SELLS Animal health update October 2021
14 Oct 2021
South East monthly disease surveillance activities
South East Local Land Services district veterinarians
Sheep staggers syndromes
A number of stagger syndromes are being reported and investigated at the moment. Feedback from the State Diagnostic Laboratory suggests that these types of cases are being submitted from across the state, with many being associated with the consumption of certain plants or weeds. The term “staggers” refers to a diverse group of different syndromes of abnormal movements when walking or running. Many of the affected individuals do not recover and gradually waste to the point of requiring euthanasia. Diagnosis is best achieved with a post-mortem with samples of the brain and spinal cord sent to the lab. Sheep that are between 18 months and five years old are eligible for the TSE program (Transmissible Spongiform Encephalopathy) which helps to prove Australia’s freedom from this disease. Producer are paid a subsidy for brains submitted and the lab fees for the diagnosis are covered. Unfortunately, many cases of staggers occur in hoggets, but district surveillance funding can help to subsidise the costs of testing.
Recent investigations have found Phalaris staggers to be the cause where a producer had 10% of his hoggets affected. The syndrome showed more when the sheep were moved, affected sheep developed a head tremor, a bunny hopping gait and then would fall over shaking. The toxic phalaris was ingested during the late autumn/winter, but the damage persisted.
In another similar case the nerve damage was thought to have been caused by ingestion of paddock weeds such as onion grass, or tribulus (cats head).
In a case where sheep were found dead, after being moved to a new lush pasture PEM (Polioencephalomalacia) was diagnosed as the cause. More affected sheep were seen standing separate from the mob with the head down and teeth grinding, and others were star gazing and blind, eyes flicking with nystagmus. PEM is a brain damage caused by a sudden deficiency of thiamine (B1) as a result of Thiaminase enzyme in the rumen, due to the lush conditions. Prompt diagnosis and treatment with vitamin B1 from the veterinarian saved lesser affected sheep.
Sudden death in ewes post lambing on pasture was caused by hypocalcaemia, a deficiency of calcium in the blood. Mature ewes are more at risk, and it is more likely to occur on crops or lush pasture. Providing a loose lick of calcium, magnesium and salt can help to prevent this disorder and hypomagnesaemia.
Still born calves and pregnancy losses
Still births have been investigated and Pestivirus (BVDV) has been shown to be the cause on most properties affected. This has been proven by submitting tail hairs or an ear notch from still born calves for the AGID (PI) test showing them to be positive for the virus. Blood testing of affected cows and between 5-10 cohorts has shown evidence of recent exposure on the antibody test.
Internal parasites in sheep
Faecal egg counts (worm egg counts) are our best weapon against internal parasites. Counts are rapidly rising, and in many cases these counts are a mixed infection of scour worms. With the rising temperatures > 15°c barber’s pole numbers will also be on the rise, and infections can build quickly. Conditions are so ideal for worms we recommend using FECs to monitor your mobs every 4-6 weeks during the spring. This season is different requiring more action earlier on worms.
Vaginal prolapse in sheep
A small sheep flock in the southern tablelands had an outbreak of vaginal prolapse in 50 per cent of their breeding ewes, from four weeks prior to lambing. Several ewes and lambs were lost due to associated complications. While vaginal prolapse is known to occur at low rates as an accepted risk of pregnancy, an outbreak of this extent is unusual. While causes are being investigated, it would be interesting to hear if other producers in the area experienced similar problems this lambing season. Vaginal prolapse is a multifactorial condition, usually affecting older ewes who have had multiple lambs and are carrying multiple foetuses. It is more common on properties with sloping as opposed to flat ground. Some of the other causes postulated include metabolic conditions, mineral deficiencies, tail docking length and Vitamin D status. Vaginal prolapse is a different condition to uterine prolapse which can occur after a difficult birth. If you have had more vaginal prolapses than usual this season, please contact Lou Baskind, District Veterinarian at Braidwood on 0427 422 530 or send an email to email@example.com
Numbers do build during winter, and we commonly get asked about them at this time of year. Lice numbers tend to be associated with reduced nutritional plane or stress, with stock on poorer feeds suffering heavier infestations. Smaller lice burdens will usually resolve with the spring. If your stock are suffering with a heavy lice burden double check that they are on a sufficient plane of nutrition and consider treatment. Commercial products for lice are readily available and effective and some drenches will also treat lice. It is essential to carefully read the label to ensure proper dosing volume and intervals.
