Epidemiological and bacteriological survey of buffalo mastitis in Nepal

A total of 355 Murrah cross buffaloes, consisting of 23 subclinical and 332 clinical mastitis cases brought to the Veterinary Teaching Hospital, Chitwan, Nepal from 2002 to 2005, were analyzed to determine the organisms involved, the seasonal occurrence of mastitis, and antibiotic susceptibility of mastitis pathogens. Coagulase negative Staphylococci (CNS) such as Staphylococcus albus and S. epidermidis were the predominant organisms associated with subclinical cases, and CNS and Coliforms in clinical cases. The maximum number (16%) of clinical cases of mastitis were observed in the month of July, when temperature and humidity are highest. The incidence of clinical mastitis was higher in animals during 1st calving and during the 1st month of parturition. Resistance to antibiotics was determined for 55, 23 and 149 isolates of Staphylococcus spp., Streptococcus spp. and Coliforms, respectively. In vitro drug sensitivity testing revealed that enrofloxacin had the highest average sensitivity (91%) for all types of bacteria. The effectiveness of other drugs detected were gentamicin (87%), tetracycline (83%) and chloramphenicol (82%). The antibiogram showed that both gentamicin and enrofloxacin are slowly becoming resistant. Mastitis pathogens have developed resistance to ampicillin and penicillin.     

A benefit cost analysis of dry-cow mastitis therapy in Ontario dairy herds

Data collected from 297 dairy farms in Ontario were analyzed to investigate the economic consequences of using dry-cow antibiotic therapy, and to demonstrate the elements of an economic evaluation. Benefit/cost ratios ranged from 0.5 to 31.0 depending on the methods used to assess the benefits of therapy. In general, within the assumptions outlined in this analysis, dry-cow therapy was found to be economically advantageous. However, many factors can influence milk production and somatic cell counts. In this observational study, it is possible that some such factors were confounded with the use of dry-cow therapy, and may have biased the estimates of economic impact.     

Summer mastitis in heifers: a bacteriological examination of secretions from clinical cases of summer mastitis in Denmark

A total of 166 samples of secretions collected from Danish heifers suffering from clinically diagnosed summer mastitis were examined bacteriologically. One hundred and sixty three samples yielded positive findings whereas no growth was obtained from 3 specimens. The majority of samples revealed a mixed flora in which the predominant components were Actinomyces pyogenes, Peptostreptococcus indolicus, a microaerophilic coccus (Stuart-Schwan coccus), Fusobacterium necrophorum, Bacteriodes melaninogenicus and Streptococcus dysgalactiae. Pure cultures were recovered in only 7% of cases. P. indolicus was isolated from 875 of the cases, a microaerophilic coccus from 84%, A. pyogenes from 72%, Fusobacterium necrophorum from 52%, Str. dysgalactiae from 37%, B. melaninogenicus from 33% and various unidentified obligate anaerobic Gram-negative rods from 31%. The results confirm the complex bacterial aetiology of summer mastitis.     

Clinical mastitis in dairy cattle in Ontario: frequency of occurrence and bacteriological isolates.

The objective of this study was to describe the frequency of occurrence of clinical mastitis in dairy herds in Ontario. The study group consisted of 65 dairy farms involved in a 2-year observational study, which included recording all clinical mastitis cases and milk sampling of quarters with clinical mastitis. Lactational incidence risks of 9.8% for abnormal milk only, 8.2% for abnormal milk with a hard or swollen udder, and 4.4% for abnormal milk plus systemic signs of illness related to mastitis were calculated for 2840 cows and heifers. Overall, 19.8% of cows experienced one or more cases of clinical mastitis during location. Teat injuries occurred in 2.1% of lactations. Standard bacteriology was performed on pretreatment milk samples from 834 cows with clinical mastitis. The bacteria isolated were Staphylococcus aureus (6.7%), Streptococcus agalactiae (0.7%), other Streptococcus spp. (14.1%), coliforms (17.2%), gram-positive bacilli (5.5%), Corynebacterium bovis (1.7%), and other Staphylococcus spp. (28.7%). There was no growth in 17.7% of samples, and 8.3% of samples were contaminated. Clinical mastitis is a common disease in dairy cows in Ontario; approximately 1 in 5 cow lactations have at lease one episode of clinical mastitis. There is, however, considerable variation in the incidence of clinical mastitis among farms. The majority of 1st cases of clinical mastitis occur early in lactation, and the risk of clinical mastitis increases with increasing parity. Environmental, contagious, and minor pathogens were all associated with cases of clinical mastitis.     

