Herd health planning: farmers' perceptions in relation to lameness and mastitis

Between December 2002 and December 2003, the herd health planning activities on 61 dairy farms in the uk were compared with several measures of lameness and mastitis. Lameness had been reported as a problem in 53 of the herds directly by the farm and in the other eight by the nominating local veterinary practice; 54 of the farms also reported having a mastitis problem. Fifty-three (87 per cent) of the farms had some form of written herd health plan, of which 21 (40 per cent) had been in place for 12 months or less. All the farms were recording mastitis in some way, although 38 (62 per cent) of the farmers did not review these records and only four retained the results of a comprehensive record review. Farms defined as having a high incidence of mastitis were more likely to be reviewing their health records, but farms defined as having a high prevalence of lameness in a sentinel group of early lactation heifers were less likely to be reviewing their health records.     

Pathohistological studies on so-called subclinical mastitis

Three different localisations of each one of 118 udder quarters were histologically tested. All the 118 quarters had been clinically unchanged for not less than three months before slaughter, and the milk obtained from them had been without any major change over at least six weeks. Sixty-two quarters that had produced positive response to the highspeed mastitis test just before slaughter exhibited 45 inflammatory changes (72 per cent), most of them in terms of proliferative lobular mastitis or exudative alveolitis. One of such changes was recorded from 20 in 47 quarters (21 per cent) which had reacted negatively to the highspeed mastitis test. Comparison with the clinical history of the udders showed that 47 per cent of the established changes could be interpreted as sequels of previous clinical disorder in udder condition, while the greater part of all findings was based on completely negative udder histories.     

Disposal and disease rates in 340 British dairy herds

Data derived from 340 dairy herds, mainly in southern England, between April 1998 and March 1999, showed that the average total culling rate was 22.1 per cent, with 5.6 per cent for infertility, 3.6 per cent for mastitis, 1.7 per cent for lameness, 2.0 per cent for poor milk yield, 3.7 per cent for age and 5.5 per cent for miscellaneous reasons which included death. The average annual rate of assisted calvings was 8.7 per cent, of injury 0.9 per cent, digestive disease 1.3 per cent ketosis 0.4 per cent, hypomagnesaemia 0.7 per cent, hypocalcaemia 5.3 per cent, mastitis 36.6 per cent, and lameness 23.7 per cent. There was a significant association (P<0.001) between higher rates of mastitis in cows housed in straw yards as opposed to cubicles and also between higher rates of lameness in cows housed in cubicles as opposed to yards (P<0.015). However, there were farms with low rates of mastitis in cows kept in straw yards and low rates of lameness in cows kept in cubicles. Larger herds tended to have more problems with lameness and higher bulk milk somatic cell counts (BMSCC). There was a positive association between BMSCC and mastitis rate.     

The cost of summer mastitis.

The incidence of summer mastitis on 95 dairy farms in southern England was monitored in the summer of 1987. Data on the type of animal infected, the fate of the animals immediately and over the succeeding lactation, and the procedures used in treating the infections were collected for 144 cases. Twenty-five per cent of cases were attended by veterinary surgeons. Most of the animals received parenteral antibiotics and on average each received five tubes of intramammary antibiotic. The incidence of infection was highest in pregnant and calving heifers, more than 2 per cent of the animals at risk, and lowest (0.04 per cent) in calves, although more than twice as many dry cows were infected. Over half of the farms reported summer mastitis, with 36 per cent suffering more than one case. The greatest economic loss, 49 per cent of the total, was from lost milk production; and 37 per cent was from lost animal value, cull and calf losses. The average loss was 192 pounds per case. Using national incidence data from England and Wales, the cost to the UK dairy industry in 1987 was 6.22 million pounds.     

