0.75, 3.0 and 1.0%, respectively, are effective at inactivating Ranavirus after 1 min exposure time.

Population health of Fallow deer (Dama dama) on Little St. Simons Island, Georgia, USA.

Fallow deer (Dama dama) were introduced to Little St. Simons Island, Georgia, USA in the 1920s and thrive at high population densities, to the exclusion of white-tailed deer (Odocoileus virginina). The presence of introduced pathogens and parasites as a result of their introduction is currently unknown, as is the impact of native disease on the exotic fallow deer. Hunter-killed fallow deer from 2003-2005 were necropsied and surveyed for evidence of infectious disease, parasitic agents, and toxicologic parameters. Fallow deer were positive for antibodies to bovine virus diarrhea virus I and II, bluetongue virus, and bovine adenovirus. Twenty species of bacteria were isolated from the internal organs, and 14 species of parasites were recovered including one abomasal nematode, Spiculopteragia asymmetrica, which is not known to occur in native North American ungulates. Concentrations of liver and copper were low, while lead, zinc, and iron were considered within normal levels. No clinical signs of disease were noted, and the overall health of the insular fallow deer was considered good.

Pathologic findings in larval and juvenile anurans inhabiting farm ponds in Tennessee, USA.

Amphibian populations are declining globally, yet general pathologic surveys for free-ranging amphibians are uncommon. Pathologic surveys are necessary to provide insight into the impacts of humans on emergence of pathogens in amphibian populations. During 2005, 104 American bullfrog (Rana catesbeiana) and 80 green frog (Rana clamitans) larvae and 40 green frog juveniles were collected from farm ponds in Tennessee, and complete necropsies were performed. Diagnostic testing included bacterial culture, virus testing, fecal parasite analysis, and histologic examination. Gross and histologic examination revealed that all individuals, except one bullfrog tadpole, could be classified as clinically normal. The clinically abnormal tadpole had swollen erythemic legs, and was positive for Aeromonas hydrophila but negative for Ranavirus. Parasites were common (43%) among specimens, with myxosporidium and trematodes most often noted. Commensal and opportunistic microorganisms were cultured from the tissues. Ranavirus was detected in 29% of individuals but generally not associated with significant histopathologic changes. Myxosporidia and Ranavirus coinfections occurred in 7 and 26% of green and bullfrog tadpoles, respectively, with the highest coinfection rate (83%) in bullfrog tadpoles during winter. Protozoans were most common in fecal examination. These data can serve as a baseline to evaluate the presence of clinical disease in larval and juvenile amphibians.

Hematology, parasitology, and serology of free-ranging coyotes (Canis latrans) from South Carolina.

Blood and feces were collected from 34 adult (19 males, 15 females) and seven juvenile (three males, one female, three not reported) free-ranging coyotes (Canis latrans) on the US Department of Energy's Savannah River Site (South Carolina, USA). Significant (P<0.05) hematologic differences by sex were noted for red blood cell counts, hemoglobin, and hematocrit. Biochemical differences by sex occurred only for albumen (P<0.05). Twenty-one adults were antibody positive for at least one of four viruses: canine adenovirus type 1 (CAV-1; 68%), West Nile virus (WNV; 60%), Eastern equine encephalitis virus (EEEV; 38%), and Canine distemper virus (CDV; 15%). Of the seven Leptospira serovars tested for, seven (25%) of 28 adults were positive for one or more of five serovars: Pomona, Grippotyphosa, Icterohaemorrhagiae, Bratislava, and Autumnalis. Three (43%) of seven juveniles had seropositivity for a virus, one each for CDV, CAV-1, and WNV. No juveniles were seropositive for EEEV or any of the seven Leptospira serovars. Blood smears of 12 adults were positive for Dirofilaria immitis microfilaria, but blood smears from all juveniles were negative. Parvovirus was identified by electron microscopy from the feces of one adult. Ancylostoma spp., Trichuris spp., and Isospora spp. were observed in fecal samples. These data may aid in understanding the role of coyotes in disease ecology.

