Showing papers in "Veterinary Record in 1998"

Preliminary observations on the pathogenesis of experimental bovine spongiform encephalopathy (BSE): an update

Abstract: Further preliminary observations are reported of an experiment to examine the spread of infectivity and the occurrence of pathological changes in cattle exposed orally to infection with bovine spongiform encephalopathy. Calves were dosed at four months of age and clinically monitored groups were killed sequentially from two to 40 months after inoculation. Tissues were collected for bioassay, for histopathological examinations and for the detection of PrP. Previous reported observations have included the presence of infectivity in the distal ileum of cattle killed after six to 18 months, the earliest onset of clinical signs in an exposed animal after 35 months, and diagnostic histopathological changes in the brain, in association with clinical disease, after 36, 38 and 40 months. In spite of the relative inefficiency of the bioassay of scrapie-like agents across a species barrier the new observations confirm that the onset of clinical signs and pathological changes in the central nervous system (CNS) occur at approximately the same time. The earliest pathological change, the presence of abnormal PrP 32 months after inoculation, coincided with the earliest detected infectivity in the CNS and occurred shortly before there was evidence of typical spongiform changes in the brain 36 months after inoculation. Infectivity has now been demonstrated in the peripheral nervous system, in the cervical and thoracic dorsal root ganglia 32 to 40 months after inoculation and in the trigeminal ganglion 36 and 38 months after inoculation. At the time of writing evidence of infectivity in other tissues is confined to the distal ileum, not only after six to 18 months but also after 38 and 40 months, but these findings may be supplemented by the results of further mouse assays. Nevertheless, they are in general agreement with current knowledge of the pathogenesis of scrapie.

Tonsillar biopsy and PrPSc detection in the preclinical diagnosis of scrapie

Abstract: Preliminary findings have indicated that in naturally infected sheep, fully susceptible to scrapie (vRQ-homozygous), PrPSc can be detected in the tonsils approximately one year before the expected onset of clinical disease, whereas no immunostaining can be detected in animals with a semi-resistant genotype. This paper describes the technique for taking tonsillar biopsies from sheep and gives the results of the completed experiment. In another experiment PrPSc was detected even earlier in comparable vRQ-homozygous sheep born and raised in different surroundings. At three-and-a-half months of age no PrPSc could be detected in three homozygous susceptible sheep (VRQ/VRQ), but PrpSc was detected at four months in one similar sheep. At eight months of age all seven sampled VRQ/VRQ sheep showed positive immunostaining in the biopsies, but none of the biopsies from three VRQ/ARQ heterozygotes showed any immunostaining; they were positive when sampled at 14 to 15 months of age. Biopsies from VRQ/ARR sheep were negative throughout this period. On the basis of the established or expected incubation period, PrPSc could thus be detected in the tonsils of live susceptible animals at between one-third and a half of the incubation period, more than oneand- a-half years before clinical signs normally appear in both these genotypes.

Comparison of pethidine, buprenorphine and ketoprofen for postoperative analgesia after ovariohysterectomy in the cat.

Abstract: Sixty cats which underwent an ovariohysterectomy were randomly allocated into four treatment groups. One group (controls) received no analgesics postoperatively, and the others received either a single dose of buprenorphine (0.006 mg/kg) intramuscularly, or pethidine (5 mg/kg) intramuscularly, or ketoprofen (2 mg/kg) subcutaneously. The analgesia obtained after each treatment was assessed by three measures. There were significant differences between the groups both for the requirement for intervention analgesia (P = 0.0008) and for the overall clinical assessment (P = 0.0003) with ketoprofen requiring least intervention analgesia and having the best overall clinical assessment, followed by buprenorphine then pethidine. The control group required the most intervention analgesia and had the worst overall clinical assessment. Visual analogue scale scoring for pain produced significant differences between the groups from one hour after the operation, with the cats which were given ketoprofen tending to have lower pain scores than the other groups.