Disposal and disease rates in British dairy herds between April 1998 and March 2002

Data derived over four years from 434 dairy herds in 1998/99 to 244 in 2001/02 revealed average disposal rates of 22.6 per cent per year, half of which were for poor fertility, mastitis and lameness. The quartile of herds with the lowest disposal rates sold an average of 11.5 per cent annually and the quartile with the highest rates sold 35.5 per cent. Average annual disease rates over the four years were as follows: for assisted calving 7.8 per cent, for digestive disease 1.2 per cent, for ketosis 0.5 per cent, for hypomagnesaemia 0.5 per cent, for hypocalcaemia 5.0 per cent and for injuries 0.8 per cent. The incidence of mastitis increased from 36.0 to 43.3 per cent of cows per year. The incidence of lameness decreased from 23.3 per cent in 1998/99 to 20.7 per cent in 2000/01 but increased to 21.9 per cent in 2001/02. Data received from the same 219 farms during the first three years showed no effective differences from the full set of data for each of the three years. The lowest annual incidences of mastitis and lameness on individual farms were below 7 per cent and 2.5 per cent, respectively. In general, housing cows in cubicles was associated with a greater risk of lameness, and housing them in straw yards with a greater risk of mastitis. However, some of the lowest rates of lameness were recorded in cubicle-housed cows and some of the lowest rates of mastitis were recorded in cows housed in yards. Larger herds were not associated, in general, with higher rates of mastitis.     

The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 1: Characteristics and control

The foot-and-mouth disease epidemic in Dumfries and Galloway in south-west Scotland comprised 177 infected premises (IPS) in 24 geographical clusters, and ran from March 1 until May 23, 2001. Initial seeding of infection was by livestock (predominantly sheep) that had passed through Longtown Market in adjacent Cumbria. Thereafter, spread within existing, and to new, clusters was associated with the movement of personnel and vehicles, with further transmission by Longtown Market contacts and across common boundaries. Sheep and cattle premises were equally affected. After the peak of the epidemic at the beginning of the third week of March, the upper possible limit of attack rates for premises contiguous to IPS, and premises within 3 km, remained around 10 per cent, with new clusters emerging more distantly. Control procedures included traditional methods of slaughter of all animals on IPS and, elsewhere, of animals considered by veterinary assessment to be Dangerous Contacts; movement restrictions; enhanced biosecurity; tracing of potential sources and spread of virus; and surveillance of premises subsequently considered at risk. These methods were supplemented by the novel pre-emptive slaughter, without veterinary assessment, of all susceptible livestock on all premises contiguous to IPS, and of small ruminants and pigs within a 3 km radius (known as the Protection Zone) around IPS. In total, approximately 80,000 cattle, 564,000 sheep, 2600 pigs and 500 goats were slaughtered, the novel methods accounting for 29 per cent of all cattle and 75 per cent of all sheep killed. Limitations of existing national databases necessitated the development of local databases to administer control procedures.     

Identification of subclinical mastitis with a hand-held electrical conductivity meter

A hand-held, commercially available instrument for measuring the electrical conductivity of milk (the Milk Checker) has been examined for its usefulness and accuracy in detecting subclinical and clinical mastitis. Foremilk from uninfected quarters had an electrical conductivity of 5.4 to 5.6 millisiemens (mS)/cm. Milk from cows with subclinical Staphylococcus aureus infections had a higher milk conductivity (7.1 to 7.5 mS/cm) but milk from cows with subclinical S uberis infections showed no increase in conductivity (5.3 to 5.6 mS/cm). However, experimental S uberis infections could be detected by a 50 per cent increase in the electrical conductivity of foremilk two milkings before visible signs of mastitis were apparent. The equipment could be a useful advisory/veterinary tool but is unlikely to be used routinely in the milking parlour.     

Supracondylar femoral fractures in 159 dogs and cats treated using a normograde intramedullary pinning technique

Three separate studies that collectively represent 107 dogs and 52 cats with supracondylar femoral fractures are presented. The animals were treated using a normograde intramedullary pinning technique at the Norwegian School of Veterinary Science during the period 1964 to 1993. The surgical technique involves insertion of one or two intramedullary pins normograde from the stifle joint without passing their proximal end proximal to the level of the femoral neck. The results of treatment were obtained for 73 dogs and 39 cats. Of these cases, 58 dogs (79.5 per cent) and 32 cats (82.1 per cent) were found to be free of lameness after the completion of treatment. Differences in the results of treatment, based on species or size, were not found. Of all cases in which the results of treatment were known (n = 112), complications were recorded in nine animals (8.0 per cent). Infection and instability were the most common complications, affecting four and three cases, respectively.     

