Animal Health Newsletter

Issue 4
Spring 2015

How will a hot dry Spring and Summer
 affect your farm?

With Bureau of Meteorology weather predictions tipping that we are heading for a dry and hot spring and summer we need to manage the risks that these conditions may pose.

These predictions are based on an increasing risk of an El Nino which usually means that we are in for below average rainfall and above average daytime temperatures over the southern half of the country. This means that the upcoming spring and summer could bring similar conditions to the big El Niño events of 1982 and 1997.

A dry spring and summer and an increase in heatwaves can certainly make for difficult farming conditions. Producers should start preparing their farm for the possible effects of El Niño. Following are a few items to consider for your farm:
  • What are your farm objectives and how would a warm and dry spring affect your operations in the short and longer term?
  • Start auditing your farm’s resources on a regular basis (pasture, feeds, water and livestock condition) so you aren’t presented with any nasty surprises.
  • Start monitoring hay and feed prices now, and develop relationships with suppliers to work out potential contingency plans for dry weather if it hits.
  • Develop a feed budget and alternative options if fodder becomes less available in your region.
  • Consider at what point you will sell or agist stock.  Often it is best to sell stock early in the dry period when prices are good and the condition of the cattle hasn’t deteriorated.
  • Which stock are best to sell? Which types of livestock will best handle a dry period and which stock will give you the best returns after the El Niño breaks?
Taking advantage of the good cattle prices that are currently on offer and reducing stocking rates before dry conditions set in is often the best strategy.  

Further information on drought management:

A drought preparedness plan is as important as a fire plan

Whilst we hope for a good Spring, the forecast for a dry period is still strong. Often the first step in assessing your pasture conditions is to have a look at your cattle droppings.

If the season and pasture availability starts to get a bit tight and the stock are beginning to feel the pinch, one of the first signs that the stock are being challenged with a nutrition problem is the size and shape of the droppings.

Normally cattle droppings hit the ground and flatten on impact indicating that feed quality and pasture digestibility is good. However, once the droppings start to harden up and form a cone structure, the nutrient value and moisture content of the pasture is low and the fibre content is high. This is a tell tale sign that your stock are beginning to do it tough.

Now is the time to start to consider what your next step will be if the rain does not come. What are your plans? Sell stock while the prices are good or can you afford to buy in feed and maybe even water?

NLIS Tag Reminder 

Luke Booth
Senior Biosecurity Ranger
Recently there has been an increase in requests for clarification over which NLIS tags should be used.
An NLIS device is a permanent whole-of-life identifier that should be attached to the right ear of the animal. Once attached, an NLIS device must not be removed.
White tags are breeder devices and must only be attached to cattle that were born on the property to which the PIC on the device relates. Only white breeder devices provide lifetime traceable status. Lifetime traceability of livestock and livestock products is a crucial part of Australia's agreement with export markets and underpins Australia's biosecurity system. We all have a responsibility to maintain this system.

Attaching breeder devices to cattle that were not bred on that property falsely implies that the cattle are traceable to their property of birth and is illegal.

Orange tags are post-breeder devices and must be attached to cattle that were not born on that property.

Post-breeder devices may also be attached to animals bred on that property where the producer is uncertain which animals were or were not born there, or if the producer has insufficient breeder devices available.

All cattle identified with a post-breeder device lose lifetime traceable status and it is preferable that they are destined for slaughter rather than restocking so the cattle are ‘out of the system’ sooner.

Special identifiers   

Orange post-breeder devices that are typically known as “emergency tags” provide NO life time traceability 
They are only available through the Local Land Services or Saleyards operators and may be issued and used only if a permanent identifier is already attached to the stock – but is unreadable, or a previously attached device has been lost,

We suggest that when ordering Breeder NLIS (White) tags, the producer also orders and has on hand some Post – Breeder (Orange) tags to cover for any of the circumstances as mentioned above.

For any further clarification contact Luke on (02) 49398967.

