Hepatic disease in Alberta horses: A retrospective study of 'alsike clover poisoning' (1973-1988)

Over sixteen years, 49 horses were diagnosed by Alberta Agriculture Animal Health laboratories as having “alsike clover poisoning”. There was a distinct northwestern distribution of cases, the majority coming from the Peace River district. This distribution is opposite to that of the Alberta horse population, but coincides with areas of alsike clover cultivation. Cases could be divided into chronic or nervous clinical presentations, as described by Schofield. Tissues from 45 animals were retrieved and examined microscopically. Significant histological lesions were confined to the liver and consisted of biliary fibrosis and epithelial proliferation.

I conclude that alsike clover poisoning is a specific disease entity, likely due to exposure to an exogenous toxin. The evidence is not strong enough to incriminate alsike clover as the etiology.

     

三叶草遗传多样性的SRAP分析

利用SRAP(sequence related amplified polymorphism)标记技术对红三叶(Trifolium pretense)、白三叶 (T.repens)、杂三叶(T.hybridum)及白三叶中的叶型变异植株共11份材料的遗传多样性以及亲缘关系进行研究。结果表明,40对引物共产生了426个多态性条带,平均每对引物产生10.7个多态性条带,多态性位点百分率为53.8%。7份白三叶的遗传相似系数变化范围为0.455～0.927,平均相似系数为0.854,白三叶叶型变异植株有特异性条带出现;3份红三叶的遗传相似系数变化范围为0.757～0.837,平均相似系数为0.791,说明白三叶和红三叶种内均存在一定的遗传多样性。种间聚类表明,杂三叶与红三叶的亲缘关系较为接近。表明SRAP技术可有效地用于三叶草的种间种内亲缘关系、种质资源鉴定和遗传多样性分析。     

豆科牧草对多花黑麦草化感作用的种间差异

实验室砂培法检测了红三叶、白三叶、杂三叶、黄花草木樨、紫花苜蓿、红豆草和毛苕子等7种豆科牧草茎叶及根的10%水浸提液处理对多花黑麦草种子萌发和幼苗生长的化感作用,结果表明:供试豆科牧草茎叶和根的水浸提液处理对多花黑麦草种子发芽势和幼苗根的生长均有显著(p<0.05)的化感抑制作用;10%水浸提液处理对多花黑麦草幼叶伸长无显著(p>0.05)影响,但对幼叶的干物质积累具有抑制作用;豆科牧草对多花黑麦草幼苗生长的化感作用在作用强度和作用机制两方面存在显著的种间差异。     

Lead and Zinc Poisoning and the Interaction Between Pb and Zn Poisoning in the Foal

Groups of young growing horses were fed toxic amounts of lead only, zinc only and the same amounts of lead and zinc together. Those fed Pb only developed pharyngeal and laryngeal paralysis (“roaring”) whereas those fed Zn only and Pb and Zn together developed the same clinical syndrome which included swelling at the epiphyseal region of the long bones, stiffness and lameness. Anemia and decreased weight gains were most pronounced in animals fed Zn for the longest periods. Animals fed Pb only did not become anemic and weight loss did not occur until after there was an interference in swallowing.

The clinical signs and tissue Pb values from animals fed toxic amounts of both Pb and Zn continuously, differed markedly from those present in animals fed comparable amounts of Pb only. Th clinical signs were similar to those caused by Zn poisoning. The hepatic and renal tissue Pb values were approximately twice as high and the epiphyseal and cancellous bone sample results were one half as high as the comparable Pb values from animals fed toxic amounts of Pb only.

It appeared that toxic amounts of Zn prevented the development of clinical signs of Pb poisoning in the young growing horse.

     

Nitrofuran Production Efficiency In Chickens

Two nitrofuran feed additives, 0.011% nihydrazone and a combination of 0.0055% nitrofurazone and 0.0008% furazolidone, improved weight gains and feed conversions in chickens with “air sac infection.” Both nitrofurans caused a significant reduction in the total chickens condemned at the dressing plant from this disease, but nihydrazone gave the best results.

Nihydrazone^*, a new nitrofuran feed additive for chickens, was found by Wolfgang et al. (1) to be effective against coccidiosis due to Eimeria tenella and E. necatrix. In chickens nihydrazone was shown by Edgar et al. (2) to result in fewer chickens condemned from “air sac infection” than with any other drug used. Rosenberg et al. (3) found nihydrazone caused significant reduction in condemnations due to this disease. Cosgrove (4) showed that nihydrazone prevented an outbreak of cecal coccidiosis, reduced the incidence of “air sac infection,” improved weight gains, feed conversions and livability. Bierer (5) found nihydrazone active against fowl typhoid.

