A high percentage of heifers calve with intramammary infections. One of the measures available to control intramammary infections is treatment with antibiotics before calving. In this study, the effects of prepartum treatment of nonlactating heifers with a 600-mg cloxacillin dry cow treatment on the prevalence of culture-positive milk samples at calving and 10 to 14 d in milk (DIM), the incidence of clinical mastitis, somatic cell count (SCC), and milk production during first lactation were quantified. A total of 184 heifers on 13 dairy farms were treated with antibiotics 8 to 10 wk before the expected calving date. Another 185 heifers served as untreated controls. Coagulase-negative staphylococci were the most frequently isolated group of bacteria in the treatment and control groups at calving (32 and 42%), and at 10 to 14 DIM (15 and 19%), respectively. The prevalence of minor pathogens at calving was lower in the treatment group compared with the control group (34 and 43%, respectively). Staphylococcus aureus was the most frequently isolated major pathogen in the treated and control heifers at calving (4 and 5%) and at 10 to 14 DIM (2 and 3%), respectively. The prevalence of major pathogens was lower in the treated heifers at 10 to 14 DIM compared with the control group (4 and 6%, respectively). Cumulative incidence risk of clinical mastitis during the lactation was 9 and 18% in the treatment and control groups, respectively. Treatment with cloxacillin 8 to 10 wk before calving resulted in a lower prevalence of culture-positive milk samples at calving and lower quarter milk SCC in early lactation [30,000 +/- 4,600 (standard deviation) cells/mL in treated heifers versus 40,000 +/- 4,600 cells/mL in control heifers], and was associated with lower average test-day SCC (55,000 +/- 1,400 cells/mL in treated heifers versus 71,000 +/- 1,500 cells/mL in control heifers) and lower incidence of clinical mastitis throughout lactation. The improved udder health resulted in a higher average test-day milk production in the first lactation (24.5 +/- 3.2 kg in treated heifers versus 23.6 +/- 3.1 kg in control heifers). Dairy farms with heifer mastitis problems need to analyze their mastitis management. Prepartum treatment of heifers with dry cow antibiotics may be helpful by decreasing the prevalence of mastitis-causing pathogens at calving and at 10 to 14 DIM.

In this study, the prevalence of intramammary infection (IMI) with coagulase-negative staphylococci (CNS) in The Netherlands was estimated on 49 randomly selected herds with at least 40 lactating cows. In total, 4220 quarter milk samples were collected. The prevalence of CNS IMI in The Netherlands was estimated at 10.8% at quarter level and 34.4% at cow level, making it the most frequently isolated group of pathogens. Fourteen species of CNS were identified; the most frequently isolated species was Staphylococcus chromogenes (30.3%) followed by Staphylococcus epidermidis (12.9%) and Staphylococcus capitis (11.0%). Prevalence of CNS IMI was higher in heifers compared to older cows. Geometric mean quarter SCC of CNS-positive quarters was 109,000 cells/ml, which was approximately twice as high as culture-negative quarters. Quarters infected with S. chromogenes, S. capitis and Staphylococcus xylosus had a higher SCC (P<0.05) than culture-negative quarters, while quarters that were culture-positive for S. epidermidis and Staphylococcus hyicus tended to have a higher SCC than culture-negative quarters. An increased prevalence of CNS IMI was associated with the herd-level variables source of drinking water not being tap water, housing of dry cows in one group instead of multiple groups, measurement of cow SCC every month, udder health monitoring by the veterinarian, pasturing during outdoor season, percentage of stalls contaminated with milk, and BMSCC>250,000 cells/ml. Although a causal relation between these factors and prevalence of CNS is not proven and for some factors not even likely, knowledge of the associations found may be helpful when approaching CNS problems on dairy farms.

