Showing papers in "Veterinary Record in 1981"
157Â citations
TL;DR: The blastomeres of eight-cell cow embryos were separated by micromanipulation into four pairs, inserted in foreign zonae pellucidae, embedded in agar and cultured for approximately four days in ligated sheep oviducts, and 15 of the embryos had continued to develop including two sets of monozygotic quadruplets and one set of mon allele triplets.
Abstract: The blastomeres of eight-cell cow embryos were separated by micromanipulation into four pairs, inserted in foreign zonae pellucidae, embedded in agar and cultured for approximately four days in ligated sheep oviducts. Of 44 "quarter" embryos (11 monozygotic groups) transferred to sheep, 91 per cent had continued to develop at a normal rate and 77 per cent had formed small blastocysts with a single inner cell mass. Twenty-six blastocysts freed from the agar were transferred to heifers, each heifer receiving two monozygotic embryos, one to the tip of each uterine horn. Nine recipients were diagnosed pregnant by rectal palpation on day 50, six carrying twins. Thus 15 of the embryos had continued to develop including two sets of monozygotic quadruplets and one set of monozygotic triplets. Eight fetuses developed to full term, one set of monozygotic triplets, two sets of monozygotic twins (one set born dead) and one single.
149Â citations
TL;DR: Hereford cross beef heifers at pasture were inseminated at a detected oestrus with thawed semen and slaughtered at the following intervals after insemination, finding fertilisation failure can account for up to 20 per cent of reproductive wastage.
Abstract: Hereford cross beef heifers at pasture were inseminated at a detected oestrus with thawed semen and were slaughtered at the following intervals after insemination: day 3 (60 heifers); day 8 (71); day 14 (65); day 18 (78) and day 28 (29). The recovery rates of ova at days 3 and 8 were 87 and 77 per cent respectively. The percentage of heifers that were pregnant at the respective time intervals after slaughter were 81, 84, 75, 60 and 62. There was no difference in the proportion of normally developing ova or embryos between days 3 and 8, 8 and 14, 14 and 18 or 18 and 28. There were significant differences in the number of animals with variable embryos between days 3 and days 18 + 28 (P less than 0.025); 8 and 18 + 28 (P less than 0.01); and 14 and 18 + 28 (P less than 0.05). Based on the results and other data in the literature, fertilisation failure can account for up to 20 per cent of reproductive wastage. Embryonic mortality accounts for most of the remaining wastage and occurs gradually between days 8 and 18. Pregnancy rates at days 18 and 28 approximate to calving data.
131Â citations
121Â citations
TL;DR: Comparison of clinical and pathological features of breast cancer suggests that the cat is an appropriate surrogate for the experimental study of human breast cancer, and the apparent lack of oestrogen dependency in feline breast cancer also suggests the cat may be especially suited for evaluating therapeutic regimens for breast cancers that do not respond to hormonal manipulation.
Abstract: An epidemiological survey involving 132 cats with mammary neoplasia, seen at 15 North American veterinary medical teaching hospitals, was conducted. The ratio of malignant to benign tumours was 9:1. There were 113 cases of carcinomas of all types (including two males), with adenocarcinoma being the predominant cell-type. Relative risk analysis indicated that the Siamese breed had twice the risk (P less than 0.01) of developing mammary carcinoma compared to all breeds combined. The age at diagnosis in Siamese females tended to be younger than in other breeds. Comparison of clinical and pathological features of breast cancer suggests that the cat is an appropriate surrogate for the experimental study of human breast cancer. The apparent lack of oestrogen dependency in feline breast cancer also suggests that the cat may be especially suited for evaluating therapeutic regimens for breast cancers that do not respond to hormonal manipulation.
114Â citations
TL;DR: Kidneys of cattle, mice and badgers were cultured for leptospires and no evidence of infection was found in either badgers or mice, indicating that cattle act as the maintenance host for serotype hardjo.
Abstract: Kidneys of cattle, mice and badgers were cultured for leptospires in an attempt to evaluate the relative importance of these species in the epidemiology of bovine leptospirosis caused by the Hebdomadis serogroup. Leptospires closely related to serotype hardjo were recovered from 57 (28.5 per cent) of 200 cattle examined but no evidence of infection was found in either badgers or mice, indicating that cattle act as the maintenance host for serotype hardjo. Many cattle were seronegative carriers.