Unusual history and initial clinical signs of Mycoplasma bovis mastitis and arthritis in first-lactation cows in a closed commercial dairy herd

CASE DESCRIPTION: 9 first-lactation dairy cows in a closed dairy herd had swelling in the forelimbs and forelimb lameness. Mycoplasmal arthritis and mastitis were diagnosed. CLINICAL FINDINGS: Swelling of the carpal joint, diffuse subcutaneous edema from the carpal to metacarpophalangeal joints, and forelimb lameness were evident in 9 first-lactation cows 7 to 21 days after parturition. Diagnostic testing revealed that 3 of 3 bulk-tank milk samples, 3 milk samples from cows with clinical mastitis, 2 fluid samples obtained from arthritic joints, and samples from the lungs and spleen of a cow that had died yielded positive results for Mycoplasma spp. Nucleic acid sequence analysis performed by use of a PCR assay on the joint fluid and lung tissues confirmed infection with Mycoplasma bovis. TREATMENT AND OUTCOME: Affected cows were treated by IM administration of flunixin meglumine and dexamethasone for 3 days. All cows were nonresponsive to treatment (3 cows died, and the other 6 were culled). Follow-up culture for Mycoplasma spp of milk samples from the bulk tank and from all lactating cows was recommended to screen for chronic subclinical carriers. CLINICAL RELEVANCE: Mycoplasmal infections may cause unusual initial clinical signs or an atypical history. When dairy cattle, including those residing in closed herds, have lameness, swelling of the carpal or metacarpophalangeal joints, edema of the distal portions of the forelimbs, or polyarthritis, infection with Mycoplasma spp should be investigated. Delay in diagnosis of mycoplasmal infections in dairy herds can result in substantial financial loss and the establishment of chronic subclinical carriers.     

Staphylococcal infections in rabbit does on two industrial farms

The main reasons for culling adult rabbit does on two Spanish rabbit farms were investigated for a year. The most important conditions were mastitis (33.3 per cent), followed by subcutaneous abscesses (9.9 per cent) and pyometra (8.7 per cent). Staphylococcus aureus infections were the most severe problem, the organism being isolated from 69.2 per cent of infected animals. Pasteurella species were more prevalent in cases of pyometra and pneumonia. Two strains of S aureus were identified by using polymorphism of the coagulase gene as the criterion. One of these strains was responsible for the majority of the staphylococcal infections and was isolated from several pathological processes.     

Occurrence of PSE and DFD meat in swine slaughtered under emergency conditions

The occurrence of qualitative changes in meat was studied in a set of 1008 pigs slaughtered in four sanitation slaughter houses for the period of 12 months. PSE meat was found in 206 pigs (20.43 per cent) and DFD meat only in 9 pigs (0.89 percent) of the total number of pigs examined. The rule was applied that the defect should be demonstrated by two of three commonly used parameters (the pH value, colour and water loss by dripping). The highest occurrence of qualitative changes in meat of PSE type was registered in the group of animals with a defect of the respiratory organs (32.53 per cent) and the lowest in animals with diseases of sexual organs, including parturition complications (5.00 per cent). A similar trend was recorder even in the DFD meat occurrence. As to the seasons, the highest percentage of occurrence of PSE defects was in July and August (35.41 and 29.06 per cent) and the lowest (8.64 and 10.97 per cent) in March and January. The actual disease is proved to be only one of the secondary stress to induce the PSE meat formation.     

Patellar luxation in 70 large breed dogs

O bjectives : To report the signalment, history, clinical features, and outcome in dogs weighing greater than 15 kg, treated surgically and non-surgically for patellar luxation. Risk factors for the development of patellar luxation, postoperative complications, and outcome were evaluated.
M ethods : Details regarding signalment, bodyweight, breed, aetiology, unilateral or bilateral luxation, duration of lameness, grade of luxation, direction of luxation, grade of lameness at presentation, concomitant cranial cruciate ligament rupture, method of treatment, surgical technique, surgeon, and complications were obtained from the medical records. Outcome was graded as excellent, good, fair, or poor, according to the degree of lameness.
R esults : Seventy dogs (45 males and 25 females) were included. Thirty-five had bilateral luxations (105 limbs). Mean age was two years, and mean weight was 30 kg. The relative risk for Labrador retrievers was 3·3 (P<0·001). All luxations were developmental. Luxations were medial in 102 stifles and lateral in three. Fourteen stifles had concomitant cranial cruciate ligament rupture. As the grade of patellar luxation increased, so did the grade of lameness (P<0·001). Surgery was performed in 70 stifles, and outcome was excellent/good in 94 per cent and fair/poor in 6 per cent of stifles. Complications occurred in 29 per cent of stifles, and increasing bodyweight was found to be a risk factor (P=0·03). Thirty-five stifles were managed non-surgically, and outcome was excellent/good in 86 per cent and fair/poor in 14 per cent of stifles.
C linical S ignificance : In view of the potential risk of postoperative complications, all surgically treated cases of patellar luxation in large breed dogs should be managed with a femoral trochleoplasty, a tibial tuberosity transposition (stabilised with K-wires and a tension band wire), and soft tissue releasing and tightening procedures.     

