Its coming into green grass and cold weather time and we need to remember the challenges this can create for our cattle. 

Vet Andrew Denman explains what causes grass tetany and how we can pro-actively manage our cattle to reduce its incidence....and when it's time to call the vet. 

"Grass Tetany (grass staggers, lactation tetany, hypomagnesaemia) is a fatal disease that occurs in cattle when their blood level of magnesium becomes critically low. Cattle can only store a little amount of magnesium in their body and they loose magnesium in many ways (but will loose large amounts in their milk). If they do not replenish this loss then they will become low in magneisum and clinical sings of hypomagnesaemia will occur.

We now know that grass tetany is not just caused by low levels of magnesium in the pasture or rumen, but other factors can effect the absorption of magnesium into the blood stream. The levels of potassium, chlorine, sodium and manganese can interfere with the amount of magnesium a cow absorbs from its rumen. Stress also plays a role in magnesium absorption into the blood.

At OVH we see most of our cases of grass tetany when cows are in peak lactation (INCREASED LOSS) and on lush green feed (DECREASED UPTAKE) during bad weather (DECREASED UPTAKE).

The signs of grass tetany vary, with mild cases showing slight twitching of the face and ears, wary behaviour and stiff gait that worsens with stress. Moderate signs show a typical "high goose stepping gait", very aggressive behaviour and staggers. Severe signs can include sudden death or cows down seizuring.

Treatment involves replenishing magnesium levels in the blood, which can be done by subcutaneous or intravenous injections of magnesium. If you suspect grass tetany in your herd please contact OVH immediately for safe and effective treatment (overdosing with Mg can kill cows).

As with all metabolic diseases in cattle prevention is the best treatment. Various ways to prevent grass tetany are available including spraying hay with Mg products, blocks, loose licks and Mg supplementation in water troughs. Again please contact the veterinary hospital and talk to any of the vets about these strategies."

Choke is the common name for oesophageal obstruction. In horses it is not an obstruction of the airway (like it is in humans). It is however still classified as an emergency and veterinary attention should be sought immediately.

Dry hay, apples and sugar beet are examples of feed which may be caught in the food pipe once swallowed. Feed can rapidly expand after swallowing preventing it from being passed down into the stomach. Eating too quickly can also cause choke. In rare and extreme cases, choke can cause oesophageal scar formation, oesophageal rupture and pneumonia.

Common signs of choke include:

• excess salivation
• discharge from the nose
• coughing
• swallowing
• anxiety
• reduced water consumption and dehydration

Often the obstruction will pass on its own but if not we provide sedation and pass a tube through the nose and down into the oesophagus to gently push the obstruction into the stomach. In severe cases the horse may need to be anaesthetised to do this safely. Anti-inflammatory and antibiotic medication may be prescribed for the aftercare of some choke cases.

To help prevent choke in your horse we recommend soaking dry feedstuffs, feeding greedy horses separately from others, and maintaining good dental care.

If you suspect your horse might have choke please call us.

With much of Australia experiencing considerable summer rain, many regions have suffered significant barber's pole worm losses this autumn. If you've had a lot of rain this summer, or if you're buying lambs from these regions, you need to be on the lookout.

We've heard reports of rapidly escalating worm infections. Sheep are fine one week, and severely ill the next.

The lamb pictured to the left is suffering from barber’s pole worm infection. The most notable issue is the swelling under its chin frequently referred to as "bottle jaw." Barber’s pole worm is not only production limiting, but in severe infestations will cause anaemia, lethargy, collapse, and death. All classes of stock are susceptible, but as with all parasites, the youngest and the oldest are particularly vulnerable.

Drenching using combination drenches will be the most effective, and if you are unsure what is working on your farm, DrenchTests are important.

Remember, all new stock require a quarantine drench to avoid bringing resistant worms onto your farm.

The best source of information on all things sheep and drench related is found at WormBoss - and remember we're also here if you have questions.