Pathogenesis of infection with Theileria recondita (Wales) isolated from Haemaphysalis punctata from north Wales

The pathogenicity of Theileria recondita infection in both splenectomised and non-splenectomised sheep was investigated. Following transmission of T. recondita to splenectomised animals both by adult ticks and blood transfusion a fever and severe macrocytic hypochromic anaemia developed which lasted the 9 days or more of patent infection. The prepatent period following tick attachment was about 8 days, but was variable following blood transfusion. Infection of normal animals caused a transient macrocytic hypochromic anaemia and slight fever which lasted throughout the period of low parasitaemia (7 days). The increase in mean cell volume was due to an increase in numbers of juvenile red cells in the peripheral blood. There was a transient neutrophilia and lymphocytopenia but no significant changes in thrombocyte or leucocyte numbers.     

Serum and cerebrospinal fluid concentrations of immunoglobulin G in Suffolk sheep with scrapie

Determinations were made by laser nephelometry of serum and CSF immunoglobulin (Ig) G concentrations in Suffolk sheep with naturally occurring scrapie. The serum IgG concentrations in 3 sheep with confirmed or suspected scrapie were between 2,140 and 3,290 mg of IgG/100 ml, and the CSF values were between less than 10 and 75 mg of IgG/100 ml. In 8 clinically healthy (control) sheep, serum IgG concentrations were 2,647 to 7,380 mg/100 ml and CSF IgG concentrations were between 0 (undetectable) and 162 mg/100 ml. A sheep with pulmonary adenomatosis had 1,445 mg of IgG/100 ml of serum. The results indicated that neither serum nor CSF IgG concentrations were increased in sheep with naturally occurring infection with scrapie and that the severity of the disease did not correspond with the IgG concentration.     

Morphology and transmission of Theileria recondita (Theileriidae: Sporozoa) isolated from Haemaphysalis punctata from north Wales

Adult Haemaphysalis punctata (Canestrini and Fanzago 1877) collected from an area of rough grazing at Mynydd Mawr, Aberdaron, North Wales, transmitted Theileria recondita (Wales); field-collected nymphs failed to transmit this parasite. Following adult tick infestation, piroplasms were first observed in the blood of splenectomised infested sheep 8 days after tick attachment; the parasitaemia lasted 9 days. The parasite can also be transferred by syringe passage of blood from splenectomised to normal sheep and vice versa. Parasitaemias were higher and of longer duration in splenectomised animals. A rise in parasitaemia was detected in a splenectomised ewe after parturition, 19 months following blood-transmitted infection from which it had recovered clinically. The morphometrics of the piroplasms of T. recondita (Wales) were investigated; the rod and the ring forms were the most common. The mean length of the rod form was 2.09 microns and the mean diameter of the ring form was 1.22 micron.     

The Preventive Effect of Nicotinic Acid on Carbon Tetrachloride Toxicity in Sheep

The blood glucose response following the intravenous injection of butyric acid, 2.5 mM/kg, was studied in normal and carbon tetrachloride poisoned sheep. In normal sheep there was a rapid increase in blood glucose. Carbon tetrachloride greatly reduced the glucose response. In animals pretreated with nicotinic acid, 50 mg/kg, on the day before carbon tetrachloride administration, the glucose response was not altered. When a larger dose of nicotinic acid, 100 mg/kg, was given simultaneously with carbon tetrachloride, the glucose response was reduced more than after only carbon tetrachloride. Nicotinic acid alone at the dose of 100 mg/kg reduced the glucose rise somewhat more than carbon tetrachloride. There was a good agreement between the glucose rise following butyric acid and the glycogen content of the liver. It thus seemed clear that butyric acid has a glycogenolytic effect when given intravenously. Carbon tetrachloride caused severe necrosis and fatty changes in the liver. These pathological changes were reduced by pretreating the animals with 50 mg/kg of nicotinic acid. The larger dose of nicotinic acid, 100 mg/kg, caused a diffuse degeneration of the liver cells and a complete disappearence of glycogen. All liver injuries were followed by a rise in serum OCT.     