In this study, the accuracy of two phenotypic tests, API Staph ID 32 and Staph-Zym, was determined for identification of coagulase-negative staphylococci (CNS) from bovine milk samples in comparison with identification based on DNA-sequencing. A total of 172 CNS isolated from bovine milk were classified into 17 species. The most frequently isolated species based on rpoB sequencing were Staphylococcus chromogenes and Staphylococcus epidermidis, followed by Staphylococcus xylosus, Staphylococcus warneri and Staphylococcus equorum (37, 13, 9, 8 and 6% of isolates, respectively). The API Staph ID 32 correctly identified 41% of the CNS isolates. Best agreement with rpoB sequence based species identification was found for S. epidermidis, Staphylococcus hyicus and S. xylosus (100, 89 and 87%, respectively). The positive predictive value was 89, 100 and 52%, respectively. Poor sensitivity was observed for 3 of the 5 most frequently found species, S. chromogenes (37%), Staphylococcus warneri (15%) and S. equorum (0%) albeit with specificity of 100%. The Staph-Zym needed additional tests for 66% of the isolates and identified 31% of the CNS isolates correctly. Good sensitivity was found for S. epidermidis, S. simulans and S. xyloxus (100, 78 and 73%, respectively). The positive predictive value was 89, 78 and 98%, respectively. Poor sensitivity was observed for S. chromogenes, S. warneri and S. equorum (0, 54 and 0%, respectively) but with a specificity of 100, 99 and 100%, respectively. Both phenotypic tests misidentified a large proportion of CNS isolates and were thus unsuitable for identification of CNS species from bovine milk samples.

The most important characteristics of Mycoplasma mastitis on dairy farms are described, based on two case studies. Clinical symptoms, diagnostics, epidemiology, and a plan of action are presented. In the herds investigated, Mycoplasma mastitis was characterized by multiple affected quarters unresponsive to treatment with antibiotic and/or anti-inflammatory agents. Most striking were a sandy sediment, brown colouring, and rice-like structure of the milk of affected animals. Clinical symptoms differed in the two affected herds. Diagnosis was based on bacteriological investigation of samples of milk and synovial fluid taken from infected cows. Affected animals were culled immediately, and the herds were monitored by repeated testing of bulk milk samples. It was concluded that a consequence of the increasing size of cattle herds in the Netherlands is that subclinical/clinical Mycoplasma mastitis may be diagnosed more frequently than in the past. In the case of Mycoplasma mastitis, farmers and veterinary practitioners are advised to draw up a plan of action together, incorporating aspects such as diagnostics at cow level, direct culling of affected animals, hygiene during milking, including post-milking teat disinfection, and routine monitoring of bulk milk. Unpasteurized milk should not be given to calves.

De laatste jaren worden in Nederland in toenemende mate coagulase negatieve staphylococcen geisoleerd uit melkmonsters van melkkoeien. Van de bacteriologisch positieve melkmonsters, afkomstig van koeien met een subklinische mastitis, werden bij GD in 1999 in 16,2 procent en in 2004 in 42,2 procent van de isolaten coagulase negatieve staphylococcen gevonden. Deze percentages lagen voor de isolaten afkomstig van klinische mastitiden respectievelijk op 7,3 en 14,1 procent. In dit onderzoek werd van 108 coagulase negatieve staphylococcen, geisoleerd uit melkmonsters van Nederlands rundvee lijdend aan een mastitis, de gevoeligheid voor oxacilline, cefquinome, streptomycine, neomycine, penicilline en de combinatie van nafcilline, penicilline en streptomycine getest. Dezelfde 108 isolaten werden met behulp van de Api-Staph getypeerd. Er werden acht species gevonden. Staphylococcus chromogenes was de meest voorkomende (41,7 procent) coagulase negatieve staphylococ, gevolgd door Staphylococcus xylosus (15,7 procent) en Staphylococcus simulans (10,2 procent). In de agarverdunningstest bleken alle 108 stammen gevoelig te zijn voor cefquinome en negentig procent was gevoelig voor oxacilline. In drie isolaten (2,8 procent) werd het mecA-gen aangetoond. Ondanks de uitslag van de agarverdunningstest dienen deze drie isolaten als resistent te worden beschouwd tegen alle beta-lactam antibiotica (penicillinen, combinaties van penicillinen en een beta-lactamaseremmer en alle generaties cefalosporinen). In de agardiffusietest waren alle isolaten gevoelig voor de combinatie nafcilline-penicilline-streptomycine, 99 procent van de isolaten was gevoelig voor neomycine en een procent intermediair gevoelig en voor streptomycine was 95 procent van de isolaten gevoelig, vier procent ongevoelig en een procent intermediair gevoelig. 37,4 procent van de CNS-isolaten was resistent tegen penicilline. Het percentage resistentie voor penicilline varieerde tussen de species van nul procent voor Staphylococcus simulans tot honderd procent voor Staphylococcus saprophyticus. Gezien de aanwezigheid van resistentie in CNS tegen diverse antibiotica is een gevoeligheidstest belangrijk voor een gerichte behandeling van een mastitis.