106Â citations
TL;DR: The method by which airborne disease spread is assessed in the United Kingdom is described, which involves determining the likelihood of spread by all of the mechanisms, one of which is from airborne virus released by infected animals.
Abstract: When an outbreak of Foot-and-mouth Disease (FMD) occurs it is essential to assess the potential for spread from any source farm. This involves determining the likelihood of spread by all of the mechanisms, one of which is from airborne virus released by infected animals. This paper describes the method by which airborne disease spread is assessed in the United Kingdom. The Institute for Animal Health Pirbright Laboratory (IAH), Met Office UK and Department for Food Environment and Rural Affairs (Defra) have actively researched both laboratory and field outbreaks of FMD and the results have informed the current operational procedure. One of the major tools used in the assessment process is the Met Office UK NAME model (Numerical Atmospheric Modelling Environment). This computer model requires, as input, a detailed description of the disease on the infected premises together with knowledge of the airborne characteristics of the virus strain involved and meteorological data representative of the area. If the outbreak is situated in a valley or hillside local flows may substantially influence the pattern of disease spread; this may be assessed by the inclusion of a local flow model within NAME. Providing an accurate assessment of the risk of airborne disease spread is a complex task and experience shows that each outbreak is unique. The significance of airborne disease transmission depends upon the interaction of individual components in the transmission chain. Consequently, before an area of risk can be determined with confidence, all of the available information must be carefully recorded and assessed. To be of operational use this task must be completed quickly and therefore requires a rugged and fully flexible system to be in place and to have been tested regularly.
99Â citations
96Â citations
TL;DR: Investigation of the relationship between measurements of fat mobilisation and fat deposition in liver and muscle in high yielding dairy cows found that cows with higher levels of indices of mobilisation, namely plasma free fatty acid and D(--) -3- hydroxybutyrate concentration and subcutaneous adipose tissue loss, had higher indices of fat deposition.
Abstract: High yielding dairy cows undergo a period of energy deficit in early lactation and mobilise body reserves for milk production. In this period a high proportion of cows develop moderate or severe fatty liver. Fat is deposited in other tissues at the same time, particularly skeletal muscle. The relationship between measurements of fat mobilisation and fat deposition in liver and muscle has been investigated in a group of 19 cows in the post calving period. Cows with higher levels of indices of mobilisation, namely plasma free fatty acid and D(--) -3- hydroxybutyrate concentration and subcutaneous adipose tissue loss, had higher indices of fat deposition in liver and skeletal muscle. Statistical analysis of the data indicated that fatty liver was part of a more general fat mobilisation syndrome which was not specific to any one organ or tissue.
90Â citations
82Â citations
TL;DR: It is confirmed that N'Dama cattle are innately less susceptible to trypanosomiasis than Zebu cattle and can survive and be productive in endemic areas of trypanOSomiasis where Zebe perish.
Abstract: The use of trypanotolerant livestock is considered to be an important strategy for the control of African animal trypanosomiasis. In order to define the extent of the differences in susceptibility and productivity, 10 Zebu cows (a breed considered trypanosusceptible) and 10 N'Dama cows (a breed recognised for trypanotolerance) were exposed to a natural field challenge from Glossina morsitans submorsitans Newstead. The animals were two-and-a-half to three years old and had not been previously exposed to trypanosomiasis. All Zebu died of trypanosomiasis within eight months of first exposure. In contrast, only three N'Dama died of trypanosomiasis; they had all been suckling calves before they succumbed 11 to 14 months after initial exposure. The prevalence, level and duration of parasitaemia were significantly less in the N'Dama, which, unlike the Zebu, did not become febrile during parasitaemia. The differences in parasitaemia were largely attributable to Trypanosoma vivax. The N'Dama also developed much less severe anaemia than the Zebu. The mean and standard deviation of the packed red cell volume of the N'Dama was not significantly different between eight months after exposure when all Zebu were dead, and 21 months when the experiment was terminated. The relative productivity of the N'Dama was impressive. In addition to reduced mortality, the N'Dama experienced no abortions and produced five calves, three of which were alive at the end of the experiment, at which time three of the surviving N'Dama were pregnant. In the Zebu, in marked contrast, abortions occurred both in early and late pregnancy and no live calves were produced. The study confirmed that N'Dama cattle are innately less susceptible to trypanosomiasis than Zebu cattle and can survive and be productive in endemic areas of trypanosomiasis where Zebu perish.