Prevalence of antibodies to bovine virus diarrhoea virus and other viruses in bulk tank milk in England and Wales

Abstract: Bulk tank milk samples from 1070 dairy herds in England and Wales were tested by ELISA for antibodies to bovine virus diarrhoea virus (BVDV). A subset of 341 herds was tested by ELISA for antibodies to bovine herpesvirus 1 (BHV-1), bovine respiratory syncytial virus (BRsV) and bovine coronavirus (BCV). None of the herds had less than 40 dairy cows and none had been vaccinated against BVDV. The prevalence of BVDV antibody-positive herds in the national population was estimated at 95 per cent and approximately 65 per cent of the herds had a high level of bulk tank antibody suggestive of recent infection with BVDV. Dairy herds in East Anglia and the south-east of England had a significantly lower risk of being BVDV antibody-positive than herds in the rest of England and Wales. However, these regional differences tended to diminish with increasing herd size. Around 69 per cent of the herds were BHV-1 antibody-positive and all the herds were antibody positive to BRSV and BCV. Comparison with earlier serological surveys revealed that there had been little change in the prevalence and distribution of BVDV antibody-positive herds in England and Wales over the last 20 years, but that there had been an increase in the prevalence of BHV-1 antibodypositive herds.

Comparison of three treatments for bovine endometritis.

Abstract: Three commercial preparations for the treatment of bovine endometritis were compared: an intrauterine infusion of 1500 mg oxtytetracycline hydrochloride solution, an intramuscular injection of 500 micrograms cloprostenol (a synthetic analogue of prostaglandin F2 alpha), and an intramuscular injection of 3 mg oestradiol benzoate/500 kg estimated bodyweight. A total of 300 cases of endometritis were treated, of which 225 involved first, 67 involved second, and eight involved third or subsequent treatments. The overall success rate of treatment was 68 per cent. Oxytetracycline was successful in 73 per cent of cases, cloprostenol in 67 per cent and oestradiol in 63 per cent of cases. There was no significant difference between the success rates of the treatments, except for cows with mild endometritis in which oxytetracycline was more successful than oestradol (86 v 66 per cent, P 7 ng/ml at the time of treatment (P < 0.05). The presence of a smelly discharge at the time of treatment reduced the success rate by 17 per cent (P < 0.02). The treatment to conception interval for all successful treatments of endometritis by prostaglandin F2 alpha was 18.1 days shorter than for oestradiol (68.3 v 86.4 days, P < 0.02), and the interval for oxytetracycline was 16.2 days shorter than for oestradiol (70.2 v 86.4 days, P < 0.05).

Activation of extracellular matrix metalloproteinases in equine laminitis

Abstract: Samples of connective tissue obtained from the hoof of six laminitic and eight non-laminitic adult horses were analysed zymographically to investigate whether connective tissue matrix metalloproteinases are activated or induced during laminitis. The activity of matrix metalloproteinases was substantially greater in the tissues from the laminitic horses than in the tissues from the non-laminitic horses. A comparison of the collagenolytic activity in the laminitic and control tissues showed that collagenolytic activities corresponding to the 92 kDa (P<0.001), 72 kDa (P<0.01) and 66 kDa (P<0.01) bands were induced in the laminitic tissues.

Associations between age, parity, hormonal therapy and breed, and pyometra in Finnish dogs.

Abstract: A case-control study of 953 dogs with pyometra and 10,660 unmatched control dogs was used to investigate the relationships between age, parity, hormonal therapy and breed, and pyometra in Finnish dogs. Cases were reported in animals between nine months and 18 years of age, with a median age at diagnosis of nine years. Nulliparous bitches had a moderately higher risk of developing pyometra than primiparous and multiparous animals (adjusted odds ratio point estimate, 6.63). The administration of oestrogen increased the risk of pyometra in bitches up to four years of age (odds ratio point estimate > 6). No significant risk-enhancing effect of progestin treatment was detected and it is unlikely that such a risk, if present, is high (likelihood of the odds ratio exceeding 2 < 0.18). Seventeen breeds had an increased risk, and the wire-haired dachshund and mongrels had a decreased risk of developing the condition.

A retrospective study of mortality associated with general anaesthesia in horses: emergency procedures

Abstract: A retrospective analysis examined mortality associated with all procedures requiring general anaesthetic, performed at the Philip Leverhulme Large Animal Teaching Hospital, during the five-year period from February 1991 to December 1995. The study involved details relating to 2276 equine general anaesthetics and a variety of patient variables were examined. Within a group of 1279 animals undergoing anaesthesia for elective procedures, 46 (3.6 per cent) died or were euthanased owing to a poor prognosis or financial implications. Mortality relating directly to the surgery or anaesthesia occurred in eight of these cases. Therefore, the surgicaVanaesthetic death rate was 0.63 per cent. Death which was apparently attributable directly to the anaesthesia (no organic cause of death found at postmortem examination) occurred only once, giving an anaesthetic death rate of 0.08 per cent.

