Experimental evaluation of urinary bladder marsupialization in male goats

OBJECTIVE: To evaluate the outcome of urinary bladder marsupialization in male goats. STUDY DESIGN: Prospective, experimental study. ANIMALS: Six healthy mixed-breed male goats. METHODS: After experimentally induced urethral obstruction, 6 male goats had urinary bladder marsupialization. Renal ultrasonography, complete blood count, and serum biochemical analysis were evaluated preoperatively (day 0), at 7 postoperative days, and then at 30-day intervals until 180 days. Stomal diameter was recorded immediately postoperatively and at each postoperative interval. Necropsy examination was performed on day 180 or when stomal stricture or death occurred. RESULTS: Stomal stricture occurred in 1 goat at 120 days. Another goat was found dead at 150 days; severe, suppurative cystitis was identified on necropsy. All goats had mild urine scald dermatitis. Serum biochemical values remained within normal limits, but significant decreases in white blood cell count, serum creatinine concentration, and stomal diameter occurred. At necropsy, all bladders were tubular in shape. Histological evidence of chronic suppurative cystitis and chronic, mild lymphoplasmacytic pyelitis occurred in all goats. Bacterial culture of renal tissue yielded growth in 3 goats, and bladder mucosal swabs yielded bacterial growth in all goats. CONCLUSIONS: Although clinical signs of ascending urinary tract infection were not observed in goats with patent stomata, urinary bladder marsupialization may result in ascending urinary tract inflammation or infection. CLINICAL RELEVANCE: Based on our results, urinary bladder marsupialization should be recommended with caution as the primary method for management of urinary tract obstruction in clinical cases.     

Differentiation of Haemobartonella canis and Mycoplasma haemofelis on the basis of comparative analysis of gene sequences

OBJECTIVE: To determine whether Haemobartonella canis and Mycoplasma haemofelis (formerly known as H felis [large form]) can be differentiated by use of comparative analysis of gene sequences. SAMPLE POPULATION: Blood samples obtained from 3 dogs infected with H canis and 2 cats infected with M haemofelis. PROCEDURE: The partial 16S rDNA and ribonuclease P RNA (RNase P) genes were amplified, cloned, and sequenced in blood samples obtained from H canis-infected dogs and M haemofelis-infected cats. The DNA sequences were subjected to comparative analysis. RESULTS: The 16S rDNA sequences of H canis and M haemofelis were nearly identical (homology of 99.3 to 99.7%). In contrast, RNase P gene sequences had a lower degree of sequence homology between the 2 organisms (94.3 to 95.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Haemobartonella canis and M haemofelis are not identical organisms. Molecular differentiation of H canis and M haemofelis is more clearly evident by use of comparative analysis of RNase P gene sequences than by comparative analysis of 16S rDNA gene sequences.     

Estimating the incubation period of raccoon rabies: a time-space clustering approach

We used a time-space clustering approach to estimate the incubation period of raccoon rabies in the wild using data from the 1999-2001 invasion of raccoon rabies into eastern Ontario from northern New York State. The time differences and geographical distances between all possible pairs of rabies cases were computed, classified and assembled into a time-space matrix. The rows of that matrix represented differences in cases in weeks and the columns represent distances between cases in kilometers and the values in the cells of the matrix represent the counts of cases at specific time and distance intervals. There was a significant cluster of pairs 5 weeks apart with apparent harmonics at additional 5-week intervals. These results are explained by assuming the incubation period of raccoon rabies had a mode of 5 weeks. The time clusters appeared consistently at distance intervals of 5 km. We discuss the possibility that the spatial intervals were influenced by the 5 km radius of the point infection control depopulation process used in 1999 and the 10-15 km radial areas used in 2000. With the practical limits of those radii, there was an intensive effort to eliminate raccoons. Our procedure is easy to implement and provides an estimate of the shape of the distribution of incubation periods for raccoon rabies.     

Predicting nutrient and sediment loadings to streams from landscape metrics: A multiple watershed study from the United States Mid-Atlantic Region

There has been an increasing interest in evaluating the relative condition or health of water resources at regional and national scales. Of particular interest is an ability to identify those areas where surface and ground waters have the greatest potential for high levels of nutrient and sediment loadings. High levels of nutrient and sediment loadings can have adverse effects on both humans and aquatic ecosystems. We analyzed the ability of landscape metrics generated from readily available, spatial data to predict nutrient and sediment yield to streams in the Mid-Atlantic Region in the United States. We used landscape metric coverages generated from a previous assessment of the entire Mid-Atlantic Region, and a set of stream sample data from the U.S. Geological Survey. Landscape metrics consistently explained high amounts of variation in nitrogen yields to streams (65 to 86% of the total variation). They also explained 73 and 79% of the variability in dissolved phosphorus and suspended sediment. Although there were differences in the nitrogen, phosphorus, and sediment models, the amount of agriculture, riparian forests, and atmospheric nitrate deposition (nitrogen only) consistently explained a high proportion of the variation in these models. Differences in the models also suggest potential differences in landscape-stream relationships between ecoregions or biophysical settings. The results of the study suggest that readily available, spatial data can be used to assess potential nutrient and sediment loadings to streams, but that it will be important to develop and test landscape models in different biophysical settings.     

Hand-assisted laparoscopic ovariohysterectomy in the mare

OBJECTIVE: To develop a minimally invasive, hand-assisted laparoscopic ovariohysterectomy (HALS-OHE) technique in the mare and to evaluate safety and any associated complications. STUDY DESIGN: Experimental study. ANIMALS: Eight, 11-24-year-old mares with anatomically normal urogenital tracts. METHODS: The surgical technique was developed in 2 non-survival mares and subsequently evaluated in 6 survival procedures. Food was withheld for 48 hours, then mares were anesthetized and positioned in dorsal recumbency for laparoscopic surgery. A hand access device (Omniport) was placed followed by 4 laparoscopic portals. Transection of the ovarian pedicles and broad ligaments was achieved using a combination of a laparoscopic stapling instrument (Endo GIA II), an ultrasonically activated instrument (Harmonic Scalpel), and endoscopic clips (Endo Clip II ML). The genital tract was exteriorized through the laparotomy, and the uterus transected and sutured in a conventional pattern. Horses were evaluated through postoperative day 14 when a necropsy was performed. RESULTS: Four mares recuperated well after surgery, 1 mare was euthanatized because of bilateral femur fracture during anesthetic recovery, and another developed severe pleuropneumonia. At necropsy all but 1 abdominal incision was healing routinely. One mare had abscessed along the celiotomy incision and developed visceral adhesions. Uncomplicated healing of transected mesovarial, mesometrial, and uterine remnants was observed. CONCLUSIONS: Ovariohysterectomy in horses can be accomplished using HALS technique. CLINICAL RELEVANCE: HALS-OHE technique represents a minimally invasive and technically feasible alternative for conventional OHE. Careful patient selection and preparation may reduce the complications observed. The HALS technique may be useful in other laparoscopic surgical procedures.