Fatal pentastomiasis in captive African dwarf crocodile hatchlings (Osteolaemus tetraspis).

Six eggs from a captive African dwarf crocodile (Osteolaemus tetraspis) nest were artificially incubated. Two abnormal hatchlings with incomplete absorption of their yolk sacs died within 48 hr of hatching. No parasites were detected grossly or histologically in either hatchling. The remaining four apparently healthy hatchlings died without clinical signs at 3 wk of age, 1 wk after being fed live wild-caught fish and commercially raised goldfish. Necropsy revealed multiple white small wormlike organisms within the lungs, liver, and gastrointestinal tract of all four hatchlings. Histopathologic cross sections suggested that pentastomiasis was the cause of death, and whole parasites were identified as Sebekia mississippiensis. This infection was probably contracted by ingestion of live fish intermediate hosts infected with nymphal parasites. Avoiding the use of infected live fish or untreated fish products can prevent mortality of hatchling crocodilians caused by S. mississippiensis within zoological collections.     

Diagnosis of suspected hypovitaminosis A using magnetic resonance imaging in African lions (Panthera leo)

Vitamin A deficiency is described in captive lions. Ante mortem diagnosis can either be made by serum analysis or liver biopsy, both of which may be problematic. This study utilised magnetic resonance imaging to identify vitamin A deficiency in lions with relatively mild clinical signs, which could otherwise be attributed to numerous other neurological conditions. Magnetic resonance imaging is a non-invasive, reliable diagnostic tool to demonstrate pathology typically associated with this condition. To accommodate varying lion ages and sizes, a number of cranium and brain measurements were compared with that of the maximum diameter of the occular vitreous humor. Occular ratios of the tentorium cerebelli osseum and occipital bone were most reliable in diagnosing the thickened osseous structures characteristic of hypovitaminosis A. The ratio of maximum:minimum dorsoventral diameter of the C1 spinal cord was also of value.     

Commercial crocodile farming in Botswana

A survey-based study was carried out to assess the state of crocodile farming in Botswana. A prepared, structured questionnaire was dispatched to crocodile farmers based on a directory provided by the Fisheries section of the Department of Wildlife and National Parks in the Ministry of Environment, Wildlife and National Parks. The oldest farm was established in 1986. An average of three farms have been in operation since then, all of which obtained their stock from the Okavango and Thamalakane rivers in Botswana. The current stock averages 5 419 animals as follows: breeders 4%, hatchlings 56%, and growers 40%. The average clutch size and average hatchability were 47 eggs/clutch and 67% respectively. Mortality among hatchings and growers averaged 8.3% up to 12 weeks of age. Only one farm encountered some problems with Salmonella and fungal infections of the belly. Raw skins are sold to South Africa as a result of the absence of a tannery. Crocodile farming should be encouraged in Botswana since a good market for crocodile products already exists.     

The pathology of blindness in new-born calves caused by hypovitaminosis A

Blindness attributed to vitamin A deficiency afflicted 47 out of 197, and 15 out of 29 new-born dairy calves on 2 farms. Other clinical signs included doming of the forehead, thickening of the carpal joints, incoordination and weakness. Gross lesions in 8 of the calves examined consisted in hydrocephalus and thickened occipital and sphenoid bones. In 4 of these calves the optic nerves were constricted as a result of a reduction in size and dorsoventral narrowing of the optic canals. Microscopical changes in the optic nerves were characterized by necrosis, demyelination and fibrosis. Oedema or gliosis of the optic disc occurred in some of the calves. Retinal lesions included atrophy and gliosis of the ganglion cell layer and the nerve fibre layer. Three of the calves showed focal retinal dysplasia with occasional rosette formation.     

一起皖西白鹅内脏型合并关节型痛风的病例报告

本文报道了一起雏鹅痛风病例。对患鹅进行发病情况调查、临床症状观察、病理解剖和实验室检查,并分析了饲料成分。结果发现,雏鹅共有2300只,5日龄起发病,死亡率19.6%。患鹅食欲下降或废绝,排白色稀便,跛行甚至腿瘫,跗关节肿大,严重者死亡。病理剖检发现患鹅关节腔、内脏表面、肾脏和输尿管内有白色尿酸盐沉积。饲料粗蛋白含量为20.5%。与同群未发生临床痛风鹅相比,患鹅血清尿酸、尿素氮和肌酐显著升高(P0.05),而乳酸脱氢酶无显著差异(P0.05)。患鹅肝组织有坏死灶和炎性浸润,肝细胞索紊乱,肝细胞脂肪变性;肾组织内可见许多结晶,肾小管上皮细胞坏死、空泡变性、脱落,肾小球萎缩;心肌结构紊乱、有炎性浸润,心肌纤维间距增大。未发生临床痛风鹅的内脏也发生较轻微的病变,血清尿酸值较高,处于亚临床状态。结合发病情况、临床症状、病理剖解和实验室检查,判断该起鹅痛风是由饲喂高蛋白饲料,同时缺乏青绿饲料引起的内脏型痛风合并关节型痛风。     

