sheep worming

What is the life cycle of Fasciola hepatica?

Fluke ingested as metacercaria migrates to intestine, then to liver, settles in bile ducts, matures to adult and lays eggs after 8 weeks.

What clinical signs are associated with liver fluke infection?

Weight loss, poor fleece quality, oedema, and possible mortality.

When should FEC be conducted in relation to liver fluke infection?

FEC should be conducted more than 8 weeks after infection, as eggs are not shed before this time.

Which drug is effective against all stages of liver fluke?

Triclabendazole.

What are some prevention strategies for liver fluke in sheep?

Improve pasture management and reduce access to snail habitats.

What are the main worms associated with PGE in sheep?

Nematodirus battus, Haemonchus contortus, Teladorsagia, Trichostrongylus.

What does a low FWEC indicate regarding Nematodirus battus?

If no lambs were on pasture the previous year, it indicates low risk.

Which parasites are treated in lambs under 300g/day DLWG?

Lambs showing poor growth rates must be tested and treated for parasites.

What can indicate an increased risk of PGE in ewes?

Nutritional stress and periparturient relaxation of immunity.

What is the clinical disease caused by Nematodirus battus?

Dehydration and death, with eggs present on FWEC.

What type of examination is performed during post-mortem for liver fluke?

Examine for pale/anaemic liver, necrosis, and calcified bile ducts.

What is the effect of Albendazole in treating liver fluke?

It kills adult flukes.

How long can Nematodirus battus eggs survive on pasture?

They can survive for 2 years.

What vaccination is available for lungworm in sheep?

A vaccine is available but immunity is short-lived.

What are the classes of anthelmintic drugs?

Group 1 - benzimidazoles, Group 2 - levamisole, Group 3 - macrocyclic lactones, Group 4 and 5 - newer agents.

What is a sign of acute fluke observed in post-mortem examination?

Pale or anaemic liver with necrosis.

How do you differentiate liver fluke from Johne’s disease?

Low albumin and globulin indicate fluke; low albumin with normal globulin indicates Johne’s.

What is the consequence of not maintaining a refugia population during deworming?

It may lead to anthelmintic resistance.

When should you treat ewes at risk for PGE?

Around lambing time, especially if under nutritional stress.

What is the main risk associated with treating all animals with anthelmintics?

The risk of developing drug resistance.

What should be monitored in relation to anthelmintic resistance?

Conduct drench testing and FEC reduction tests.

What is the target treatment strategy for lambs?

Treat those showing low body condition scores or concurrent disease.

What is one method of managing grazing to reduce parasite load?

Move lambs to low-risk pastures.

What clinical signs indicate a possible need for deworming in lambs?

Weight loss or if FWEC results indicate high parasite levels.

What is the role of macrocyclic lactones in sheep treatment?

Effective against adult PGE and lungworm, but have withdrawal times.

What is a sign of chronic liver fluke during examination?

Presence of adults, calcified bile ducts, and severe inflammation.

What condition can result from fluke migrating through the abdomen?

Evidence of peritonitis and possible haemorrhage.

What action should be taken if fluke eggs are seen?

Implement treatment protocols for fluke.

What is the effect of winter on the hatching of Nematodirus battus eggs?

Hatching is stimulated by a cold period followed by a warmer period.

What type of parasites does Closantel effectively target?

It is effective against larvae older than 6 weeks.

How should new arrivals in a flock be managed?

Use Group 4/5 anthelmintics and keep them isolated for 3 weeks.

Which parasite is known for causing bottle jaw in sheep?

Liver fluke.

What happens to fluke eggs after being laid in the bile ducts?

They are shed into the environment, where they can contaminate pastures.

What might indicate a flock's need for treatment other than regular schedules?

High FEC results or clinical signs of parasite infestation.

What is periparturient relaxation of immunity?

It is the decrease in immunity around lambing which makes ewes more susceptible to parasites.

What can be used to prevent wormer resistance?

Using the correct anthelmintic for the right animals at the right time.

What are the clinical signs you would observe in a sheep with a heavy Nematodirus infestation?

Dehydration and possible mortality, as well as eggs on FWEC.