District vets switch places

Ratepayers might see some new faces when their local district veterinarian next answers their call for animal health help.

Dr Jane Bennett, a veterinarian of 30 years’ experience in mixed, equine and small animal practice in the Scone area has recently joined Hunter Local Land Services (LLS) as the Upper Hunter district veterinarian. We are pleased to have Jane join our team.

Jane’s background also includes teaching vet nursing with TAFE and a strong involvement with pony, swim and hockey clubs and as a member of the Scone Grammar School Board for the last eight years. Jane brings a range of valuable skills and experience to Hunter LLS.

The employment of Jane enables an internal shuffle of existing district vet staff. Jim Kerr takes up the Tocal post with Digby Rayward and Lyndell Stone moves to the Wingham office. Kylie Greentree continues to work out of the Maitland office.

These changes are designed to ensure a continued high level of service delivery to ratepayers by providing a flexible five member district veterinarian team that is able to continue to meet animal health, livestock production and emergency responses.

Spring livestock health Issues

Cattle bloat risk continues - warning to graziers

Hunter Local Land Services is urging producers to be alert to the continued risk of bloat in cattle grazing clover and medic rich pastures primarily in the Upper Hunter region, following an increased number of cattle bloating and cattle deaths.

Recent rains have again encouraged a flush of rapid legume growth at a time when dry paddock feed is lacking, increasing the risk that cattle develop bloat.

Producers from Singleton through to Scone and Merriwa have been managing an intense Bloat risk period through Winter and this is now continuing into Spring. However, Lower Hunter and Manning Great Lakes producers should also begin to monitor clover and lucerne crops. In some areas pasture conditions are beginning to mirror those experienced by Upper Hunter farmers over the past months.

Legumes can cause bloat as they contain soluble proteins which act as foaming agents and the young plants also lack fibre.

When young legume rich pasture isn't balanced with adequate fibrous feed a frothy foam forms and the animal is unable to belch the gas. The trapped gas distends the rumen placing pressure on blood vessels, lungs and heart and the animal dies from heart failure and asphyxiation. Treatment is difficult to provide with the speed required hence being alert to the signs in both the pasture and the animal is crucial.

Cattle with bloat initially have a distended left abdomen and are reluctant to move. This can progress to respiratory distress with rapid breathing, staggering and death.

Prevention is key. Whilst bloat bombs are no longer available, there is a range of anti-bloat products such as bloat oils, liquids, bloat blocks and dry licks. Anti-bloat products can applied to the pasture, added to water troughs or in the case of licks placed near watering points. Flank sprays and drenches are also available. Product choice depends on the farm's situation.

Increasing the fibre content of the diet by feeding hay or limiting legume consumption by strip grazing are also key steps to take. Inonophors such as monensin can also be added to feed. Producers with a high bloat risk might require a combination of methods .

Hunter LLS recommends producers contact their private or district veterinarian to discuss bloat prevention options . 

Further information:

Additional Spring Animal Health Considerations for the Hunter

Spring can create a range of animal health challenges that need to be managed. This can include an increased risk of cattle deaths due to:

Enterotoxaemia (Pulpy kidney)

Enterotoxaemia is an acute poisoning condition caused by the bacterium Clostridium perfringens type D. This bacterium is a normal inhabitant of the intestine but is usually present in low numbers. Sudden changes in diet, grazing lush, rapidly growing pastures or heavy grain feeding (as in feedlots) enables the bacteria to multiply rapidly and produce a toxin which kills the animal. Introduction of cattle or sheep onto winter oats or rye grass pastures, or even the occurrence of a spring flush of pasture, provides suitable conditions for enterotoxaemia deaths. It is often the best animals in the group that die of enterotoxaemia, as they are the greediest eaters.

Enterotoxaemia deaths can easily be confused with bloat deaths because affected animals often bloat terminally, and their carcases typically blow up rapidly. This has led to the misconception that 5-in-1 vaccine is protective against bloat. 5-in-1 vaccine (and 7-in-1 vaccine) is actually protective against enterotoxaemia, which can look like bloat.

