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To describe the incidence, aetiology, treatment, and outcomes of farmer-reported clinical mastitis on New Zealand dairy sheep farms. A prospective cohort study was conducted on 20 spring-lambing New Zealand sheep milking farms over the 2022–2023 season. Clinical mastitis was defined as a change in the appearance of milk and/or signs of inflammation in the gland. Farmers were required to report all cases of clinical mastitis and collect information on affected ewes' demographics, clinical features, treatments (where applicable), and outcomes. Milk samples from mastitic glands were submitted for microbiological culture and identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF). Partial or complete clinical mastitis data were available for 236 cases from 221 ewes on 18/20 study farms. Clinical mastitis was diagnosed in 0–6% of ewes at the farm level, with an overall incidence of 1.8 (95% CI = 1.0–3.2)% using the study data, or 2.3 (95% CI = 1.6–3.3)% using the study data and farmer estimates that included unreported cases. Cases occurred mostly in early lactation, with 59% detected during the lambing period (August–October), at a median of 7 (IQR 3, 40) days in milk. The majority of cases featured clots in the milk (59%), swelling (55%), and unevenness (71%) of the glands. Pyrexia (rectal temperature $\ge$ ≥ 40.0°C) was diagnosed in 25% of cases and depression (lethargy, inappetence, or inability to stand) in 26% of cases. Treatment was given to 46% of cases, with tylosin being the most commonly used treatment (50% of treated cases). The most common outcome was immediate drying off to be culled without treatment (32%), followed by still milking and recovered but with lasting problems (25%). Nearly half of all the milk samples submitted were culture negative. Streptococcus uberis (14%), non-aureus staphylococci (12%), and Staphylococcus aureus (11%) were the most common isolates, found on 12, 8 and 8 of the 16 farms with microbiological data, respectively. Clinical mastitis affected up to 6% of ewes at the farm level. Systemic signs were observed in one quarter of affected ewes, suggesting a role for supportive treatment. Clinical mastitis can be severe and challenging to fully resolve in New Zealand dairy sheep. This is the first systematic study of clinical mastitis in New Zealand dairy ewes. It provides baseline information specific to New Zealand conditions for farmers, veterinarians, and other advisors to guide the management of mastitis for the relatively new dairy sheep industry in New Zealand. [ABSTRACT FROM AUTHOR]

To assess potential cow-level risk factors for clinical mastitis during the dry period in cows infused with internal teat sealant (ITS) alone at drying off, and associations with elevated somatic cell counts (SCC) at the first herd test, or clinical mastitis in the subsequent lactation. Ten herds reporting an incidence of clinical mastitis during the dry period of >3% amongst cows infused with ITS alone at the end of the 2018/2019 lactation were enrolled. Cow data collected included age, breed, milk yield and SCC at the last herd test before drying off, drying off date, clinical mastitis records during the dry period and in the subsequent lactation, and SCC at the first herd test following calving. Overall, 2,401 cows were infused with ITS alone and 196/2,401 (8.2%) cows were diagnosed with clinical mastitis during the dry period. In the final multivariable model for risk of clinical mastitis there was an interaction between age and milk yield at the last herd test (p < 0.001), with cows aged >4 years and producing ≥10 L/cow/day having a higher risk of clinical mastitis than younger cows or those producing <10 L/cow/day. The risk of clinical mastitis was higher for cows dried off in the last week of lactation than for cows dried off >1 week before the end of lactation for the herd (p = 0.033). The percentage of cows with elevated SCC (>150,000 cells/mL) at the first herd test in the following lactation was higher amongst those diagnosed with clinical mastitis over the dry period compared with those that were not (p = 0.048). The hazard of clinical mastitis in the first 60 days after calving was also higher in cows diagnosed with clinical mastitis in the dry period than those that were not (p < 0.001). The risk of clinical mastitis in the dry period following infusion of ITS alone at the end of lactation was associated with cow age, milk yield before drying off and timing of drying off. Cows diagnosed with clinical mastitis over the dry period had a higher risk of clinical mastitis and of elevated SCC in the subsequent lactation. This was an observational study so no causal inferences can be made, however herdowners and veterinarians should follow current recommendations regarding management of milk yield before drying off, and selection of cows for treatment with ITS alone. [ABSTRACT FROM AUTHOR]