Effects of probenecid on blood levels and tissue distribution of ampicillin in fowls and turkeys

The effect of probenecid (a benzoic acid derivative which competitively inhibits active secretion of weak organic acids by the renal tubules) on serum ampicillin concentrations and the distribution of ampicillin in body organs was examined in fowls and turkeys. An aqueous solution of probenecid coadministered intramuscularly, at 200 mg/kg, with sodium ampicillin solution, at 25 mg/kg, resulted in peak serum antibiotic concentration of 16.5 microgram/ml. A similar dose of ampicillin administered alone produced a peak level of 4.6 microgram/ml. Subcutaneous injections of sodium ampicillin at 25 mg/kg with aqueous probenecid at 200 mg/kg resulted in a peak serum ampicillin concentration (12.8 microgram/ml) three times as high as the peak produced by the subcutaneous injection of ampicillin alone at 50 mg/kg (4.2 microgram/ml). The elimination half-life (t 1/2) of the drug (30 min) was increased to 1.5 hr by coadministration of probenecid parenterally, and serum antibiotic levels greater than or equal to 5.0 microgram/ml were maintained during 3 hours. Ampicillin seemed to be poorly absorbed from the gastrointestinal tract of fowls. A single oral bolus administration of ampicillin trihydrate aqueous suspension produced a peak of 0.6 microgram/ml, and coadministrations of aqueous probenecid suspension at 20, 50, and 100 mg/kg respectively produced peaks of 0.9, 1.25, and 1.5 microgram/ml. During 4 and 5 days, when ampicillin was added to the drinking water at rates of 200 and 50 mg/liter, serum ampicillin levels were rather low (peaks of 0.20 and 0.12 microgram/ml, respectively), and although these levels were increased by 50% with the coadministration of probenecid they were considered to be of limited clinical value for treating systemic bacterial infections. Probenecid did not change the distribution of ampicillin in the organs.     

Radioimmunoassay for β-endorphin/β-lipotropin in unextracted plasma from sheep

A double antibody radioimmunoassay (RIA) was developed and validated for the quantification of β-endorphin (EP) in unextracted plasma from sheep. The RIA crossreacted on a molar basis approximately 100% with β-lipotropin (LPH). Almost all of the immunoreactivity in silicic acid extracts of plasma migrated on gel filtration as either EP or LPH. Incubation of radioiodinated EP with unextracted plasma under assay conditions resulted in the formation of a radioiodinated product which could still bind to the anti-EP serum. Basal concentrations of EP/LPH ranged from .1 to .2 ng/ml plasma, but transient peaks of 1.4 to 2.4 ng/ml were sometimes observed.     

Clinicopathological changes and effect of imidocarb therapy in dogs experimentally infected with Babesia canis

In this study one spleen-intact dog (A) and two splenectomised dogs (BSE, CSE) were infected with Babesia canis. All animals developed an acute disease characterised by fever, haemoglobinuria and anaemia, the latter being more severe in the splenectomised dogs. Fever and parasitised red blood cells were detected for three days after imidocarb treatment in the splenectomised animals. Haematological abnormalities included regenerative anaemia, thrombocytopenia and leukopenia (due to neutropenia and lymphopenia) in the acute phase, soon followed by leukocytosis, neutrophilia and left shift a few days later. Acute hepatopathy was detected in all dogs with elevated ALT activity, which was more seriously altered in the splenectomised dogs. Diffuse changes in liver structure and hepatomegaly were seen by ultrasonography. Liver biopsy and histology revealed acute, non-purulent hepatitis in the splenectomised dogs. Both splenectomised dogs were successfully cured after collection of 400 ml highly parasitised blood, proving that large-amount antigen production is possible with rescuing the experimental animals. Whole blood transfusion, imidocarb and supportive care with infusions, antipyretics, glucocorticoids and diuretics were applied. The spleen-intact dog clinically recovered after receiving supportive treatment, with no imidocarb therapy. Microbial infections developed in both splenectomised animals (BSE: haemobartonellosis, CSE: osteomyelitis caused by Escherichia coli), probably as a consequence of immunosuppression after splenectomy and glucocorticoid therapy.     