5-in-1 vaccine and 7-in-1 vaccine protect livestock against enterotoxaemia, as well as several other clostridial diseases including tetanus and blackleg. However, the protection offered by these vaccinations against enterotoxaemia only lasts for a few months (read the label to confirm this for yourself). It is therefore important to plan giving booster 5-in-1 vaccinations to your cattle/sheep/goats two weeks before you plan to expose them to a change of diet such as starting to strip feed oats or starting them on grain. Ideally, annual 5-in-1 boosters should be timed to occur in late winter in order to protect livestock against a sudden flush of feed in spring. An added benefit of vaccinating your winter/spring-calving cows in winter is that they will confer good colostral immunity to their calves against blackleg until the calves are old enough to be vaccinated themselves.

Further information:

Tick-associated diseases

Tick paralysis

Tick paralysis is caused by a toxin injected by the paralysis tick (Ixodes holocyclus) when sucking blood from livestock, pets, or people. Bandicoots and other small marsupials are the natural hosts for the paralysis tick. Tick paralysis problems in livestock are consequently most common in bushy or scrubby paddocks which provide shelter for these host animals.

Spring is a high risk season for tick paralysis. Ticks are active by early spring after a period of dormancy in winter. In early spring there are plenty of young calves running around whose small body size makes them susceptible to the effects of tick paralysis.

Unfortunately, protection of the very young calves that are most susceptible can require preventative treatment almost immediately after birth if they are running in a high risk paddock. As such early and repeated intervention is not always feasible in extensive livestock operations, calving paddocks should be free of high risk scrubby areas in order to reduce calf losses. 

There are pour-on medications, sprays and insecticidal ear-tags available for protection of young livestock. Private veterinary practitioners can provide antitoxin treatment for affected livestock and pets.

Further information:


Theileriosis is a disease of cattle caused by a protozoan parasite carried by the common bush tick (Haemaphysalis longicornis). Cattle become infected when bitten by an infected tick. Lice, biting flies and use of a common needle and syringe may also play a role in spreading the disease. After an animal is infected, the theileria parasite multiplies over a period of weeks, resulting in the destruction of red blood cells. If too many red blood cells are destroyed, the affected animal will become pale and weak (anaemic), and may even die.

Badly affected animals cannot tolerate exertion, and will typically lag behind the mob and spend most of the time lying down. They often seek shade. 

Carcase of an anaemic calf which died from theileriosis, showing the pale muscles and yellow liver typical of the condition

Theileriosis is endemic in the Gloucester and Great Lakes districts of the Hunter LLS region. Cattle bred in these districts are generally exposed as calves, and are immune to theileria by 6 months of age. Calf losses do occur on some properties, most commonly between 6 and 12 weeks of age.

Theileriosis occurs sporadically in the Hunter Valley, with cattle deaths having been recorded from Maitland to Scone. The further you move up the valley from the coast, the less likely it is that the cattle are immune. 
Cattle introduced into the Gloucester and Great Lakes districts from districts further west (e.g. tablelands or west of the Dividing Range) are at risk of theileriosis. Spring seems to be a particularly high risk time to introduce naïve cattle, with clinical disease often occurring 6-8 weeks after arrival. Calves and pregnant females are at greatest risk of developing severe disease.

None of the treatments that have been used to treat theileriosis have produced convincing results (other than blood transfusion). In fact, the exertion required of affected cattle in moving them to cattle yards for treatment has sometimes been responsible for killing cattle that might otherwise have survived if left quietly in the shade. If broad-spectrum antibiotics such as oxytetracyclines can be administered without causing the patient undue stress, their use can probably be justified in preventing secondary infections (particularly pneumonia). Otherwise, the best approach is merely to provide the animal with easy access to water, food and shelter. Steep dam banks and boggy dam edges can prove fatal to anaemic cattle.