Malignant catarrhal fever caused by ovine herpesvirus-2 in pigs in Norway

Abstract: This paper describes the first cases of malignant catarrhal fever (MCF) in pigs in which the diagnosis was verified aetiologically by polymerase chain reaction (PCR) and DNA analysis and by the demonstration of antibodies Three pigs on two separate premises showed clinical signs, gross pathological and histopathological lesions which were in many respects similar to those of MCF in ruminants The pigs were housed adjacent to sheep and DNA of ovine herpesvirus-2 (OHV-2) was detected by PCR in tissues of all the pigs In addition, antibody to alcelaphine herpesvirus-1 was detected in the serum of the pigs and in five in-contact sheep It is concluded that the disease described is MCF of pigs caused by OHV-2

A review of the road transport of slaughter sheep

Abstract: The transport of farm animals has been the subject of much research in recent years. This paper reviews the past and recent scientific literature pertinent to the road transport of slaughter sheep. The state of knowledge is summarised and recommendations for best practice based upon this are given. Areas which require further work are also identified.

Preclinical detection of PrPSc in nictitating membrane lymphoid tissue of sheep

Abstract: observed in donkeys infected by larvae of Rhinoestrus usbekistanicus (Kaboret and others 1996). The pathology is probably caused by permanent antigenic stimulation during the infection. In both of these myiases, considerable numbers of eosinophils and mast cells have been observed in the lung parenchyma, mainly in the peribronchial region. In the absence of any other lung parasite and any cause of allergic pneumonia it is presumed that aspirated larval antigen induces pulmonary sensitisation. It has recently been suggested that mast cells could induce lung fibrosis; histamine and serotonin stimulate the growth factor for fibroblasts in vitro and in vivo. In vitro co-cultivation of fibroblasts and mast cells resulted, first, in the maturation of mast cells which, in turn, stimulated the growth of fibroblasts and the synthesis of collagen (Tunon de Lara and others 1996). The same hypothesis could possibly explain the development of interstitial pneumonia in oestrosis in both sheep and donkeys.

Incidence of clinical mastitis in dairy herds in England

Abstract: The annual incidence of clinical mastitis was measured in 144 Holstein/Friesian dairy herds in England (average size 132 cows) during 1994, 1995 and 1996 by means of carefully defined mastitis indices. The mean annual incidence of the disease over the three-year period was 43.4 quarter-cases per 100 cows, and the disease affected 25.9 per cent of the cows in the herds, with 1.6 quarter-cases per affected cow. In terms of cow-cases, the mean incidence was 39.9 cases per 100 cows in the herd and hence the ratio of quarter-cases to cow-cases was on average 1:1. The proportion of repeat quarter-cases was on average 19.4 per cent, and the recurrence rate was 18.3 per cent. The new infection rate was 28.3 per cent.

Morphology of congenital intrahepatic portacaval shunts in dogs and cats

Abstract: The preoperative ultrasound images and biplanar operative mesenteric portograms of 28 dogs and six cats with congenital intrahepatic portacaval shunts were reviewed retrospectively. On the basis of the combined surgical, postmortem and imaging data, the shunts were classified according to their location within the liver and their shape. Thirteen dogs and four cats had a left-divisional shunt with a relatively consistent bent tubular shape that drained into the left hepatic vein. Another 13 dogs had a central-divisional shunt that took the form of a foramen between dilated portions of the intrahepatic portal vein and caudal vena cava. One cat with a central-divisional shunt had a tortuous vessel. The remaining two dogs and one cat had right-divisional shunts that were large, tortuous vessels. The morphology of a left-divisional shunt is compatible with patent ductus venosus, but the pathogenesis of central and right-divisional shunts is unknown. It is concluded that intrahepatic portacaval shunts in dogs and cats may be classified as left, central or right divisional. Ultrasound enables a preoperative morphological assessment that correlates well with the results of portography and may aid surgical planning.