Concurrent infection with ranavirus, Batrachochytrium dendrobatidis, and Aeromonas in a captive anuran colony.

Four species (Dendrobates auratus, Phyllobates terribilis, Pyxicephalus adspersus, and Rhacophorus dennysi) of captive anurans with a clinical history of lethargy and inappetence were found dead and were submitted for necropsy. Gross lesions included irregular patches of sloughed skin and rare dermal ulcerations. Histologic findings included epidermal proliferation that was most pronounced on the digits and that included intracytoplasmic chytrid organisms. Bacteria were often associated with the epidermal lesions. Intracytoplasmic inclusion bodies were observed in hepatocytes. Real-time polymerase chain reaction yielded positive results for both Ranavirus and Batrachochytrium dendrobatidis (Bd). Bacterial culture of internal organs yielded Aeromonas hydrophila. This is the first report of concurrent infections in anurans by Ranavirus and Bd and A. hydrophila.

Frog virus 3 prevalence in tadpole populations inhabiting cattle-access and non-access wetlands in Tennessee, USA.

Ranaviruses have been associated with most of the reported larval anuran die-offs in the United States. It is hypothesized that anthropogenically induced stress may increase pathogen prevalence in amphibian populations by compromising immunity. Cattle use of wetlands may stress resident tadpole populations by reducing water quality. We isolated a Ranavirus from green frog Rana clamitans (n = 80) and American bullfrog R. catesbeiana (n = 104) tadpoles collected at 5 cattle-access and 3 non-access wetlands on the Cumberland Plateau, Tennessee, USA. Sequencing confirmed Frog virus 3 (FV3); therefore, we compared its prevalence between tadpole populations inhabiting cattle-access and non-access wetlands, and among 3 seasons (winter, summer, and autumn) in 2005. We found FV3 in both tadpole species and cattle land-use types; however, prevalence of FV3 was greater in green frog tadpoles residing in cattle-access wetlands compared to those in non-access wetlands. No difference in FV3 prevalence was detected between cattle land uses for American bullfrog tadpoles. A seasonal trend in FV3 prevalence also existed, with prevalence greater in autumn and winter than in summer for both species. In addition, we found that FV3 prevalence decreased significantly as Gosner stage increased in American bullfrog tadpoles. No trend was detected between FV3 prevalence and developmental stage for green frog tadpoles. Our results suggest that cattle use of wetlands may increase prevalence of FV3 in Rana tadpoles, although this effect may depend on species, season, and tadpole developmental stage.

The relationship of soil province to molecular characterization and phylogenetic analysis of Cryptosporidium parvum isolated from calves in Georgia.

Although Cryptosporidium spp. are found throughout the world and in multiple environmental conditions, few data are available that explore the possibility of an association between specific environmental parameters and the species or strain of Cryptosporidium. This study examines the potential association between a particular Cryptosporidium species/strain found in calves and soil provinces in Georgia, USA. Necropsy cases spanning the years 1996-2002 were tested. No significant differences (P=0.962, chi(2) test of homogeneity) between numbers of positive cases were noted among soil provinces. Phylogenetic analysis of the sequences for the PCR products revealed sequence similarity of the products with Cryptosporidium parvum strain C1. Although, clinical Cryptosporidiosis in calves was not found to be affected by soil province and may be caused by a single genotype, other genotypes may be responsible for subclinical infection and warrant further investigation.

Eastern equine encephalitis in dogs.