TL;DR: An investigation into fibre composition and glycogen depletion pattern within the middle gluteal of 16 horses participating in an 80 km endurance ride was carried out, and it was found that the horses with the highest proportion of these fibres usually had the best performance records.
Abstract: An investigation into fibre composition and glycogen depletion pattern within the middle gluteal of 16 horses participating in an 80 km endurance ride was carried out. Although the proportion of slow twitch high oxidative (ST) fibres in the horses varied between 7 and 38 per cent, it was found that the horses with the highest proportion of these fibres usually had the best performance records. The cross-sectional area of the fast twitch low oxidative (FT) fibres was greatest, with the ST and fast twitch high oxidative (FTH) being similar in size. Most marked histological evidence of glycogen depletion after the ride was in the ST fibres, which were apparently totally depleted. A variable degree of depletion was found in both the FTH and FT fibres. Biochemical measurement of muscle glycogen showed a 56 +/- 7.2 per cent (mean +/- SEM) decrease in content.
TL;DR: It is suggested that thermal stress in the tropics has significant adverse effects on spermatogenesis only in bulls of non-indigenous breeds andSenile testicular degeneration could be a significant factor in the low reproductive performance of the local bulls.
Abstract: The spermiogram of 10 mature bulls, ranging in age between three and 10 years and comprising five indigenous (Bos indicus) and five exotic (Bos taurus) bulls, was studied for 12 months. There were no significant seasonal variations in sperm cell concentration, percentage live sperm cells and sperm cell abnormalities in the indigenous bulls but the exotic breed showed significant seasonal fluctuations with higher sperm cell abnormalities, lower percentage live-sperm cells and lower sperm cell concentration during the hot periods. In both groups the sperm cell concentration was significantly higher in the relatively younger, mature bulls (three to seven years) than in the older bulls (seven-and-a-half to 10 years) Histological study of the testes of 240 indigenous bulls over the same period showed that percentage spermatogenesis was lower in the older than in the younger bulls. This lower sperm output was associated with degenerative changes in the seminiferous tubules. It is suggested that thermal stress in the tropics has significant adverse effects on spermatogenesis only in bulls of non-indigenous breeds. Senile testicular degeneration could be a significant factor in the low reproductive performance of the local bulls.
TL;DR: An outbreak of paresis occurred on a small isolated stud farm in July 1980 and one mare died and serological studies confirmed that 24 of 26 animals sampled had experienced infection.
Abstract: An outbreak of paresis occurred on a small isolated stud farm in July 1980. Of the 42 horses on the stud, infection was confined to a group of nine in-foal mares and their foals and eight other horses which were either housed together at night or grazed adjacent pastures. Eight mares and two geldings developed ataxia or paresis and one mare died. Equid herpesvirus 1 was isolated from 17 animals and serological studies confirmed that 24 of 26 animals sampled had experienced infection.
TL;DR: An acute pneumonia developed in 28 calves which had been housed together from one to two weeks of age and the clinical signs included pyrexia, tachypnoea, respiratory distress and coughing, and some of the calves died.
Abstract: An acute pneumonia developed in 28 calves which had been housed together from one to two weeks of age. The clinical signs included pyrexia, tachypnoea, respiratory distress and coughing. Some of the calves died. The pneumonia was characterised by an alveolitis with multinucleated syncytia, alveolar epithelial hyperplasia and bronchiolitis. Interstitial emphysema was also present. Fifteen of 19 calves examined serologically had rising neutralising antibody titres to respiratory syncytial virus; in nine calves the rise was fourfold or greater. Respiratory syncytial virus was not isolated from the calves. There was no evidence of parainfluenza type 3 virus involvement. The adult cows being sucked by the calves remained clinically normal throughout the incident. Six calves examined six weeks after the outbreak started had a chronic cuffing pneumonia characterised by lymphocytic bronchiolitis; some of the calves also had bronchiolitis obliterans. Mycoplasma dispar was found in two of them.
