A comparison of three combinations of injectable anesthetics in miniature donkeys

Objective To compare three combinations of injectable anesthetics in miniature donkeys for quality of induction, recovery, muscle relaxation, cardiopulmonary changes during anesthesia and duration of recumbency. Design Prospective, randomized experimental study. Animals Six miniature donkeys (< 90 cm in height at the withers) weighing 92–127 kg were used. Materials and methods The drug combinations were: xylazine?butorphanol?ketamine (XBK), xylazine?butorphanol?tiletamine?zolazepam (XBT) and xylazine?propofol (XP). Each miniature donkey was anesthetized with each combination at 1‐week intervals in random order. Heart and respiratory rates, indirect blood pressure and temperature were measured before and at 5‐minute intervals during recumbency. Arterial blood samples were drawn for blood‐gas analysis before and at 5, 15 and 30 minutes of anesthesia when samples could be collected. Recumbency time to sternal and time to standing were recorded and a subjective evaluation of induction, muscle relaxation and recovery were made. Results Mean recumbency time ± SD was 14.7 ± 9.4, 33.8 ± 6.3 and 14.6 ± 1.9 minutes with XBK, XBT and XP, respectively. Mean time to standing ± SD was 28.4 ± 11.3, 43.7 ± 7.2 and 26.3 ± 2.9 minutes with XBK, XBT and XP, respectively. Heart and respiratory rates and blood pressures varied from baseline but were always within normal ranges. Hemoglobin saturation, pH and PaO₂ tended to be lower with these doses of XBT and XP. Conclusions and clinical relevance Overall quality of anesthesia was poor with XBK. At the doses used this combination did not provide sufficient anesthesia compared with the combinations of XBT and XP, which appeared to provide acceptable anesthesia of short duration in miniature donkeys.     

Water quantity and quality requirements of guayule: Current assessment

Because of the stragetic and industrial importance of natural rubber, there is renewed interest in cultivating guayule (Parthenium argentatum) in the Southwestern U.S.A. and several other arid regions of the world. This review was made to assess the quantity and quality of water required to cultivate this crop under irrigation. Data from Arizona and West Texas show that under high transplant densities (44 000 to 54 000 plants per ha), shrub and rubber yields increase almost linearly with increasing irrigation up to 300 cm for the first 2 years. The amount of water required to produce a ton of dry shrub in 2 years ranges from 1200 to 1600 m₃ for a wide range of irrigation regimes and irrigation water salinity. Although rubber content in the shrubs increases with increasing water stress, the increase is generally insufficient to offset the reduction in shrub yield under high plant densities. Salinity stress may increase rubber content slightly, but reduces shrub and rubber yields when salinity of irrigation water exceeds 4 to 6 dS m^?1 in sandy soils. The amount of water required to produce 1 kg of rubber with existing cultivars (with rubber contents of 40 to 70 g kg^?1) ranges from 20 to 30 m³, and should decrease substantially with the development of cultivars with higher rubber contents. The resin content in the shrubs does not change greatly with irrigation or salinity levels, thus the resin yield increases proportionally with shrub yield or irrigation amount. If guayule is to be established through direct seeding, additional water of low salinity needs to be allocated. Nursery grown seedlings have been transplanted successfully in spring months with 10–25 cm of water having salinity less than about 4 dS m^?1. If high rubber yields are to be achieved in 2–3 years, water requirements for guayule would be comparable to those for alfalfa. However, guayule can be grown with less quantities of water because of its high drought tolerance, especially when rubber production is the sole purpose.     

Immunodiffusion test antigen from bluetongue virus-infected newborn mouse brains

Three methods of extracting bluetongue virus (BTV)-infected newborn mouse brains to prepare immunodiffusion (ID) test antigen were used. The most readily readable and reproducible results were obtained with fluorocarbon-extracted brains homogenized in 8.5% sucrose. Mouse brain- and reference cell culture-derived antigens gave a line of identity with anti-BTV serum. Extracts of noninfected brains were nonreactive. ID tests on field-collected bovine sera, comparing the two types of antigen, resulted in only 73% agreement due to a greater sensitivity of cell culture-derived antigen. A 70.5% agreement resulted when comparing mouse brain-derived antigen in ID tests with complement fixation tests, the latter being least sensitive. ID test results with sera from experimental sheep gave 95.9% agreement between cell culture- and mouse brain-derived antigens. Between ID, which detects antibody to the BTV common or group antigen, and virus neutralization, which detects type-specific antibody, the agreement was 71.4% with postchallenge sera. Data from pre- and postinjection sera, however, indicate the possible activity in Texas of viruses other than International BTV Types 10, 11, 13, and 17.     

PLAY-DOH® AND WATER-SOAKED GAUZE SPONGES AS ALTERNATIVE BOLUS MATERIAL FOR COBALT-60 TELETHERAPY

A study was performed to determine if carefully made boluses of either Play-Doh, or water-soaked cotton gauze sponges differed from the commercial bolus material, Superflab, in producing maximum radiation dose when irradiated with cobalt-60 photons. The radiation doses were measured with thermoluminescent dosimeters calibrated to be accurate for cobalt-60 photon energies at doses less than 10.0 cGy. The resulting radiation doses were similar when using Play-Doh, water-soaked sponges, or Superlab. Doses resulting from Play-Doh boluses more consistently approximated those of Superflab. The results of this study suggest that either Play-Doh or water-soaked cotton gauze sponges can suffice as material for carefully made bolus for cobalt-60 teletherapy.     