Effects of combined parenteral vitamins C and E administration on the severity of anaemia, hepatic and renal damage in Trypanosoma brucei brucei infected rabbits.

Rabbits infected with Trypanosoma brucei brucei (Basa isolate) were intraperitoneally administered with vitamins C and E at 100 mg/kg and 10 mg/kg body weight, respectively, from day 7 before infection to day 12 post-infection (p.i.). Another group of rabbits were similarly infected, but received no vitamin treatment. The uninfected (control) rabbits were either untreated or treated with vitamins like the infected group. Treatment of the infected animals did not affect the onset and level of parasitaemia. On day 12 p.i., the anaemia tended to be ameliorated, but insignificantly, by the treatment. The infection increased (p<0.05) serum urea and creatinine concentrations to similar levels in treated and untreated groups. However, the increase (p<0.05) in alanine and aspartate transaminases in the untreated infected animals was prevented in the treated infected ones. Therefore, it seemed that the treatment with antioxidant vitamins boosted their storage in hepatic cells, but not in erythrocytes and glomeruli, to annul any cellular injury due to infection. It is concluded that this may be an indirect evidence that the hepatic damage may be principally due to oxidative injury.     

Effect of Mannheimia (Pasteurella) haemolytica Infection on Acute-phase Proteins and Some Mineral Levels in Colostrum–Breast Milk-fed or Colostrum–Breast Milk-deprived Sheep

The aim of this study was to investigate the levels of acute-phase proteins and minerals as indicators for the reactivity in 1-year-old sheep. A total of 26 Chios breed sheep were fed colostrum-breast milk (control, n = 15)or were deprived afterseparation from their mother immediately after birth(experimental, n = 11). Mannheimia (Pasteurella) haemolytica serotype A1 was inoculated intratracheally and blood samples were taken in vacuumed sera on days 0, 1, 4, 7, 10, 13, 16, 19 and 22. Antibiotic treatment was initiated after blood sampling on day 22, and blood samples were taken on days 1, 4 and 7 after the treatment. The levels of C-reactive protein (CRP), haptoglobin, ceruloplasmin, fibrinogen, zinc, iron and calcium, which are the indicators of immune function and infectious diseases were analysed. No significant difference between the control and trial groups before and after the infection was determined. However, serum CRP, haptoglobin, ceruloplasmin and fibrinogen levels were increased in the course of the infection. These levels were restored to normal following treatment.     

Sheep productivity in the Ethiopian Highlands on a diet supplemented with urea-molasses block and/or noug cake

A feeding experiment was carried out in which adult ewes of the Ethiopian Highland Menz breed grazed on meadow pasture were supplemented with urea-molasses block and/or noug cake. There was low consumption of urea-molasses block (67 gd-1) and its contribution to total nitrogen requirement was minimal. Dietary treatment had no significant effect on liveweight changes of ewes, their reproductive performance and performance of the lambs. When there was liver fluke infection, ewes and their lambs which were supplemented with urea-molasses block and/or noug cake had better survival compared to those which did not get any supplements (35% mortality vs 55%). The rumen ammonia-N concentration was significantly lower in the control sheep (11 mg/100 ml) and those that received only urea-molasses (14 mg/100 ml) and highest in sheep receiving the urea-molasses block and noug cake (26 mg/100 ml). The volatile fatty acid proportions were not significantly affected by the diets. Low level of urea-molasses block consumption seemed to be a main factor limiting the usefulness of the urea-molasses block and it is recommended that factors likely to enhance its consumption be investigated.     

