Radiculomeningomyelitis due to Halicephalobus gingivalis in a horse

An adult horse was euthanatized following a clinical diagnosis of cauda equina neuritis. Significant gross postmortem and histopathologic findings were limited to the sacral spinal cord and cauda equina. The sacral spinal cord, meninges, and spinal nerve roots were expanded and partially effaced by sclerosing granulomatous inflammation with necrosis. The lesion contained numerous nematode larvae and fewer adults with a rhabditiform esophagus having a corpus, isthmus, and valved bulb. Female nematodes were amphidelphic and didelphic with reflexed ovaries. These morphologic features confirm Halicephalobus gingivalis as a novel cause of clinical signs in this case of cauda equina neuritis.     

Bayesian estimation of cluster-level test accuracy based on different sampling schemes

We develop Bayesian models to estimate cluster-level test characteristics, sensitivity, specificity, prevalence, and predictive values, based on four different sampling schemes: a single test case and three sequential test cases. The corresponding cluster-level characteristics are calculated and compared for different sample sizes, sampling schemes, individual-level sensitivities, specificities, and cut-off values. We compared posterior estimates of individual-level and cluster-level characteristics for these four sampling schemes with simulated data. Two illustrations, one for Johne’s disease in cattle and another for Salmonella in pig herds, are used to demonstrate application of the methods.     

Vertical position of the patella in the stifle joint of clinically normal large-breed dogs

OBJECTIVE: To define the vertical position of the patella in clinically normal large-breed dogs. SAMPLE POPULATION: Cadavers of 13 clinically normal large-breed dog. PROCEDURE: Both hind limbs were harvested with intact stifle joints and mounted on a positioning device that allowed full range of motion of the stifle joint. Lateral radiographic views were obtained with the stifle joints positioned at each of 5 angles (148 degrees, 130 degrees, 113 degrees, 96 degrees, and 75 degrees). Vertical position of the patella through a range of motion was depicted on a graph of mean stifle angle versus corresponding mean proximal patellar position (PPP) and distal patellar position (DPP) relative to the femoral trochlea for each dog. Ratio of length of the patellar ligament to length of the patella (L:P) was determined for each dog. Overall mean, SD, and 95% confidence intervals for L:P were calculated for all dogs. RESULTS: Evaluation of vertical position of the patella through a range of motion revealed a nearly linear relationship between joint angle and PPP and joint angle and DPPF Evaluation of L:P results did not reveal significant differences between limbs (left or right) or among joint angles. Overall mean +/- SD L:P for all dogs was 1.68 +/- 0.18 (95% confidence interval, 1.33 to 2.03). CONCLUSIONS AND CLINICAL RELEVANCE: The L:P proved to be a repeatable measurement of vertical patellar position, which is independent of stifle angles from 75 degrees to 148 degrees.This measurement could be used as a quantitative method for diagnosing patella alta and patella baja in large-breed dogs.     

Feline calicivirus infection in kittens borne by cats persistently infected with the virus

On the basis of repeated isolation of feline calicivirus (FCV) from oropharyngeal swabs four to eight months after exposure to FCV strain 255, four carrier queen cats were identified. These cats gave birth to 16 kittens. Litters were individually housed with their mothers until nine weeks of age and were monitored virologically and serologically from birth until 15 weeks old. All kittens became infected between three and nine weeks old and shed FCV consistently for periods of three to 11 weeks. Clinical signs of FCV were observed in 11 kittens but none developed severe respiratory disease. At the time of initial infection maternal antibody titres in the kittens ranged from 1:4 to 1:24. Within one to three weeks of infection titres began to rise. The results indicated that kittens of queen cats persistently infected with FCV frequently experience mild or subclinical immunising infections.     

An outbreak of lymphadenitis associated with Stenotrophomonas (Xanthomonas) maltophilia in Omani goats

Stenotrophomonas maltophilia is a commonly isolated organism from human clinical specimens and is gaining significance as a pathogen in immunocompromised patients and nosocomial infections. In most cases it is difficult to establish the source of human infections. In veterinary medicine, S. maltophilia is not generally considered a primary pathogen. In the present study, we report the occurrence of 16 cases of caprine abscess from which S. maltophilia was isolated in pure culture from 15 animals. In six animals, the abscesses were confined to the pre-scapular lymph nodes but in the remaining nine, the cutaneous abscesses were multiple and extended from the neck to the inguinal area. The possibility is suggested that goats in Oman, which often live in close proximity to humans, might potentially serve as a reservoir of infection.     

