Results of grid keratotomy, superficial keratectomy and debridement for the management of persistent corneal erosions in 92 dogs

Ninety-two cases of persistent corneal erosions in dogs were analyzed for breed, gender, age and which eye was affected. The results of the treatment of 92 persistent corneal erosions in dogs by superficial keratectomy (SK), grid keratotomy (GK), or debridement with a sterile dry cotton swab are presented. These techniques gave better rates of healing than have been previously reported. All cases of persistent corneal erosions healed in this study. However, it must be noted that three cases treated with debridement only failed to heal after several treatments and were eventually treated with SK. After one procedure 80 out of 92 (87%) had healed. After one procedure, 63% of cases treated with debridement healed, 100% of cases treated with SK healed, and 85% of cases treated with GK healed. At the first postoperative visit, 88% (21/24 cases) of ulcers treated by SK had healed, and 75% (39/52 cases) of ulcers treated by GK had healed. Only 25% of the persistent corneal erosions had healed at the first visit after debridement. All 24 cases of persistent corneal erosions treated with SK healed after one treatment in a mean +/- SD of 9.3 +/- 3.9 days (median of 7 days). Fifty-two cases were managed with GK; 44 (83%) of these healed with one procedure and eight cases required a second GK procedure to resolve. A mean +/- SD of 13.4 +/- 5.1 days (median of 11.5 days) following GK was required for the persistent corneal erosions to heal. Nineteen cases were initially managed by debridement with a dry cotton swab under local anesthesia. Sixteen out of these 19 debridement cases healed (giving an overall healing rate of 84%) in a mean +/- SD time of 23.4 +/- 11.1 days (median 21.5). There were three cases that did not heal with debridement. These cases were debrided at 10-20 day intervals for 30-60 days, and were then treated with SK. Two of these cases healed within 7 days, the other case required 18 days to heal. Sixty-three per cent of persistent corneal erosions treated with debridement healed after one procedure; however, only four out of 19 cases (21%) were healed at the first revisit. Complications were rare: corneal edema occurred in two cases following multiple GK, and excessive granulation tissue in one case was managed with a SK. There was the occurrence of an ulcer adjacent to the surgery site in four cases, two cases following GK and two cases following SK.     

Effects of Ketamine on the Equine Electroencephalogram During Anesthesia With Halothane in Oxygen

OBJECTIVE: To investigate the effects of ketamine on the electroencephalogram (EEG) of the horse. STUDY DESIGN: Prospective experimental study. ANIMALS: Eight Welsh mountain pony geldings weighing between 280 and 330 kg, 5 to 9 years old. METHODS: During halothane anesthesia at an end-tidal halothane concentration between 0.75 and 0.85%, the EEG frequency power spectrum and the auditory evoked potential were recorded while an infusion of ketamine was given. Ketamine 200 mg was infused over 5 minutes in 8 ponies. The effects of ketamine on the EEG were recorded continuously during the infusion and for a further 55 minutes. RESULTS: The ketamine infusion produced a plasma ketamine concentration that was significantly greater than the baseline until 7 minutes after the start of the infusion. The highest recorded ketamine concentration was 4.2+/-1.1 microg/ml recorded at 5 minutes after the start of the infusion. The spectral edge and median frequency of the EEG and the midlatency of the auditory evoked potential were compared with those recorded before the start of the infusion. The spectral edge, median frequencies and mid-latency of the auditory evoked potential were reduced by 21+/-13%, 31+/-20% and 19+/-36% respectively (mean +/- SD). Only the reduction in spectral edge frequency reached statistical significance. CONCLUSIONS: These results compared with those from other anesthetic and sedative agents suggest that the spectral edge frequency is an indicator of general central nervous system depression whereas the median frequency may be an indicator of antinociception.     

Pulmonic stenosis in dogs: balloon dilation improves clinical outcome

Medical records of 81 dogs with severe pulmonic stenosis from 2 referral centers were examined retrospectively. Forty dogs underwent balloon valvuloplasty (BV), which was performed by 1 operator, whereas 41 did not. The mean age at latest follow-up was 41.5 months. A statistical comparison of the clinical outcome and survival was performed. Dogs revealing clinical signs at presentation showed a 16-fold increase in risk of death compared with asymptomatic dogs (P < .001). Statistical analyses demonstrated that an increase of 1 mm Hg in transstenotic pressure gradient (PG) at presentation was associated with a 3% increase in hazard rate (P < .001). Thirty-seven dogs survived BV with a median reduction in PG of 46%. The median preoperative PG was 120 mm Hg, and median PG 24 hours postoperatively was 55 mm Hg with a median of 55 mm Hg 6 months post-BV. Twenty (49%) of the non-BV (NBV) dogs remained asymptomatic at last follow-up. Fourteen (34%) of the NBV dogs died or were euthanized because of heart disease related to pulmonic stenosis. Twelve of these dogs died suddenly, whereas only 1 of the BV dogs died suddenly. After adjusting for PG, clinical signs at presentation, and age, BV or dilation was associated with a 53% reduction in hazard rate (P = .005). This study indicates that BV, when performed by an experienced operator, appears to be successful both in alleviating clinical signs and in prolonging survival in dogs with severe pulmonic stenosis.     