Eastern equine encephalitis virus (EEEV) is an Alphavirus that is endemic in the Southeastern United States. From 1993 to January 2005, the Veterinary Diagnostic and Investigational Laboratory in Tifton, Georgia, performed postmortem examinations on over 101 domestic canines exhibiting clinical neurological disturbances. In 12 of these dogs, brains were histologically suggestive of infection with EEEV. All dogs were less than 6 months of age, with no breed predilection. Clinical signs included pyrexia, depression, nystagmus, and lateral recumbency. Microscopically, brains from all 12 puppies contained infiltrates of lymphocytes, plasma cells, and histiocytes, with occasional neutrophils and random foci of astrocytosis and gliosis. There were mild to moderate perivascular infiltrates of neutrophils along with scattered lymphocytes, plasma cells, and macrophages in the meninges. Viruses isolated from brain homogenates of all 12 puppies were confirmed by indirect fluorescent antibody testing to be EEEV. Additionally, RNA extracted from the brains and viral cultures of 2 dogs were determined by a specific reverse-transcriptase polymerase chain reaction (RT-PCR) to contain EEEV. The single available serum sample exhibited a 1:8 serum neutralization titer to EEEV.

Serologic survey of wild turkeys (Meleagris gallopavo) and evidence of exposure to avian encephalomyelitis virus in Georgia and Florida, USA.

Wild Turkeys (Meleagris gallopavo) are susceptible to many of the same diseases as domestic turkeys. Before 2005, most Wild Turkeys in southern Georgia, US, had little or no exposure to commercial poultry operations. As part of a pathogen survey examining the effects of commercial poultry on Wild Turkeys, samples were collected from Wild Turkeys from March 2005 through May 2008. The turkeys were collected from 13 counties in southern Georgia and Madison County, Florida, and tested for antibodies to various pathogens of poultry. Three (13%) of the turkeys were positive for antibodies to Salmonella. Thirteen turkeys (54%) were positive for Newcastle disease virus antibodies, and 15 turkeys (63%) were positive for antibodies to reticuloendotheliosis virus. One turkey (4%) from Madison County was positive for avian encephalomyelitis virus antibodies.

Seroprevalence and comparison of isolates of endometriotropic bovine herpesvirus-4.

Sixty-eight cases of suppurative, ulcerative endometritis associated with Bovine Herpesvirus-4 (BHV-4) in postparturient dairy cows (62 Holsteins and 6 Jerseys, mean age 4.2 years) were confirmed by a combination of histopathology, fluorescent antibody assays, electron microscopic evaluation of uterus, and polymerase chain reaction (PCR). All cases occurred in the 3- to 28-day postpartum period, and histologic lesions among various cows were consistent when compared with postpartum interval. The endometrial lining epithelium was necrotic and ulcerated from 3 to 7 days postpartum, with only mild inflammation in the lamina propria and submucosa. From 1 to 4 weeks postpartum, the ulcers were confluent to diffuse. Epithelium was replaced by fibrinonecrotic, suppurative mats, resulting in severe bacterial pyometra by day 24. Seroprevalence to BHV-4 in one dairy with a history of 18 mortality cases was 36% (107 of 296). In a random sample of 8 cows from this herd, none had serologic titers in blood sampled 2 weeks prepartum, but 3 of 8 seroconverted with significant titers of 1:8 to 1:16 at 2 weeks postpartum. By 10 weeks postpartum, all 8 cows returned to negative serologic status. Two of 6 cats from the premises also had positive titers. Random serum samples taken from 480 dairy cattle at sale barns indicated 76 (16%) were positive by serum neutralization. Clinical signs, postparturient timing, and histologic lesions were very similar to those previously reported in Belgium with BHV-4. But sequence analysis of PCR products of the glycoprotein B region of 4 separate field isolates of endometriotropic BHV-4 suggests these field isolates were more closely related to the North American nonvirulent strain DN-599 than to the endometriotropic European strain V.

Pathologic findings in hatchling and posthatchling leatherback sea turtles (Dermochelys coriacea) from Florida.

In an attempt to identify critical health issues affecting the survival of endangered leatherback sea turtles (Dermochelys coriacea), a prospective study was conducted in several dead-in-nest hatchlings and captive posthatchlings to examine pathologic changes and presence of pathogenic microorganisms. Numerous histopathologic changes were identified. Although bacterial etiologies were suspected in deaths of captive individuals, a single causative organism was not identified but rather, a mixed population of bacterial flora was cultured. Muscle degeneration observed in most samples implicates a potential environmental factor in species survival and needs future investigation.