Seasonal Variations in Vertical Redox Stratification and Potential Influence on Trace Metal Speciation in Minerotrophic Peat Sediments

Seasonal variations in pore water and solid phase geochemistry were investigated in urbanized minerotrophic peat sediments located in southwestern Michigan, USA. Sediment pore waters were collected anaerobically, using pore water equilibrators with dialysis membranes (“peepers”) and analyzed for pH, alkalinity, dissolved ΣPO₄ ^?3, ΣNH₄ ⁺, ΣS^?2, SO₄ ^?2, Fe⁺³, Fe⁺², and Mn⁺² at 1-2 cm intervals to a depth of 50 cm. Cores collected adjacent to the peepers during all four seasons were analyzed for reactive solid phase Fe according to extraction methods proposed by Kostka and Luther (1994). The association of Fe and trace metals (Mn, Pb, Zn, Cu, Cr, Co, Cd, U) with operationally defined solid phase fractions (carbonates, iron and manganese oxides, sulfides/organics and residual) was assessed for cores extracted during winter and spring using extraction methods proposed by Tessier et al. (1979, 1982). Pore water Fe and S data demonstrate a clear seasonal variation in redox stratification of these sediments. The redox stratification becomes more compressed in spring and summer, with relatively more reducing conditions closer to the sediment water interface (SWI), and less reducing conditions near the SWI in fall and winter. In the upper 10–15 cm of sediment, the pool of ascorbate extractable Fe, thought to be indicative of reactive Fe(III) oxides, diminishes during spring and summer, in agreement with seasonal changes in redox stratification indicated by the pore water data. Tessier extractions indicate that the total extractable quantity of all metals analyzed in this study decrease with depth, and that the majority of the non-residual Fe, Pb, Zn, Cu, Cr, Co, Cd, and U is typically associated with the sulfide/organic fraction of the sediments at all depths. Non-residual Mn, in contrast, is significantly associated with carbonates in the upper 15–25 cm of the sediment, and predominantly associated with the sulfide/organic fraction only in deeper sediments.     

Forage yield and crude protein of interseeded legume‐bermudagrass mixtures as affected by phosphorus fertilizer 1

Bermudagrass (Cynodon dactylon L.) is a warm season perennial that is well adapted in the southern Great Plains. It is one of the region's most important forage crops used for livestock production, and is commonly grown without legume interseeding. Recent research has investigated ways of improving the quality and quantity of this forage. The objectives of this study were to determine the effect of interseeded legumes and phosphorus (P) fertilizer on bermudagrass pasture forage yield and crude protein content. One experiment was initiated in 1993 in eastern Oklahoma in an established bermudagrass pasture. Red clover (Trifolium pratense L.), ladino clover (Trifolium repens L.), and two varieties of alfalfa (Medicago sativah), ’alfagraze’ and'common’, were interseeded by hand into an established stand of bermudagrass. The effect of P on forage yield and crude protein was evaluated using a 30‐kg P ha^‐1 rate applied at establishment versus no applied P. Forage yield was collected three times throughout the growing season each year from 1994 through 1997. When both alfalfa varieties were interseeded into a bermudagrass pasture without applying additional P fertilizer, forage yields for the legume‐grass mixtures decreased below those obtained from the monoculture bermudagrass in the first year of the stand. The alfalfa variety ‘alfagraze’ interseeded into established bermudagrass decreased total forage yield over the entire 4‐yr study. Interseeded red clover and ladino clover increased crude protein of the forage compared with monoculture bermudagrass the first two years of the study, with red clover continuing to increase crude protein in the fourth year. However, when 30 kg P ha^‐1 was applied to the bermudagrass prior to establishment of the legumes, no change in yield or protein was observed for both alfalfa varieties’ interseeding treatments versus the unfertilized mixtures. Although forage yield may not be increased, interseeding legumes into established bermudagrass could provide an efficient way to improve pasture crude protein without the use of inorganic fertilizers. However, if alfalfa ('common’ or ‘alfagraze') is interseeded, additional P may need to be applied at legume establishment to prevent possible yield decreases.