Comparative bacteriological studies on summer mastitis in grazing cattle and pyogenes mastitis in stabled cattle in Denmark.

A total of 143 secretions from clinical cases of summer mastitis (SM) in grazing cattle and from 89 cases of pyogenes mastitis (PM) in stabled cattle were examined bacteriologically. The typical bacteriological finding was a mixed flora in which the predominant organisms were Actinomyces pyogenes (SM-70%, PM-85%), Peptostreptococcus indolicus (54%, 54%), a microaerophilic coccus (Stuart-Schwan coccus) (26%, 25%), Fusobacterium necrophorum biovar B (22%, 12%), Bacteroides melaninogenicus (20%, 9%) and Streptococcus dysgalactiae (21%, 5%). All except six cases occurred in non-lactating animals or within three weeks after parturition. The majority of animals (about 90%) had only one quarter affected and no differences in quarter distribution were observed between the two groups.     

Calving Interval in Dairy Cows in Relation to Heifer Rearing Conditions in Southwest Sweden

Sustained reproductive performance throughout the life of domestic animals can be suspected to require successful rearing of replacements. We studied associations between replacement heifer rearing conditions and reproductive performance throughout the productive life of dairy cows in southwest Sweden by linear mixed modelling. Data consisted of 3542 lactations in 1550 Swedish Reds, Swedish Holsteins or dairy cows of other or mixed breeds, representing all female animals born during 1998 in 107 herds. Median calving interval (CI) was 381, 380 and 377 days in parities 1, 2 and ≥3, respectively. Median observed productive lifetime was 27 months. The applied model included effects of cow housing system, breed, parity, respiratory disease before 3 months of age, whether oestrous detection was performed only at feeding, oestrous-detection ability, calving year, post-calving reproductive disease in a given lactation, milk yield 30 days post-calving relative to the herd mean, the interaction of breed by calfhood respiratory disease and random effects of cow and herd. Severe respiratory disease before 3 months of age in Swedish Red cows was associated with an increase in CI by 12%. Of the total variation in CI, 9.5% was due to herd factors and 12% to cow factors, as opposed to variation between lactations.     

A survey of mastitis in selected ontario dairy herds

A mastitis survey involving 74 Ontario dairy herds was conducted. The prevalence of infection at the quarter level was found to be 4.1% with Streptococcus agalactiae, 4.5% with other streptococcal species and 8.0% with Staphylococcus aureus. Regardless of the infection status, the geometric mean somatic cell count was found to increase with age of the cow but no increase was observed with increasing stage of lactation. The percentage of cows from which a bacterial pathogen was isolated increased with age but not with stage of lactation.     

Experimental staphylococcal mastitis in bitches: clinical, bacteriological, cytological, haematological and pathological features

