Evaluation of Canine-Derived Fibrin Sealant as a Hemostatic Agent

The purpose of this study was to determine whether canine-derived fibrinogen concentrate applied with bovine thrombin was a safe and effective topical hemostatic agent. A canine liver biopsy model was selected to test this product. Cryoprecipitate was prepared from frozen canine plasma using two freeze/thaw/centrifugation cycles. Six healthy adult dogs (weighing more than 18 kg) were used in the fibrin sealant study, and an additional three dogs were used as controls for the liver biopsy. A 1 × 3 cm liver biopsy specimen was obtained, digital pressure was applied to reduce bleeding, and the fibrinogen concentrate was immediately sprayed on the bleeding surface simultaneously with bovine thrombin (1,000 IU/mL). The mean ± standard error of the mean (SEM) blood pressure at time of biopsy was 98 ± 9 mm Hg, and the rate of hemorrhage from the cut liver edge was 8.0 ± 1.1 mL/min. The total blood loss during fibrin sealant application was 37 ± 9 mL and total time for hemostasis was 5.5± 1.3 minutes. There was no additional hemorrhage after application of the fibrin sealant. In the three control dogs, fibrin sealant was not applied and only digital compression was used to decrease hemorrhage. Before digital compression, the rate of hemorrhage from the cut liver edge was 13.1 ±3.1 mL/min. Bleeding had not stopped after 10 minutes of compression and the mean postcompression rate of hemorrhage was 4.0 ± 2.6 mL/min. Signs of secondary bleeding after fibrin sealant was applied were not evident during the immediate postoperative period or over the next 14 days. The coagulation profile, alanine amino transferase (ALT), alkaline phosphatase (AP), and bile acids were not significantly different on day 14 from preoperative values, suggesting that the liver was only mildly affected. The dogs were euthanatized and gross and histological examinations of the biopsy site were performed on day 14. There were minimal or no adhesions at the biopsy site. In all dogs, the hepatic capsule was less than 1 mm thick and histological signs of secondary bleeding, hepatocellular damage, thrombosis, infection, or inflammation were not observed. In this study, canine-derived fibrin sealant was a safe and effective topical hemostatic agent.     

Zearalenone intoxication of pigs

Mycotoxicosis due to ingestion of zearalenone was detected on 2 pig farms on the Atherton Tableland in northern Queensland. In one herd of 200 pigs, this resulted from feeding maize which had been stored with a high moisture content. In the other herd of 1400 pigs, it resulted from feeding sorghum grain which was rain affected before harvest. Concentrations of zearalenone in the feeds ranged up to 8 mg/kg. Most prepubertal gilts in the herds displayed enlarged teats and signs of oestrus such as having red, swollen vulvas. In several cases both rectal and vaginal prolapses occurred. On one of the farms, 25 pigs died as a direct result of prolapses. Autopsy of a 3-month-old gilt revealed apparently enlarged ovaries and uterine horns. Sows and boars seemed to be unaffected. Four gilts failed to conceive following mating during the period of zearalenone ingestion, but apart from this and the deaths from prolapses, production of the herds appeared to be unaffected.     

Computed tomographic assessment of vascular invasion and resectability of mediastinal masses in dogs and a cat

AIMS: To assess the sensitivity of non-angiographic contrast-enhanced computed tomography (CT) to determine the presence of vascular invasion of cranial mediastinal masses in dogs and a cat, and to evaluate the association between vascular invasion and peri-operative mortality.

METHODS: A retrospective study was conducted on 25 dogs and one cat. CT scans were completed with slices ranging from 2 to 10 mm. CT images were evaluated by a board-certifi ed radiologist blinded to previous diagnoses and surgical fi ndings. Each CT study was evaluated for vascular invasion, defi ned as disruption of the vessel wall and extension of the mass into the vessel lumen. Data retrieved from the surgery reports included surgical approach, whether vascular invasion was present, the surgeon's decision on operability, and post-operative complications.