During recent years the prevalence of coagulase-negative staphylococci in milk samples from Dutch dairy cows has increased. In 1999 16.2% of the bacteria isolated from milk collected from cows with subclinical mastitis were coagulase-negative staphylococci. In 2004 this proportion was 42.2%. The proportion of coagulase-negative staphylococci of the bacteria isolated from milk samples from cows with clinical mastitis was 7.3% in 1999 and 14.1% in 2004. In this study, the susceptibility of 108 coagulase-negative staphylococci to oxacillin, cefquinome, streptomycin, neomycin, penicillin, and the combination of nafcillin, penicillin, and streptomycin was tested. The isolates were cultured from milk collected from cows with mastitis and typed using the Api-Staph system. Eight species were identified. Staphylococcus chromogenes was the predominant species (41.7%), followed by Staphylococcus xylosus (15.7%) and Staphylococcus simulans (10.2%). With the agar dilution method all strains proved to be sensitive to cefquinome and 90% to oxacillin. Three isolates (2.8%) were mecA-positive. Despite the agar dilution results, these three isolates should be considered resistant to all beta-lactam antibiotics (penicillins, penicillins combined with a beta-lactamase inhibitor and all generations of cephalosporins). In the agar diffusion test, all isolates proved to be sensitive to the combination of nafcillin-penicillin-streptomycin, 99% were sensitive to neomycin and 1% intermediate sensitive, and 95% were sensitive to streptomycin, 4% resistant, and 1% intermediate sensitive. The coagulase-negative staphylococci were highly resistant to penicillin (37.4%), although the level of resistance varied between species, from 0% for Staphylococcus simulans to 100% for Staphylococcus saprophyticus. Because coagulase-negative staphylococci are resistant to several antibiotics, sensitivity testing is important for targeted treatment of mastitis.

A serious outbreak of mastitis caused by Klebsiella pneumoniae is described. Shortly after drying off, three cows died of mastitis caused by Klebsiella pneumoniae and five other cows became seriously ill but survived. Sawdust contiminated with Klebsiella pneumoniae was identified as the most likely source of these infections. In addition to detection of possible sources of infection, another important aspect of eradication is the detection of quarters infected with Klebsiella pneumoniae. Rigorous application of these measures led to resolution of the outbreak within a few months.

A high percentage of heifers have an intramammary infection (IMI) at calving. Treatment with antibiotics before calving has been shown to reduce the number of IMI's at calving and to increase milk-production.To quantify this effect a trial was carded out on 13 Dutch dairy farms where 196 heifers were treated with 600 mg dynomilled cloxacillin (Orbenin Extra Dry Cow, Pfizer (R)) 8-10 weeks before the expected calving date. Another 196 heifers served as untreated controls. An employee of the Animal health Service performed the random selection and treatment. Bacteriological culturing and determination of the somatic cell count (SCC) was carried out at calving and repeated 10 days Later. All farms recorded milk-production and cow SCC.There was a difference between farms. Farms with Less than 15% of heifers with a cow SCC above 150.000 cells/ml at the start of the trial were considered to have a low prevalence of heifer mastitis (LPF group) white farms with over 15% were considered as high prevalence farms (HPF group). The expected 305-day milk-production, in the treated heifers, was significantly higher (496L) in the HPF group in comparison with the untreated animals but this difference was only 77L (not significant) in the LPF group. In both groups of farms the cow SCC was significantly tower in the treated heifers compared to the untreated controls.It is concluded that treatment of heifers is beneficial on HPF but not on LPF farms. Determination of the causes of heifer mastitis is recommended on HPF farms.

Subclinical mastitis with a raised somatic cell count was diagnosed in a cow in her fifth lactation. It was caused by Yersinia pseudotuberculosis, which can also infect humans. This is the first time that Yersinia pseudotuberculosis has been isolated from a mastitis sample in The Netherlands. Despite treatment with antibiotics in the dry period, Yersinia pseudotuberculosis was still present in the same quarter in the subsequent lactation. The somatic cell count was still high and milk production was much lower than in previous lactation. The pathogen did not spread to other quarters of the same cow or to herd mates on the farm over a 1-year period.