Study of leg weakness in two commercial broiler flocks

Abstract: The major causes of leg weakness/lameness were investigated in two male commercial broiler flocks. The numbers of dead and lame birds culled from the flocks each day were recorded by the flock managers. Forty-four lame birds and 22 sound birds were examined postmortem during a period of six weeks and the proximal and distal end of each femur, tibiotarsus and tarsometatarsus were examined histologically. Attempts were made to isolate bacteria and viruses from the proximal end of each femur. Blood samples were examined for antibodies to chicken anaemia virus (CAV), infectious bursal disease virus (IBDV) and Mycoplasma species. Bacterial chondronecrosis with osteomyelitis was identified in the proximal end of the femur of eight of the 44 lame birds, and in the proximal end of the tibiotarsus of a further bird (20.4 per cent). Gram-positive bacteria were present in all the lesions. Staphylococcus aureus was recovered from 62.5 per cent of the lesions confirmed by histology. Bacterial chondronecrosis associated with S aureus has thus been identified as an important cause of leg weakness in these commercial broilers. Lesions suggestive of the condition were visible macroscopically in only 11.1 per cent of the cases subsequently diagnosed by histology and bone histology is therefore required before a diagnosis can be excluded. Angular limb deformities (13.6 per cent) and spondylolisthesis (11.4 per cent) were the most common macroscopic lesions identified as causes of lameness. The overall incidence of tibial dyschondroplasia was similar in both the lame and sound broilers, but severe lesions were found only in lame birds (4.5 per cent).

Causes of death of wild birds of the family Fringillidae in Britain

Abstract: The provision of supplementary food for wild birds in gardens during the winter months is common in the UK, but it is possible that it may precipitate infectious diseases in the birds. This paper describes the results of postmortem examinations of 116 wild finches carried out over a period of four years. The two commonest causes of death in areas where high mortality had been reported were infections with the bacteria Salmonella typhimurium DT4o and Escherichia coli O86. Coccidia of the genera Atoxoplasma or Isospora were found in several of the birds but were considered to be incidental. Megabacteria were also identified in some of the birds, for the first time in flocks of wild birds in the UK, but they were not considered to be significant.

Development of snake antivenom antibodies in chickens and their purification from yolk.

Abstract: Adult white leghorn hens hyperimmunised with Brazilian snake venoms of the genus Bothrops and/or Crotalus produced antibodies capable of recognising, combining with and neutralising the toxic and lethal components of the venoms. The antibodies were first detected by an enzyme-linked immunosorbent assay two weeks after starting the immunisation schedule, reached the highest titres by the third week and remained high for at least 24 weeks. These antibodies are transferred to the egg yolk from which they were isolated as enriched IgY preparations by a combination of methods using positive and negative precipitation with sodium sulphate and/or caprylic acid. The yolk-derived IgY preparations contained antibodies which blocked the phospholipase A2-dependent haemolytic activity of both venoms and the haemorrhagic activity of Bothrops venom, and neutralised the toxic lethal activities of the venoms with good efficacy. The median effective dose (ED50) of the IgY anti-Bothrops venom was 592.5 μl/2LD50 and, 1.0 ml neutralised 0.0675 mg of venom. The ED50 of the IgY anti-Crotalus venom was 457.5 μl/3LD50 and 1.0 ml neutralised 0.075 mg of venom.

