Liisa Kaartinen

Cross-sectional prospective survey to study indication-based usage of antimicrobials in animals: Results of use in cattle

BackgroundIndication-based data on the use of antimicrobials in animals were collected using a prospective cross-sectional survey, similarly as for surveys carried out in human medicine, but adapting the questionnaire to include veterinary-specific issues. The participating veterinarians were randomly selected from a sample population of practising veterinarians. The sampling was stratified to take into account the proportions of different types of veterinary practice in the country. All patients consulting the veterinary practice during a 1-week period were included in the study and veterinarians returned a completed questionnaire for each patient receiving antimicrobial treatment. As cattle received most of the treatments, results from the survey are given using cattle as an example species.ResultsThe survey was sent to 681 veterinarians, of whom 262 (39%) responded. In total 2850 questionnaires were completed. The largest quantities of antimicrobials, measured in kilograms, were used for cattle, followed by pigs, dogs and horses. The species that were treated most were cattle (n = 1308), dogs (n = 989) and cats (n = 311). For cattle, the most common reason for treatment was acute mastitis (52%), followed by dry-cow therapy (21%), subclinical mastitis (6%) and treatment for acute enteritis (4%). The remaining treatments covered 17% of cattle patients and 15 different indications. For acute mastitis, parenteral or intramammary treatment was used in 36% and 34% of the cases, respectively. The remaining 30% received both treatments simultaneously. Of the parenteral treatments (n = 459), benzyl penicillin was used in 83% of the treated animals (n = 379), while fluoroquinolones were used in 49 cases (11%). Of the 433 cows receiving intramammary treatment, ampicillin combined with cloxacillin was most commonly used (n = 157; 36%), followed by cephalexin+streptomycin (n = 113; 26%).ConclusionThis cross-sectional prospective survey provided a useful method for the collection of information on the indication-based use of antimicrobials in different animal species. Cattle were the most commonly treated animal species during the study period. The most common indication for antimicrobial use in cows was mastitis. Benzyl penicillin was the drug most frequently used for the treatment of mastitis, which seems appropriate according to the national guidelines on the use of antimicrobials in cattle in Finland.

Milking performance and udder health of cows milked with two different liners.

The effects of milking cows with two different liners were measured for a period of 8 months with 115 Danish Holstein cows divided into two groups. Group H and L animals were milked with liners with mouthpiece cavity heights of 30 and 18 mm respectively (other dimensions also differed between the two liners). Average teat lengths of first lactation cows were 45 and 40 mm for front and rear teats. Older cows had teats approximately 10 mm longer. There was no difference in milk yield or milk flow rates between the two groups. Average machine-on time was shorter for group L, and first lactation cows of group L were less restive. The frequency of red and blue discoloured teats immediately after milking was higher for group H, and teat length increased on average 5 mm during lactation with no increase for group L. The small overall differences in udder health between the two groups were not significant. Udder health was better for first lactation cows of group L, even though liners of group L slipped more often and cows with recorded liner slip had poorer udder health. We conclude that special attention should be given to first lactation cows when liner type is selected for a herd. We propose that breeding programmes should ensure that teat length is kept above 50 mm.

Condition-based use of antimicrobials in cats in Finland: Results from two surveys

Two surveys were carried out to investigate how antimicrobials are used in cats in Finland. Information was retrieved from 419 prescriptions and 311 questionnaire sheets concerning antimicrobial treatment for feline patients. Infected wounds, skin disorders and urinary tract infections were the most common reasons for antimicrobial treatment in cats. Compliance with prudent use guidelines was good. β-Lactams such as amoxycillin and amoxycillin with clavulanic acid were frequently used. Fluoroquinolones were used judiciously. The median length of treatment was 10 days for most conditions. Diagnosis was mainly based on clinical signs, and bacteriological culture and sensitivity testing was rarely performed. This study provides basic descriptive information on how antimicrobials are used in cats and that could help when revising guidelines for the condition-based use of antimicrobials in animals.

Changes in milk plasminogen, plasmin and in vitro bacterial growth in whey during early lactation.

The activity of milk plasmin, plasminogen and N-acetyl-beta-glucosaminidase (NAGase) and the trypsin-inhibitor capacity (TIC) were monitored in 40 quarters during the first month of lactation. TIC and NAGase activity decreased rapidly and plasmin activity more slowly during the first week. Conversely milk plasminogen increased as time elapsed from parturition. When the quality of whey was analysed as a growth medium for mastitis pathogens, a slight inhibition in the growth of Escherichia coli, Staphylococcus aureus and Streptococcus agalactiae was seen at the day of parturition. There was a distinct stimulatory effect on the growth of Str. agalactiae during the second week of lactation. No relationship was found between in vitro bacterial growth and respective plasmin or plasminogen activity in milk.

Use of N -acetyl- β -glucosaminidase to detect teat canal inflammations

Infections of the bovine mammary gland are considered to be ascending infections through the teat canal (Forbes & Hebert, 1968). With respect to skin and wound infections, staphylococci in particular adhere to and colonize traumatized areas (Mertz et al. 1987). Staphylococcus aureus and coagulase-negative staphylococci can colonize the teat canal for weeks before they invade upper parts of the mammary gland (Forbes & Hebert, 1968). Such teat canal infections predispose the mammary gland to mastitic infections, particularly with the so-called ‘contagious’ mastitis pathogens, namely Staph. aureus, Streptococcus agalactiae and Str. dysgalactiae .