Harwood et al. (6) reported bifuran^** effective against E. tenella and E. necatrix coccidiosis and it has been used commercially for this purpose. Bierer (5) (7) found Bifuran^*** active in prevention of pullorum disease and fowl typhoid in chicks.

The mode of action of nihydrazone and nitrofurazone against E. tenella coccidiosis was shown by Johnson and Van Ryzin (8).

This production efficiency study was undertaken to evaluate nihydrazone and bifuran in the presence of “air sac infection” and concomitant diseases under field conditions. Camden (9) states that the only satisfactory test of a drug is the performance it gives under field conditions.

Nihydrazone (1) (5) and Bifuran (5) (6) have both antibacterial and antiprotozoal activity and under field conditions, normal densities of bacterial and other parasitic organisms are encountered (9). Thus a coccidiostat having antibacterial and antiprotozoal properties is desirable (7).

     

Epidemiological features of calf mortality due to hemophilosis in a large feedlot

Hemophilosis was the most significant cause of mortality in fall-placed calves in a large feedlot in Saskatchewan, despite routine single immunization of calves with a commercial Haemophilus somnus bacterin on arrival. Common manifestations of fatal H. somnus infection were myocarditis and pleuritis; occasionally, thrombotic meningoencephalomyelitis (TME), peracute septicemia, and pneumonia were observed. Circumstantial evidence suggested that H. somnus may be a pathogen in polyarthritis. Death from pneumonia mainly occurred during the first five weeks in the feedlot. Death from myocarditis, pleuritis, TME, and septicemia, and euthanasia because of polyarthritis, occurred mainly after the third week in the feedlot.

The median fatal disease onset (FDO) for pneumonia was day 12; for septicemia, day 17; for polyarthritis, day 18; for myocarditis and pleuritis, day 22; and for TME, day 29. Calves that died from myocarditis frequently were found dead in their “home” pen; however, 88% of these animals had been treated previously. Fifty-seven percent of the calves that died from pleuritis were never treated, and those that died from TME or septicemia were either never treated or died shortly after initial treatment.

     

Moldy sweet clover (dicoumarol) poisoning in Saskatchewan cattle

Information pertaining to 286 animals from 56 herds affected by moldy sweet clover poisoning in Saskatchewan during 1983 was tabulated from the toxicology laboratory records. The morbidity in the affected herds was 12.1%, with a case fatality of 65.5%. Aborted fetuses and calves less than two weeks of age were affected with sweet clover poisoning most often. Sweet clover poisoning was more common during the period from January to April, 91.6% of the morbid animals were seen at this time. The rates of poisoning in beef and dairy cattle were estimated to be 0.156 and 0.095 cases per 1000 cattle respectively. Sweet clover poisoning was observed with the use of large of small bales of sweet clover in 78.9% of the affected herds. The geographical distribution of sweet clover poisoning in Saskatchewan followed the northern regions of the dark brown soil zone and the southern regions of the black soil zone which extend from the mid northwest portion of the province to the extreme southeast region.

Dicoumarol concentrations were determined on a variety of tissues including liver, plasma, serum, kidney and muscle. Significant differences in the liver dicoumarol concentrations were found between animals of different ages (P = 0.045). Livers from younger animals, in particular, the fetus, contained lower concentrations of dicoumarol.

     

Mycoplasma Ovipneumoniae Demonstrated in Icelandic Sheep

For at least thirty years chronic pneumonia of suckling lambs has occurred in many sheep flocks in the north-eastern part of Iceland, Thingeyjarsýsla. Owing to the retarded growth rate of affected lambs, the farmers named it “kregda” which means “the poor eater”. A similar syndrome has also been observed in some areas of South Iceland (Gíslason 1963).     

Seasonal and Diurnal Variation in Water-Soluble Carbohydrate Concentrations of Repeatedly Defoliated Red and White Clovers in Central Kentucky

Nonstructural carbohydrates of pasture plants, comprising water-soluble carbohydrates (WSCs) and starch, may contribute to excessive consumption of rapidly fermentable carbohydrates by grazing horses. Seasonal and diurnal variation in WSCs were studied in red (Trifolium pratense L.) and white clovers (Trifolium repens L.) subjected to a typical management regime of rotationally grazed horse pastures. Two red and two white clover cultivars from monoculture plots were harvested after 4 weeks of growth from April to October of 2015, in the morning and afternoon of each harvest date. Water-soluble carbohydrates were quantified for each harvest, and starch was quantified for two harvests. Mean monthly WSC concentrations ranged from 80 to 99 mg/g (freeze-dried weight basis), whereas mean starch concentrations were 31 and 40 mg/g. In September, white clover had 14% more WSCs than red clover (P < .0001). Water-soluble carbohydrate concentrations were 10% higher in the afternoon than in the morning (P < .0001). Starch concentrations were 290% higher in the afternoon than in the morning (P < .0001), and nonstructural carbohydrate concentrations in the afternoon averaged 150 mg/g. Further studies are needed to determine whether the mixed grass-legume pastures of central Kentucky accumulate enough nonstructural carbohydrates to present risk factors for equine metabolic or digestive dysfunction.     