Canine piroplasmosis due to Babesia gibsoni: clinical and morphological aspects

Abstract: a significant fall in MAP during the observation time, even though Clarke and others (1991) have described a late hypotensive effect of romifidine from 60 to 90 minutes. Atropine sulphate has been evaluated in combination with alpha-2 agonists in horses (Short and others 1986, Gasthuys and others 1990). In a preliminary report, atropine administered 15 minutes before romifidine prevented the drop in heart rate caused by the alpha-2 agonist and resulted in marked hypertension (Young and others 1994). Similar results were observed when hyoscine was administered before detomidine to horses (Valadao and others 1994). In the present study, hyoscine pretreatment also prevented the bradycardia and second degree atrioventricular heart block related to romifidine. These effects were probably mediated by blocking muscarinic receptors, increasing sinoatrial and atrioventricular node excitability (Brown 1990). Singh and others (1996) observed that glycopyrrolate pretreatment stimulated the cardiovascular function of xylazine/ketamineanaesthetised horses, resulting in increased heart rate, cardiac index and arterial blood pressure, with no changes in systemic vascular resistance. The hypertensive response observed was attributable to the higher cardiac output observed after anticholinergic pretreatment. In contrast, Klide and others (1975) observed that atropine did not improve the cardiac output of xylazine-sedated dogs, even though heart rate was higher. These data suggest that further studies are necessary to investigate whether prevention of the bradycardia observed after hyoscine pretreatment is associated with changes in cardiac output. Alibhai and others (1996) investigated the effects of atropine and medetomidine in dogs and commented that, if bradycardia becomes profound, anticholinergic treatment is necessary to save life. However, they also observed prolonged and intense hypertension in association with tachycardia and stated that it is questionable whether routine use of such drugs is advantageous. In the present study, anticholinergic pretreatment also increased the intensity and duration of the hypertensive effects caused by romifidine. Additionally, it should be pointed out that tachycardia and hypertension may be associated with increased afterload and elevation in myocardial oxygen consumption (Sonnenblick and others 1968). Hyoscine produces a lower reduction in gastrointestinal activity than atropine in horses (Ducharme and Fubini 1983, Roelvink and others 1991). To the authors' knowledge, there is little evidence that hyoscine causes fewer problems than atropine in terms of cardiovascular function, but the relatively brief period of gut stasis produced by hyoscine may make this drug a good choice if anticholinergic treatment is required in horses. Although hyoscine prevented the bradyarrhythmia produced by the alpha-2 agonist, its routine use with romifidine should be considered in regard to its additional hypertensive response.

Effect on viraemia of an American and a European serotype PRRSV vaccine after challenge with European wild-type strains of the virus.

Abstract: Three groups of 10 pigs were vaccinated with an American serotype porcine reproductive and respiratory syndrome virus (PRRSV) vaccine and three groups of 10 pigs were vaccinated with a European serotype PRRSV vaccine. A control group of 12 pigs was left unvaccinated. Four weeks after vaccination the PRRSV-specific antibody titres were determined and each group was challenged with either a Spanish, German or Dutch PRRSV wild-type strain. The serological responses four weeks after vaccination confirmed that the two vaccines were of different serotypes. Vaccination with the American serotype vaccine hardly reduced the level of viraemia after challenge with the European PRRSV wild-type strains, and only after challenge with the Spanish PRRSV strain was a moderate, statistically significant reduction in viraemia observed. In contrast, after vaccination with the European serotype vaccine, viraemia was completely suppressed after challenge with the German PRRSV isolate and almost completely suppressed after challenge with the Spanish and Dutch PRRSV isolates.

Early manifestations of granulocytic ehrlichiosis in dogs inoculated experimentally with a Swedish Ehrlichia species isolate.

Abstract: Seven beagles were inoculated experimentally with a Swedish canine Ehrlichia species isolate to study its pathogenicity. With respect to the 16S rRNA gene sequence, the isolate was identical to the human granulocytic ehrlichiosis (HGE) agent and closely related to both Ehrlichia equi and E phagocytophila . After an incubation period of four to 11 days, the most prominent clinical signs were high fever for two to five days and depression. AU the dogs developed profound thrombocytopenia, moderate leukopenia and a strong serological antibody response. Ehrlichial inclusions were detected in blood neutrophils from four to 14 days after inoculation for four to eight days. Ehrlichial DNA could be detected by polymerase chain reaction during the parasitaemic stage and a few days before and after microscopic inclusions were visible. Postmortem, the dogs showed reactive splenic hyperplasia and non-specific mononuclear reactive hepatitis.

Mycobacterial antigen-specific antibody responses in bovine tuberculosis: an ELISA with potential to confirm disease status

Abstract: Serological assays may help to identify animals in advanced stages of bovine tuberculosis, but most of the tests available have suboptimal sensitivities and specificities. This study was designed to determine whether the antibody responses to defined antigens (rMPB70, rMPB64 and rMPB59) of Mycobacterium bovis at the immunoglobulin subclass level could be used to develop improved serological tests. In experimentally infected cattle it was found that the predominant serum antibody response was to rMPB70, and that an IgG1 response to this antigen was boosted strongly by skin testing. Studies in naturally infected cattle suggested that this memory IgG1 anti-rMPB70 response may be able to differentiate between skin test-reactor animals with and without lesions by comparing the ratio of the antibody response before and after skin testing. The study has provided a clearer understanding of the kinetics of antibody responses to defined mycobacterial antigens at the subclass level in bovine tuberculosis and has made it possible to develop a novel ELISA system which may be useful in disease diagnosis.

