Vet Viewpoint: Advice on flies, BVD, coccidiosis and mastitis

Summer has arrived across the country, bringing with it a host of issues for the vets in this month’s Vet Viewpoint.

In this edition, vets from around the country offer advice on fly control and coccidiosis in calves and lambs. They also discuss selective dry cow therapy and we get an update on the Welsh bovine viral diarrhoea (BVD) programme.

See also: Vet Viewpoint: Sheep lameness, abortion and fluke advice

John Cammack

John Cammack

Glenthorne Veterinary Group, Uttoxeter, Staffordshire

Flies on cattle can cause reduced milk yields, decreased feed intakes and a rise in diseases such as mastitis and New Forest eye.

So, as we move into peak fly season, a robust control plan is needed and this should take the form of a two-pronged approach of environmental and animal control.

Aside from general hygiene, a range of treatments are available to reduce the environmental reservoir of flies, including adulticidal and larvicidal sprays, fly lamps and fly traps.

Using fly parasites that feed on the developing maggots and prevent them developing into adult flies is a novel approach to environmental control. It relies on the fly parasites being released around ideal breeding sites such as dung heaps.

Animal control relies on the regular application of insecticides, usually as pour-on preparations.

Midges, which transmit the diseases bluetongue and Schmallenberg, will also be controlled by a similar strategy to flies.

See also: Vet Viewpoint: Metabolic profiling, abomasal bloat and grass staggers

Danielle Priestley

Danielle Priestley

St Boniface Veterinary Clinic, Crediton, Devon

Many of the practice’s dairy herds are autumn block calving and will shortly be considering their selective dry cow management. Therefore, we thought we would share a few reminders about why a selective approach is best.

There is no sense in giving antibiotics to an uninfected cow. In fact, if you do give antibiotics to low-somatic cell count cows, their risk of coliform mastitis in the next lactation actually increases.

Of 52 UK farms studied, those using selective dry cow management were significantly less likely to have cows developing mastitis in the first 30 days of lactation.

And protection against new infection in the dry period is much better achieved by using teat sealants and will reduce the risk by about 25%.

Roderick Dunse

Roderick Dunse

Dunmuir Veterinary Group, Castle Douglas, Dumfries and Galloway

Once again, we have come through a long and wearing winter here in south-west Scotland. Persistent damp conditions have allowed coccidiosis to increasingly flourish in calves and lambs over recent years.

Those affected by coccidiosis can possibly set their watches by it and know when to expect it and when to treat.

For those of us who have not yet met coccidiosis, it is a little protozoan parasite that loves moist conditions. And if an area is overstocked, so much the better for the little blighters.

The good news is that immunity develops to coccidiosis, the bad news is it really damages the digestive tracts before calves or lambs catch on to what is going on.

Simon-Wilson

Simon Wilson

Cain Veterinary Centre, Llansantffraid, Powys

Here in mid-Wales, we have recently been making extra use of the TB test by taking the opportunity to blood sample youngstock for BVD exposure.

This free test forms part of the Welsh BVD eradication project, which aims to find which herds have the active virus circulating in them and then to eradicate the disease from Wales.

Farms testing positive benefit from funding to look for persistently infected (PI) “carrier” animals. It is only by removal of these PI animals from a herd that the cycle of BVD infection can be stopped.

Hopefully, through this scheme more farms can become free from the negative effects BVD has on fertility and immunity and we can prevent the creation of more poor-performing PI animals. The scheme has certainly raised awareness of the disease in our area.

Vet Viewpoint is a regional monthly round-up of key issues from XL Vet Group.