2015 November

The quiz questions are taken from:

• WormBoss Online Learning
• FlyBoss Online Learning
• LiceBoss Online Learning

The online learning pages focus on the important topics within worms, flies and lice and offer two approaches to learning: structured reading and question and answer.

We also welcome suggested questions for the quiz, (either reply on the ParaBoss News email if you are subscribed or use Contact Us, at the bottom of the web page).

Answers and links to further information are provided below the image.

Questions

1. Name two common signs associated with a severe infection of either barber’s pole worm or liver fluke.

2. What are the causes of scouring that would need to be managed to reduce flystrike risk? 

3. If sheep are being brought onto the property, what are your options to manage lice?

The sheep blowfly, Lucilia cuprina. Image courtesy Australian Wool Innovation.

Answers

1. Name two common signs associated with a severe infection of either barber’s pole worm or liver fluke.

Severe acute or ongoing (chronic) blood loss from either barber’s pole worm or liver fluke leads to obvious signs of anaemia. These are pale gums and conjunctiva (inside the eyelids); lack of stamina causing lagging or collapse when mustered; and ultimately death from lack of red blood cells needed to carry oxygen around the body.

Swelling under the jaw (bottle jaw) results from both severe barber’s pole worm and liver fluke infections. The loss of blood results in anaemia and less protein in the blood. This imbalance in the normal body fluids results in fluid accumulating under the jaw in some, but not all, affected animals. It does not always occur during an outbreak of barber’s pole worm disease, and can also be caused by other factors (e.g. a severe lack of protein in under-nourished sheep).

2. What are the causes of scouring that would need to be managed to reduce flystrike risk? 

In summer rainfall areas the major causes of scouring and dags are

• worm or larval challenge in sheep with little immunity
• rapid change to a high quality pasture
• occasionally coccidia

In winter rainfall environments the major causes of scouring and dags are

• heavy worm burdens or larval challenge in sheep with little immunity
• larval hypersensitivity in worm immune sheep

3. If sheep are being brought onto the property, what are your options to manage lice?

A good biosecurity plan must assume that introduced sheep are infested with lice regardless of their history or whether there are no lice or signs of lice. Your decision on how to manage the introduced sheep will be a risk management choice. This is based on

• The number of sheep being introduced, the cost of their treatment and impact of out-of-season shearing compared with the cost and impact of treating the whole flock if lice spread to them.
• Your ability to properly quarantine the introduced sheep until 2–4 months (depending on the product active) after off-shears treatment.

Management options in descending order of biosecurity rigour are:

1. Shear and apply an off-shears treatment, then quarantine for a minimum of 2–4 months (depending on the product active).
2. Sheep introduced with less than 6 weeks wool should have an off-shears treatment applied, then be quarantined for a minimum of 2–4 months (depending on the product active). Note: this may produce high wool residues if the sheep have already been treated off-shears.
3. Quarantine introduced sheep until after they receive an off-shears treatment at their next shearing. Quarantine should continue for a minimum of 2–4 months off-shears (depending on the product active). Introduced sheep with more than 6 weeks wool may require a long wool treatment to suppress (not eradicate) lice; consult the Long Wool Tool to see if this is warranted (ensure treatment adheres to wool rehandling and harvesting intervals).
4. Don’t apply quarantine or treatment to introduced sheep. Then treat the entire flock off-shears, or if lice or signs of lice are not detected consider not treating.