The foot-and-mouth disease epidemic in Dumfries and Galloway, 2001. 2: Serosurveillance, and efficiency and effectiveness of control procedures after the national ban on animal movements

After the foot-and-mouth disease (FMD) epidemic in Dumfries and Galloway in south-west Scotland in 2001, serosurveillance of sheep remaining in the 3 km radius Protection Zones around Infected Premises (IPS), and within a 10 km radius of IPS, revealed no evidence of infection. The epidemic was brought under control by a range of traditional techniques: slaughter of all animals on IPS and of veterinary-assessed Dangerous Contacts (DCS), movement restrictions, biosecurity, tracing of potential sources and spread of virus, and surveillance of At-Risk premises. Novel pre-emptive slaughter of FMD-susceptible animals on premises contiguous to IPS, and small ruminants and pigs on premises within 3 km of IPSs, commenced after the epidemic had peaked. Most of the traditional control procedures were undertaken quickly and with appropriate priority. Animals on IPS were usually slaughtered within one day of confirmation, and veterinary-assessed DCS within two days of confirmation of relevant IPS (a median of two days). The pre-emptive contiguous and 3 km culls took somewhat longer (medians of five and 17 days, respectively). IPS were most commonly identified as a result of reporting by farmers or their veterinarians (72 per cent of IPS); veterinary clinical patrols identified 16 per cent, while veterinary assessment of DCS and tracing each identified 5 per cent. No evidence of infection was found on any pre-emptively contiguously culled premises, and IPS were declared only on three 3 km cull premises. The time from estimated first lesion to end of slaughter on an IP was found, by regression analysis, to be a key component in effective control, manifested by a reduction in the estimated dissemination rate (EDR); there was little evidence that the intensity of contiguous culling affected the EDR. Patrols and serological surveillance of residual animals within 10 km of IPS, supported by more extensive evidence from elsewhere in the UK, suggested that cryptic infection in sheep was not widespread. Ultimately, there was insufficient evidence to support the effectiveness of 3 km pre-emptive culling as a control procedure.     

Degenerative lumbosacral stenosis in 18 dogs

Eighteen dogs with degenerative lumbosacral stenosis were presented to the University of Queensland Small Animal Clinic (UQSAC) over a three-year period. Presenting clinical signs included lumbosacral pain (89 per cent), hindlimb paresis and proprioceptive deficits (56 per cent), lameness (49 per cent), flaccid tails (22 per cent), and urinary dysfunction (16 per cent). All 18 dogs were treated by decompressive laminectomy. Two dogs were also treated by a pin fixation-fusion technique. The major compressive lesion was a type II disc protrusion (72 per cent). Seventeen dogs (94 per cent) showed improvement postoperatively with minimal complications. Confirmation of diagnosis is difficult in that many aged dogs without clinical signs show radiographic signs compatible with stenosis.     