Foot rot in sheep
Take great care when restocking that you don’t buy foot rot in. Keep any new sheep that you have purchased isolated from the rest of the flock until the end of spring. Ensure your boundary fencing is good and that you check all strays.
Much of the district has entered an ideal foot rot spread period, due to high winter and spring rain fall, high pasture growth rates with good clover density, and rising temperatures > 10°C. The bacteria Dichelobacter nodosus causes benign and virulent footrot. There are many different strains with variable amounts of power to underrun the heel. Benign as well as virulent foot rot are expressing. Virulent foot rot is a notifiable disease, meaning that you must call your local district vet if you notice lame sheep and underrunning of the hoof at the heel. The district vet will look at the proportion of sheep that are affected, and how severely affected they are, to classify the disease as benign or virulent. They will then work with you to develop a short and long-term plan to minimise and eliminate the disease if required.
Foot bathing is a very effective management tool. 10% Zinc sulphate is the most frequently used chemical. To use it most effectively it requires a contact time of at least 5 minutes, followed by at least an hour of drying time. For more information read our foot bathing factsheet.
Your district vet is a source of impartial advice and work with your private practioner veterinarians, rural resellers and agricultural advisors to provide you with an accurate diagnosis of the cause of disease and treatment and prevention options. This month we have provided a lot of advice on vaccination and pain relief options for lamb and calf marking, pink eye management in sheep and cattle, and calf diarrhoea management in beef herds.
It's Theileria time of year for coastal cattle
Mark Doyle, District Veterinarian - Bega
A reminder that with Spring and warming weather it’s not just the bugs we can see that cause the problems. Theileriosis will be an issue through the warmer months for potentially all introduced cattle to and from the coast, and we have already seen cases in young locally-born calves.
What is it?
Theilieria Ikeda is a blood-borne parasitic organism transmitted between animals by vectors, mostly ticks but also other biting insects.
What does it do?
It causes a breakdown of red blood cells and anaemia. This results in ill thrift and extreme lethargy and can, in worse-case scenarios, cause abortion and even death.
Which animals are most at risk?
Introduced/naïve stock, that means potentially any stock introduced to a farm where Theileria Ikeda is endemic.
Where is it found?
All of the coastal areas in the Southeast are endemic for Theileria Ikeda. Check with your local District Veterinarian if you are unsure if you should be concerned.
What can I do?
If you’re in an endemic area, don’t buy in stock in the warmer months if you can help it, especially pregnant females. There are mitigation tactics you can adopt in times of heavy insect load. If you are worried you may have trouble with your younger animals or are bringing animals onto your farm call your district veterinarian for advice.
Landholder responsibilities during the COVID-19 pandemic
Henry Clutterbuck, District Veterinarian - Goulburn
The COVID-19 pandemic has required that we do things differently, and we thank landholders for their ongoing understanding and support. It is important to clarify landholder responsibilities regarding the care and management of their stock. This is particularly important for landholders whose primary residence is in Greater Sydney.
Animal owners have a legal responsibility under the Prevention of Cruelty to Animals Act 1979 to ensure the welfare of their livestock and companion animals, which allow you to travel during restrictions for the welfare of your animals following strict hygiene and social distancing requirements.
Movement of owners and their animal to a veterinarian or a veterinarian attending a property are, at the time of writing, permitted activities under the Health Orders and should not be put off.
