Vet Viewpoint: Listeriosis, cryptosporidium and mag staggers

Vets from Scotland to Somerset share their experiences in this month’s Vet Viewpoint.

Diseases discussed in this round-up include listeriosis and cryptosporidium – and how to reduce the risk of them affecting herds and flocks.

And thanks to the drop in temperature and energy-dense forages fed this winter, another issue to be aware of in freshly calved cows and freshly lambed ewes is magnesium deficiency.

Will Davey

Hook Norton Veterinary Group, Hook Norton, Oxfordshire.

Will Davey

Over the past month we have seen an increased number of cases of listeriosis in cattle and sheep.

This year, silage was largely baled with a high dry matter percentage – which reduces the fermentation, raising the pH. This makes a perfect environment for listeria to multiply and thrive.

The most common signs of listeriosis are neurological: affected animals may drool, circle or have facial paralysis. However, abortion may also occur.

Listeria travels from the mouth through the facial nerves towards the brain and so a prompt diagnosis results in a more successful outcome, with appropriate antibiotic therapy.

To reduce the chance of infection on farm, it is important to feed the best-quality silage available around lambing/calving time and to remove any mouldy or spoiled areas.

Listeria is a zoonotic disease (spread between animals and people) and so appropriate precautions must be taken in suspected cases.

See also: How to tackle cryptosporidium in calves

Jennifer Oldroyd

Armour Veterinary Group, Mauchline, Scotland

Jennifer Oldroyd

In our Ayrshire practice we have recently been dealing with cases of calf diarrhoea as a result of cryptosporidiosis. In the UK, cryptosporidium is the most common cause of calf scour.

Outbreaks are often seen during the winter housing period, when stocking density is high and a build-up of infection can occur.

Disease is seen in calves less than six weeks old, often starting with a profuse yellow scour and progressing to dehydration, abdominal pain and loss of appetite.

Affected calves will show reduced weight gain. In severe cases, death can occur.

A focus on hygiene during the calving period is essential to prevent this disease.

To reduce the build-up of infectious agents, calving areas should regularly be steam-cleaned, disinfected and allowed to dry.

Straw pens should also be bedded up regularly, to keep animals as clean as possible.

Paddy Gordon

Shepton Veterinary Group, Shepton Mallet, Somerset

Paddy Gordon

Dairy Tech was an enjoyable and stimulating day out. The show had plenty of new automated systems for heat detection and health monitoring: ear tags, neck collars and leg-mounted devices.

It is difficult to wade through the sales blurb and work out which is best at present.

However, early on-farm experience is that they do give an extra pair of eyes and ears to the farm and will help with fertility and early identification of disease.

Potentially, they can help with lameness and calving identification, too.

If that sounds like too big an investment, then XLVets practices are running courses on Cow First Aid, Fresh Cow Checks and Mastering Medicines.

They are all aimed at helping to give you and your staff the skills to promptly identify any sick animal, and then make the correct treatment decisions.

For more details, visit the FarmSkills website.

James Marsden

Shropshire Farm Vets, Shrewsbury, Shropshire

James Marsden

On many farms, freshly calved cows and freshly lambed ewes are currently showing some signs of staggers (magnesium deficiency).

As the unseasonably warm weather abates, the cold nights cause magnesium levels in the grass to drop off.

Furthermore, excellent energy density in a lot of last year’s silages means that housed animals may be eating less, and thus consuming less magnesium from forages.

As well as supplementing magnesium via the ration, as appropriate for animal, breed and system, be sure to have some injectable magnesium sulphate (25% w/v) available.

This must be given under the skin only (at about 1ml/kg bodyweight).

Watch for the following symptoms, as staggers can progress quickly and is often fatal:

• Nervous/twitchy/excitable animals
• Unsteady “staggering” gait
• Loose muck
• Grinding teeth
• Down, with paddling limbs and foaming at the mouth

Always discuss diagnosis with your vet to be sure, and to facilitate management, as prevention is better than cure.