RESULTS: Computed tomographic evaluation revealed 25/26 masses had no evidence of vascular invasion. During surgical exploration, 10/26 masses were found to invade major regional vasculature; the cranial vena cava (CVC) was the vessel most commonly invaded (7/10 animals), and 4/7 (57%) patients with invasion of the CVC were euthanised or died in the perioperative period, from surgical or disease-related problems, which was signifi cantly higher than patients without vascular invasion (p=0.045).

CONCLUSIONS: Non-angiographic contrast-enhanced CT was signifi cantly less sensitive for detecting vascular invasion of cranial mediastinal masses when compared with surgical evaluation. If the CVC was invaded by a tumour there was a signifi cant risk of death peri-operatively when compared with non-invasive cases.

CLINICAL RELEVANCE: Due to the signifi cantly higher mortality risk associated with invasion of the CVC, a more sensitive method than CT should be investigated to determine vascular invasion of mediastinal masses pre-operatively.     

Multiple resistance in Trichostrongylus and Teladorsagia (Ostertagia) in goats to oxfendazole,levamisole and moxidectin,and ineffi cacy of trichlorphon

Extract

We wish to report the identification, from a flock of commercially-traded goats, of nematode worms that we have been unable to kill using the anthelmintic groups currently registered for use in sheep in New Zealand.     

Anthelmintic resistance and management of nematode parasites on beef cattle-rearing farms in the North Island of New Zealand

AIM: To provide information on current farmers’ opinions and farming practices thought to be related to anthelmintic resistance, and to test for associations between the presence of anthelmintic resistance and management practices on beef cattle- rearing farms in the North Island of New Zealand.

METHODS: A study using an interview-based questionnaire about management of internal parasites was conducted on 62 beef cattle-rearing farms in the North Island of New Zealand, using case-control analyses to test for associations between management practices and the presence or absence of resistance to ivermectin or albendazole. Resistance was inferred from faecal nematode egg count (FEC) reduction (FECR) tests (FECRTs) when there was <90% reduction in FEC 7-10 days after treatment of calves <12 months of age.

RESULTS: Of the 59 farmers who completed the questionnaire, most (n=40) ranked parasites highly, and at about the same level as quality and quantity of feed, as important production-limiting factors for their enterprises. In contrast, anthelmintic resistance was not perceived to be a problem on 13 farms, and its importance was rated low on 24, moderate on 15, and high on only six farms. Despite all farms having planned parasite control programmes, there was heavy reliance on clinical signs of parasitism to determine frequency of treatments. About one in three farmers with beef breeder cows routinely treated their calves at marking, one in five treated mixed-age cows, and almost half treated rising 2-year-old cows before calving. One in four farmers used anthelmintics on calves on 8–12 occasions in their first year of life. Co-grazing with other species was rare, but follow-on grazing within 3 months after older cattle or sheep was common. On most farms, grazing cattle was restricted to part of the farm, a finding with implications for parasite control and persistence of larvae in refugia. Macrocyclic lactone (ML) anthelmintics or their combinations with other action families were currently, and for the past 5 years, used more frequently than benzimidazoles and levamisole, and benzimidazole-levami- sole combinations. The prevalence of resistance to ivermectin was high (82%) and no plausible model of associations could be constructed from the data. The prevalence of resistance to albendazole was 60%, and the risk of resistance increased as the number of rising 1-year-old cattle present mid-winter increased, and decreased as the number of breeding cows >2 years old present mid-winter increased.

CONCLUSION: It is clear that in practice anthelmintic resistance is a secondary consideration to obtaining productivity advantages from the use of anthelmintics in beef cattle. Farmers’ opinions were divided on many issues and the overall impres- sion was of confused and diverse thinking regarding the principles of the use of anthelmintics. The overall outlook regarding anthelmintic resistance in cattle is bleak unless the need for integrated and long-term research activities is acted upon soon.     