Glasser's Disease of Swine Produced by the Intratracheal Inoculation of Haemophilus suis

The intracheal inoculation of pigs with Haemophilus suis led to the production of Glasser's disease at every attempt without significant pulmonary involvement. Isolation of this organism from the experimental animals was possible only in the acute phase of the disease.

The indirect fluorescent antibody technique when applied to frozen sections of tissues obtained from the experimentally infected pigs at autopsy, revealed a few rod forms but mostly “round bodies” of H. suis in animals from which the organism was isolated, and “round bodies” only in the pigs from which the organism was not isolated.

Attention is drawn to the similarities between the lesions caused by H. suis and Mycoplasma hyorhinis, and to the confusion which may result therefrom. It is stressed that the laboratory diagnosis of these two diseases is complicated by the fact that both agents may not be isolated on the media commonly used in diagnostic laboratories. Both organisms necessitate the use of special media where the clinical and autopsy results indicate polyserositis and arthritis.

     

Study of serum drug levels in calves following intramuscular administration of three tetracycline drug preparations

Three antibiotic formulations, oxytetracycline (A) in propylene glycol and oxytetracycline (B) in polyvinyl pyrrolidine and pyrrolidino-methyltetracycline in an oil suspension were given to calves by the intramuscular route. Only oxytetracycline (A) appeared to cause much pain after injection.

The half-time elimination (t_½cl) for oxytetracycline (A) was 14.000 ± 3.580 h for oxytetracycline (B) 10.290 ±5.159 h and for pyrrolidinomethyltetracycline 8.160 ± 0.920 h. The rate of elimination `beta slope” for oxytetracycline (A) was 0.052 ± 0.012 h⁻¹ for oxytetracycline (B) 0.077 ± 0.261 h⁻¹ and for pyrrolidinomethyltetracycline 0.086 ± 0.010 h⁻¹. The Y intercept of the “beta” elimination slope C_os (μg/mL) for oxytetracycline (A) was 2.490 ± 1.040, for oxytetracycline (B) 3.463 ± 1.874 and for pyrrolidinomethyltetracycline 2.852 ± 1.360.

Pyrrolidinomethyltetracycline appeared to have a two component elimination curve, however, only the “beta slope” was used for the calculations.

     

Pasture‐use patterns on dairy and beef farms in the natal midlands

Abstract

Pasture sites for each of the species grown are classified for both dryland and irrigated pastures in the Natal Midlands. Only six species viz. kikuyu, Italian ryegrass, Eragrostis curvula, Festuca arundinacea (tall fescue), Dactylis glomerata (cocksfoot) and Trifolium repens (white clover) are widely used. Italian ryegrass pastures are grown almost exclusively under irrigation; clover is more widely used than is generally appreciated; a reasonably large proportion of E. curvula, cocksfoot and tall fescue pastures have a longevity in excess of 10 years; and the siting of pastures appears to be primarily a function of availability of suitable land and is Largely independent of soil type and aspect. Pastures are largely sited on high potential arable land, with little apparent trend towards intensification of steep non‐arable sites.

The survey suggests that research should be directed at a small number of important species rather than dissipated over many species which are unlikely to make any major contribution to pasture production.     

Q fever - a review

Q or “query” fever is a zoonosis caused by the organism Coxiella burnetii. Cattle, sheep and goats are the most common reservoirs of this organism. The placenta of infected animals contains high numbers (up to 10⁹/g) of C. burnetii. Aerosols occur at the time of parturition and man becomes infected following inhalation of the microorganism. The spectrum of illness in man is wide and consists of acute and chronic forms. Acute Q fever is most often a self-limited flu-like illness but may include pneumonia, hepatitis, or meningoencephalitis. Chronic Q fever almost always means endocarditis and rarely osteomyelitis. Chronic Q fever is not known to occur in animals other than man. An increased abortion and stillbirth rate are seen in infected domestic ungulates.