雏鹅痛风病的诊断

为了探究江苏某鹅场患痛风病鹅的发病原因,笔者采集患病雏鹅病料进行了实验室检测及病原的分离鉴定,发现病鹅为星状病毒感染,结合流行病学、临床症状、剖检病理变化等,最终确诊导致痛风病的病原为鹅星状病毒,分析了病因并提出了防控措施。     

Clinical and pathological findings associated with congenital hypovitaminosis A in extensively grazed beef cattle

Objective   To determine the cause of exceptionally high mortality (41.4%) in perinatal calves on a beef cattle property 50 km south-west of Julia Creek in north-western Queensland.
Design   Investigations were based on clinical assessment of affected calves and laboratory analysis of pre- and postmortem specimens taken from 12 calves aged from 6 to 36 h of age.
Methods   Associations between gross and histopathological findings and biochemical analyses conducted on serum and tissue samples were examined in relation to clinical observations.
Results   Clinical signs varied, but commonly included mild to severe ataxia, difficulty finding a teat and sucking, blindness (partial or complete, as judged by avoidance of obstacles) and depression with prominent drooping of the head. Gross and histopathological findings included herniation of the cerebellar vermis through the foramen magnum, squamous metaplasia of interlobular ducts in the parotid salivary glands and Wallerian degeneration of the optic nerves. Biochemical analysis of serum and liver samples available from four of the calves revealed low or undetectable levels of both vitamin A and vitamin E.
Conclusion   Although vitamin E is known to have a sparing effect on vitamin A, the role (if any) played by deficiency of this vitamin was uncertain. The combination of clinical signs, postmortem findings, histopathological features and biochemical findings indicate that gestational vitamin A deficiency was highly likely to have been an important contributor to perinatal calf mortalities in this herd.     

Hypocalcemia and hypovitaminosis D in dogs with induced endotoxemia

Background

Hypocalcemia is a documented electrolyte disturbance in people and animals with sepsis, but its mechanism is poorly understood.

Objective

To investigate mechanisms of hypocalcemia in dogs with experimentally induced endotoxemia.

Animals

Six healthy mixed breed dogs were included in this nonrandomized, placebo‐controlled, crossover study.

Methods

Dogs initially were injected with placebo (0.9% NaCl; 1 mL, IV) and then lipopolysaccharide (LPS; 2 μg/kg, IV) after a 5‐day washout period. Blood and urine samples were collected for measurement of serum total calcium (tCa), ionized calcium (iCa), total magnesium (tMg), ionized magnesium (iMg), parathyroid hormone (PTH), 25‐hydroxyvitamin D (vitamin D), venous blood gases, and fractional excretion (FE) of calcium.

Results

After LPS administration, body temperature increased and blood pressure decreased. Both iCa and tCa decreased (P < .01), but iMg was not significantly different between control and LPS treatments. PTH concentrations increased (P < .01) and vitamin D concentrations decreased (P < .01). Venous pH, bicarbonate, base excess, and blood glucose also decreased (P < .01). Urine tCa concentration was below the limit of detection for all dogs after LPS administration.

Conclusions

Hypocalcemia occurs during endotoxemia in dogs and is associated with hypovitaminosis D. Hypomagnesemia, hypoparathyroidism, alkalosis, and increased calciuresis are not associated with hypocalcemia in endotoxemic dogs.     

The effect of hypovitaminosis A on the pathogenesis of Pasteurella multocida in turkeys

It has been proposed that Pasteurella multocida can invade the host tissues via the mucous membrane. Vitamin A (VitA) deficiency has been associated with mucous membrane damage, such as squamous metaplasia. The objective of this study was to determine the early stages in the pathogenesis of P. multocida in VitA-deficient turkeys and clinically healthy turkeys. Fifteen-week-old VitA-deficient and clinically healthy turkeys were inoculated with P. multocida P-1059, a virulent strain, and the portal of entry, invasion, and localization of P. multocida were studied by microbial examination of the trachea, liver, and lung and histologic examinations of internal organs. Higher mortality was found in VitA-deficient turkeys. Pasteurella multocida was first reisolated from the trachea, secondarily from the liver and blood, and finally from the lung in both groups. Invasion of P. multocida into tissues occurred between 3 hr and 24 hr postinoculation in both groups. Our findings suggest that altered membrane integrity in VitA-deficient birds did not appear to change the time course of the systemic spread of P. multocida infection in turkeys and that the increased mortality seen in the VitA-deficient turkeys may be associated with immune system impairment.