Your queries on mastitis answered by our vets

Q I’ve had a problem with metritis. We don’t usually have a problem with retained placentas, but this year we have had three cows with it out of 30 and one went on to develop a really nasty infection with a high temperature which made her stiff through the pelvis. Is it unusual to get metritis this bad? Why could it have been so bad?

A If your herd has an incidence of retained fetal membranes (RFM) above 10% you need to pull your health team – vet and nutritionist – together to find an effective health solution. Retained fetal membranes end up as metritis in 25-50% of cases. Metritis may require antibiotic, anti-inflammatories and rehydration therapies – for this you should seek advice from your local vet to establish a set metritis treatment protocol.

Some critical points to work through with your health team are:

• Mechanical factors: difficult birth (dystocia), twins, stillborn, abortion
• Nutritional factors: sub-optimal dry matter intake in the dry period, mineral and vitamin deficiency, low levels of calcium in blood, sub-clinical ketosis
• Management factors: stress, obesity
• Infectious diseases: BVD, IBR, leptospirosis

After a normal calving, the immune system recognises the foetal placenta as foreign and attacks it. The unions between uterus and placenta are destroyed and the foetal membranes are expelled. However, when the immune system is weakened, it fails to degrade those unions and retained fetal membrane occurs.

Factors for a good immune response that should be taken into consideration to prevent retained fetal membranes are:

• Reduced dry matter intake pre- and post-calving: Prevent bodyweight loss during close-up of the dry period and provide easy access to fresh palatable food to stimulate appetite
• Calcium blood levels: check the dietary cation-anion difference (DCAD)
• Dietary minerals and vitamins: ensure the dry cow ration is properly formulated
• Quality silages: mould and mycotoxins impair the immune response
• Stress: minimise pen movements and diet changes close to calving

Indiscriminate treatment of cows immediately after calving with oxytocin, prostaglandin or calcium has shown poor results on retained fetal membrane prevention. I would not recommend forcefully removing retained fetal membranes, as after calving the uterine walls can be thin and friable and manipulation of the uterus may cause harm.

Cows with retained fetal membranes normally drop the fetal membranes within a week. The best approach in this case is to watch the cow closely and initiate treatment when indicated by a farm-specific protocol drawn up with your vet.

Jon Mouncey is a vet at the Sevenoaks practice. Jon has recently completed his diploma in bovine reproduction, which has allowed him to pursue his interests in dairy cow fertility, nutrition and dairy data analysis.

Q I’ve been stripping three “summer mastitis” quarters for more than a month now and the cow is about one week from calving. I’m seeing water with some blobs of white “cream” still. Some quarters more than others. What is the most likely explanation of what I’m observing? Particularly with regard to whether the blobs are freshly produced or old material being cleared?

A Summer mastitis usually refers to a dry-period infection with a bacterium called Trueperella pyogenes. Other bacteria are involved to produce a characteristic mastitis, generally with the production of a thick yellow pus, which may smell very obnoxious. The effect on the cow is variable. Some may show no signs, apart from a dry quarter at calving, others may be extremely ill.

If you have been stripping quarters for a month or more you may be seeing the leftover effects of the damage inflicted by the infection, rather than signs of an active infection. The secretory tissue becomes “leaky”, leading to watery fluid from the blood supply oozing into the quarter, together with the white blobs of pus produced as the cow “tidies up” her quarter afterwards. I would suggest that dry cow management is reviewed with your vet, including the use of teat sealants, antibiotics and fly control.

Keith Baxter is a vet at the Midhurst practice. He has a particular interest in mastitis investigation and control, computerised recording and analysis of farm data and bull fertility.

If you have a livestock-related health question you would like answering, or have a query or worry about health-related issues on your farm, then send it to us. We will do our best to answer your query in Dairy Update, Farmers Weekly or on FWi. You can email your questions to fwlivestock@rbi.co.uk or post at www.fwi.co.uk/livestocklines 

Ask the Vet is a series in association with Westpoint Vet Group. For further information on Westpoint call 01306 628 086 or visit www.westpointfarmvets.co.uk