The objectives of the work were to study the features of experimentally induced canine mastitis and to present hypotheses regarding the pathogenesis of the disease. The right caudal abdominal mammary gland of six bitches was inoculated on day 8 after whelping with Staphylococcus intermedius to induce mastitis; adjacent mammary glands were used as controls. Clinical examination, bacteriological and cytological (whiteside test, Giemsa) examination of mammary secretion, as well as haematological tests were performed from 5 days before until 34 days after challenge. Mastectomy was sequentially performed 1, 2, 4, 18, 26 and 34 days after challenge in each of the bitches, in order to carry out a pathological examination of mammary glands. All animals developed clinical mastitis: challenged glands became painful, hot, enlarged and oedematous; secretion was brownish, purulent, with flakes or clots, subsequently becoming yellowish and thick. Staphylococci were isolated from all inoculated glands (up to 22 days). WST was positive in 41/46 samples from inoculated glands and 66/138 samples from control glands; neutrophils predominated during the acute stage. Blood leukocyte counts increased, whilst platelet counts decreased. Gross pathological findings initially included congestion, purulent discharge and subcutaneous oedema; then abscesses, brownish areas and size decrease were seen. Salient histopathological features were initially neutrophilic infiltration, haemorrhages, destruction of mammary epithelial cells and alveoli, and then infiltration by lymphocytes, shrunken alveoli, loss of glandular architecture and fibrous tissue proliferation. We conclude that in bitches, intrammamary inoculation of Staphylococcus intermedius can induce clinical mastitis, followed by subclinical disease. The disorder is characterized by bacterial isolation and leukocyte influx in challenged glands, by leukocyte presence in adjacent mammary glands, by increased blood leukocyte counts and by destruction of mammary parenchyma.     

A serological and bacteriological survey of leptospiral infection in dogs in Edinburgh and Glasgow

Sera collected from 511 unvaccinated urban dogs were examined for antibodies to serovars of Leptospira interrogans representing nine serogroups found in the United Kingdom. The point estimates of the seroprevalence of leptospiral titres in Edinburgh and Glasgow at a minimum serum dilution of 1:10 were 23-5 per cent and 27-5 per cent, respectively, and, in Glasgow, the seroprevalence was significantly higher in males than females, for both crude and age-adjusted values. Serovar canicola was the dominant strain identified, followed by serovars icterohaemorrhagiae, bratislava and ballum. Antibodies against serovars javanica and hardjo also were detected. Urine samples were collected from 84 of the male blood-sampled dogs, and cultured. Serovars canicola and bratislava were isolated from three and four samples, respectively.     

Effect of preculture freezing and incubation on bacteriological isolation from subclinical mastitis samples

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 24h at 37 degrees C in broth, followed by culture using the standard culture technique. In the third method, the whole milk sample was frozen for 24h, and then incubated for 24h at 37 degrees C, 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.     

真菌性乳房炎病原菌的分离鉴定与流行病学调查

本研究对山东省济南、泰安、临沂三地区共386份乳房炎奶样进行了真菌的分离鉴定与流行情况调查。经鉴定其病原为白色念珠菌。调查结果表明真菌性乳房炎在不同地区均有发生。个体养殖户奶牛奶样的真菌阳性率（19．3％）明显高于规模化养殖场（7．62％）；临床型乳房炎的真菌阳性率（13．11％）高于隐型乳房炎（3．75％）。本文的调查结果为更好地了解真菌在我国奶牛业的感染情况和采取有效的防治措施提供了一定的依据。     

Heifer development: reproduction and nutrition.

The nutritional development of heifers from birth to the time they become pregnant with their second calf is a critical component of cowherd management. Veterinarians can use targeted body weights and condition scores to monitor progress and gauge future reproductive success throughout heifer development. Meeting Nutrient Requirements of Beef Cattle recommendations for net energy and metabolizable protein is the single most successful strategy for maximizing reproductive performance from birth through the second pregnancy. Supplementation with fat, minerals, and additional undegraded intake protein has not been consistently reported to enhance the reproductive function of heifers.     