Barium selenate: a long-acting selenium preparation for subcutaneous injection

Three flocks of sheep in typical selenium-deficient areas were injected with 2 ml Deposel® (100 mg selenium as barium selenate) in the autumn of 1982 and/or 1983. The selenium status in 10 ewes from each flock, and their offspring, was monitored by selenium analyses of blood samples. The injection induced an adequate increase in blood selenium within 8 weeks. Adequate selenium levels were maintained throughout the lambing season and the following summer. The selenium status in lambs from treated ewes was adequate until they were put out to pasture. Elevated selenium levels were maintained even throughout the next lambing season, and the second injection gave significantly higher blood selenium as compared to the first. The present preparation seems to be suitable and safe for protecting sheep against selenium deficiency. The dosage used seems sufficient to maintain an adequate selenium status for as long as 2 consecutive lambing seasons.     

Comparative efficacy of diminazene diaceturate and imidocarb dipropionate against Babesia equi infection in donkeys

Diminazene diaceturate (Berenil, Hoechst) at 12 mg/kg intramuscularly (i/m) and repeated after 24 hours controlled the rising parasitaemia of Babesia equi infection in four out of five splenectomised donkeys. The drug was more effective in the early stages of the disease and had a prophylactic effect for at least 30–35 days.A new babesicide, imidocarb (Imizol, Burroughs Wellcome), was 100% effective in three splenectomised donkeys at 5 mg/kg, i/m and repeated after 48 hours. However, imidocarb at 5 or 2 mg/kg i/m with a single injection was only partially effective or ineffective.     

Natural Antibodies in Sera of Mink Before and After The Development of Aleutian Disease (Viral Plasmacytosis)

The effect of infection of mink with aleutian disease virus on the level of natural antibodies in the serum was investigated. The level of natural antibodies to chicken red blood cells was increased following infection but there was no correlation between the degree of hypergamma globulinemia in the diseased mink and the increase in titers. On the other hand, serum levels of natural hemolytic antibodies to sheep red blood cells in mink did not increase during the course of aleutian disease. These data indicate that the aleutian disease virus does not stimulate a broad spectrum of pre-existing antibody producing cells.     

Sheep scab control using trans-cinnamic acid

A series of in vitro and in vivo assays were conducted to examine the effects of trans-cinnamic acid ethyl ester on Psoroptes mange mites. In vitro, 24h after exposure to the test material at concentrations of 10, 1 or 0.1% (v/v), 100, 74 and 20% of mites had died, respectively, compared to 8% following exposure to the control (0.05% SDS only). The different life-cycle stages were affected similarly by the test compound. The concentration required to produce 95% mortality 24h after exposure to the test compound was 6.29% (95% confidence interval 4.98-8.88). Tarsal contact of the mites with the test compound was also sufficient to achieve high levels of mortality; 100% death was observed when the mites were placed in contact with either sheep skin circles treated to give 0.01 ml/cm(2) or polyester cloth circles treated with 0.03 ml/cm(2). However, the residual activity of both skin and cloth treated with 0.03 ml/cm(2) was completely lost after 7 days. In vivo, trans-cinnamic acid ethyl ester suspended in 2% (w/v) lecithin was applied as a spray formulation to eight sheep with active artificial infestations of sheep scab. Seven of the 8 treated sheep were cured and remained completely clear of scab mites for 56 days. However, 33 days after treatment 2 adult female mites were observed on one of the eight treated sheep and the mite population on this sheep subsequently recovered. In contrast, in a control group of two infested sheep, treated with a 2% (w/v) lecithin only, mite populations increased as expected in a typical scab infestation, but eventually self-cured in one animal. The data suggest that, with appropriate development of suitable application technology, trans-cinnamic acid ethyl ester could have a role as a potential therapeutic treatment for active sheep scab, however the short residual period of activity is likely to limit its use in commercial sheep flocks.     

