Many cases of clinical mastitis resolve by themselves. Clinical mastitis is generally caused by bacterial infection. However, by the time of diagnosis, and over the next few days, a proportion of mastitis cases self-cure. Treatment of clinical cases of mastitis with a non-steroidal anti-inflammatory (e.g. Metacam) increases bacteriological cure rate over antibiotics alone. We aim to test whether treatment of mild clinical mastitis cases (i.e. those where there is no evidence that the cow is systemically ill) with Metacam alone, results in better outcomes than placebo treatment. 
 
Cows will be eligible if diagnosed with mastitis for the first time in the current lactation, have only 1 gland effected, do not have severe teat end damage, and that have not been treated with antibiotics or nonsteroidal anti-inflammatories in the 14 days before diagnosis. Any cow with severe mastitis, that is, any signs that the cow herself is systemically affected (depressed, dehydrated, not eating etc.) will be excluded. 
 
Please ring 0800 627 840 if you have a suitable case and a technician will come to farm to collect a milk sample and apply the treatment. The treatment will be a standard dose of Metacam (i.e. injection of 2.5 mL/100 kg live weight) or injection of a similar volume of the placebo. The milk withhold is 84 hours (3.5 days), and the meat withhold is 10 days. At 14 (+/-3) days and 21 (+/- 3) days after treatment, a technician will come and collect milk samples again. Cows will be monitored for at least 100 days post treatment, by downloading electronic farm records and/or recovering on-farm paper records. 
 
We will pay for the treatments, credit your vet account by $50 per cow that completes the project, and provide the microbiology results (worth about $15/cow). 
 
If you have a potentially suitable case, please ring 0800 627 840 (at any time) or for more general questions contact Scott McDougall on 021 800 341 or via email at  [email protected]