30/09/2022
Deworming in animals- An overview of Anthemintics
1. An Overview of Anthelmintics Dr Nisar Ahmad, PhD Assistant Professor Department of Parasitology UVAS, Lahore
2. What is Deworming? Sometimes known as Worming or Drenching, is the giving of an Anthelmintic drug (a wormer, dewormer, or drench) to an animal
3. How Parasites Hurt Animals •Absorb digested nutrients •Suck blood •Cause mechanical obstruction •Destroy tissue •Secret toxins •Immune Suppression
4. Symptoms of Worm Infestation •Animal lacks vigor: Dull and depressed •Poor appetite •Loss of body weight •Diarrhea with mucus, blood or worms •Animal eats soil or other organic matters •Rough hair coat and anemia
5. Symptoms of Worm Infestation Diarrhea
6. Parasitic Infestation Emaciation
7. Parasitic Infestation Anemia Submandibular Swelling
8. Risk Factors For Parasites •Warm Weather •2 inches of rain in a month •Pasture Grazing •High Stocking Rate •Thin Animals •Animal in Lactation •Long Residence on a Pasture
9. Classification Four families of drugs for internal parasites 1. Benzimidazoles (white dewormers) – Albendazole, Fenbendazole, mebendazole, and Oxfendazole 2. Imidazothiazoles –Pyrantel, Levamisole, and Moratel 3. Macrolytic Lactones or Avermectins Ivermectin (Ivomec), Doramectin, and Moxidectin 4. Others- Praziquantel, Clorsulon, etc
10. Spectrum of Anthelmintics
11. Guideline for Anthelmintic Dosages • Albendazole -20 mg/kg (Not in 1st trimester) • Fenbendazole- 10 mg/kg • Ivermectin- 0.4 mg/kg • Levamisole- 12 mg/kg • Moxidectin- 0.5 mg/kg
12. Mode of action of Avermectin • Ivermectin binds with high affinity to glutamate-gated chloride channels which occur in invertebrate nerve and muscle cells, causing an increase in the permeability of the cell membrane to chloride ions with hyper polarization of the nerve or muscle cell. Hyper polarization results in paralysis and death of the parasite either directly or by causing the worms to starve.
13. Avermectin
14. Mode of action of Benzimidazoles • Benzimidazoles selectively bind to nematode ß-tubulin, thus preventing the formation of microtubules and so stopping cell division. Impaired uptake of glucose, leading to depletion of glycogen which causes the nematodes to starve to death.
15. Mode of Action of Praziquantel • Praziquantel works by causing severe spasms and paralysis of the worms' muscles. This paralysis is accompanied by a rapid Ca 2+ influx inside the parasite. This influx of Ca results in tetanic contractions of the parasitic musculature and an intense vacuolation of their integument.
16. Selection of a Dewormer • Animal being treated (calf vs. cow, beef vs. dairy) • Product efficacy • Ease of application • Broad Spectrum of control ( immature, mature, inhibited) • Cost effectiveness • Slaughter/milk withdrawal time • Personal Safety
17. Deworming in sheep/goat • Sheep and goats are susceptible to worms due to their close grazing behavior and slow-to-develop immunity. Goats are more susceptible than sheep when forced to graze (versus browse) • Lambs should be wormed at approximately 8 weeks of age, and again every 4-8 weeks until a year of age.
18. Cont… • Ewes should be wormed 2-4 weeks before lambing to reduce the passage of parasites to the lambs. • Does in early pregnancy (up to 2 months) should not be dewormed to avoid abortion. • At least once per year, goats/sheep should be dewormed for tapeworms
19. Cattle and Buffalo • Cattle can be infected by roundworms (nematodes), tapeworms (cestodes) and flukes (trematode) • Roundworms are considered the most economically devastating internal parasites of livestock 1. The barber pole worm (Haemonchus) 2. The small brown stomach worm (Ostertagia) 3. Cooperia
20. • Internal parasites of lesser concern are tapeworms and lungworms • Tapeworms, which are visible in the manure, can cause weight loss and death in extreme cases. • Tapeworms can be controlled by administering an Anthelmintics from the benzimidazole family
21. Commonly available Anthelmintics Oxyclozanide, Oxfendazole Cobalt and Selenium Albandazole
22. Nitroxynil Ivermectin
23. Cont… TRADE NAME GENERIC NAME Profax (Oxfendazole) Fasisym (Triclabendazole) Zanil ( Oxyclozanide) Nilzan plus (Levamisole + Oxyclozanide +Selenium+ cobalt)
24. Characteristics of a Good Dewormer • Not Poisonous • Easy to administer • Effective for all stages of parasites • Economical • Effective for a longer period of time • Act specifically at the target site
25. Natural/Herbal Dewormer
26. Efficacy of a Dewormer • An effective dewormer will reduce f***l counts by 95% 7-14 days after administration. • F***l Egg Count before deworming, 1,000 eggs per gram(EPG) • For example:10 days after deworming 200 EPG= 80% F***l Egg Count Reduction.
27. Anthelmintics Resistance • Drug resistance in parasites is extremely common. The effectiveness of an Anthelmintics should always be tested before being used. • Do not worm unnecessarily • Make sure you are giving the correct dose. Don’t overdose or under dose • Change the type of wormer used so you are using a different type of drug to prevent resistance
28. ANY QUESTIONS ?
29. THANKS
