Hiperkeratosis and teat end
1
Vet J. 2008 Oct 23. [Epub ahead of print]
Udder shape and teat-end lesions as potential risk factors for high
somatic cell counts and intra-mammary infections in dairy cows.
Bhutto AL, Murray RD, Woldehiwet Z.
Department of Veterinary Clinical Sciences, University of Liverpool Veterinary Teaching Hospital, Leahurst,
Neston, Wirral CH64 7TE, UK.
The association of common bacterial pathogens in milk samples during calving with udder shape or the
presence of 'teat-end' lesions was investigated in 240 dairy cows from two herds. Sixty-three of 120 cows
(53%) in one herd (herd A) and 54/120 animals (45%) in a second herd (herd B) had normal-shaped
udders. The remaining animals had udder shapes defined as follows: large pendulous (18% herd A, 26%
herd B); large between hindquarter (10% herd A, 17% herd B); overall small (8% herd A, 5% herd B); or
small but pendulous (11% herd A, 7% herd B). At calving teat-end lesions were present in 63% and 76%
of the quarters of herd A and B animals, respectively. There was no herd effect on udder shape or teat-end
lesions. Analysis of variance revealed that udder shape and teat-end lesions did not have a significant
association with quarter somatic cell count. However there was some association between mammary
infection and udder shape and teat-end lesions. Compared to other udder shapes, cows with large
between hindquarter shape had significantly less Staphylococcus aureus and Streptococcus uberis
infection (P<0.001). There was a similar albeit less significant negative association with Escherichia coli
infection (P<0.01). Infection with Streptococcus agalactiae and Streptococcus dysgalactiae was more
frequent in cows with large pendulous and overall small udder conformations. The results also suggest an
association between intra-mammary infection at calving and the presence of hyperkeratotic teat-end
lesions, given that S. aureus, coagulase-negative staphylococci, S. uberis, S. agalactiae and E. coli were
cultured from significantly more quarters with such lesions than from quarters without lesions or with other
types of lesion (P<0.001).
PMID: 18951819 [PubMed - as supplied by publisher]
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;134(1-2):3-8. Epub 2008 Sep 11.
Coagulase-negative staphylococci-emerging mastitis pathogens.
Pyörälä S, Taponen S.
University of Helsinki, Department of Production Animal Medicine, FI-04920 Saarentaus, Finland.
satu.pyorala@helsinki.fi
Coagulase-negative staphylococci (CNS) have become the most common bovine mastitis isolate in many
countries and could therefore be described as emerging mastitis pathogens. The prevalence of CNS
mastitis is higher in primiparous cows than in older cows. CNS are not as pathogenic as the other principal
mastitis pathogens and infection mostly remains subclinical. However, CNS can cause persistent
infections, which result in increased milk somatic cell count (SCC) and decreased milk quality. CNS
infection can damage udder tissue and lead to decreased milk production. Staphylococcus simulans and
Staphylococcus chromogenes are currently the predominant CNS species in bovine mastitis. S.
chromogenes is the major CNS species affecting nulliparous and primiparous cows whereas S. simulans
has been isolated more frequently from older cows. Multiparous cows generally become infected with CNS
during later lactation whereas primiparous cows develop infection before or shortly after calving. CNS
mastitis is not a therapeutic problem as cure rates after antimicrobial treatment are usually high. Based on
current knowledge, it is difficult to determine whether CNS species behave as contagious or environmental
pathogens. Control measures against contagious mastitis pathogens, such as post-milking teat
disinfection, reduce CNS infections in the herd. Phenotypic methods for identification of CNS are not
sufficiently reliable, and molecular methods may soon replace them. Knowledge of the CNS species
involved in bovine mastitis is limited. The dairy industry would benefit from more research on the
epidemiology of CNS mastitis and more reliable methods for species identification.
PMID: 18848410 [PubMed - indexed for MEDLINE]
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20
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1
J Dairy Sci. 2009 Oct;92(10):4962-70.
Bovine subclinical mastitis caused by different types of coagulasenegative staphylococci.
Thorberg BM, Danielsson-Tham ML, Emanuelson U, Persson Waller K.
Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural
Sciences, SE-75007 Uppsala, Sweden. Karin.Persson-Waller@sva.se
Subclinical mastitis caused by intramammary infections (IMI) with coagulase-negative staphylococci (CNS)
is common in dairy cows and may cause herd problems. Control of CNS mastitis is complicated by the fact
that CNS contain a large number of different species. The aim of the study was to investigate the
epidemiology of different CNS species in dairy herds with problems caused by subclinical CNS mastitis. In
11 herds, udder quarter samples were taken twice 1 mo apart, and CNS isolates were identified to the
species level by biochemical methods. The ability of different CNS species to induce a persistent infection,
and their associations with milk production, cow milk somatic cell count, lactation number, and month of
lactation in cows with subclinical mastitis were studied. Persistent IMI were common in quarters infected
with Staphylococcus chromogenes, Staphylococcus epidermidis, and Staphylococcus simulans. The
results did not indicate differences between these CNS species in their association with daily milk
production, cow milk somatic cell count, and month of lactation in cows with subclinical mastitis. In cows
with subclinical mastitis, S. epidermidis IMI were mainly found in multiparous cows, whereas S.
chromogenes IMI were mainly found in primiparous cows.
PMID: 19762813 [PubMed - indexed for MEDLINE]
Publication Types, MeSH
Reprod Domest Anim. 2008 Jul;43 Suppl 2:252-9.
Mastitis in post-partum dairy cows.
Pyörälä S.
Department of Production Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki,
Saarentaus, Finland. satu.pyorala@helsinki.fi
Transition from the dry period to lactation is a high risk period for the modern dairy cow. The biggest
challenge at that time is mastitis. Environmental bacteria are the most problematic pathogens around
parturition. Coliforms are able to cause severe infections in multiparous cows, and heifers are likely to be
infected with coagulase-negative staphylococci. During the periparturient period, hormonal and other
factors make the dairy cows more or less immunocompromised. A successful mastitis control programme
is focused on the management of dry and calving cows and heifers. Clean and comfortable environment,
proper feeding and adequate supplementation of the diet with vitamins and trace elements are essential
for maintaining good udder health. Strategies which would enhance closure of the teat canal in the
beginning of the dry period and would protect teat end from bacteria until the keratin plug has formed
decrease the risk for mastitis after calving. Dry cow therapy has been used with considerable success. Yet,
a selective approach could be recommended rather than blanket therapy. Non-antibiotic approaches can
be useful tools to prevent new infections during the dry period, in herds where the risk for environmental
mastitis is high. Vaccination has been suggested as a means to support the immune defence of the dairy
cow around parturition. In some countries, implementation of Escherichia coli core antigen vaccine has
reduced the incidence of severe coliform mastitis after calving.
PMID: 18638132 [PubMed - indexed for MEDLINE]
Basic concepts of the bovine teat canal.
Paulrud CO.
Department of Animal Health and Welfare, Danish Institute of Agricultural Sciences, Research Centre
Foulum, P.O. Box 50, DK-8830 Tjele, Denmark.
The bovine teat canal is highly specialized in its unique function of preventing both leakage of milk and
entry of bacteria and thereby plays a major role in the defence of the udder against mastitis. The teat canal
is a longitudinally folded cylinder-shaped body opening, covered with approximately the same type of
epithelia as the normal skin and surrounded with a net-like integrated musculoelastic system facilitating its
opening and closure. During milking, dead, flattened, enucleated squamae (cellular detritus) are sloughed
from the teat canal surface and are continually replaced by inner cells differentiating outwards. The
epidermis is characterized by a polarized pattern of epithelial growth and differentiation, with a single layer
of proliferating keratinocytes and multiple overlying differentiated layers. Morphologically, the cells transit
from the basal layers on the basement membrane of the dermis through stratum corneum before they
finally end up as the keratin of the teat canal. The majority of the epidermal protein synthesizing machinery
is devoted to making keratin. This is reflected in the fact that keratins are the major structural proteins,
constituting up to 85% of a fully differentiated keratinocyte. Epidermal keratin is a 40-70 kDa alpha-helical
coiled-coil dimer of the intermediate filament family that, among other marker proteins, characterizes each
stage of keratinocyte differentiation. Studies of skin fragility disorders show that the primary role of keratins
in epidermal cells is to reinforce them so that they do not lyse upon physical pressure and to provide cells
with subtly different properties of resistance and plasticity to equip the epithelial cells for the physical
stress of each particular body site. Epithelial cell specialization for function also depends, however, on the
lipid composition and organization and on the epidermal architecture. Epidermal architecture depends on
epidermal turnover time, which in turn depends on cell number as well as the proliferative condition. Both
in vitro and in vivo studies have implicated calcium as a major modulator of epidermal differentiation.
Calcium is a factor known to enhance differentiation and promote expression of the differentiation-specific
keratin genes. In animals and humans, both topical and systemic retinoids produce acanthosis,
hypergranulosis and a relative (but not absolute) decrease in the thickness of the stratum corneum.
Despite a high degree of epithelial specialization, we expect a somewhat similar immunological functional
importance in the teat canal epithelia as in other stratified squamous keratinized type epithelia.
PMID: 15736856 [PubMed - indexed for MEDLINE]