Anti Parasitics Flashcards
What is the ideal anti-parasitic?
- Effective against a wide range of mature and immature targets
- Usable for a range of host species
- Wide margin of safety for non targets
- Cheap and stable
- Low residues - WHP, ESI
- Easy to administer
- Compatible with other products
What is the WHP?
Witholding Period: minimum period which must elapse between last administration or application of a vet chemical product and the collection, harvesting or use of animal commodity for human consumption.
Mandatory for domestic slaughter
What is ESI?
Export Salughter Interval: time which should elapse between administration of a vet chemical to animals and their slaughter for export.
manage differences b/w maximum residue limits allowed for trading
What are anthelminitics?
drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host.
Name 3 broad-spectrum anthelmintics for sheep
- Benzimidazoles
- Levamisole
- Macrocyclic lactones
Name 3 narrow spectrum anthelmintics for sheep
- Closantel
- Triclabendazole
- Praziquantel
Name 3 anthelmintics for cattle
- Benzimidazoles
- Levamisole
- Macrocyclic lactones
Name 3 anthelmintics for horses
- Benzimidazoles
- Tetrahydropyramidines (THPs)
- Macrocyclic lactones
When is antheliminctic resistance present?
When there is a greater frequency of individuals within a population able to tolerate doses of a compound than in a normal population of the same species
-resistance is heritable
When will observable resistance develop?
When individual worms are able to survive drug treatment, then pass on their genes to subsequent generations.
When does side resistance occur?
When parasites resistant to one active ingredient within a chemical class are also resistant to other active ingredients in the same class
When does multiple resistance occur?
When parasites of the same genus are resistant to different chemical classes at the same time
What are some testing methods of anthelmintic resistance?
- Faecal egg count reduction test
- WEC and find wormy, young animals to test
- Treat groups of animals and have an untreated control group
How does anthelmintic resistance develop?
- High treatment frequency
- Underdosing
- Using ineffective products
- Poor treatment techniques
- Persistant poducts
- Poor quarantine protocol
- Treatments at times of low refugia
- Blanket drenching of all sheep onthe farm
Does cross resistance occur between differenr chemical classes?
NO
