Intestinal surgery of adult cattle.

Surgical disorders of the gastrointestinal tract of cattle occur occasionally, and veterinarians are challenged to determine an accurate diagnosis and treatment for these conditions. Although surgical diseases most commonly occur in the forestomachs (dislocated abomasum, reticuloperitonitis) and the colons (cecal dilation), this article focuses n lesions in the small intestine (duodenum, jejunum, ileum).     

The use of salmonella vaccine in outbreaks of salmonellosis in sheep

Extract

Salmonellosis in sheep has become an increasingly important problem on fat lamb and better classes of hill country in southern Hawke's Bay. Outbreaks of the disease most commonly occur in mixed-age ewe flocks, but occasionally outbreaks occur in two-tooths. Most outbreaks occur during the months from January to April inclusive. The mortality rate varies between 2 and 5%, but may be higher if associated with gross errors in flock management. Many outbreaks are associated with mob-stocking techniques (up to 20 ewes per acre), used to clean up rank feed in pastures (unpublished data).     

Ixodes (Afrixodes) drakensbergensis n. sp. from domestic and wild animals in Natal, Republic of South Africa.

Ixodes (Afrixodes) drakensbergensis n. sp., is described from females, males, nymphs and larvae collected on a drag at Giant's Castle Nature Reserve, Natal, Republic of South Africa; it was also taken from an eland in the same area and from goats and a cow in the adjacent Tank Area 118. The occurrence of I. (A.) drakensbergensis on domestic animals suggests that it may be of economic importance in this area. Information is provided to separate the new species from other closely related Ixodes species that occur or may occur in this region.     

Physiologic effects of succinylcholine chloride in mechanically ventilated horses anesthetized with halothane in oxygen.

Succinylcholine chloride, administered to horses anesthetized with halothane in oxygen and mechanically ventilated, caused slight but significant (P less than 0.01) increases in heart rate. Significant alteration in mean arterial blood pressure did not occur, and there were clinically insignificant increases in serum K+ and C1- concentration. Cardiac dysrhythmia and myoglobinuria did not occur. Thus, effects of halothane anesthesia and mechanical ventilation prevented cardiac dysrhythmia and hypertension and greatly reduced the tachycardia generally associated with siccinylcholine administration.     

Radiographic signs of osteochondritis dissecans of the lateral ridge of the trochlea tali in the dog

Osteochondritis dissecans lesions of the lateral ridge of the trochlea of the talus occur infrequently and are difficult to diagnose. They occur mainly in the proximal or proximodorsal section of the lateral ridge of the trochlea and are best seen in the plantaromedial-dorsolateral oblique projection (with the X-ray beam angled 30 to 45^o from the vertical), and in the fully flexed and extended mediolateral projections. The flexed dorsoplantar projection using a horizontal beam is also useful.     

DIGITAL RADIOGRAPHY ARTIFACTS

Radiographic artifacts may mimic a clinical feature, impair image quality, or obscure abnormalities. With the development of digital radiography (DR), a new set of artifacts is introduced. Regardless of the technology, the classic technical errors that occur with film screen radiography still occur using DR. Artifacts created using computed radiography, DR, and incorrect image processing are discussed. Methods for correction of the artifacts are presented.     

A review of tendon injury: Why is the equine superficial digital flexor tendon most at risk?

Tendon injury is one of the most common causes of wastage in the performance horse; the majority of tendon injuries occur to the superficial digital flexor tendon (SDFT) whereas few occur to the common digital extensor tendon. This review outlines the epidemiology and aetiology of equine tendon injury, reviews the different functions of the tendons in the equine forelimb and suggests possible reasons for the high rate of failure of the SDFT. An understanding of the mechanisms leading to matrix degeneration and subsequent tendon gross failure is the key to developing appropriate treatment and preventative measures.     

出生前山羊延髓主要灰质核团的形成和发育

对从胚胎期第6周到出生前山羊的延髓主要灰质核团发育的组织学变化进行了系统研究。结果表明：（1）第6周山羊胚胎延髓处在组织发生末期和核团形成初期，是其内部核团构建的关键时期。（2）延髓内不同核团中的神经元发育变化在时间上有较大的差异，在同一核团内神经元胞体发育分化在时间上也有差异，即同一核团内较为成熟的神经元胞体的数量由少到多，细胞质内的尼氏小体也存在由少到多，由小变大的过程。（3）延髓灰质结构形成和神经元发育分化的规律：有些结构发生早，而神经元分化较晚，如下橄榄核、三叉神经脊束核和孤束核；有些结构发生略晚，但其中的神经元胞体分化和发育则较早，如舌下神经核、疑核及延髓的网状结构；有些结构发生早，神经元发育也早，如迷走神经背核。     

