Failure to induce toxicity in lambs by administering saponins from Narthecium ossifragum

It has been suggested that saponins produced by Narthecium ossifragum (Bog asphodel) may be the direct cause of the toxicity leading to the hepatogenous photosensitivity disease alveld seen in Norwegian lambs. Lambs fed large quantities of freeze-dried N. ossifragum did not develop alveld. Chemical investigations on the freeze-dried material and fresh N. ossifragum showed no difference in their saponin content. These results indicate that alveld is not caused solely by the saponins produced by N. ossifragum.     

An outbreak of Haemophilus agni-Histophilus ovis septicaemia in lambs

Extract

An outbreak of an acute, highly fatal septicaemia caused by Haemophilus agni-Histophilus ovis (H-H) infection occurred in a group of 700 lambs aged 4–5 months. The clinical signs included dullness, disinclination to move, lameness and death within 24 hours. About 74 lambs died in the course of 4–5 weeks. Five dull, fevered lambs were treated with penicillin-streptomycin or oxytetracycline. They survived but developed chronic polyarthritis and were unthrifty.     

Fluorescence spectra and measurement of phylloerythrin (phytoporphyrin) in plasma from clinically healthy sheep,goats, cattle and horses

AIM: To measure the background concentration of phylloerythrin in plasma from clinically healthy sheep, goats, cattle and horses on pasture.

METHODS: Blood samples were taken from 34 sheep of the Dala breed, 20 female Norwegian dairy goats, 35 Norwegian Red cows and 34 horses of different breeds. All animals were grazing green pasture when blood samples were taken. Blood samples were collected from each of four clinically healthy newborn lambs, goats, calves and foals, and pooled into one sample per species. Plasma samples were analysed for phylloerythrin by fluorescence spectroscopy, using a Perkin-Elmer LS-50B luminescence spectrometer equipped with a red-sensitive photo- multiplier. The fluorescence spectra of phylloerythrin in plasma from the adult ruminants were compared with those in plasma from the neonatal ruminants, to which a known concentration of phylloerythrin had been added.

RESULTS: Plasma obtained from the adult ruminants had spectral characteristics similar to those of phylloerythrin, namely weak emission peaks at 650 and 711 nm, when excited at 425 nm. Emission spectra obtained from plasma from the neonatal ruminants showed no fluorescence at these wavelengths. On average, 0.012 (SD 0.004), 0.06 (SD 0.04), and 0.05 (SD 0.03) μmol/l phylloerythrin were present in plasma samples from the sheep, goats, and cattle, respectively. The fluorescence spectra of plasma from the newborn foals were similar to spectra of plasma from adult horses, with weak emission at 669 nm.

CONCLUSION: Small concentrations of phylloerythrin were detected in plasma from clinically healthy sheep, goats and cattle, but none could be detected in plasma from clinically healthy horses.     

An outbreak of severe iodine-deficiency goitre in a sheep flock in north-east Victoria

Background Several outbreaks of goitre, considered to be related to iodine deficiency, occurred in sheep flocks throughout Victoria in 2010. Objective We describe one outbreak in Merino–Border Leicester‐cross ewes and their lambs in north‐east Victoria that appeared to be associated with increased rainfall and pasture growth, particularly during the preceding summer and autumn. Results The outbreak was characterised by a four‐fold increase in neonatal lamb deaths and goitre, alopecia and poor skeletal development in the lambs. Most cases occurred in lambs born to 2‐year‐old crossbred ewes that had grazed long, lush perennial pastures throughout their entire pregnancy, whereas few cases occurred in mature crossbred or Merino ewes that had grazed shorter, annual pastures on hill country for 3 weeks in late pregnancy but were otherwise managed similarly. Conclusion Existing recommendations for south‐eastern Australia are that only spring‐lambing ewes in iodine‐deficient areas require iodine supplementation to prevent goitre in years with high autumn–winter rainfall. Aspects of this outbreak suggest that ewes lambing at other times of the year and grazing abundant pasture for prolonged periods may also require supplementation to prevent goitre, even if autumn–winter rainfall does not exceed previously established thresholds.     

An outbreak of tuberculosis affecting cattle and people on an Irish dairy farm,following the consumption of raw milk

Bovine tuberculosis is an ongoing problem in Ireland, and herd incidence has remained at approximately 5% for some years. Spillover of infection from cattle to people remains an ever-present possibility, given the ongoing pool of infection in the Irish cattle population. This paper describes an outbreak of tuberculosis affecting cattle and people on a dairy farm in southeastern Ireland following the consumption of milk from a seven-year-old cow with tuberculous mastitis. Twenty-five of 28 calves born during autumn 2004 and spring 2005 were subsequently identified as TB reactors, and five of six family members were positive on the Mantoux test. During 2005, milk from this cow had mainly been used to feed calves, and was added only occasionally to the bulk tank. Therefore, the calves each received infected milk on an almost continuous basis between birth and weaning. The family collected milk from the bulk milk tank, and consumed it without pasteurisation. This case highlights the risks associated with the consumption of raw milk. In this family, TB has had a very significant impact on the health of two young children. These risks are well recognised, and relevant information for farmers is available. It is of concern, therefore, that raw milk consumption remains prevalent on Irish farms. New strategies are needed, in partnership with industry, to address this important issue. Keywords: bovine tuberculosis, Ireland, mastitis, milk, Mycobacterium bovis, pasteurisation, TB, zoonosis.     