In recent years an increasing number of Dutch farms had to deal with teat lesions, which in extreme cases resulted in sloughing of the teat (2004: on average 1 animal on 5% of the farms). This phenomenon was almost exclusively seen in heifers and it affected usually one heifer on a farm in the year. In a few cases the heifers Licked or bit off the teat.There are 2 manifestations of the phenomenon.The first is periparturient and usually affects the whole teat. The skin of the teat is hardened and has a purple colour. It appears as if there is a fluid filled blister, parts of the affected skin slough and the teat gets hard and stiff thereafter.The other manifestation starts with a vesicle on the teat, which ruptures becoming a small fissure, which then deepens. This fissure is usually at the base of the teat, close to the udder although it has also been seen elsewhere on the teat but not on the udder itself. The fissure deepens slowly and in some cases perforates into the teat canal and results in sloughing of the teat. In a few cases it extends over the udder skin from one teat to another. This manifestation also usually starts periparturient but can be seen Later in Lactation. There is minimal response to treatment and, where there is a response, the healing process is slow taking weeks to months. There is no adequate therapy. This phenomenon was not related to bovine herpes mamilitis virus (BHV2), pseudocopox or papova viruses. In a few cases BHV4 was suspected. Fungi could not be detected, although in a few cases there was a response to antifungal treatment. Staphylococcus aureus and Arcanobacterium pyogenes were both isolated twice in 2 of the 25 examined cases.There seems to be a relationship to a disturbed blood supply, selenium supply, sudden change in ration, the periparturient period, uddercleft dermatitis and, according to farmers, interdigital dermatitis.

Drying off cows with antibiotics is an effective method to cure existing infections at drying off and to prevent new infections during the dry period. In the recent years, a shift has been observed from contagious to environmental pathogens. This influences the general preventive measures and the choice for the drying off treatment. Important factors influencing the efficacy of dry cow products are general hygienic measures, length of the dry period, production at drying-off, somatic cell count at drying-off and the udder pathogens circulating on the farm.

Veterinary RecordVolume 154, Issue 7 p. 208-209 Short Communications Allergic contact dermatitis of bovine teat skin caused by milking machine cluster rubber M. Holzhauer DVM, M. Holzhauer DVM Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorO. C. Sampimon BSc, O. C. Sampimon BSc Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorJ. Sol DVM, PhD, J. Sol DVM, PhD Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorA. van Walderveen DVM, A. van Walderveen DVM Veterinary Practice Ederveen-Renswoude, Smidstraat 30, 6744 WT, Ederveen, The NetherlandsSearch for more papers by this authorC. J. W. van Ginkel MSc, PhD, C. J. W. van Ginkel MSc, PhD Department of Dermatology, University Medical Centre, Utrecht, The NetherlandsSearch for more papers by this author M. Holzhauer DVM, M. Holzhauer DVM Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorO. C. Sampimon BSc, O. C. Sampimon BSc Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorJ. Sol DVM, PhD, J. Sol DVM, PhD Animal Health Service, PO Box 9, 7400 AA, Deventer, The NetherlandsSearch for more papers by this authorA. van Walderveen DVM, A. van Walderveen DVM Veterinary Practice Ederveen-Renswoude, Smidstraat 30, 6744 WT, Ederveen, The NetherlandsSearch for more papers by this authorC. J. W. van Ginkel MSc, PhD, C. J. W. van Ginkel MSc, PhD Department of Dermatology, University Medical Centre, Utrecht, The NetherlandsSearch for more papers by this author First published: 14 February 2004 https://doi.org/10.1136/vr.154.7.208Citations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume154, Issue7February 2004Pages 208-209 RelatedInformation

Earlier field observations suggest that teat apex colonization by Staphylococcus chromogenes pre-partum in dairy heifers protects udder quarters against elevated somatic cell counts early post-partum. To explain these findings, the in vitro inhibitory capability of S. chromogenes from teat apices of heifers towards some major mastitis pathogens was tested using a modified cross-streaking method. Two out of 10 S. chromogenes isolates, both originating from two different teats from the same heifer, consistently inhibited growth of all Staphylococcus aureus, Streptococcus dysgalactiae, and Streptococcus uberis strains, but none of the Escherichia coli strains. The present study, therefore, supports the protective effect of teat apex colonization by S. chromogenes by in vitro production of inhibitory substances.

From September 1998 to September 1999, at drying off 397 cows on 73 Dutch farms were treated, with two antibiotic containing dry cow products (cloxacillin; penicillin-neomycin). Farms and cows were selected on an increased bulk milk somatic cell count (BMSCC) and individual cow somatic cell count. The objective of the trial was to compare the efficacy of both products under field conditions. Both products proved to be highly effective against streptococci and penicillin sensitive staphylococci. Because of the low incidence of infections caused by Escherichia coli and penicillin resistant staphylococci no conclusions could be drawn on differences in activity for these two pathogens. No significant differences were found between the two products in cure rate of existing infections at drying off, incidence of new infections during the dry period, incidence of clinical mastitis during the dry period and the course of the individual cow cell counts during the trial.