Autonomic and Cardiovascular Effects of Neuromuscular Blockade Antagonism in the Dog

Autonomic and cardiovascular changes were studied when neuromuscular blockade was antagonized in 96 dogs with one of eight anticholinesterase-antimuscarinic drug combinations. Neostigmine (50 or 100 micrograms/kg) was administered before or after atropine (40 micrograms/kg) or glycopyrrolate (10 micrograms/kg). The high dose of neostigmine (100 micrograms/kg) caused bradyarrhythmias, salivation, and signs of bronchosecretion when used with either antimuscarinic agent and irrespective of the administration sequence. The heart rate increased, but not significantly, when atropine was injected before either dose of neostigmine. This did not occur when this administration sequence was reversed. Arrhythmias and cardiovascular and autonomic changes did not occur when glycopyrrolate was injected before or after neostigmine at 50 micrograms/kg.     

Prions as the driving force in transmissible spongiform encephalopathies

Transmissible spongiform encephalopathies are degenerative disorders affecting the central nervous system (CNS) occurring in a variety of species. The causative agent is thought to be composed of an abnormal form of the host encoded prion protein (PrPC), termed PrPSc. The conformational change of PrPC into PrPSc can occur spontaneously, however, it can also be induced by PrPSc. Prion diseases such as bovine spongiform encephalopathy (BSE), scrapie and variant Creutzfeldt-Jakob-Disease (vCJD) are most likely caused by peripheral uptake of prions. The process by which prions proceed to the CNS following peripheral uptake is referred to as neuroinvasion. Infection with prions is thought to occur in two phases: After ingestion prions first replicate in lymphatic tissue and then gain access to the CNS via peripheral nerves. Studies looking at the biochemical and clinical characteristics of BSE and vCJD demonstrated that BSE is most likely responsible for vCJD in humans.     

Adverse drug interactions of importance in veterinary practice

Multiple drug therapy is often used in veterinary practice; occasionally, inappropriate combinations of drugs may be administered which interact to produce adverse responses. Such interactions may occur in vitro because of physically or chemically incompatible drugs having been mixed before administration or in vivo. A number of important in vitro incompatibilities concerning parenteral drugs are tabulated, consideration having been given both to problems attending the use of intravenous fluids as vehicles for their administration and to incompatibilities between the drugs themselves. Interactions which occur in vivo are also examined; these have been grouped according to the various mechanisms by which they occur.     

Equine castration: A review of techniques,complications and their management

Complications associated with castration occur commonly and, although the majority are mild and resolve easily, potentially life‐threatening complications can occur. The preoperative identification of risk factors for these complications can help the veterinarian to take the appropriate measures to reduce these risks. However, even with proper surgical technique, complications can occur. Therefore prompt recognition and initiation of appropriate therapy are essential to prevent further morbidity, death or lawsuits.     

LPS-induced sickness behavior is not affected by selenium but is switched off by psychogenic stress in rats

Veterinary Research Communications - Sickness behavior (SB) is considered part of the adaptive behavioral and neuroimmune changes that occur in response to inflammatory processes. However, SB is a...     

Adverse drug reactions in the horse

Adverse drug reactions occasionally occur in the horse. The majority can be anticipated and avoided. The practicing veterinarian should understand the various types of adverse reactions as well as their mechanisms so that should such a reaction occur, the practitioner can promptly recognize the problem and institute corrective measures.     

Effects of training on muscle composition in horses

Biopsy samples were obtained from the middle gluteal muscle of 10 Thoroughbred horses undergoing a commercial race-training program. Samples were obtained before the program began and again after 6 and 12 weeks of training. All horses had raced at least once by the 12th week of training. Serial sections of muscle were examined histochemically for myosin adenosinetriphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) preincubation, and then muscle fibers were identified as types I, IIA, IIB, or IIC. The oxidative capacity of individual fibers was assessed, using the reduced nicotinamide dinucleotide tetrazolium-reductase stain, and the number of intermyofibrillar capillaries adjacent to each fiber were counted after staining, using the alpha-amylase-periodic acid-Schiff technique. Biochemical analyses involved the fluorometric measurement of 3 enzymes--citrate synthase, 3-hydroxy-acyl coenzyme A dehydrogenase, and lactate dehydrogenase--as markers of end terminal oxidative, beta-oxidative, and glycolytic potentials, respectively. Changes in fiber-type percentages did not occur in response to training. There was a significant (P less than 0.01) increase in the percentage of type IIB fibers, having high nicotinamide dinucleotide-tetrazolium reductase staining after 12 weeks of training. Alterations in the number of capillaries adjacent to each fiber type did not occur during the training period. There were increases in the activities of both citrate synthase and 3-hydroxy-acyl coenzyme A dehydrogenase after 6 weeks (P less than 0.05) and 12 weeks (P less than 0.001) of training. Alterations in the activity of lactate dehydrogenase did not occur in response to training.     

