Pharm II Exam 2: Large & Small Animal Endoparasites, SA Ectoparasites

Horses

In what animal are these external parasites commonly seen:

-Flies (Stable, House, Horse, Gasterophilus)

-Ticks

-Midges

Horses

What animal has these internal parasites commonly:

-Parascaris (Ascarids)

-Strongylus (Large strongyles)

-Cyathostomes (Small strongyles)

-Oxyuris equi (Pinworms)

Stable and house fly control

What are these feed-throughs used for in horses:

-Tetrachlorvinphos (Equitrol)

-Diflubenzuron (Equitrol II)

-Cyromazine (Solitude IGR)

No (they're active against the immature forms)

Do these fly controls in horses have an effect on the adult flies:

-Tetrachlorvinphos (Equitrol)

-Diflubenzuron (Equitrol II)

-Cyromazine (Solitude IGR)

True

True or False: If a feed-through fly control is being used, ALL HORSES in the stable must be given the product.

Pyrethroids

What chemical derivative of pyrethrin should topical fly sprays for horses contain?

*This chemical excites the nervous system & causes paralysis

Bot flies

What external parasite in horses are controlled by Ivermectin & Moxidectin?

*Both are macrocytic lactones

Ivermectin

Which of these macrocytic lactones is the oldest/original product & has a high resistance rate?

-Moxidectin

-Doramectin

-Ivermectin

-Eprinomectin

Ivermectin, moxidectin

What medications are effective against bots & the majority of equine internal parasites except tapeworms?

-Effective against benzimidazole resistant cyathostome (sm strongyles)

Adult and larval tapeworms (cestodes)

What internal parasite (and what stage) in horses does praziquantel treat?

Benzimidazoles

Drug class that includes Fenbendazole (panacur), oxibendazole, & albendazole (ruminants)

Fenbendazole, Oxibendazole

Benzimidazole anthelmintics that are effective against these internal parasites in horses:

-Large strongyles

-Small strongyles

-Pinworm

-Ascarids (particularly effective for this parasite)

Oxibendazole

Is Fenbendazole or Oxibendazole more effective at treating horses with small strongyles?

Tetrahydropyrimidines

A group of nicotinic agonists that includes:

• Pyrantel pamoate

• Pyrantel tartrate

• Morantel (ruminants)

Roundworms (AKA nematodes, Parascaris group that includes ascarids)

Tetrahydropyrimidines (pyrantels) are used as a 1st line of defense against what equine internal parasites?

Tapeworms

Pyrantel pamoate & Pyrantel tartrate are effective against the 4 main internal parasites in horses. What other internal parasite is pyrantel pamoate effective against (extra-label)?

Pamoate, tartrate

Pyrantels:

-_______ salt = paste/suspension, poorly absorbed from GI tract = safe product for young or debilitated animals

-_______ salt = feed pellets, absorbed from GI tract = designated for continuous feeding

Small strongyles, ascarids

Equine Parasites with Drug Resistance:

-Tetrahydropyrimidines & Benzimidazoles = ____ ____

-Tetrahydropyrimidines (some) & Macrocyclic lactones = _____

Treat selectivity (> 200 epg) to improve refugia

What is the new dogma to internal parasite control in horses?

-Perform quantitative egg counts

-Follow fecal egg count reductions to assure efficacy (

Yes (Cyathostome efficacy returned to 97.8%)

Are there benefits to a 4-way rotation of anti-parasitic drugs in equine?

-Pyrantel pamoate: June

-Ivermectin & Praziquantel (tapeworms): September

-Fenbendazole: December

-Moxidectin: March

Cattle

In what animal are these external parasites commonly seen:

• Horn Fly

• Face Fly

• Hypoderma (cattle grub, bot fly)

Cattle

In what animal are these internal parasites commonly seen:

• Oesophagostomum

• Ostertagia

• Haemonchus

• Dictyocaulus vivparus

• Fasciola

Ear tags, sprays

These following are medications used in cattle to prevent external parasites. What form do these medication come in?

• Doramectin

• Eprinomectin

• Ivermectin

• Moxidectin

Synthetic Pyrethroids, Organophosphates

What are the 2 types of drugs that are used in cattle ear tags & sprays for external parasite control?

*Rarely see macrocytic lactones

Sucking lice, biting (chewing) lice

What 2 types of lice in cattle are eliminated via Macrocytic lactones?

Biting (chewing) lice

Both sucking & biting (chewing) lice in cattle respond to pour-on macrocytic lactones. Which lice does NOT respond to the injectable form?

Dictyocaulus viviparus (lungworms)

Which of these internal parasites in cattle is very susceptible to ivermectin (ie not a lot of resistance)?

• Oesophagostomum (roundworm spp)

• Ostertagia (roundworm spp)

• Haemonchus (roundworm spp)

• Dictyocaulus viviparus (lungworms)

• Fasciola (liver fluke)

Ivermectin, doramectin, Moxidectin, Eprinomectin

What 4 macrocytic lactones are effective against these external & internal parasites in cattle:

• Horn Fly

• Face Fly

• Hypoderma (cattle grub)

• Oesophagostomum

• Ostertagia

• Haemonchus

• Dictyocaulus

Doramectin

What is the only macrocytic lactone with known activity against the screwworm in cattle?