Choosing appropriate space allowances for slaughter pigs transported by road: a review

Abstract: In the United Kingdom pigs can spend up to 11 hours in transit to slaughter but on average travel for two to three hours. In the past, international journeys have lasted up to 40 hours and have been over 900 miles long. There is evidence that pigs, like calves and sheep, but unlike adult cattle, prefer to lie down if provided with suitable conditions, particularly bedding, on the vehicle. They will, however, sometimes stand during short journeys, possibly when excessive vibration or uncomfortable flooring, particularly a lack of sufficient bedding, cause discomfort. Current UK legislation and EU Directive 95/29/EC specify that, in general, pigs must have sufficient space to lie down during transit. Measurements of the space needed for sternal recumbency, and direct observations of pigs at different stocking densities, suggest that the minimum space required is equivalent to about 250 kg/m2 for normal slaughter pigs of 90 to 100 kg liveweight. This figure may not be appropriate for very small or very large pigs. In the UK at present, more than half of all slaughter pigs are transported at densities greater than that prescribed (235 kg/m2) in the EU Directive. At stocking densities above about 250 kg/m2 there may not be enough room available for all the pigs to lie down, leading to continual disturbance of recumbent animals by those seeking a place to rest. A stocking density of 322 kg/m2 leads to clear evidence of physical stress. During long journeys (> or = 25 hours) meat quality is reduced by high stocking densities, implying muscle glycogen depletion and possibly fatigue. Higher stocking densities are also associated with higher mortality. There is evidence of wide variations in air temperature inside transporters, particularly for international journeys. Although there are small variations within vehicles, the temperature of the air inside is closely related to the outside temperature. It has been recommended that the temperature within the vehicle should not exceed 30 degrees C in order to remain within the pig's thermoneutral zone. Such temperatures, together with acceptably low concentrations of potentially noxious gases, such as carbon dioxide, can be achieved in moving vehicles by adequate ventilation, provided there is adequate space above the animals' heads. In triple-decked lorries, the height between decks has tended to be reduced and can be as little as 90 cm. Further work is needed to decide whether this is sufficient for modern slaughter pigs.

Effect of ovariohysterectomy in bitches with mammary neoplasms.

Abstract: Ninety bitches with mammary tumours were studied for two years after the surgical removal of the primary tumour(s). Twenty-nine of the bitches had been spayed before the development of the mammary tumour, 22 were spayed when the tumours were removed and 39 were left entire. Fifty-eight of the bitches (64 per cent) had benign tumours and, of these, 15 (26 per cent) developed a new mammary tumour within two years, irrespective of whether the bitch was spayed. The other 32 bitches had malignant tumours which were grouped into 'invasive' and 'well defined' carcinomas. Sixty-three per cent of the spayed bitches and 57 per cent of the entire bitches, with invasive carcinoma were dead within two years of surgery as a result of their mammary tumours. For those with well defined carcinomas the tumour-related death rates were 18 per cent and 33 per cent respectively for the spayed and entire bitches. These findings suggest that ovariohysterectomy when mammary tumours are removed does not have a significant effect on the progression of malignant disease, and that about one in four bitches with a benign mammary tumour is likely to develop a further tumour in another gland.

Investigations into field cases of porcine colitis with particular reference to infection with Serpulina pilosicoli