Antimicrobial susceptibilities and bacteriological characteristics of bovine Pseudomonas aeruginosa and Serratia marcescens isolates from mastitis

The presence of metallo-β-lactamase (MBL)-producing and multidrug-resistant Pseudomonas aeruginosa (MDRP) strains among bovine isolates of Gram-negative bacilli, and O-serotypes of bovine Serratia marcescens and P. aeruginosa isolates have been reported rarely. The aims of this study were to (1) elucidate antimicrobial susceptibilities and O-serotypes of P. aeruginosa and S. marcescens isolates from bovine mastitis and the presence of MBL-producers and MDRP strains among them and (2) evaluate their relationships to human isolates. We investigated the MICs of 24 antimicrobials and O-serotypes for 116 P. aeruginosa and 55 S. marcescens isolates in Japan, primarily in 2006. A total of 171 isolates exhibited high antimicrobial susceptibilities with the exception of a partial drug. P. aeruginosa isolates exhibited high susceptibilities of ≥ 95.7% to ciprofloxacin, imipenem, meropenem, piperacillin, ceftazidime, cefepime, cefoperazone/sulbactam, amikacin, tobramycin, and gentamicin; however, they exhibited a susceptibility of only 69.8% to aztreonam. They exhibited substantial resistances to ceftriaxone, enrofloxacin, cefotaxime, and moxalactam. S. marcescens isolates exhibited high susceptibilities of ≥ 90.9% to kanamycin, ceftiofur, sulfamethoxazole-trimethoprim, and the 15 aforementioned drugs, but exhibited resistance to minocycline. Neither MBL-producers nor MDRP strains were detected among the 171 strains. The dominant serotypes of P. aeruginosa isolates were OG, OA, OB, OI, OF, OE, and OK; those of S. marcescens isolates were O6 and O5. Every S. marcescens isolate was pigmented. These findings suggest that bovine P. aeruginosa and S. marcescens isolates differ from human isolates from both antibiogram and phenotypic perspectives, and could help to evaluate differences in bacteriological characteristics between bovine and human isolates.     

Feeding dairy calves and replacement heifers in South-western Sweden: a survey

Daily feed rations, their nutrient contents and live weight gains were recorded for calves and replacement heifers from birth to calving in 122 Swedish dairy herds. Preweaned calves were fed whole milk (45% of the herds), milk replacer alone or milk replacer combined with whole milk. Calf starters were the most frequently used concentrates for preweaned calves, whereas grain dominated for weaned calves and heifers. Grain was supplemented with protein concentrates until 6 months of age and at calving. Grass/clover hay was the dominant forage for preweaned calves, whereas grass/clover silage alone or in combination with hay was the most common forage for calves and replacement heifers from 6 months of age. Heifers grazed semi-natural grasslands, leys or a combination of semi-natural grasslands and leys in 33, 15 and 52% of the herds, respectively. According to Swedish recommendations, calves in a majority of the herds were fed too low concentrations of crude protein from weaning to 6 months of age and calves were fed too low a metabolizable energy content inadequate for a daily weight gain of 700 g at weaning. Median live weight gain from birth to calving was only 567 g per day. Correct feed ration formulations and strategic grazing management could be means to increase weight gain and hence to decrease rearing costs of calves and replacement heifers in Swedish dairy herds.     

Canine urolithiasis in Sweden and Norway: Retrospective survey of prevalence and epidemiology

It was estimated that 23 to 24 dogs per 10,000 in Sweden were operated on for urolithiasis between 1956 and 1982. During this period urinary calculi were confirmed in 2898 dogs of 95 breeds, chiefly in chondrodystrophic and well proportioned (not short legged) miniature breeds. The distribution between the sexes in the period 1956 to 1970 was estimated at 57 per cent male and 43 per cent female in the chondrodystrophic breeds, 74 per cent male and 26 per cent female in the well proportioned miniatures, and 83 per cent and 17 per cent female in the large breeds; in the dalmatian (1956 to 1982) 94 per cent were male and 6 per cent female. Urinary calculi were found at a younger age in the chondrodystrophic breeds (1956 to 1970) than in the well proportioned miniature dogs and in large dogs (P<0–001). It was estimated that five dogs per 10,000 in Norway were operated on for urolithiasis between 1956 and 1970. During this period urinary calculi were diagnosed in 71 dogs of 28 breeds. Seventy-nine per cent were male and 21 per cent were female. Urolithiasis in dogs appears to be chiefly constitutionally dependent. Chondrodystrophic breeds and small breeds are particularly susceptible.