No

Can Ivermectin & doramectin be used in lactating cattle or veal calves?

Eprinomectin (0 days, Moxi is 21, dora is 30, iver is 35)

Which of these macrocytic lactones in cattle has the shortest slaughter withdrawal time for internal parasite control?

-Moxidectin

-Doramectin

-Ivermectin

-Eprinomectin

Pour-on (injectable is NOT approved)

Which form of Moxidectin can be given to lactating dairy cows?

*For internal parasite control

Eprinomectin

While pour-on moxidectin can be given, which ML was specifically designed for use in lactating dairy cattle?

Clorsulon

Benzene sulfonamide that's effective against immature & mature Fasciola hepatica (common liver fluke) in cattle

Fascioloides magna

What liver fluke is Clorsulon in cattle NOT effective against?

Ivermectin, clorsulon

What medications does Ivomec Plus contain?

*An injection for treating internal parasites in cows

Albendazole

Newest benzimidazole anthelmintic in cattle that has good activity against Fasciola hepatica & Fascioloides magna

*Effective against H FOOD: Haemonchus, Fasciola, Oesophagostomum, Ostertagia, Dictyocaulus

Embryotoxic

Why can albendazole not be given to pregnant beef cows during the first 45 days of gestation?

*Do not give to lactating dairy cattle

Fenbendazole, oxfendazole (albendazole protects against all of these EXCEPT tapeworms)

What 2 benzimidazole anthelmintics in cattle protects against:

• Haemonchus

• Oesophagostomum

• Dictyocaulus

• Ostertagia

• Tapeworms

Levamisole and oxfendazole (both are 7 days, Fen is 8, alben is 27)

Which Benzimidazole anthelmintic in cattle has the shortest slaughter withdrawal time for internal parasite control?

-Albendazole

-Oxfendazole

-Fenbendazole

-Levamisole

Tapeworms

Fenbendazole, oxfendazole, & Levamisole protects against these internal parasites in cattle:

• Haemonchus

• Oesophagostomum

• Ostertagia

• Dictyocaulus

Compared to Fenbendazole & oxfendazole, what parasite does levamisole NOT protect against?

Cholinergic toxicity

What adverse reaction can occasionally occur in cattle that received levamisole?

*salivation, head shaking, ataxia, muscle tremors

Morantel tartrate

Tetrahydropyrimidine analogue of pyrantel used in cattle to protect against mature forms of:

• Haemonchus

• Ostertagia

• Oesophagostomum

• Tapeworms

Morantel tartrate

What internal parasite control is approved for dairy cattle with no milk discard?

-14-day slaughter withdrawal

Medication formulation

Antiparasitics in sheep & goats are very similar to cattle. What is the main difference?

Roundworms, hookworms

SA GI parasites

-_____ = Toxocara spp. & Toxascaris sp.

-_____ = Ancylostoma spp. & Uncinaria sp.

Whipworms, tapeworms

SA GI parasites

-______= Trichuris sp.

-______= Dipylidium, Taenia &., Echinococcus spp.

Protozoal, lungworm

SA Parasites:

-____ = Giardia & Coccidia sp.

-____ = Aelurostrongylus abstrusus

Heartworm, stomach

SA Parasites:

-____ = Dirofilaria sp.

-_____ worm = physaloptera

Heterocyclic compound

What Pharmaceutical class contains piperazine?

Tetrahydropyrimidines

What Pharmaceutical class contains pyrantel pamoate?

Fenbendazole

Most common benzimidazole product used in almost all veterinary species

Isoquinolone

What Pharmaceutical class contains Praziquantel & Epsiprantel?

Cyclic depsipeptide

What Pharmaceutical class contains emodepside?

Macrocyclic lactones

What Pharmaceutical class contains avermectins & milbemycins?

Avermectin

Group of Macrocyclic lactones that includes:

- Ivermectin

- Selamectin

- Eprinomectin

Milbemycin

Group of Macrocyclic lactones that includes:

• Milbemycin oxime

• Moxidectin

Gaba agonist

What is the MOA of Piperazine?

-Causes an influx of Cl → hyperpolarization → flaccid paralysis

Roundworms

What parasite does piperazine treat?

*Narrow spectrum drug

Urine

Piperazine is rapidly absorbed in the GI tract and eliminated in?

Nicotinic agonist (mimics Ach)

What is the MOA of Pyrantel Pamoate?

-Triggers depolarization→ spastic paralysis → death

Feces

Pyrantel pamoate is poorly absorbed in the GI tract and eliminated in?

Roundworms, hookworms

What parasites does Pyrantel pamoate treat in SA?

Tubulin

What component of the parasite's cytoskeleton does Fenbendazole & Febantel bind to?