Restoring catalase activity in Staphylococcus aureus subsp. anaerobius leads to loss of pathogenicity for lambs

Staphylococcus aureus subsp. anaerobius, a microaerophilic and catalase-negative bacterium, is the etiological agent of abscess disease, a specific chronic condition of sheep and goats, which is characterized by formation of necrotic lesions that are located typically in superficial lymph nodes. We constructed an isogenic mutant of S. aureus subsp. anaerobius (RDKA84) that carried a repaired and functional catalase gene from S. aureus ATCC 12600, to investigate whether the lack of catalase in S. aureus subsp. anaerobius plays a role in its physiological and pathogenic characteristics. The catalase activity had no apparent influence on the in vitro growth characteristics of RDKA84, which, like the wild-type, did not grow on aerobically incubated agar plates. Restoration of catalase activity in RDKA84 substantially increased resistance to H₂O₂ when analyzed in a death assay. The intracellular survival rates of the catalase-positive mutant RDKA84 in polymorphonuclear neutrophils (PMN) isolated from adult sheep were significantly higher than those of the wild-type, while no differences were found with PMN isolated from lambs. RDKA84 showed significantly lower survival rates in murine macrophages (J774A.1 cells) than the wild-type strains did, whereas, in bovine mammary epithelial cells (MAC-T), no differences in intracellular survival were observed. Interestingly, the virulence for lambs, the natural host for abscess disease, of the catalase-positive mutant RDKA84 was reduced dramatically in comparison with wild-type S. aureus subsp. anaerobius in two experimental models of infection.     

Comparison of arterial and venous blood-gas values in anesthetized Dorset cross-bred lambs (Ovis aries) using a point-of-care analyzer

Objective

To determine the degree of agreement between arterial and venous blood gases in anesthetized lambs using a point-of-care analyzer.

Looking for prognosticators in ovine anaplasmosis: discriminant analysis of clinical and haematological parameters in lambs belonging to differently susceptible breeds experimentally infected with Anaplasma ovis

Background

A study was carried out to evaluate the response of different native sheep breeds to experimental infection with Anaplasma ovis, the most prevalent sheep tick-borne pathogen in Apulia (Southern Italy). Thirty-four lambs belonging to a Northern European breed (Suffolk) and two Southern Italian breeds (Comisana and Altamurana) were infected. Eleven clinical as well as haematological parameters were monitored at different temporal resolutions on the same subjects before and after the infection, resulting in a data set of 435 observations. The present work, aiming to further the research, presents the results of a multivariate analysis carried out to identify which parameters out of the eleven considered are the most reliable parameters to be considered as markers of the disease phenotype as well as prognosticators of practical clinical importance.

Results

Data were analysed by discriminant analysis. Out of the eleven considered variables (red blood cells, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin content, haemoglobin concentration, white blood cells, neutrophils, leukocytes, platelets, rectal temperature), only seven were included in the step-wise model since significantly increasing the Mahlanobis distance between the two closest groups. Both discriminant functions resulted to be highly significant (P < 0.0001) and the percentage of variation accounted for by the first discriminant function was 63.6% of the variance in the grouping variable.

Conclusions

Taken together, the observed results stress the marked differentiation among the three breeds in terms of physio-pathological phenotypes indicating packed cell volume and red blood cell count as the most informative parameters in the routine clinical practice for A. ovis infection in sheep.     

A note on the effect of number (single or twin) and sex of contemporary siblings on male-like play behavior of lambs (Ovis aries)

This study evaluates the effect of the number and sex of contemporary siblings on male-like play behavior of Suffolk lambs (Ovis aries). Fourteen males and 14 females, all single born, plus 26 ram lambs born co-twin to another male (n = 14) or female (n = 12) as well as 26 ewe lambs born co-twin to another male (n = 12) or female (n = 14) were observed daily for 7 weeks from 1 week of age. Two observers sitting outside a sand-bedded pen (10 × 5 m) recorded received and performed behavior (butts, nudging, attempts to mount, and mounts) by the lambs in the pen from 08:00 to 09:00 and 16:00 to 17:00 hours. Animals were in the pen only during the observation periods; the rest of the day they remained with their mothers in individual pens. Male-like play behavior patterns were displayed by both male and female lambs. Males were more active (P < 0.05) than females. Butting was the most frequent activity and performed mostly by ram lambs, recipients were generally males, and most resulted in reciprocal simultaneous encounters (sparring). Single males performed most of the nudging activity, which was the least frequent of the observed behaviors. Males with twin brothers mounted significantly (P < 0.05) more than males with twin sisters, and females with twin sisters performed the lowest amount of gutting and nudging. Lower (P < 0.05) levels of activity were found during the first 2 weeks. Overall, it was concluded that male lambs performed and received more male-like play behaviors than female lambs and the influence of sex of contemporary sibling was restricted to some behaviors: butting and nudging in females and mounting in males.     