TL;DR: Twenty-six incidents of salmonellosis occurring in Scotland between 1973 and 1979 and attributed to environmental pollution are reviewed and the factors causing pollutions are discussed.
Abstract: Twenty-six incidents of salmonellosis occurring in Scotland between 1973 and 1979 and attributed to environmental pollution are reviewed. The apparent sources of pollution were sewage effluent (10 incidents), septic tank effluent (eight), sewage sludge (three), seagulls (three) and abattoir effluents (two). Cattle were the species predominantly affected. Human infection was primary in three incidents and was secondary to bovine infection in another four. Thirteen salmonella serotypes were recovered from infected humans or animals and 17 during related environmental investigations. The factors causing pollutions and possible control measures are discussed.
TL;DR: A retrospective study of a seasonal infertility problem in a large intensive piggery showed that during the periods of infertility there was a significant increase in the numbers of sows returning to oestrus in the periods 22 to 37 and 44 to 53 days after mating.
Abstract: A retrospective study of a seasonal infertility problem in a large intensive piggery showed that during the periods of infertility there was a significant increase in the numbers of sows returning to oestrus in the periods 22 to 37 and 44 to 53 days after mating. A prospective study showed that the majority of sows affected by the seasonal infertility problem returned to oestrus during the fourth of fifth week after mating. However, some sows did not exhibit a normal behavioural oestrus at this time and so the oestrus was undetected until and sow completed another oestrous cycle accounting for the second period of increased returns at 44 to 53 days. Some sows failed to exhibit behavioural evidence of oestrus at this second to exhibit behavioural evidence of oestrus at this second oestrus and so had very prolonged mating to detectable oestrus intervals.
TL;DR: It was concluded that the xylazine-ketamine combination had advantages over other current techniques of inducing anaesthesia in horses.
Abstract: One hundred anaesthetics were administered in a clinical trial to 95 equine patients, ranging in age from nine months to 19 years and in weight from 140 to 1270 kg, undergoing a variety of surgical procedures. Acepromazine maleate premedication (0.01 to 0.03 mg per kg intramuscularly) was given to seven animals, the remainder were not premedicated. Xylazine (1.1 mg per kg) was injected intravenously over a two minute period and after a pause of two minutes ketamine (2.2 mg per kg) was injected rapidly by the same route. For 30 procedures no other anaesthetic was given but in 59 cases anaesthesia was prolonged with halothane-oxygen while in 11 additional intravenous agents were administered. Recumbency followed one-and-a-half to two minutes after completion of the ketamine injection and limb movements occurring immediately after the animal lay down gradually subsided over the next 30 to 60 seconds. On 26 occasions when no other agent was given satisfactory operating conditions were produced for a mean (+/- sd) of 20 +/- 7 minutes and on four occasions when absence of complete muscle relaxation was observed surgery was still possible. When no other agent was given the onset of recovery was abrupt but recovery was always extremely quiet; the animals stood 33 +/- 10 minutes after induction of anaesthesia and showed a remarkable absence of ataxia. A similar recovery was seen in the 56 animals receiving halothane-oxygen and all stood 28 +/- 14 minutes after disconnection from the anaesthetic system. Heart block was observed during induction of anaesthesia bu otherwise cardiovascular and respiratory parameters were well maintained. It was concluded that the xylazine-ketamine combination had advantages over other current techniques of inducing anaesthesia in horses.
TL;DR: It is suggested that for the sake of animal welfare captive bolt shooting at the nape of the neck should be abandoned.