Stock structure of blue threadfin Eleutheronema tetradactylum across northern Australia as inferred from stable isotopes in sagittal otolith carbonate

Abstract Stable isotopes of δ¹⁸O and δ¹³C in sagittal otolith carbonates were used to determine the stock structure of the polynemid Eleutheronema tetradactylum (Shaw) across tropical northern Australia, where this species is an important component of inshore commercial and recreational fisheries. Stable isotopes from the sagittal otolith carbonate of 470 fish from 11 discrete locations across western, northern and eastern Australia were sampled between 2007 and 2009. Analysis of these stable isotopes revealed different location‐specific signatures, indicating strong population subdivision. The significant differences in the isotopic signatures of E. tetradactylum demonstrated that there is unlikely to be substantial movement of fish between these locations. The spatial separation of these populations indicates a complex fine spatial scale stock structure across northern Australia, with at least 11 stocks or management units present. The population subdivision of E. tetradactylum was evident along expansive stretches of open beach systems and within coastal embayments with no physical barriers such as headlands. These results indicate that optimal fisheries management will require a review of the current spatial arrangements, particularly the potential for localised depletion of stocks on small spatial scales.     

长江口沿岸碎波带刀鲚仔稚鱼的数量分布

2007年5-10月,每月大潮期间在长江口沿岸碎波带13个站位用小型拖网各采样1次.195次拖网共采获刀鲚(Coilia nasus)仔稚鱼9 358尾,体长范围为3.0～61.2mm,优势体长为6.0～25.0 mm,以10.0～16.0 mm的弯曲期和13.0～21.0 mm的后弯曲期仔鱼为主.采获数量以7月最高,占总数55.0%,主要分布在长江口南支和北支上游,有3个站位(St.5、St.7、St.10)数量较高.其中有1个站位(St.7)刀鲚仔鱼的平均体长按月呈递增趋势,表明刀鲚仔稚鱼有利用沿岸碎波带作为早期生长场所的习性.根据刀鲚仔稚鱼在长江口沿岸碎波带分布和数量变动的调查结果,结合目前刀鲚成鱼资源量贫乏的现状,建议有关部门限制鳗苗定置网等作业,并加强对沿岸碎波带保育场的保护.     

宫内生长迟缓仔猪T细胞的发育研究

研究旨在探讨从出生到断奶不同日龄宫内生长迟缓(IUGR)猪T细胞的发育变化情况。选用体重相近和配种期相同的达兰初产妊娠母猪30头,分娩时从每窝仔猪中挑选1头正常体重猪和1头IUGR猪,分别在1、7、14、21、28日龄时屠宰取胸腺,分离T细胞,通过流式细胞仪测定CD3、CD4、CD8T细胞的数量,每个日龄6个重复。结果表明:出生后第1天IUGR仔猪与正常仔猪的CD4+CD8+细胞(双阳性T细胞)占总T细胞的百分比差异显著(P<0.05);出生后第7天IUGR仔猪与正常仔猪的CD4细胞占总T细胞的百分比差异极显著(P<0.01);后期各细胞亚群之间没有差异。结果提示,子宫内各种因素的综合影响能造成出生后早期IUGR仔猪T细胞亚群发育不完善,这就从T细胞亚群的发育方面解释了IUGR仔猪免疫力低的原因。     

Study of the population dynamics of dipterous stem-borer larvae of ryegrass swards under rotationally grazed or cut conditions

Observations made between 1980 and 1982 showed that dipterous stem-borers were more common in grazed than cut swards. The two forms of Oscinella frit were particularly prevalent in grazed swards but O. vastator was more evenly distributed and dominated the larval populations of the cut sward in 1981. The population dynamics of all species were probably affected by the number of days on which weather was suitable for high stem-borer adult activity. It was also found that stem-borer larval numbers could expand rapidly after periods suitable for high adult activity even when adult numbers had been low for long periods. Despite low numbers of O. vastator being present in winter 1981, their numbers increased markedly and built up to a large population which peaked in September 1981.