Four provinces (Nova Scotia, New Brunswick, Ontario and Alberta) reported cases of Q fever in 1989.

A vaccine for Q fever has recently been licensed in Australia.

     

Lack of cross-protection against Mycoplasma haemofelis infection and signs of enhancement in “Candidatus Mycoplasma turicensis”-recovered cats

“Mycoplasma haemofelis” and “Candidatus Mycoplasma turicensis” are feline hemoplasmas that induce hemolytic anemia. Protection from homologous re-challenge was recently demonstrated in cats recovered from primary infection. Here, we determined if cats recovered from “Cand. M. turicensis” infection were protected against infections with the more pathogenic M. haemofelis. Ten specified pathogen-free cats were exposed to M. haemofelis. Five of the ten cats had recovered from “Cand. M. turicensis” bacteremia (group A), and five cats were naïve controls (group B). No cross-protection was observed. By contrast, the “Cand. M. turicensis”-recovered cats displayed faster M. haemofelis infection onset (earlier PCR-positive and anemic) than the controls. No “Cand. M. turicensis” was detected in any cat. M. haemofelis shedding was observed in saliva, feces and urine. In both groups, evidence of a Th1 response was observed (high IFN-γ, low IL-4), but IL-10 levels were also high. In group A, total, CD4+ and CD8+ T cells increased within days after M. haemofelis exposure. At times of maximal bacteremia, macrocytic hypochromic anemia, neutropenia, monocytosis and a decrease in leukocyte, eosinophil, and lymphocyte counts and subsets thereof (B- and T-cells, CD4+, CD8+ and CD4+CD25+ cells) were particularly significant in group A. Moreover, an increase in protein concentrations, hypoalbuminemia and a polyclonal hypergammaglobulinemia were observed. Five of ten M. haemofelis-infected cats subsequently cleared bacteremia without antibiotic treatment. In conclusion, the study suggests that a previous hemoplasma infection, even when the cat has ostensibly recovered, may influence subsequent infections, lead to an enhancement phenomenon and other differences in infection kinetics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-015-0240-x) contains supplementary material, which is available to authorized users.     

Endoscopically Visualized Lesions,Histologic Findings,and Bacterial Invasion in the Gastrointestinal Mucosa of Dogs with Acute Hemorrhagic Diarrhea Syndrome

Background

Etiology of hemorrhagic gastroenteritis (HGE) syndrome in dogs is unknown and histopathologic and microbial investigations have only been performed post mortem.

Objective

To identify characteristic intra vitam endoscopic and histologic mucosal lesions, as well as bacterial species, within the mucosa of dogs with HGE.

Animals

Ten dogs diagnosed with HGE were included. Eleven dogs with gastroduodenoscopy and different intestinal diseases were used as controls for microbial changes. Dogs pretreated with antibiotics or diagnosed with any disease known to cause bloody diarrhea were excluded from the study.

Methods

In this prospective study, gastrointestinal biopsies were collected from 10 dogs with HGE. Endoscopic and histologic changes were assessed according to WSAVA guidelines. Biopsies from the stomach, duodenum, ileum, and colon were investigated by histology and by immunohistochemistry for the presence of Clostridium spp. and parvovirus. The first duodenal biopsy taken with a sterile forceps was submitted for bacterial culture.

Results

Acute mucosal lesions were only found in the intestines, not in the stomach. Clostridium spp., identified as Clostridium perfringens in 6/9 cases, were detected on the small intestinal mucosa in all dogs with HGE, either by culture or immunohistopathology. In the control group, C. perfringens could only be cultured in one of 11 dogs.

Conclusions and Clinical Importance

The results of this study demonstrate an apparent association between C. perfringens and the occurrence of acute hemorrhagic diarrhea. The term “HGE,” which implies the involvement of the stomach, should be renamed as “acute hemorrhagic diarrhea syndrome.”     

Glucocorticoid Induced Stress Susceptibility in Swine: Adrenocortical Pathology

The studies reported here were undertaken to better characterize the role of the adrenal cortex in the increased susceptibility to stress observed in porcine stress syndrome. Since adrenal hypofunction was suggested during early studies as a factor in events leading to porcine stress syndrome it was decided to produce such a state by the exogenous administration of the glucocorticoids prednisolone and fluoroprednisolone.

A total of 34 pigs (weighing 90 to 100 kg) received a series of graded doses (given intramuscularly) of one or the other of the foregoing compounds and were necropsied 48, 72, and 120 hours after the last treatment. The major adrenocortical changes produced by these treatments were atrophy, an accentuation of degenerative changes which could be observed in milder form in many of the 30 control pigs examined, a marked increase in stainable lipid 120 hours after the last fluoroprednisolone treatment and, ultrastructurally, an increase in lysosome-like bodies and cellular debris (“myelin bodies”).