In this study the sensitivity of three methods of isolation of udder pathogens from milk samples from subclinical mastitis cases was compared. For analysis 1827 quarter milk samples were selected. Milk was cultured using a standard culture technique (0.01 ml of fresh milk streaked on a sheep blood agar plate and on Edward's medium). In addition, an inoculum of 0.01 ml of the original milk sample was incubated for 24 h at 37 degreesC in broth, followed by culture using the standard culture technique. In the third method, the whole milk sample was frozen for 24 h, and then incubated for 24 h at 37 degreesC, followed by culture using standard culture technique. The isolation percentage of Staphylococcus aureus was 4.7% for standard culture technique, 14.2% for incubation in broth, and 21.5% for the combination of freezing plus incubation. Isolation percentage of Streptococcus dysgalactiae and Streptococcus agalactiae was highest using the standard culture technique, while isolation rate of Streptococcus uberis was not different among the three methods used. With increasing somatic cell count, the likelihood of S. aureus, S. dysgalactiae and S. uberis isolation increased. Based on the relative sensitivity, defined as the isolation rate using a single technique compared to the isolation rate of the three techniques together, a combination of standard culture technique and freezing plus incubation was most attractive for achieving a high isolation rate of S. agalactiae and S. dysgalactiae. Relative sensitivity of S. uberis isolation was highest using the standard culture technique and incubation in broth, while S. aureus was most often isolated using a combination of incubation in broth and freezing plus incubation. A combination of the three methods increased the isolation rate for S. dysgalactiae, S. uberis and S. aureus. The standard culture technique, together with the combination of freezing plus incubation, can be recommended for isolating major udder pathogens. If S. aureus is the pathogen of main interest, using incubation in broth together with the combination of freezing plus incubation performed best. (C) 2002 Published by Elsevier Science B.V.

In 1999, among 164 randomly selected Dutch sheep farmers, a questionnaire was carried out to estimate the prevalence of myiasis in sheep and to investigate factors associated with the occurrence of myiasis. The total number of sheep and/or lambs on the reference date 1 August 1999 was 12,200: 5243 ewes, 225 rams, 3393 ewe- and 3339 ram lambs. On 86 (52.4%) of the farms 349 (2.9%) of all sheep and/or lambs contracted myiasis, of which two died. Myiasis was seen significantly more frequently on farms with over 25 ewes compared to smaller farms. Cases of myiasis were detected from April to September, with a peak (47.1%) in August. Occurrence of myiasis was most frequently associated with hot and humid weather and was mainly observed (69.1%) in the area around the tail.Ewes and ewe lambs had significantly more myiasis when compared with rams and ram lambs. There was no relationship with tail docking, with breed, with the time of shearing, with the kind of soil (clay, sand, etc.), with the environment (bush, trees, water, etc.), with the type of treatment (pour on, dipping, spraying), the used insecticides (synthetic pyrethroïds, diazinon, cyromazin, etc.), the number of preventive treatments, the time of treatment or the number of observations on the herd (once a day, once a week, etc.).

An infestation with Hypoderma diana in roe deer in the Netherlands is described. The condition of the infested deer was poor. Hypoderma diana is no threat for cattle.

Veterinary RecordVolume 149, Issue 6 p. 183-184 Short Communication Salinomycin poisoning in veal calves M. W. C. Huyben DVM, M. W. C. Huyben DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorJ. Sol DVM, J. Sol DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorM. P. H. M. Roumen DVM, M. P. H. M. Roumen DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorG. H. A. Borst DVM, G. H. A. Borst DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this author M. W. C. Huyben DVM, M. W. C. Huyben DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorJ. Sol DVM, J. Sol DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorM. P. H. M. Roumen DVM, M. P. H. M. Roumen DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this authorG. H. A. Borst DVM, G. H. A. Borst DVM Animal Health Service, Arnsbergstraat 7, 7418 EZ Deventer, The NetherlandsSearch for more papers by this author First published: 11 August 2001 https://doi.org/10.1136/vr.149.6.183Citations: 2 Correspondence to Dr Sol Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume149, Issue6August 2001Pages 183-184 RelatedInformation