-Inhibits microtubule formation needed for movement

-Blocks glucose uptake → depletes energy

-Ovicidal

Fenbendazole

Broad spectrum parasiticide in dogs for rounds, hooks, whips, & Taenia

*Extra-label: Giardia & Physaloptera

*Repeat in 30-60 days to treat whipworms

Fenbendazole

Extra label parasiticide in cats for rounds, hooks, whips, lungworms, & Giardia

*Repeat in 30-60 days to treat whipworms

Febantel

Oral benzimidazole that's metabolized into fenbendazole & oxfendazole in dogs & cats

Febantel

Benzimidazole that treats hooks, rounds, whips, & tapeworms (echinococcus) in BOTH dogs & cats

Praziquantel

Oral/injectable Isoquinolone for dogs/cats to treat Dipylidium, Taenia, & Echinococcus

Yes

Is Praziquantel & Epsiprantel safe for breeding/pregnant animals?

Epsiprantel

Oral Isoquinolone for dogs/cats to treat Dipylidium, & Taenia

*Poor oral absorption

Echinococcus

What tapeworm species does Praziquantel treat that Epsiprantel doesn't?

*Both Isoquinolones treat Dipylidium & Taenia

Roundworms, hookworms, tapeworms

What parasites can Praziquantel + Pyrantel treat together?

Praziquantel, Pyrantel, Febantel

What 3 parasiticides (Drontal Plus) can be given in combo orally to dogs to treat:

-Roundworms

-Hookworms

-Tapeworms

-Whipworms

Increases abortion risk 3x

Why is Drontal Plus (Praziquantel + Pyrantel + Febantel) contraindicated in pregnant animals?

Emodepside

What cyclic depsipeptide binds to the presynaptic latrophilin-like receptor in the pharynx & body wall muscle of parasites?

-Opens Ca +2-activated K+ channel → Efflux of K+ → hyperpolarization → flaccid paralysis → death

Emodepside

Topical formulation with praziquantel for cats

*Systemically absorbed to treat round, hook, & tapeworms

*Extra-label for lungworms

Emodepside

Cyclic depsipeptide with a narrow safety margin (avoid in pregnant dogs/women & dogs with MRD1)

*Can be used as a Microfilaricidal (HW test before use) & Extra-label oral tx for MADR hookworms in dogs

MDR1 (ABCB1)

Gene mutation in dogs that causes adverse reactions to Emodepside

*Rare but can occur in cats too

No

Can emodepside be used in pregnant animals or in pets with pregnant owners?

Resistant hookworms

What are these treatments for:

1) Febantel PO/pyrantel pamoate PO/praziquantel PO + topical moxidectin

2) Fenbendazole PO x 3 d + pyrantel pamoate PO + topical moxidectin

3) Oral emodepside - last resort

Ivermectin 1% solution

Macrocyclic Lactone for extra-label oral use in dogs/cats for:

• Roundworms

• Hookworms

• Physaloptera

Topical Moxidectin

Macrocyclic Lactone used in dogs & cats to treat roundworms, hookworms (manage LL), & whipworms (dogs)

larval leak

Occurs after treatment of an hookworm adult population when arrested larvae move into the SI & replace adults that were removed

*Managed by topical moxidectin

Injectable moxidectin

AKA Proheart, heartworm prevention injection that kills hookworms around the administration site

- Hook Reinfection is possible

45+ days

90% of ivermectin & moxidectin are excreted in feces at different times. However, how long can these medications persist in the manure?

Roundworms, hookworms

What parasites are treated via oral ivermectin in SA?

Neurotoxicity, coprophagia

A dog recently got dewormed & has a MDR1 gene mutation. What are signs of this defect?

Selamectin

Topical ML that treats rounds, hookworms, fleas, & ear mites in cats

*Extra label for lungworms

*Kills demodex if combined with Sarolaner (revolution® Plus)

No intestinal coverage

What parasites does topical selamectin in dogs treat?

*Macrocyclic Lactones

Milbemycin oxime

Macrocyclic Lactone given orally to dogs & cats to treat rounds, hooks, & whips (dogs only)

Dogs

Does Milbemycin oxime treat whipworms in dogs or cats? (remember it treats hooks & rounds in both species)

Eprinomectin

TOPICAL Macrocyclic Lactone that should be avoided in cats with a MDR1 gene mutation

Eprinomectin

Which macrocyclic lactone is used in caution in patients with a hx of seizures or neuro disoders?

Roundworms, hookworms

Nexgard Combo: Contains praziquantel for tapeworms, Esafoxalaner for fleas/ticks, & Eprinomectin for ... (2)

Pyrantel pamoate

Extra-label Treatment for Roundworms & hookworm in cats

Whipworm

what unique parasite does fenbendazole & febantel treat?

*Also treats rounds/hooks

Coccidia

What parasite in small animals is treated using sulfadimethoxine or ponazuril?

Yes (rounds, hooks, and whips +/- tapes)

Does topical moxidectin protect against the same parasites as oral milbemycin in small animals?

All of the above

Which factors should be considered before selecting an insecticide in SA?

A) Speed of kill

B) Administration route

C) Client preference

D) All of the above