Further information:

Grass tetany

Grass tetany is a disorder in cattle where the level of magnesium in the blood drops below a critical level at which the muscles of the body cease working properly. As a result, the animal dies because it cannot breathe.

Low levels of blood magnesium are a consequence of inadequate absorption of magnesium from the rumen. This can occur when there is inadequate magnesium in the diet, or when excess potassium in the diet interferes with magnesium absorption. Potassium concentrations in the rumen increase when cattle graze pastures fertilised with inappropriately high levels of potassium fertiliser, or when the diet is changed from hay or dry feed to lush pasture (e.g. cattle put onto oats pasture)

Low levels of blood magnesium (hypomagnesaemia) are often associated with low levels of blood calcium in late pregnant cows and cows with calves at foot i.e. pregnant and lactating cows are at greater risk of grass tetany.

Mildly affected cattle may not show any signs until they are put under stress by being yarded or trucked. A stiff gait, twitching of the face , ears and muscles, and bad temper may be the first signs. The condition may rapidly progress to excitement, bellowing, staggering, collapse, paddling and death.

Affected animals require urgent treatment with an intravenous solution containing magnesium (typically '4-in-1' solution familiar to dairy farmers). Preventative dietary supplementation for cattle in high risk situations commonly involves the use of hay treated with magnesium oxide – MgO (Causmag).

Further information:

How serious is drench resistance?

An exciting agreement between Dairy NSW, the Hunter Dairy Development Group (HDDG), the Dairy Advancement Group (DAGs) and Hunter Local Land Services (LLS) aims to shed some light on the degree of worm and drench resistance on Hunter dairy farms.

Drench resistance is an emerging problem and can affect heifer weight gain, growth and subsequent milk production. As district veterinarians we are acutely aware of the risk that drench resistance can present to farm productivity.

We have initiated this study to enhance the industrys’ knowledge and understanding of the current level of drench resistance and which worm species are involved. Practices used on farm that promote or delay resistance will also be explored.

The study looks at resistance to the three classes of commonly used drenches, these being the Macrocylic Lactones, Benzimidazoles , and Levamisoles and where possible a combination drench. Assessing the merits of a combination drench will prove interesting if resistance is an issue on farm.

Farms which meet the studies’ criteria and have 60-75 dairy heifers around 6 months of age are invited to find out more about the study by contacting your local district veterinarian. The study hopes to involve eleven dairy farms in the Manning/Gloucester, Lower and Upper Hunter regions. On each of these farms heifers will be split into groups, drenched according to the studies’ plan and worm burdens assessed. Participating farmers will also be asked about their drenching history and other farm management practices used for worm management such as paddock rotation systems. 

The trial will be undertaken by Hunter LLS veterinarians over the next 12 months. Dave Williams (local Vacy dairy farmer and chair of the HDDG) acknowledged the input of the Hunter LLS.

“We are very lucky to have the expertise and enthusiasm of the LLS veterinarians in pulling this project together. They will be putting significant resources into the trial which should be of benefit to all dairies in the Hunter and I really look forward to seeing the results.”
Sudden Livestock Death investigations

in the Hunter
Multiple sick and dead livestock are always cause for concern and should be investigated to help refine farm management systems. However, as district veterinarians, we are also very aware of the need to exclude a range of emergency or endemic diseases that could threaten the continued viability of our regions’ farms. Following are two recent disease investigations undertaken by Hunter Local Land Services (LLS) on behalf of Hunter LLS ratepayers.

A Lower Hunter Emergency Animal Disease Exclusion

In June 2015 a producer in the Lower Hunter reported sudden death in 1 cow. After death the producer noticed blood in the urine and from the nostrils. 

Lower Hunter district veterinarian, Dr Kylie Greentree, attended the property and conducted an Anthrax cow side test to rule out Anthrax infection. The results were negative for Anthrax. This is an important step to protect human health, prevent escalating cattle deaths and also protect Australia export markets.