Abstract: Captive bolt stunning frontally, occipitally and on the nape of he neck was studied in 30 veal calves. The state of consciousness was judged from the electroencephalogram (EEG) recorded via surgically pre-implanted electrodes frontally on the right side of the head. Frontal stunning on the left side of the head and occipital stunning almost certainly ensured immediate unconsciousness because delta and theta waves (tending to an iso-electric line) appeared on the EEG directly after stunning. Additionally the corneal reflex was absent. Occipital placing did not result in macroscopical damage to the cortex as did frontal stunning. Shooting witha captive bolt in the nape of the neck caused unconsciousness after mean (+/- sd) 21 +/- 6 seconds. Until then the calves were fully conscious, according to the electroencephalogram and also showed a positive corneal reflex. It is therefore suggested that for the sake of animal welfare captive bolt shooting at the nape of the neck should be abandoned.
TL;DR: The authors are not certain that surgical treatment of elbow osteochondrosis is justified; more extended long-term studies are necessary before surgical and conservative therapeutic regimens can be fully evaluated.
Abstract: Of 26 dogs with elbow osteochondrosis, 11 had osteochondritis dissecans of the medial humeral condyle, seven had fragmentation of the coronoid process of the ulna and eight had both these lesions. Sixteen cases had bilateral involvement. The labrador and retriever breeds were most often affected and the male sex predominated. The clinical features included a foreleg lameness in a young immature dog with pain localised to the elbow joint. The most consistent radiological feature was the presence of osteophyte development especially on the dorsal aspect of the anconeal process, caused by secondary osteoarthritis. The authors are not certain that surgical treatment of elbow osteochondrosis is justified; more extended long-term studies are necessary before surgical and conservative therapeutic regimens can be fully evaluated.
TL;DR: Three horses were referred for investigation of a unilateral foul smelling scanty nasal discharge, complicated in one case by intermittent epistaxis, and topical treatment with natamycin solution in all cases plus nystatin in two of the horses resulted in complete recovery from the condition but in one cases the problem recurred.
Abstract: Three horses were referred for investigation of a unilateral foul smelling scanty nasal discharge, complicated in one case by intermittent epistaxis. Thick purulent material or a mycotic plaque was identified by an endoscopic examination of the middle meatus but in two horses this had to be repeated under general anaesthesia before the abnormalities were detected. Aspergillus fumigatus was cultured from all three cases and septate hyphae were identified on smears from lesions. Histological examination of the lesion in one case revealed a fungal mycelium. Topical treatment with natamycin solution in all cases plus nystatin in two of the horses resulted in complete recovery from the condition in two cases but in one case the problem recurred. The aetiology of nasal aspergillosis remains uncertain.
TL;DR: The results indicate that although B bronchiseptica can produce non-progressive turbinate changes in pigs that have inadequate antibody protection, the relationship between these lesions and the chronic progressive field disease needs further investigation.
Abstract: Clinical atrophic rhinitis in seven pig herds could not be associated with the infection rate or higher numbers of B bronchiseptica in nasal swabs when compared with unaffected herds. B bronchiseptica isolates from herds with atrophic rhinitis and receiving sulphonamide medication were resistant to sulphonamides in vitro and there was a beneficial clinical response after changing to oxytetracycline medication. In an unaffected herd three piglets naturally infected with B bronchiseptica but possessing low levels of passive antibody showed marked turbinate hypoplasia when killed at seven weeks, the lesions had resolved in four of six litter mates by 21 weeks and did not occur in another litter of nine piglets which had a high level of passive antibody. The results indicate that although B bronchiseptica can produce non-progressive turbinate changes in pigs that have inadequate antibody protection, the relationship between these lesions and the chronic progressive field disease needs further investigation.
TL;DR: Factors such as cold, heat, relative humidity and air pollution are considered with particular reference to the aetiology of respiratory diseases, and effects of weather on survival and spread of microorganisms, local resistance to infection and systemic resistance to disease are discussed.
Abstract: The incidence and severity of many diseases of cattle, particularly the endemic enteric and respiratory diseases, appear from clinical impression or epidemiological survey to be associated with particular types of weather. Infectious diseases of cattle (excluding parasitic ones) for which there appears to be a real association between climate, weather and disease are reviewed. Effects of weather on survival and spread of microorganisms, local resistance to infection and systemic resistance to disease are discussed. Factors such as cold, heat, relative humidity and air pollution are considered with particular reference to the aetiology of respiratory diseases.