Abstract: Investigations into the possible causes of colitis and typhlocolitis were carried out on 85 pig units in the United Kingdom between 1992 and 1996. Serpulina pilosicoli was identified most commonly, occurring as the suggested primary agent on 21 (25 per cent) of the units but forming part of mixed infections on another 23 (27 per cent) of the units, the main co-infections being Yersinia pseudotuberculosis (eight units), proliferative enteropathy (six units), Salmonella species (four units) or Serpulina hyodysenteriae (two units). 'Atypical' Serpulina species, S hyodysenteriae, Salmonella typhimurium, Y pseudotuberculosis and Lawsonia intracellularis (proliferative enteropathy) were the suggested primary agents on seven, six, four, four and three units, respectively. Various combinations of mixed infections involving the latter organisms and other possibly incidental agents were recorded on another 10 units. Investigations on a further six units failed to detect any recognised pathogens. On units where S pilosicoli was the suggested primary agent, pigs ranging between 20 to 40 kg (eight to 16 weeks of age), but occasionally up to 50 kg, had diarrhoea and grew poorly over a period of two to three weeks. The prevalence was estimated to be between 5 and 15 per cent in affected batches, with a mortality of approximately 1 per cent. The clinical signs usually developed seven to 14 days after the moving and mixing of pigs. At postmortem examination, affected pigs had liquid contents in their colon, which contained accumulations of mucus in some chronic cases. Gross and histological lesions of colitis were prominent in the mid-spiral region of the colon. In mixed infections with Y pseudotuberculosis, Salmonella typhimurium or S hyodysenteriae, lesions were more extensive and affected the caecum as well as the colon. In the colon, lesions of proliferative enteropathy were usually confined to the proximal half of the ascending spiral but mixed infection with S pilosicoli caused more extensive colitis. Mixed infections were reported to prolong the time taken for pigs to recover naturally and to have a more detrimental effect on growth rates than S pilosicoli infection alone. Despite the successful treatment of batches of pigs with tiamulin or lincomycin, S pilosicoli infection persisted as a chronic problem on many units, with diarrhoea and colitis in successive batches of pigs unless prophylactic medication was used.

Serum haptoglobin concentrations in Holstein dairy cattle with toxic puerperal metritis

Abstract: The serum concentration of haptoglobin was measured in 51 cows with toxic puerperal metritis which were being treated with one of three different antimicrobial regimens. The mean concentration of haptoglobin was 19.0 mg/dl on the day that the treatments began and declined steadily during the five day treatment period to a mean concentration of 7.35 mg/dl. There was no correlation between the serum haptoglobin concentrations and the rectal temperatures of the cows during the five days.

Evaluation of false ultrasonographic diagnoses in cows by measuring plasma levels of bovine pregnancy-associated glycoprotein 1.

Abstract: Between days 27 and 59 after artificial insemination (AI), 189 ultrasonographic pregnancy diagnoses were made in 56 dairy cows using a 7.5 MHz linear-array rectal transducer. Blood samples were withdrawn from a jugular vein on the day of Al, on day 21, and after each ultrasonographic examination between days 27 and 31, days 34 and 38, days 41 and 45 and days 55 and 59 after AI. Plasma concentrations of bovine pregnancy- associated glycoprotein 1 (bPAG-1) were measured by radioimmunoassay. The results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non-pregnant. In five of these animals, the uterus was located far cranial to the pelvic inlet. Five of the cows examined between days 27 and 31 were pregnant on the basis of plasma bPAG-1 levels on the same day, using 0.5 ng/ml as the cut-off point. Plasma levels of bPAG-1 and progesterone proved that four of the cows which had early positive ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.

Porcine dermatitis and nephropathy syndrome in Spain

Abstract: In August 1995, the first case of porcine dermatitis and nephropathy syndrome was diagnosed in the north-eastern part of Spain; the pig showed characteristic dermal and renal lesions. Between then and January 1996, nine further animals from five different herds were diagnosed; they showed signs of anorexia, depression and, sometimes, pyrexia. Diarrhoea, Glasser9s disease, conjunctivitis and gastric ulcers also occurred on the farms where the diagnoses were made. The affected pigs died of renal failure with diffuse fibrinous glomerulonephritis and a systemic necrotising vasculitis. Chronic interstitial nephritis, glomerulosclerosis and scar-like marks on the skin were observed in chronic cases. Other common findings in both acute and chronic cases were a diffuse depletion of lymph node lymphocytes with infiltration by syncytial cells (50 per cent of cases) and interstitial pneumonia. All the animals tested positive for porcine reproductive and respiratory syndrome virus (PRRSV) by serological tests and virus isolation. Serum urea and creatinine concentrations were above normal in the acutely affected animals. The pathogenesis of the condition is unknown but the lesions and immunopathological observations by other authors suggest that a type III hypersensitivity is a possible aetiology. The occurrence of PRRSV in these pigs suggests that the virus might be implicated in the pathogenesis of porcine dermatitis and nephropathy syndrome.