The implications of land preparation, crop establishment method and weed management on rice yield variation in the rice-wheat system in the Indo-Gangetic plains

The implications of adopting alternative seeding methods for rice and wheat establishment were examined at three geographically separate sites in the rice-wheat system of the Indo-Gangetic plains, across northern India. Rice yields in cultivated plots, established by either wet or dry seeding methods, were evaluated in comparison to yields from zero-tillage plots and under conventional transplanting methods. In the same trials, the effects of crop establishment methods in wheat were assessed both on wheat yields and rice yields. Rice crop establishment methods markedly influenced the emerging weed flora and attainable yields were measured in relation to intensity of weed management. Over four years, average rice grain yields in the absence of weed competition were greatest (6.56 t ha⁻¹) under wet seeding (sowing pre-germinated rice seed on puddled soil), and similar to those from transplanted rice (6.17 t ha⁻¹) into puddled soil, and dry seeded rice after dry soil tillage (6.15 t ha⁻¹). Lowest yields were observed from dry seeded rice sown without tillage (5.44 t ha⁻¹). Rice yield losses due to uncontrolled weed growth were least in transplanted rice (12%) but otherwise large (c. 85%) where rice had been sown to dry cultivated fields or to puddled soil, rising to 98% in dry seeded rice sown without soil tillage. Weed competition reduced multiple rice yield components, and weed biomass in wet seeded rice was six-fold greater that in rice transplanted into puddled soil and twice as much again in dry seeded rice sown either after dry tillage or without tillage. Wheat grain yields were significantly higher from crops sown into tilled soil (3.89 t ha⁻¹) than those sown without tillage (3.51 t ha⁻¹), and also were elevated (5% on average) where the soil had been dry cultivated in preparation for the previous rice crops rather than puddled. The method of wheat cultivation did not influence rice yield. Soil infiltration rates in the wheat season were least where the land had been puddled for rice (1.52 mm h⁻¹), and greater where the soil had been dry-tilled (2.63 mm h⁻¹) and greatest after zero-tillage (3.54 mm h⁻¹).These studies demonstrated at research managed sites across a wide geographic area, and on farmers’ fields, that yields of dry seeded rice sown after dry cultivation of soil were broadly comparable with those of transplanted rice, providing weed competition was absent. These results support the proposition that direct seeding of rice could provide an alternative to the conventional practice of transplanting, and help address rising costs and threats to sustainability in the rice-wheat rotation. Further, analysis of patterns of long-term rainfall data indicated that farmers reliant on monsoon rainfall could prepare fields for dry direct seeded rice some 30 days before they could prepare fields for either transplanting or seeding with pre-germinated seed. Dry, direct seeding of rice contributes a valuable component of an adaptive strategy to address monsoonal variability that also may advance the time of wheat establishment and yield. Whilst the results illustrate the robustness, feasibility and significant potential of direct seeded rice, they also highlight the critical nature of effective weed control in successful implementation of direct seeding systems for rice.     

Anticoccidial Vaccination of Broiler Chickens in Various Management Programmes: Relationship between Oocyst Accumulation in Litter and the Development of Protective Immunity

Paracox anticoccidial vaccine was administered to a 7-day-old flock of commercial broiler breeder stock subsequently reared to point-of-lay in the same house. For comparison, three subgroups of another flock of broiler breeders were also vaccinated with Paracox at 7 days of age, reared to 42 days and then transferred to new litter on another farm until point-of-lay. The first subgroup received no further treatment, but the second and third each received a second vaccination with Paracox, either immediately after transfer to the new litter or 42 days after transfer. Using an Eimeria necatrix model, protective immunity was demonstrated by virulent challenge of samples of birds from all groups by the age of 37–40 days (30–33 days after the first vaccination), and was maintained to at least 122–125 days of age, whether the birds remained on the same litter or were transferred to another farm, and whether they received one or two anticoccidial vaccinations. Therefore, there is no disadvantage in transferring birds onto new litter 35 days after a single Paracox vaccination, nor is there any advantage in giving a second vaccination after such a transfer. Vaccinated birds seeded the new litter with oocysts, despite being clinically immune to coccidiosis. A supplementary laboratory experiment showed that birds vaccinated at 8 days of age passed almost no oocysts after a second vaccination at 43 days of age. This indicated that they were not only protected against clinical coccidiosis, but were almost solidly immune to a homologous infection 5 weeks after a single vaccination. Nevertheless, oocysts appeared in the litter of all four groups of commercial breeders throughout the trial, showing that wild-type heterologous infections occurred whether the birds were transferred to new litter or not, but these did not overwhelm the acquired protective immunity and cause clinical coccidiosis.     

Carcinoma of the apocrine glands of the anal sac in dogs: 113 cases (1985-1995)

OBJECTIVE: To characterize the signalment, clinical signs, biological behavior, and response to treatment of carcinoma of the apocrine glands of the anal sac in dogs. DESIGN: Retrospective study. ANIMALS: 113 dogs with histologically confirmed carcinoma of the apocrine glands of the anal sac. PROCEDURE: Data on signalment, clinical signs, and staging were reviewed and analyzed along with treatment modality for potential association with survival time. RESULTS: Sex distribution was approximately equal (54% female, 46% male). One hundred four dogs underwent treatment consisting of surgery, radiation therapy, chemotherapy, or multimodal treatment. Median survival for treated dogs was 544 days (range, 0 to 1,873 days). Dogs treated with chemotherapy alone had significantly shorter survival (median, 212 days) than those receiving other treatments (median, 584 days). Dogs not treated with surgery had significantly shorter survival (median, 402 days) than those that underwent surgery as part of their treatment (median, 548 days). Dogs with tumors > or = 10 cm2 had significantly shorter survival (median, 292 days) than dogs with tumors < 10 cm2 (median, 584 days). Hypercalcemia was identified in 27% (n = 29) of dogs, and those dogs had significantly shorter survival (median, 256 days), compared with those that were normocalcemic (median, 584 days). Dogs with pulmonary metastasis had significantly shorter survival (median, 219 days) than dogs without evidence of pulmonary metastasis (median, 548 days). CONCLUSIONS AND CLINICAL RELEVANCE: Unlike most previous reports, this study revealed an approximately equal sex distribution, and results suggest a more favorable prognosis.     

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.