Adrenocortical atrophy is not a feature of porcine stress syndrome nor were the localized depositions of stainable lipid within the zona reticularis, described in porcine stress syndrome, found in the glucocorticoid treated pigs. Consequently, the findings reported here bear a somewhat limited resemblance to those observed in pigs affected by porcine stress syndrome and cast some doubt on whether adrenal hypofunction plays a role in the pathogenesis of the latter condition.

     

Cellular proliferation of bile ductules and gamma‐glutamyl transpeptidase in livers and sera of young cattle following a single infection with Fasciola hepatica

Summary

During the course of experimental single infection with Fasciola hepatica in calves, the origin of the increased concentration of gamma‐glutamyl transpeptidase (γ‐GT) found to be present in the serum during the biliary stage of the disease, was studied.

The enzyme originates from the liver after flukes have caused intermittent and selective cholestasis in the bile‐duct system. The enzyme which normally is present in the bile ducts can under these circumstances enter the surrounding interstitial tissues through broken‐up junctions of the bile drainage system or be added to these from proliferating bile‐ductule epithelium. The multiplication of bile‐ductule cells can be looked upon as a neogenesis of cholangioles, which becomes essential when newly formed perilobular connective tissues prevent restoration of the anatomical connections of the bile capillaries with the biliary tree. The connective tissue growth is induced by bile fluid. An initially regional perilobular fibrosis is eventually distributed diffusely through the liver by migration of flukes.

The continued and extending fibrosis is due to the constant recurrence of intermittent and selective cholestasis. The transient occlusions of branches of the bile ducts are very likely to be attributable to persistent cholangitis. The growth of connective tissues has a considerable effect on the gain in weight of the liver.     

豆科牧草种子丸衣化接种根瘤菌技术及其效益

本文通过近几年对豆科牧草种子丸衣化接种根瘤菌的试验研究,总结出在云南种植豆科牧草所采用的红三叶、白三叶等品种进行接种根瘤菌时对丸衣材料、粘着剂的选择和具体接种制作丸衣的技术;采用此技术在牧草种植中所获得的经济、社会、生态效益;是种植豆科牧草必不可少的一项农业技术措施。     

Critical Observations on BSE Control in Italy

Eleven native sheep, 1–2 years old, of both sexes were randomly divided into two groups, 6 sheep being allocated to the experimental group and 5 serving as controls. The sheep in the experimental group were fed 80% Tribulus terrestris and 20% alfalfa hay and wheat straw, while the control sheep were given a mixture of 40% alfalfa hay and 60% wheat straw. Clinical signs of hepatogenous photosensitivity were observed from day 11, including reddening and crust formation on the muzzle, nose, ears and eyelids, depression, weight loss, icterus, conjunctivitis, and yellow discoloration of the urine. Laboratory findings on weekly samples indicated significant differences (p<0.05) in white blood cell count, total plasma protein and fibrinogen, total and direct bilirubin, blood urea nitrogen and creatinine concentrations, and aspartate aminotransferase and alkaline phosphatase activities. There were no significant differences in the packed cell volume, in the neutrophil, lymphocyte or eosinophil counts, or in the serum calcium, phosphorus, potassium, sodium or chloride concentrations. At necropsy of the experimental animals, there were various degrees of generalized icterus and the livers were swollen and discolored by bile pigment. Histopathological examination revealed varying amounts of crystalloid material in the bile ducts and renal tubules, hepatocellular degeneration, biliary fibrosis and proliferation, renal tubular necrosis and focal necrosis of cardiac muscle.     

Epizootiologic Studies of Shipping Fever of Cattle: I. The Microbial Agents Isolated

Nineteen strains of Pasteurella spp., but no viruses cytopathogenic for bovine embryonic kidney cells were isolated from pneumonic lesions present in “normal” veal calves at slaughter.

In studies on two herds of native cattle and six lots of western feeder calves, Pasteurella spp. were isolated from nasal swabs from healthy cattle and those with shipping fever. Viruses of the psittacosis-lymphogranuloma group were isolated from nasal swabs from animals in five groups. Viruses provisionally identified as bovine enteroviruses were isolated from nasal swabs of calves in two lots.

There was serologic evidence of a temporal association of myxovirus para-influenza 3 (PI3) with shipping fever in three lots of calves. From two of these three lots, strains of PI3 were isolated from ten animals, four of which had clinical shipping fever at the time of virus isolation.