August

www.lls.nsw.gov.au/riverina

RIVERINA LOCAL LIVESTOCK UPDATE

August reminders REMINDERSKEEP AN EYE ON THE FEET OF YOUR SHEEP!District Veterinarian Dione HowardA reminder from Wagga that we are starting to see environmental factors that favour the spread of footrot infection - a quick reminder of what they are:• an average daily temperature of 10°C or higher for 4-5

days• adequate moisture - are your boots damp at 10am after a

paddock walk?• adequate pasture length or pasture density to make feet

susceptible to infection - this includes a combination of good groundcover as damp conditions in the pasture

So how is the region shaping up?We have had an unusual winter with successive days of mean daily temperatures conducive to the spread of footrot. Many paddocks have also had adequate moisture and groundcover during this time, particularly where sheep have been grazing crops. Moving forward into spring we will see a greater number of successive days of mean daily temperatures over 10°C - along with the amount of pasture cover currently available this will further favour the spread of footrot

How do footrot lesions develop?1. Warm moist environmental conditions described above

predispose the claws to inflammation.2. If the footrot bacteria Dichelobacter nodosus is present,

it will invade the inflamed claw along with other bacteria. The footrot bacteria may be a benign strain or a virulent strain, and each strain will behave differently depending on the environmental conditions.

3. The susceptibility of the host will affect whether lesions develop, for example younger sheep are generally more susceptible than older sheep.

Footrot is a notifiable disease in NSW - this means that if you suspect footrot in your flock you are required to notify an authorised officer within 1 working day. Notification when lameness is first observed will allow an early diagnosis of the cause of the lameness. If you have any concerns, please contact your local LLS office.

Image below: Trimmed hoof showing underrunning of the sole from the inside of the hoof to the outer edges

A Biosecurity Management Plan (the Plan) applies to this place. Failure to comply with the Plan may be an offence

under the NSW Biosecurity Act 2015.

Please phone or visit the office before entering to obtain a copy of the Plan or to discuss your obligations.

DO NOT ENTER WITHOUT PRIOR APPROVALVehicles, people and equipment may carry

weed seeds, pests and diseases

VISITORS

CHANGES TO THE BIOSECURITY ACT AND HOW IT AFFECTS LANDHOLDERS

The NSW Government has announced a number of changes to the Biosecurity Act 2015 which came into effect on 1 August.

The amendments provide stronger protection for landholders against trespassers on their property, which to date have posed a major biosecurity breach. Anyone who enters a designated biosecurity area without permission and without complying with the plan’s requirements may be guilty of an offence under the Act, and subject to the new, harsher penalties.

Landholders will need to have a biosecurity plan in place and appropriate signage. Signs, or stickers to be placed on your existing signs, are currently available from LLS offices.

Riverina Local Land Services will be distributing signs, stickers and brochures to landholders from our offices and local opportunities such as field days (these will be given out free until 31 December 2019 and after that will be available for purchase).

For further information visit the NSW DPI website: www.dpi.nsw.gov.au/biosecurity/your-role-in-biosecurity/primary-producers/biosecurity-management-plan

Above image: The new Biosecurity signs. Stickers are available for existing signs to be updated. Below: Signs must be displayed at the entrance to the management area to which your plan applies. For example, if your management area identified in your biosecurity management plan is your whole property then signs are needed at all perimeter access points - see sample images below.

Case study: CHLAMYDIA

CASE HISTORY A sheep producer early weaned a mob of 1200 merino lambs in a drought lot two weeks after marking. The lambs had been vaccinated with 6-in-1 at marking and were drenched and weaned at approximately 15kg liveweight. The lambs were on a cereal grain diet with ad lib hay. One week after weaning the producer noticed that a number of the smaller lambs were getting progressively stiffer when they walked and some lambs were finding it difficult to stand. A few lambs had died over the past week, unfortunately none were viable for post-mortem so multiple clinical examinations were done on affected lambs.

CLINICAL EXAM FINDINGS• Approximately 20 lambs had a shuffling gait when they walked

and 3 lambs were down and unable to rise without assistance • Pyrexia (a high temperature) in all affected lambs • Downer lambs had normal neurological examinations, were

mildly lethargic and had pale gums (shock) • No swollen joints, but some heat noticed on palpation • Affected lambs appeared to be about 1-1.5/5 BCS below the rest

of the mob

DIAGNOSIS• Bacterial arthritis caused by Chlamydia pecorum

District Veterinarian Sophie Hemley Sheep

OBSERVATIONS • Chlamydia pecorum is a very common cause of bacterial

arthritis in lambs three to six months of age, although it typically present a few weeks post-marking. The pathway for infection with Chlamydia is not fully understood however we know the bacteria is in the environment, some sheep will shed the bacteria in their faeces and it is likely ingested or inhaled by the lamb. The bacteria then enters the blood stream (bacteraemia) which initially results in pyrexia which progresses to stiffness, lameness and reluctance to move when the bacteria colonises the joints

• Arthritis is an inflammation of the joint and joint fluid in response to an irritant, in this case Chlamydia. Chlamydial arthritis does not usually result in visibly swollen joints. When the joint is inflamed for a period of time the bony structures within the joint can become irregular which causes irreversible damage. Some lambs may also develop bilateral ocular discharge and some may die from overwhelming infection.

