1. Antiparasitics Ch 12

2. ANTIPARASITICS
Make up the largest category of products available to veterinary professionals and the general public.
Can be OTC or Rx.
Help to protect animals from diseases, as well as people.
Is an important topic of client education for veterinary technicians (let them look under the microscope, show them a heart filled with worms).
Are a quickly changing market.

3. THE IDEAL ANTIPARASITIC IS..
Selectively toxic to the parasite and not the host.
Does not induce resistance in the target parasite.
Economical.
Effective against all parasite stages with one application.
Fragrant or odorless.
Environmentally safe.

4. GENERAL RULES OF ANTIPARASITICS
Use with caution in old, young, debilitated, or pregnant animals.
Certain antiparasitics are risky for certain groups of animals.
They are only effective if most of the drug reaches the location of the parasite.
The client and veterinary team must understand which part of the parasite’s life cycle is affected by the drug and how/ when the drug should be applied.

5. TERMS _______ parasites cause infections and live inside the body.
_______ parasites cause infestations and live outside the body.
Parasites in an abnormal location in a hosts’ body are ___________.
Anthelmintics: kill helminth worms (parasitic worms)
Antinematodals: treat round worms
Anticestodals: treat tapeworms
Antitrematodals: treat flukes
Antiprotozoals: treat single-celled organisms: Coccidia, Giardia, Toxoplasma
Drench vs. Pour-on
TERMS

6. ANTINEMATODALS BENZIMIDAZOLES
In addition to nematodes, some products can treat some flukes, cestodes, and protozoa
Ysed in large animals, small animals, and exotics
Usually have to apply more than one dose consecutively
“bendazole” suffix
thiabendazole (EQUIZOLE, TBZ, OMNIZOLE)
fenbendazole (PANACUR/SAFEGUARD)
oxibendazole (ANTHELCIDE EQ)
albendazole (VALBAZEN)
mebendazole (TELMIN)
ANTINEMATODALS

7. ORGANOPHOSPHATES and CARBAMATES
Inactivate acetocholinesterase in parasites. This allows acetylcholine to overstimulate the nervous system and eventually cause paralysis (label usually says “contains a cholinesterase inhibitor”).
Not used as often with animals as they used to be.
Also used as pesticides.
Examples: coumaphos (BAYMIX), dichlorvos (TASK)
ANTINEMATODALS

8. ORGANOPHOSPHATES and CARBAMATES
To remember signs of toxicity, think SLUDDE: (salivation, lacrimation, urination, defecation, dyspnea, emesis). Also bradycardia, miosis, muscle tremors, ataxia, paralysis
Treat with ATROPINE or GLYCOPYRROLATE (block receptors for acetylcholine) and remove the insecticide. Glycopyrrolate reverses the neurological signs bc it crosses the blood brain barrier better than Atropine does.
ANTINEMATODALS

9. ANTINEMATODALS pyrantel pamoate febantel and levamisole
Tetrahydropyrimidine
NEMEX, STRONGID
Considered to be very safe
Often found in feed stores
Ineffective against whipworms
febantel and levamisole
Imidathiazoles
Effective against whipworms

10. ANTINEMATODALS MACROLIDES: Avermectins and Milbemycin
Structurally similar with a macrocyclic ring that are derived for a Streptomyces bacterium.
Cause paralysis and death of nematodes.
Among the safest compounds to use (these receptors are located behind the blood-brain barrier within the CNS in mammals)

11. ANTINEMATODALS AVERMECTINS ivermectin (many species)
Suffix –ectin
ivermectin, selamectin, doramectin, eprinomectin, moxidectin
ivermectin (many species)
HEARTGARD, EQVALAN, IVOMEC
Heartworm prevention, intestinal parasites, demodex, ear mites
Oral or injectable
Ivermectin toxicosis in collies
Genetic (recessive) trait that causes a deficiency of _____________________, a protein that moves drugs from the blood brain barrier cells back into the blood
Toxicity causes neurological signs
Heartgard doses are safe
No antidote

12. ANTINEMATODALS selamectin (small animals) doramectin (large animals)
REVOLUTION
Heartworm preventation, internal parasites, flea control, ear mites, sarcoptic mange (dogs), ticks (dogs)
Topical
doramectin (large animals)
DECTOMAX
Internal worms, grubs, lice, mange
Injectable and pour-on
ANTINEMATODALS

13. ANTINEMATODALS eprinomectin (large animals) moxidectin (many species)
EPRINEX
Internal worms, grubs, lice, mange
Pour-on
moxidectin (many species)
QUEST, CYDECTIN, PROHEART 6
Nematodes, mites, grubs, bots, lice, flies
Paste, Pour-on, Injectable

14. ANTINEMATODALS MILBEMYCIN milbemycin oxime (small animals)
INTERCEPTOR, SENTINEL
Heartworm preventative, hookworms, roundworms, ear mites, mange
Oral tablet for dogs and cats

15. ANTINEMATODALS piperazine Only effective against roundworms
Partially or fully paralyzes the worm but does not kill it.
Worms are sometimes passed a mass wiggling in the stool
Used in many species
Often used in OTC dewormers

16. ANTICESTODALS
Cause loss of intracellular calcium in the parasite, which leads to paralysis. Also, the tapeworm’s outer layer becomes permeable allowing antigens to leak out and the host to produce antibodies.
epsiprantel
CESTEX
Oral tablet for dogs and cats
Does not treat Echinococcus
Causes worm to disintegrate. Proglottids will not be seen in feces after administration. Not ovicidal.