The outdoor activities and animal welfare webpage is constantly updated with information on animal welfare responsibilities and movement restrictions.
Landholders are advised to also visit the NSW Government's COVID-19 webpage for the latest health advice. COVID-19 related questions can be emailed directly to the NSW DPI Liaison Team at firstname.lastname@example.org.
As always Local Land Services district vets are available to discuss animal health issues with landholders and help where possible.
7 steps to controlling coccidiosis in young chickens
Lou Baskind, District Veterinarian - Braidwood
Coccidiosis (commonly known as “cocci” or “coxy”) is a disease of the gut caused by a microscopic intracellular parasite. In chickens, the parasite causes severe intestinal damage resulting in diarrhoea with blood, and considerable pain. The chickens become weak, pale, ruffled and listless. Groups of chickens might have their heads sunk in towards their necks, huddled together and shivering. Cocci can cause death, often rapidly.
Coccidiosis happens quite commonly in spring and early summer because not only do we have lots of susceptible young chickens, but the parasite prefers temperatures between 20 – 30°C for development.
You can read more detail about coccidiosis in our past issue of the South East circular. Here are my tips to prevent and control coccidiosis in chicks and young chickens.
1. Dry up damp areas of the yard or brooder
The cocci parasite is most comfortable in shaded, mild to warm, moist soil. It doesn’t like to be dried out or reach temperatures above 37°C.
- If you have damp areas of the yard find any method to dry them out – improve drainage or apply lime, crusher-dust, gravel, sawdust etc.
- Repair leaking waterers and taps.
- If you have a brooder (a heated house for the little ones) sprinkle a new layer of dry substrate/litter on top, or scoop out and replace damp litter, once or twice daily. Monitor closely that the litter is not damp.
2. Avoid crowding
As tempting as it is to hatch or buy more and more chickens (we call it “chicken maths”!) crowding is a crucial risk factor for coccidiosis. Be sensible about how many chickens you can maintain in the space you have
3. Limit exposure of young chickens to any chicken droppings
- Use feeders and waterers that exclude chickens from climbing in on top of the feed and defecating in there. Feeders that have holes for access, and nipple-style waterers are ideal and can be bought or made.
- Do not feed on the ground – this allows oocyst-containing soil to mix in with feed and get inadvertently swallowed. For this reason, throwing scratch-mix or scraps is best avoided until chickens are adults.
- In brooders remove droppings, or cover them with fresh litter, twice daily.
4. Don’t move cocci around on shoes and equipment
Shoes, clothing or equipment that has soil or droppings attached can harbour and move oocysts. This is a common way that chickens become exposed to a new strain of cocci.
- Wash your hands well with soap and water before tending to chickens.
- If tending to different age groups, start at the most vulnerable (the youngest) and move through the age groups to adult chickens.
- Sick chickens should be removed from the flock and tended to last.
- After tending to the chickens wash off soil and droppings from shoes and equipment and leave in the sun to dry well.
5. Stop visitors from introducing new strains
The strains of cocci carried on visitors’ shoes might be different to what your chickens have been exposed to before and they may have no immunity.
- Have some clean slip-on garden clogs or gumboots available for visitors to use on your property.
6. Consider feed or drinking water-based preventatives
Medicated feeds and drinking-water preventatives impede the development of the cocci parasite. They hold it at a level that prevents disease but exposes the chickens enough to allow them to develop some immunity.
- Commercial chick-starter and pullet feeds containing these “coccidiostats” are a useful addition to your control program.
- Do not rely on these medications alone. Preventative medications cannot be used as a band-aid for unhygienic and crowded conditions.
7. Treat quickly
If you have good reason to suspect coccidiosis you must act fast. The disease progresses very quickly. Amprolium is a medication often used as a preventative, but can be a treatment if given at a different dose.
Follow the label directions carefully. Baycox (Toltrazuril) may be superior in severe infections but is expensive and requires a veterinary consult and prescription.
To get in touch with your local team visit our contact us page.
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