AIMS: To determine the impact of treatment with internal teat sealant (ITS) compared to no treatment at drying-off on the incidence of clinical mastitis (CM) during the dry period and 84 days after calving, and the prevalence of cows with somatic cell counts (SCC) ≥200,000 cells/mL at the first lactation herd test, for cows wintered on forage crops. METHODS: In four dairy herds in the South Island of New Zealand, cows with no history of CM or individual SCC >100,000 cells/mL during the 2015–16 season were randomly assigned to treatment with ITS in each quarter (ITS group) at drying-off or no treatment (Control group). Cows were otherwise treated similarly, wintered on forage crops and transferred to pasture for calving and lactation. Cows were monitored over the dry period and for 84 days after calving, and any case of CM recorded. Individual SCC were recorded at the first herd test after calving. RESULTS: Between drying-off and 84 days after calving 36/470 (7.7%) cows in the ITS groups and 73/442 (16.5%) cows in the Control group were diagnosed with CM (RR=0.46; 95% CI=0.26–0.73). The final multivariable logistic regression model included an interaction between treatment group and length of dry period. For a Friesian/Jersey cow, aged 4–8 years, with a dry period of 30–80 days, dried off without ITS, the probability of CM in the study period was 0.12 (95% CI=0.09–0.16), and for such a cow treated with ITS the probability was 0.07 (95% CI=0.05–0.10). For an equivalent cow, with a dry period of 81–140 days, which was untreated, the probability was 0.21 (95% CI=0.14–0.29), and for such a cow treated with ITS it was 0.05 (95% CI=0.02–0.11). At the first herd test after calving 77/383 (20.1%) cows in the Control group and 57/425 (13.4%) cows in the ITS group had SCC ≥200,000 cells/mL (RR=1.51; 95% CI=1.10–2.06). CONCLUSIONS AND CLINICAL RELEVANCE: For these farms, treatment of cows with no history of elevated SCC or CM with ITS at drying-off halved the incidence of CM between drying-off and 84 days after calving, and reduced by 33% the proportion of cows with SCC≥200,000 at the first herd test after calving, compared with untreated cows. Treatment with ITS reduced the risk of CM proportionally more for cows with a dry period of 81–140 days than for cows with a shorter dry period. [ABSTRACT FROM PUBLISHER]

AIM: To test the non-inferiority of a novel combination intramammary product containing penicillin and cloxacillin to a reference intramammary product containing oxytetracycline, oleandomycin, neomycin and prednisolone with regard to bacteriological cure and clinical cure. METHODS: Clinical cases of mastitis were sourced from 30 spring-calving dairy farms in the Southland region of New Zealand. Affected quarters were infused three times at 24 hourly intervals with either the novel combination product containing 1 g penicillin and 200 mg cloxacillin, or a reference product containing 200 mg oxytetracycline, 100 mg oleandomycin, 100 mg neomycin and 5 mg prednisolone. Cows were enrolled when a farmer detected a case of clinical mastitis. Milk samples were collected for microbiological culture immediately before treatment (Day 0) and on Days 9, 16 and 23. Bacteriological cure was compared for 187 and 178 quarters treated with the reference and novel product, respectively, and clinical cure was compared for 235 and 223 quarters, respectively. Non-inferiority was assessed by calculating the difference in cure rates between the two products and constructing a 95% CI around the difference, using the variance inflation factor to account for herd level clustering. The non-inferiority margin was 20% for both bacteriological and clinical cure. Generalising estimating equation models were used to determine predictor variables. RESULTS: The bacteriological cure percentage, adjusted to account for herd-level clustering, was 8.5 (95% CI=−1.7–21.8)% higher for quarters treated with the novel than the reference product. The adjusted clinical cure percentage was 0.3 (95% CI=−11.2–12.0)% higher for clinical quarters treated with the novel than the reference product. Bacterial species was the only covariate for bacteriological cure (p=0.003), and quarter score at enrolment (indicating udder inflammation) was the only covariate for clinical cure (p=0.032) in the multivariable models. CONCLUSION: The novel combination product was demonstrated to be non-inferior to the reference product with regards to both bacteriological cure and clinical cure. CLINICAL RELEVANCE: Clinicians treating mastitis now have access to this novel combination intramammary product, and demonstration of its non-inferiority compared to the existing reference product will provide options for treatment approaches. The novel product contains fewer antimicrobials; which are of a narrower spectrum of activity. [ABSTRACT FROM PUBLISHER]