17. ANTICESTODALS praziquantel Tablets for dogs and cats DRONCIT
Treats Dipylidium, Taenia, and Echinococcus
Causes worm to disintegrate. Proglottids will not be seen in feces after administration. Not ovicidal.
Remember that flea prevention must be administered when treating Dipylidium.
DRONTAL- praziquantel, pyrantel pamoate
DRONTAL PLUS – praziquantel, pyrantel pamoate, febantel

18. ANTITREMATODALS clorsulon is used in cattle for liver flukes
CURATREM
albendazole is used in cattle for liver flukes
VALBAZEN
praziquantel is used for lung flukes in small animals
DRONCIT

19. ANTIPROTOZOALS Treat Coccidia, Giardia, and Sarcocystis neurona (EPM)
amprolium
Causes thiamin deficiency in parasite
Treats coccidia
CORID
sulfadimethoxine
An antimicrobial that also treats coccidia
ALBON

20. ANTIPROTOZOALS metronidazole fenbendazole ponazuril
Antibacterial and anti-diarrheal that treats Giardia
High doses may cause neurological signs
FLAGYL
fenbendazole
Benzimidazole that treats Giardia
PANACUR
ponazuril
Treats Sarcocystis neurona and coccidia in horses
MARQUIS

21. ADULTICIDE melarsomine dihydrochloride Kills adult Dirofilaria immitis
Arsenic intramuscular lumbar injectable drug for dogs
IMMITICIDE
Injection site is commonly painful; many veterinarians provide pain-relieving medications
Nodules may develop at injection sites

22. ADULTICIDE melarsomine dihydrochloride
Exercise restriction is imperative (dying worms live in pulmonary arteries)
Worms will degenerate and cause inflammation in the lungs (steroids are often given for this)
Adulticide is not administered to cats

23. Please reference provided chart for all current medications on treating endo and ectoparasites in small animals.
This chart is based off of the current CAPC recommendations.
Please reference CAPC regularly to stay current on these medications as they change frequently.

24. IGRs
IGR: insect growth regulator. Affect immature stages of insects, preventing them from maturing. No adulticidal activity.
IDI: insect development inhibitor (a type of IGR) also called a chitin synthesis inhibitor
JHM: juvenile hormone mimic (a type of IGR)
Products are distributed over an animal's skin and work by direct contact with the flea. Adult females absorb the drug and incorporate the IGR into the flea eggs. These products should be used with an adulticide.

25. IGRs, IDIs, JMHs
Lufenuron is an IDI that is ingested into flea when it feeds on an animal. Affects the flea’s ability to produce chitin which is located within the egg and the larvae’s exoskeleton.
Pyriproxyfen is a JHM, which mimics juvenile hormone that is produced by the insect’s brain. When the insect’s body detects high levels of JH or a JHM, it fails to fully mature to the stage of egg production.

26. DRUGS THAT TREAT ECTOPARASITES
pyrethrins
Extract of chrysanthemums used in many insecticides.
Most end in “thrin” (ex: PERMETHRIN).
Highly toxic to cats, causes seizures and hypersalivation. Permethrin is used in a lot of products to repel ticks and people mistakenly apply it to cats. Rinse product off!
Fish are also hypersensitive to toxicity, use with care around water.

27. DRUGS THAT TREAT ECTOPARASITES
formamidines
Amitraz is the most commonly used
MITABAN for demodex treatment in dogs (also kills ticks)
Wear gloves when applying dip! May cause transient sedation for up to 72 hours, hypothermia (drip dry), and pruritus
Use caution with collars (PREVENTIC). If lost, monitor for signs of ingestion.
TAKTIC for treatment of lice, mange, and ticks on large animals
Effects an be reversed with yohimbine, tolazoline, and atipamezole

28. INSECT REPELLENTS
Repel gnats, mosquitoes, and flies. When pyrethrins/pyrethroids are added, fleas and ticks are repelled.
Sprays, tags, and topicals applied to ear tips
Used on horses and cattle to prevent flies from laying eggs on the skin (leading to bots and warbles)
Used on dogs with upright ears to prevent fly strike.
butoxypolypropylene glycol (BUTOX PPG)
diethyltoluamide (DEET) is often used in human products for insect repelling. Caused death in small animals.