Renal function studies in normal and toxemic pregnant sheep

Renal blood and plasma flow, glomerular filtration rate (GFR) and maximal tubular transport of PAH (TmPAH) were measured in nonpregnant and twin-pregnant sheep. Twin-pregnant animals were studied during normal pregnancy as well as during ovine pregnancy toxemia artificially produced by starvation. All animals were surgically prepared with aortic, post caval and renal vein cannulas at least one week prior to experimentation. Total renal blood and plasma flow was found to be elevated during pregnancy, but if expressed on the basis of body weight no changes were noted. Starvation and the resultant development of hypoglycemia and hyperketonemia caused a 25-30% decline in renal blood and plasma flow. GFR in pregnant fed sheep (193 ml/min or 2.7 ml/kg.min) was significantly higher (P less than .001) than that of nonpregnant ewes (118 or 2.3 ml/kg min). During ovine pregnancy toxemia the GFR was significantly (P less than .001) diminished (142 ml/min or 2.0 ml/kg min). TmPAH also was significantly higher (179 mg/min or 2.5 mg/kg min) in pregnant animals when compared to nonpregnant ewes (98 mg/min or 1.9 mg/kg min.), but starvation had no effect on Tm PAH in pregnant sheep. It thus appears that a functional renal hypertrophy occurs during pregnancy which is similar to that which follows unilateral nephrectomy or renal disease. During ovine pregnancy toxemia the diminution of renal function probably results from the metabolic derangements and is thus not comparable to human preeclampsia.     

Evaluation of endotoxaemia in the prognosis and treatment of scouring merino lambs

This study looked at measurement of endotoxaemia as a tool in determining prognosis and probable response to treatment in scouring lambs. One hundred eighty-three lambs in the first 15-20 days of life, from eight Merino sheep farms located in the region of La Serena, south-west Spain, were used in this experiment. Scouring and normal/control lambs were selected following a clinical examination, the scouring group was further divided into subgroups, specifically those that did or did not survive 72 h following treatment. At the time of the clinical examination, faecal and blood samples were taken. Faecal culture and commercial faecal antigen tests for detection of enteropathogens in faeces and serum endotoxin measurement using chromogenic lymulus amoebocyte lysate (LAL) were carried out. Scouring lambs received 0.07 mg/kg liveweight halofuginone once a day for 3 days, a single oral dose of 0.20 mg/kg liveweight of spectinomycin and oral rehydration fluid. The pathogens isolated were Cryptosporidium spp. and Escherichia coli. The case fatality rate was 51% in the scouring lambs. Postmortem findings were consistent with enterotoxigenic E. coli infection. The concentration of endotoxin was 0.18 +/- 0.12 ng/ml in the control group, 0.35 +/- 0.17 ng/ml in the surviving lambs and 0.46 +/- 0.14 ng/ml in the non-surviving lambs. Significant differences between groups were found. Case fatality rate of the scouring lambs with endotoxaemia below 0.30 ng/ml was 0%, while it was 100% above 0.50 ng/ml. These results may be utilized as a prognostic indicator in lambs affected by E. coli and Cryptosporidium that will help aid in decision-making as to whether to treat a lamb or not based on its chances of survival.     

Pathobiochemical mechanisms involved in the control of the disease caused by Trypanosoma congolense in African grey duiker (Sylvicapra grimmia)