AIM: To assess the effect of combining an internal teat sealant (ITS) and a long-acting cephalonium-based dry cow therapy (DCT) on the prevalence of cows with a somatic cell count (SCC) >150,000 cells/mL 60–80 days after calving, and the incidence of clinical mastitis diagnosed by farm staff in the first 100 days after calving. METHODS: Cows from a spring-calving, pasture-based, dairy farm in the South Canterbury region of New Zealand were randomly allocated to receive cephalonium DCT (n=289) or cephalonium and internal teat sealant (n=304) at the end of lactation. Cows were inspected twice daily by farm staff during the dry period and following calving for signs of mastitis. Individual SCC were determined from herd tests conducted in the previous lactation and following calving. Logistic regression models were used to determine relationships with the prevalence of cows with a SCC >150,000 cells/mL after calving, and survival analysis was used to model time to the first case of clinical mastitis following calving at the cow and quarter level. RESULTS: The OR for a cow with a SCC >150,000 cells/mL after calving, including age and individual SCC in the preceding lactation in the model, was 0.53 (95% CI=0.32–0.89) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.017). At the cow level, including age and preceding SCC in the model, the hazard ratio for diagnosis of clinical mastitis by farm staff in the first 100 days of lactation was 0.60 (95% CI=0.39–0.98) for cows treated with combination therapy compared to cows receiving cephalonium (p=0.04). At the quarter level, the hazard ratio for diagnosis of clinical mastitis, with age included in the model, was 0.41 (95% CI=0.23–0.74) for the combination therapy compared to cephalonium alone (p<0.001). CONCLUSIONS: The combination of internal teat sealant and cephalonium DCT was more effective than cephalonium alone at reducing clinical mastitis diagnosed by farm staff in the 100 days after calving, and the prevalence of cows with a SCC >150,000 cells/mL 60–80 days after calving. CLINICAL RELEVANCE: This study adds to the evidence that the prevention of intra mammary infections throughout the dry period and up to calving by using combination therapy is important in reducing the incidence of farmer-diagnosed clinical mastitis and prevalence of cows with a SCC >150,000 cells/mL 60–80 days after calving. [ABSTRACT FROM PUBLISHER]

AIM: To compare clinical and bacteriological cure rates of clinical mastitis following treatment with either antimicrobials or homeopathic preparations. METHODS: Seven spring-calving herds from the Waikato region of New Zealand were used to source cases of clinical mastitis (n?=?263 glands) during the first 90?days following calving. Duplicate milk samples were collected for bacteriology from each clinically infected gland at diagnosis and 25 (SD 5.3) days after initial treatment. Affected glands were treated with either an antimicrobial formulation or a homeopathic remedy. Generalised linear models with binomial error distribution and logit link were used to analyse the proportion of cows that were clinical treatment cures and the proportion of glands that were classified as bacteriological cures, based on initial and post-treatment milk samples. RESULTS: Mean cumulative incidence of clinical mastitis was 7% (range 2–13% across herds) of cows.Streptococcus uberiswas the most common pathogen isolated from culture-positive samples from affected glands (140/209; 67%). The clinical cure rate was higher for cows treated with antimicrobials (107/113; 95%) than for cows treated with homeopathic remedies (72/114; 63%) (p?

The article presents a study on the efficacy of two long-acting dry-cow cephalonium products in preventing and curing intramammary infections. The researchers dried-off cows in groups of up to 230 in various occasions from May 19 to July 3, 2008, which excluded the cows with clinical mastitis. They inserted the right trial dry cow treatment (DCT) preparation after further aseptic preparation with 70 percent alcohol wipes. They found that a new cephalonium DCT preparation was equal to the current positive-control cephalonium product in terms of efficacy.

The article presents a study on a new cephalonium antibiotic formulation of dry-cow therapy (DCT), which aims to test its non-inferiority to a reference formulation in curing and preventing a new intramammary infections (IMI). It states that cows were ranked based on their somatic cell count (SCC) and were assigned to various treatment including the infusion of the new formulation. It concludes that the new formulation was non-inferior than the reference formulation in IMI prevention.