Research Progress on Biological Mechanism of Epoxyeicosatrienoic Acids

Epoxyeicosatrienoic acids (EETs) are synthesized from arachidonic acid by cytochrome P450 epoxygenases.They modulate ion transport and gene expression,producing vasorelaxation as well as antiinflammatory and cell proliferation effects.Many of the functional effects of EETs occur through activation of signal transduction pathways and modulation of gene expression,events probably initiated by binding to a putative cell surface EETs receptor.However,EETs are rapidly taken up by cells and are incorporated into and released from phospholipids,it suggests that some functional effects may occur through a direct interaction between the EETs and an intracellular effector system.EETs synthesis,metabolism,mechanism of action are reviewed in this paper.     

环氧二十碳三烯酸生物学作用机制的研究进展

花生四烯酸经过细胞色素P450 (cytochrome P450,CYP)表氧化酶途径生成环氧二十碳三烯酸(epoxyeicosatrienoic acids,EETs)。EETs可以通过调节离子通道和基因表达,从而发挥促进血管舒张、抗炎和细胞增殖等作用。EETs也可通过激活信号转导途径和调节基因表达或与细胞膜受体结合发挥多种生物学功能。EETs也可快速与细胞膜磷脂结合后以共吸收的方式被细胞摄取。文章主要从EETs的来源、去路、作用机制等方面进行讨论。     

Calcium and Phosphorus Homeostasis in Dogs with Spontaneous Chronic Kidney Disease at Different Stages of Severity

Background: Studies in dogs with experimental chronic kidney disease (CKD) have demonstrated that abnormalities of calcium-phosphorus (Ca-P) homeostasis occur frequently and have a negative effect on kidney function and survival. However, the prevalence of these alterations in dogs with naturally occurring CKD at different stages of severity has not yet been investigated.
Hypothesis: Abnormalities of Ca-P metabolism occur early in the course of CKD with an increased prevalence in more severe stages.
Animals: Fifty-four dogs with CKD and 22 healthy dogs.
Methods: Blood and urine samples were obtained for a CBC, biochemistry, determination of parathyroid hormone (PTH), calcitriol, and ionized calcium concentrations and urinalysis. Based on urine protein/creatinine ratio and serum creatinine concentration, dogs were grouped according to the IRIS classification for CKD.
Results: Hyperparathyroidism (HPTH) (PTH ≥ 48 pg/mL) was diagnosed in 41 (75.9%) dogs with CKD. Its prevalence increased from 36.4% (stage 1) to 100% (stage 4). Hyperphosphatemia ( P > 5.5 mg/dL) was present in 37 (68.5%) dogs; increasing in prevalence from 18% (stage 1) to 100% (stage 4). Receiver-operating characteristic curve analysis showed that serum phosphorus concentration in the 4.5–5.5 mg/dL range correctly identified the presence of HPTH in most dogs. Calcitriol concentration progressively decreased in dogs with CKD and differences became statistically significant by stage 3.
Conclusion and Clinical Relevance: HPTH and hyperphosphatemia occur frequently in dogs with naturally occurring CKD, even at early stages of CKD in some dogs. These findings highlight the importance of monitoring these parameters early in the course of CKD.     

Management of intraoperative and postoperative anesthetic complications in ruminants and swine

Complications that can occur during and following anesthesia in ruminants and swine are discussed. Because many of these complications can be life-threatening, they must be avoided to allow provision of safe general anesthesia. Emphasis is placed on prevention and recognition of these complications and the institution of therapy when they do occur.     

The occurrence of taste buds in adults of the terrestrial ceacilian Boulengerula boulengeri Tornier, 1898 (Lissamphibia: Gymnophiona: Herpelidae)

Two generations of gustatory organs occur during amphibian ontogeny in frogs and salamanders (Anura and Caudata), and are classified as taste buds or taste discs. Taste buds are present in larval forms, whereas taste discs are typical for adults. The little research done on Gymnophiona suggests that only taste buds are present in aquatic forms (larvae and adults), and adults of the only terrestrial species studied had taste buds. Here we investigate the nature of gustatory organs in a terrestrial caecilian, Boulengerula boulengeri (Herpelidae), from Tanzania using standard light and scanning electron microscopy. We found only taste bud type organs to be present in B. boulengeri. These occur mainly in the mucosa of the front part of the oral cavity, usually near the teeth. Our results suggest that B. boulengeri possesses only one type of gustatory organ during its ontogeny.