The four-year-old cow was in a reasonable body condition and had a three month old calf at foot. The herd was not vaccinated. On post-mortem examination, one kidney was markedly shrunken (see photo one). The small kidney was very firm to cut and filled with a purulent inflammatory material. The ureters (connecting the kidneys to the bladder) also contained thick purulent material and the ureter walls were thickened.

The differential diagnoses prior to post mortem examination were Anthrax, Enterotoxaemia and toxic plant or feed contamination but after post mortem examination the suspect diagnosis was a kidney infection (Pyelonephritis).

Laboratory diagnosis confirmed a severe kidney infection  caused by the bacteria Corynebacterium renale. This condition usually develops from a bladder infection that travels up and infects the kidneys. This can occur after calving or an abnormal deformity of the vaginal tract. Stressors such as calving, peak lactation and a high protein diets will increase the pH of the urine making it an ideal environment for the colonization of bacteria such as Corynebacterium species.

Pyelonephritis is an uncommon condition, but if detected early enough and the animal is treated with a long course of antibiotics, recovery can occur. 
Sudden livestock death investigations, undertaken by HLLS District Veterinarians, are a crucial part of our animal biosecurity and disease surveillance role to protect food safety and livestock from Emergency Animal Diseases. 

Emergency animal diseases can have serious consequences for trade, production or human health. If you suspect an emergency animal disease or see symptoms or deaths in animals that may be due to an emergency animal disease, don't delay! 

Ring your local District Veterinarian or the 24 hour Emergency Animal Disease Hotline 1800 675 888.

Blindness in cattle – An Upper Hunter food Safety Investigation

A cattle producer in the Upper Hunter reported strange manic behaviour and several unexplained cattle deaths in a herd of 120 mixed-breed yearlings.

Upper Hunter district veterinarian, Lyndell Stone attended the property. The cattle appeared blind and were either excitable running into fences and waterways or lethargic. On closer examination they had a brain related blindness determined through a clinical examination. There was also some muscle trembling, grinding of teeth and nervous system signs.

Photo: grazing Brassica is a cost effective autumn feed but requires managed grazing to avoid animal health issues

From a food safety perspective, it was important to rule out lead toxicity, which commonly presents with similar signs. Lead toxicity can occur when cattle have access to lead such as in old discarded car batteries. Both Lead toxicity and liver toxic plants were high on the list of possible causes but were ruled out as no paddock contamination was found. This was also later confirmed by blood results. 

Listeriosis and Hypomagnesia were also considered.  However, a presumptive diagnosis of Brassica Blindness or Polioencephalomacia (PEM) was made as the cattle were grazing a paddock dominated by turnips.

The herd was removed from the crop and affected cattle given hay and Vitamin B injections daily for several days.  No more cases occurred and the affected cattle improved dramatically over the following 48-72 hours with only one steer showing a delayed recovery of several weeks.

The positive response to treatment for the Brassica blindness and subsequent analysis of the Sulphur content of the Brassica confirmed the diagnosis.

Brassica blindness can be due to a high Sulphur content of turnips, which can be over safe feeding levels if cattle are solely consuming turnips. The sulphur reduces the rumen levels of Vitamin B which causes the brain to swell and brings about the characteristic neurologic signs. 

Brassica forages can be a valuable and cost effective autumn feed due to their good energy and protein levels. However they are also low in fibre and can contain additional elements that require managed grazing to avoid animal health issues.
Your District Veterinarians
Digby Rayward - Paterson 

4939 8966 or 0427 493 617

Kylie Greentree - Maitland 

4932 8866 or 0428 498 687

Jane Bennett - Scone

02 6540 2419 or 0427 322 311
Lyndell Stone - Wingham

6553 4233 or 0429 532 855 

Jim Kerr - Tocal/Singleton

49398966 (Tocal), 6572 2944 (Singeton) 

or 0439185 275
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