Quantification of the relative efficiency of factory surveillance in the disclosure of tuberculosis lesions in attested Irish cattle

In Ireland, factory surveillance of cattle for gross lesions is an important supplementary method for detecting herds infected with bovine tuberculosis (tb), and in recent years between 27 and 46 per cent of all new herd breakdowns in any year have been detected by this method. The aim of this study was to determine the relative efficiency of factories in detecting lesions among attested cattle slaughtered during 2003 and 2004. National databases were available on animal slaughter, programmes of tuberculin testing for bovine tb and laboratory confirmation of suspected lesions. Factories were ranked according to their submission risk (number of animals submitted with lesions/number of attested animals killed) and confirmation risk (number of animals with laboratory-confirmed lesions/number of animals submitted with lesions), adjusting for the risk profile of the animals slaughtered, including potential confounding factors such as their age and sex, whether they were purchased or homebred, the test history of their herd, the prevalence of bovine tb in the area and the season of slaughter. Approximately 3.7 million cattle were slaughtered in 42 Irish export-licensed factories during the two years. Complete data were available for 2,374,987 animals from 84,510 attested herds in 2845 District Electoral Divisions. Samples from 7398 animals with suspected tb lesions were submitted for laboratory examination; 4767 (64.4 per cent) were positive, 2011 were negative and 620 were inconclusive. The average unadjusted submission risk for all the factories was 22 per 10,000, ranging from 0 to 58 per 10,000. The unadjusted factory confirmation risk (excluding factories that had sent in fewer than 10 lesions) varied between 34.3 per cent and 86.3 per cent. The unadjusted and adjusted submission and confirmation risks were highly correlated, and animal-related factors (including their characteristics and origin) therefore did not contribute to the variations in factory-level submission and confirmation risks.     

Disease and mortality among great bustards (Otis tarda) at Whipsnade Wild Animal Park, 1989 to 1999

Between 1989 and 1999, 351 clinical examinations and six postmortem examinations were made on the six great bustards (Otis tarda) maintained at the Whipsnade Wild Animal Park. Soft tissue-related traumatic injuries accounted for 35 per cent of all the clinical findings, musculoskeletal disorders accounted for 26 per cent, and lameness was one of the main reasons for a veterinary examination. Poor condition accounted for 30 per cent of the clinical findings and was associated with periods of cold wet weather during the winter and spring; the affected birds were isolated and provided with nutritional support. Haemosiderosis and haemochromatosis were observed in four of the five birds from which samples were taken for histopathology.     

National intervention study of mastitis control in dairy herds in England and Wales

An intervention study was carried out on 52 dairy farms in England and Wales to determine whether the implementation of a well-specified mastitis control plan in herds with an incidence of clinical mastitis of more than 35 cases per 100 cows per year would reduce the incidence of clinical mastitis, and also reduce the incidence of increases in the somatic cell counts of individual cows. A clearly defined plan for the diagnosis and control of mastitis was developed by two veterinary specialists from the research literature. The herds were randomly allocated to receive the plan either at the start of the study (intervention herds) or after one year (control herds). Data on mastitis management and the farm environment were collected during farm visits. After one year there was a significant 22 per cent reduction in the proportion of cows affected with clinical mastitis on the intervention farms compared with the control farms. There were also significant reductions of approximately 20 per cent in the incidence of clinical mastitis and in the occurrence of increases in the somatic cell counts of individual cows from below, to above 200,000 cells/ml.     

Male tortoiseshell cats in the United Kingdom

A questionnaire concerning the coat colour and sex of cats being vaccinated or neutered was sent to 2585 veterinary practices; 393 (15.2 per cent) were returned and information was obtained about 9816 cats. Of 4598 males, 20 were recorded as tortoiseshell (0.43 per cent). The frequency of the orange gene was 19.7 per cent assuming that male tortoiseshell cats had two X chromosomes. The chromosome complement and/or gonadal histology of 14 male tortoiseshell cats is described. Cytogenetic analysis of 11 animals revealed six with a 38,XX/38,XY complement, two with 39,XXY, two with 38,XX, and one with a 38,XY complement.     

A field investigation of causes of abortion in dairy cattle

Cases of abortion on dairy farms on the Lancashire/Cumbria border were investigated by means of a systematic diagnostic procedure, using the facilities of a veterinary practice's laboratory, and the Ministry of Agriculture, Fisheries and Food veterinary investigation centre. Among approximately 3600 animals, 149 abortions were investigated on 54 farms in two years, an annual abortion rate of 2 per cent. A diagnosis was made in 34 per cent of the cases, based on a pathological examination of aborted material and bacteriological and serological findings. The most common pathogens associated with abortion were bovine viral diarrhoea virus (39 cases), bacterial or fungal infections (20 cases), infectious bovine rhinotracheitis virus (19 cases), and Leptospira hardjo (18 cases), either as single or multiple infections.