Laparoscopic cryptorchidectomy using electrosurgical instrumentation in standing horses

OBJECTIVE: To describe a technique for laparoscopic cryptorchidectomy in standing horses using electrosurgical instrumentation. STUDY DESIGN: Retrospective clinical study. ANIMALS OR SAMPLE POPULATION: Ten horses, 1 to 7 years of age, with unilaterally or bilaterally retained testes. METHODS: Food was withheld for a minimum of 12 to 24 hours. Horses were sedated using xylazine hydrochloride (0.5 to 1 mg/kg) and butorphanol tartrate (0.02 mg/kg) or detomidine hydrochloride (0.02 to 0.03 mg/kg) and restrained in standing stocks. Three portal sites in the paralumbar fossae were locally desensitized using 2% mepivacaine. After trocar and laparoscope insertion, the ipsilateral testicle, mesorchium, and ductus deferens were identified. The cranial mesorchium was coagulated with either monopolar (one horse) or bipolar (nine horses) electrosurgical forceps, and then the mesorchium, ductus deferens, and ligament of the tail of the epididymis were transected from cranial to caudal using laparoscopic scissors. Once the testis was freed, the transected mesorchium was inspected for hemorrhage and the testis was removed by connecting the two instrument portals (eight horses). In two horses, the testis was placed within a laparoscopic retrieval bag and then removed without enlarging the portal incision. If the testes were retained bilaterally, the retained contralateral testis was removed similarly through the opposite paralumbar fossa. If the contralateral testis was descended, it was removed by a standard, standing castration technique. RESULTS: Vessels of the mesorchium were adequately coagulated using bipolar and monopolar electrosurgical forceps. No immediate or short-term complications occurred in 10 horses at 3 to 11 months after surgery. CONCLUSION: Standing laparoscopic cryptorchidectomy can be performed easily and safely using electrosurgical instrumentation as the sole means of providing hemostasis of the equine mesorchium. CLINICAL RELEVANCE: Standing laparoscopic cryptorchidectomy using electrosurgical instrumentation provides a safe, reliable, and efficient alternative to achieve hemostasis of the equine mesorchium.     

Inoculation of two genotypes of Hemobartonella felis (California and Ohio variants) to induce infection in cats and the response to treatment with azithromycin

OBJECTIVES: To describe clinical and laboratory findings associated with cats experimentally infected by inoculation with the 2 recognized genotypes of Hemobartonella felis (small variant, Hfsm; large variant, Hflg) and to determine the response of cats to treatment with azithromycin. ANIMALS: 18 young adult domestic shorthair cats of both sexes. PROCEDURES: Cats were inoculated with H felis and monitored weekly, using CBC counts and a polymerase chain reaction (PCR) designed to detect both genetic variants of H felis. Beginning 26 days after inoculation, 11 cats were administered azithromycin (15 mg/kg of body weight, PO, q 12 h, for 7 days). RESULTS: Inoculation resulted in coinfection with Hflg and Hfsm, and both variants were detected by PCR. Clinical abnormalities and anemia were most severe in Hflg- and dual-infected cats. Results of PCR and CBC were positive for H felis in 112/112 (100%) and 42/112 (37.5%), respectively, samples collected after inoculation. Administration of azithromycin had little effect on clinical variables, including anemia. All cats, regardless of treatment with azithromycin, had positive results for the PCR at the end of the study period. CONCLUSIONS AND CLINICAL RELEVANCE: In these cats, Hflg was more pathogenic than Hfsm, and coinfection with both variants was detected. Results of the PCR were superior to results of CBC for detecting infection with H felis. Azithromycin administered at the dose and duration reported here was not efficacious for the treatment of cats with hemobartonellosis.     

Restoring plant cover on high-elevation gravel areas, Sequoia National Park, California

Our objective was to learn whether Carex exserta sod plugs could be successfully transplanted as a technique for restoring plant cover on high-elevation gravel areas of the southern Sierra Nevada. Our study area was Siberian Outpost in Sequoia National Park, California. The plugs (either 1·9 cm or 5·1 cm in diameter and 10-cm deep) were transplanted in September 1981 and 1982 and without papier-mâché pots and fertilizer. The most promising treatment (52% survival after four years) was to transplant large-diameter sod plugs unpotted and unfertilized. Water appears to be the main factor limiting existing plant cover at Siberian Outpost. Nevertheless, plants present in the gravel could not effectively use fertilizer, and some species were reduced by fertilization.     

Interdisciplinary Irrigated Precision Farming Research

The USDA-Agricultural Research Service and Colorado State University are conducting an interdisciplinary study that focuses on developing a clearer scientific understanding of the causes of yield variability. Two years of data have been collected from two commercial center pivot irrigated fields (72 and 52 ha). Cooperating farmers manage all farming operations for crop production and provide yield maps of the maize grown on the fields. The farmers apply sufficient inputs to minimize risk of yield loss. The important variables for crop production have been sampled at a grid spacing of 76 m for two seasons. A spatial auto-regressive model was fitted to the data to determine the critical factors affecting yield variability. Thirty one layers of data were included in the analysis, and a total of over 140,000 models were examined. Up to five predictors were used in each model. Variability in water application, nitrate nitrogen, organic matter, phosphorus, topology, percent silt and soil electrical conductivity were significant in explaining the yield variability for Field 1. Variability in water application, ammonium, nematodes, percent clay, insects, potassium, soil electrical conductivity, and topology were significant in explaining the yield variability for Field 2. The tentative conclusion is that the potential economic benefit of site specific management is small where the farmer's management tolerance for risk is low. The potential of site specific management is in reducing the cost of inputs and environmental impact, but could increase risk.