An outbreak of granulomatous peritonitis caused by injectable selenium in a flock of Merino sheep

During meat inspection, unusual pigmented lesions were found in the abdomens of 411 sheep from a flock raised in the Northern Tablelands of New South Wales. In each affected sheep there were multiple discrete, soft, yellow homogeneous plaques beneath the parietal peritoneum and extending into marginating facial planes of the diaphragm and body wall. Microscopically, the lesions consisted of focal granulomatous peritonitis with intracellular acicular refractile golden-brown crystals. Energy dispersive X-ray spectroscopy revealed intralesional barium and selenium, two components of an injectable selenium compound administered to the sheep 6-8 months prior, which contains the yellow pigment, iron oxide. The mechanism of subperitoneal deposition of the compound could not be confirmed, but is presumed to have involved intraperitoneal injection of barium selenate. Meat inspectors and diagnosticians should consider barium selenate injection-site granulomas as a possible explanation for yellow pigmented lesions, especially in livestock from selenium-deficient areas. Animal care providers should be aware that incorrect administration of barium selenate can result in losses from condemnation or downgrading of meat product.     

Effects of leucocyte extract, levamisole and sulphadimidine on natural coccidial infections (Eimeria spp.) in young lambs

The efficacy of leucocyte extract (LE) and sulphadimidine in preventing coccidiosis in naturally infected lambs on pasture was evaluated in 3 separate experiments, whereas the prophylactic effect of levamisole was studied in 1 of the experiments. LE prepared from ewes immune to coccidia (Eimeria spp.) was administered either intravenously or intraperitoneally to young lambs 7, 5, or 2 days before they were turned out on pastures contaminated with coccidia. In all experiments, LE failed to transfer protective immunity to the lambs against the first coccidial infection on pasture. The LE preparations used apparently had an immunosuppressive effect, which resulted in more severe clinical signs of coccidiosis in the recipients. The lambs given LE showed a higher incidence of diarrhoea, a poorer weight gain, a higher mortality, and a higher oocyst output than the untreated control lambs. In lambs treated with sulphadimidine at 200 mg/kg on days 12, 13, and 14 after turnout there was a reduced severity of the coccidial infections in all experiments. The sulphadimidine-treated lambs had better weight gains and passed fewer oocysts than the controls during the third and fourth week after turnout, but some of them developed diarrhoea. Lambs treated with levamisole at 2 mg/kg 2 days before turnout, at turnout, and 2 days after turnout were more severely affected by the first coccidial infection on pasture than the controls.To study the lambs’ immunity against a heavy challenge infection with coccidia as compared with their immunity against the natural reinfection on pasture, some of the lambs from the original groups (untreated, sulphadimidine-treated, LE-treated) were each inoculated with 2 mill. Eimeria spp. oocysts about 6 weeks after turnout. The oocyst counts of the challenged lambs, except the LE-treated lambs, increased to a new peak 19–20 days after challenge. The challenge infection caused a softening of the faeces and a marked depression in weight gain in all challenged groups of lambs, mainly between days 10 and 17 after challenge. The lambs were thus only partially immune to coccidia after the first coccidial infection on pasture. The lambs treated with either LE or sulphadimidine in connection with the first coccidial infection on pasture were not appreciably more susceptible to the challenge infection than the untreated lambs.     

An outbreak of canine tracheobronchitis (kennel cough) in Zaria

The clinical and epidemiological features of the first recorded outbreak of canine tracheobronchititis (kennel cough) in Zaria are described. During the outbreak which occurred between October and December 1980, 21 per cent of dogs presented to the Small Animal Clinic were diagnosed clinically as suffering from kennel cough, compared with 0.2 per cent in the preceding year. Bordetella bronchiseptica was among the several microorganisms isolated from affected dogs.     

An outbreak of leptospirosis in seals (Phoca vitulina) in captivity

An outbreak of leptospirosis in seals (Phoca vitulina) in captivity is described. In a zoo in The Netherlands 5 adult seals died within 12 days. At necropsy all animals showed signs of acute septicaemia, consistent with acute leptospirosis. Serological examination of one animal was positive for antibodies against Leptospira interrogans serovar Icterohaemorrhagiae and the serologically closely related serovar Copenhageni. Polymerase chain reaction was positive in one other animal. 8 nutria (Myocastor coypus) were examined, serologically, through bacteriological culture and PCR. 81,8% (9/11) were serologically positive for Leptospira. The seals and nutria were housed in the same water system.