The course of Trypanosoma congolense infections in African grey duiker (Sylvicapra grimmia) and sheep and goats were studied. Several parameters suggested that the grey duiker was much more resistant to trypanosomosis than sheep and goats. They showed increases in weight during infection, had a much longer pre-patent period, and their peak parasitaemia levels were about 100-fold lower than those of sheep and goats. Parasites were no longer detected in grey duiker blood 35 days after infection. Anaemia, measured as drops in packed cell volume (PCV), haemoglobin (Hb) concentration and erythrocyte (RBC) counts were not observed in the grey duiker. In contrast, sheep and goats suffered severe weight losses and had continuously high parasitaemia levels. Sheep and goats developed progressively severe normocytic normochromic anaemia and leucopenia from day 14 post-infection onwards.Serum levels of total protein, globulin and albumin of grey duiker did not change significantly throughout the course of infection, while the levels of total serum protein, globulin and gamma-globulin exhibited significant increases from day 21 post-infection onwards in sheep and goats, with peak values recorded on 28 and 35 days post-infection in sheep and goats, respectively. There were inconsistent variations in albumin levels in sheep and goats throughout the course of infection.There were no significant changes in erythrocyte activities of AST and ALT, while there were transient but significant elevations of ALP level on day 35, and GGT levels between 14 and 35 days post-infection in grey duiker. Conversely, the levels of all the enzymes were progressively depressed, especially from 14 to 49 days post-infection.In vitro erythrocyte peroxidation remained relatively unchanged throughout the period of the experiment in the grey duiker, except for slight but significant increase on day 42 post-infection. However, in vitro erythrocyte peroxidation increased significantly by between 100 and 300% of pre-infection levels from 14th to 42nd day p.i. both in sheep and goats, before returning to pre-infection levels after 14 days of treatment.Haematological values, serum and erythrocyte indices studied returned to near pre-infection levels 14 days after treatment with Berenil((R)).It is concluded that the grey duiker is inherently trypanotolerant. This is shown by its ability to control parasitaemia, suffer less severe anaemia, and to a relative degree resist pathobiochemical derangements of some serum and erythrocyte metabolites and enzymes, as well as reduction of infection-induced erythrocyte lipid peroxidase damage than sheep and goats.     

Haematological and lymphocyte subset analyses in sheep inoculated with bovine immunodeficiency-like virus

Bovine immunodeficiency-like virus (BIV) was passagedin vivo by intraperitoneal transfusion of ovine whole blood. Prior to transfusion, the recipient sheep were given sodium thioglycolate intraperitoneally to induce mild non-suppurative inflammation. The anti-BIV antibody response, haematology, and peripheral blood lymphocyte subsets (B, , CD2⁺, CD4⁺ and CD8⁺) of recipient sheep were assessed for one year following transfusion. Passaging was successful since serum anti-BIV antibody responses were detected in 5 of the 6 recipient sheep; 1 of the 5 remained seropositive throughout the study. Lentivirus was not isolated from the recipient sheep, but provirus was detected by the polymerase chain reaction in DNA from peripheral blood leukocytes in 3 of the 5 sheep that seroconverted. In the BIV-inoculated sheep, neutrophils and eosinophils were significantly increased (p0.05) at 3 months and between 6 and 8 months postinoculation, respectively. B, CD2⁺ and CD4⁺ cells and the CD4⁺/CD8⁺ ratios were significantly increased (p0.05) 2 months postinoculation. Mild, transient haematological changes occurred in BIV-exposed sheep, but illness was not detected in the year.     

Effect of anemia on various reactions of the domestic swine due to physical exertion. 3. Changes in plasma glucose and lactic acid concentrations]

Six anaemic and six healthy pigs were exercised for ten minutes on a belt moving at 78 m/min. Initial blood glucose values in healthy pigs averaged 71.2 mg/100 ml, and they changed very little during and after exercise. Initial values were similar in anaemic pigs (70.7 mg/100 ml), but they increased continuously, during exercise, reaching a peak of 157.4 mg/100 ml one minute after the end of exercise. Blood lactic acid increased from 1152 to 2463 mmol/litre in healthy pigs during the first minute of exercise, and then fell gradually. In anaemic pigs it increased from 1652 to 8478 mmol/l during the ten minutes of exercise, and then fell gradually. Correlations between lactic acid and haemoglobin content, between rectal temperature and Hb, and between lactic acid and changes in rectal temperature were discussed.