THE NEXT STEPS • Unfortunately there is no vaccine commercially available for

Chlamydial arthritis currently, however the incidence can be reduced by taking steps to strengthen the immunity of weaner lambs and to reduce the bacterial load, such as:

• Adequate colostrum (the first milk) consumption - making sure the ewes are nutritionally set up (in terms of energy, protein and roughage) prior to lambing

• Hygienic lamb marking practices• Higher weaning weights, as heavier lambs typically have a

stronger immunity • Low stress handling at weaning and adequate nutrition during

weaning• Antibiotics for the affected lambs assists in a prompt recovery if

bony changes aren’t evident

Left image: joint tap from a lamb with chlamydial arthritis. The fibrin (white strand) on the end of the needle is typical. Right image: ocular discharge in a lamb with chlamydial arthritis.

Case study: PULPY KIDNEY

CASE HISTORYA sheep producer has moved his mob of 150 heavily pregnant Dorper ewes into a recently sprayed self-sown wheat crop. The rams are joined with the 770 ewes multiples times per year. The ewes are in good BCS (3.5-4/5). The ewes are only vaccinated with 5in1 as lambs and the property had an anthrax outbreak 30 years ago. Within 36 hours of moving onto the new paddock the producer found four ewes dead in a line all 20-30 metres apart. The mob was normal the afternoon prior.

CLINICAL SIGNS• The dead ewes are very bloated and have dark

liquid, possible blood dripping from their noses and mouths. Anthrax ICT tests were completed on all four ewes as well as post-mortems.

POST MORTEM FINDINGS• Anthrax - ICT test negative• Very bloated on external examination. Intestines

full of feed with little bloating• Kidneys very autolysed (breaking down and

undergoing liquefaction)• Blood clots in large blood vessels• Spleen normal DIAGNOSIS• Anthrax negative• Diagnosed as Enterotoxaemia (pulpy kidney) OBSERVATIONS• The bacteria, Clostridium perfringens type D, lives

naturally in the intestines of sheep (as well as other stock). A sudden change in diet especially one with low fibre and high carbohydrates (lush feeds) causes a rapid increase in the bacteria’s population. As the bacteria die naturally they release the enterotoxin. This toxin damages the kidneys and other organs resulting in rapid death.

THE NEXT STEPS• There is no antidote or specific treatment for sheep

affected by pulpy kidney. The producer discharged his general biosecurity duty by alerting a veterinarian to suspect Anthrax immediately (legal requirement under the Biosecurity Act 2015).

• A simple whole mob vaccination program can prevent pulpy kidney. The vaccine is against the toxin (not the bacteria). The first vaccination must be repeated four weeks later and after that annually. For additional protection a booster vaccine can be given with changes in diet.

District Veterinarian Courtney Simkin Sheep

August 30 - GRIFFITH - 1080/CPE training 1080/CPE training will be held at the Griffith LLS office (200 Murray Road, Hanwood) from 9am. The course will take approximately three hours and morning tea is provided. Bookings are essential as places are limited. Contact Eliza Bramma on 0447 531 080 for more details. September 17 - 19 – HENTY - Henty Field Days Come and visit us at the Henty Field Days! Visit www.hmfd.com.au for full information

RIVERINA SHEEP PRODUCERS! Riverina sheep producers are invited to participate in a web-based questionnaire aimed at improving extension services available to sheep producers relating to animal health and nutrition practices associated with lambing.Questions will be based around vaccination, nutritional supplementation of sheep and producer perceptions of management practices. The study is part of research being completed by PhD student Kayla Kopp at Charles Sturt University and will take participants approximately 15 minutes to complete. The study is completely confidential and participants will go into the draw to win a $50 pre-paid Visa/Mastercard gift card.To complete the survey visit www.surveymonkey.com/r/lambsurvey

EVENTS SURVEYS

Do you follow us on Facebook? Stock Chat is a series of instructional videos featuring our veterinarians. They’ll step you through the symptoms and treatment options of common animal health issues, and give you some advice along the way. Find Riverina Local Land Services on Facebook to keep in the loop!

EXPRESSIONS OF INTEREST NOW OPEN Landholders in the Riverina Local Land Services region are able to apply for incentive funding in 2019/20.Projects available this year include Farm dams for biodiversity, Paddock shade and shelter and landholder training. Expressions Of Interest for all projects open on 13 August 2019 and close on 30 August 2019. If you have any issues with submitting an EOI, please contact the Wagga office on (02) 6923 6300.For more information on each project visit www.lls.nsw.gov.au/riverina

CONTACT YOUR CLOSEST DISTRICT VETERINARIAN WAGGA

Emily Stearman - 0437 644 714 or 6923 6300Dione Howard - 0428 115 134 or 6923 6300

YOUNG Eliz Braddon - 0418 642 196 or 6381 4700Evie Duggan - 0427 147 939 or 6381 4700

NARRANDERA/GRIFFITH Sophie Hemley - 0427 696 895 or 6960 1300

HAY Courtney Simkin - 0427 418 006 or 6990 1304

GUNDAGAI Katelyn Braine - 0428 262 112 or 6940 6900