Serologic study of the incidence and prevalence of bluetongue infections in cattle in the Mexican states of Nuevo Leon,Tamaulipas, Coahuila and San Luis Potosi

Serum samples from 2156 cattle in 40 herds in northeastern Mexico were tested for antibody activity to bluetongue virus. In addition, animals from 5 other herds were sampled each month to determine when new infections were occuring. Prevalence rates ranged from 7 to 100%, with a herd average of 42%. New infections occurred on each of the five ranches sampled monthly. Attack rates for the study period were 9, 63, 22, 18 and 57%.     

A comparison of end-tidal halothane concentrations measured at proximal and distal ends of the endotracheal tube in the horse.

Measurements (n = 126) of end-tidal halothane concentrations were taken from 21 horses anesthetized for routine and emergency surgery. One hundred five paired values allowed comparison of gas samples taken near the oral end of the endotracheal tube (Y1) to samples obtained at the cuffed end of the endotracheal tube (Y2). Twenty-one paired readings were assessed to compare samples taken 25 cm beyond the cuffed end of the tube (Y3) to samples from Y1. Measurements were made at all locations at 15-minute intervals starting 30 minutes after beginning halothane. All measurements were made in triplicate at end-expiration, and both sites were sampled within 1 minute of each other. Halothane concentration was measured by rapid infrared analysis with a gas sampling rate of 150 ml/min and displayed as a digital reading. Calibration of the machine was checked regularly. The difference between readings (Y1-Y2 or Y1-Y3 = Sdif) was tested using general linear models and a significance level of p less than 0.05 was used. The variable Sdif was analyzed with respect to time, mode of ventilation, and type of recumbency; no effects of these variables were detected. The mean values (+/- SD) of 105 readings for Y1 and Y2 were 2.41 vol% (+/- 0.49) and 2.39 vol% (+/- 0.49) respectively, and the Pearson's correlation coefficient (Y1 vs Y2) was 0.96. The mean values (+/- SD) of 21 measurements for Y1 and Y3 were 2.31 vol% (+/- 0.27) and 2.32 vol% (+/- 0.28) respectively and the Pearson's correlation coefficient (Y1 vs Y3) was 0.98.     

Type-I diabetes mellitus in a bull

Although metabolic disorders are a frequent concern in cattle, they are not commonly recognized in bulls. The combination of hyperglycemia, acetonemia, ketonuria, and glycosuria in a bull was highly suggestive of diabetes mellitus. This uncommon diagnosis was confirmed by results of intravenous glucose tolerance testing. Results of the test and serum insulin values were further able to classify the disease in this bull as type-I diabetes mellitus.     

Idiopathic renal haematuria in an Egyptian Arabian stallion

A 17-year-old Egyptian Arabian stallion was presented for haematuria and blood clots in the urine of 4 days’ duration. During micturition, haematuria was noted mid-stream with passage of blood clots occurring at the end of urination. Physical examination findings were unremarkable aside from pale mucous membranes. Cystoscopic examination revealed intermittent passage of frank blood (with clots) from the left ureteral orifice compared to grossly normal-appearing urine issuing from the right ureteral orifice. Transcutaneous ultrasonographic evaluation of the right kidney yielded normal findings while the left kidney exhibited pyelectasia, a decreased cortico-medullary ratio, and markedly increased echogenicity of the renal pelvis. Diagnosis of idiopathic renal haematuria was confirmed at necropsy.     

Effects of autogenous cancellous bone on healing of homogenous cortical bone grafts

A comparative clinical and histological study was made of the effects of autogenous cancellous grafts on the rate of healing of homogenous cortical bone grafts in dogs: their right foreleg received homogenous bone grafts and their left foreleg received pre-drilled homogenous bone grafts filled with autogenous cancellous bone. Histologically, the use of homogenous cortical grafts with pre-drilled holes and autogenous cancellous bone appeared to accelerate reorganization and development of these grafts. This was seen particularly 1–2 months post-operatively and at nine months when the graft in the left leg was made up of spongy bone marrow; whereas the right leg graft still contained compact dead bone and the marrow was filled with fibrous tissue.     

Rhodococcus equi: equine neutrophil chemiluminescent and bactericidal responses to opsonizing antibody

The opsonic capacity of serum containing R. equi-specific antibody was compared with antibody-deficient sera using luminol-dependent chemilumenscence (LDCL) and bactericidal assays. These assays incorporated peripheral blood polymorphonuclear neutrophilic leukocytes (PMNL) exposed to R. equi opsonized with neonatal equine pre-colostral serum (control) or serum from foals with R. equi infections (principal). All sera were complement inactivated at 56 degrees C for 30 min. Bacteria were obtained from the lung of a foal with R. equi pneumonia. Neutrophils were obtained from one adult horse for LDCL and another for bactericidal assays. Chemiluminescence of PMNL exposed to R. equi opsonized with control or principal sera was measured in a liquid scintillation counter. Mean peak LDCL within 1 h was significantly (P less than 0.01) higher with principal sera (2.4 X 10(5) cpm) than with control sera (0.018 X 10(5) cpm). A radioisotope bactericidal assay was used to determine the effect of control or principal sera on PMNL capacity to kill R. equi. Mean peak percent kill of R. equi by PMNL within 2 h was significantly (P less than 0.01) higher with principal sera (95.2%) than with control sera (54.6%). Enzyme-linked immunosorbent assay (ELISA) values for R. equi-specific antibody were determined on all sera. Mean ELISA values were significantly (P less than 0.01) higher for principal sera (71.8) than for controls (0.0). This investigation documents the presence and biological effectiveness of opsonic activity in complement-inactivated sera from foals with R. equi infections and R. equi-specific antibody.