Lecture 21 4/11/24

Question 1

What are the avermectins?

Answer 1

-ivermectin
-doramectin
-eprinomectin

Question 2

What are the milbemycins?

Answer 2

-milbemycin oxime
-moxidectin

Question 3

Which animals are treated with macrocyclic lactones?

Answer 3

-dogs
-cats
-ferrets
-rabbits
-rodents
-cattle
-horses
-swine
-sheep
-goats
-camelids
-birds
-reptiles

Question 4

What are the adverse effects associated with macrocyclic lactones?

Answer 4

-mydriasis
-depression
-tremors
-seizures
-ataxia
-stupor
-emesis
-salivation
-coma
-microfilaricidal effects
-bloat or paralysis in cattle
pruritus and swelling in horses

Question 5

What are the characteristics of ivermectin sensitivity in collies?

Answer 5

-adverse effects at very low doses
-dose in heartworm preventative is low enough that it dose not cause toxicity
-caused by a deletion in the MDR1 gene

Question 6

How is avermectin toxicity treated in dogs?

Answer 6

-induce emesis and give activated charcoal
-fluid therapy
-nutritional support
-monitor cardiac and resp. parameters
-lipid emulsion infusion

Question 7

Which animals are treated with cyclic depsipeptides?

Answer 7

-cats
-dogs

Question 8

How do cyclic depsipeptides work?

Answer 8

bind to presynaptic receptor in pharynx and body wall muscles; flaccid paralysis and death

Question 9

What are the adverse effects of cyclic depsipeptides?

Answer 9

-dermal irritation
-excessive grooming
-vomiting
-diarrhea
-depression

Question 10

Which options are available for heartworm L3/L4 prevention?

Answer 10

-canine oral prevention
-canine topical prevention
-canine injectable prevention
-feline prevention

Question 11

Which option is available for heartworm microfilaricide?

Answer 11

Advantage Multi

Question 12

Which option is available for heartworm adulticide?

Answer 12

immiticide; arsenical compound

Question 13

What is the mode of action for immiticide?

Answer 13

thought that arsenic acts on sulfhydryl group of essential nematode enzymes

Question 14

What are the adverse effects of immiticides?

Answer 14

-death at too high of dose
-pain/swelling at injection site
-pulmonary thromboembolic disease from heartworm death

Question 15

Why is sulfadimethoxine used to treat protozoa?

Answer 15

replaces para-aminobenzoic acid used for folic acid in coccidians

Question 16

What are the antiprotozoal groupings?

Answer 16

-non-sulfonamide antibacterial drugs with antiprotozoal activity; metronidazole, ronidazole, clindamycin, azithromycin, doxycycline
-benzimidazoles; fenbendazole/albendazole
-sulfonamides
-ionophores; monensin
-thiamine inhibitor
-quinolone; decoquinate/deccox
-aromatic diamidines
-hydroxynaphthoquinone
-triazines; ponazuril

Question 17

What are the characteristics of sulfonamides?

Answer 17

-used in dogs, cats, ferrets, rabbits, rodents, cattle, horses, reptiles, poultry
-targets coccidia, bacteria
-give orally, SC, IM, IV
-inhibits DNA synthesis through folic acid antagonism
-adverse effects include crystalluria, hematuria, renal tubule obstruction

Question 18

What are the characteristics of ionophores?

Answer 18

-used in poultry, ruminants, rabbits
-targets coccidia
-feed additive
-makes biological membranes permeable to Na+ and K+, drawing in water
-fatal in horses
-paralysis in legs in birds

Question 19

What are the characteristics of thiamine inhibitors?

Answer 19

-used in poultry, cattle, sheep, goats, pigs, dogs, cats
-targets coccidia
-feed additive, oral solution, powder
-inhibits maturation of schizonts and formation of merozoites
-can cause thiamine deficiency and polioencephalomalacia in ruminants

Question 20

What are the characteristics of quinolones?

Answer 20

-used in chickens, cattle, sheep, goats
-targets coccidia, Hepatozoon americanum
-feed additive, milk replacer, milk additive
-interrupts sporozoite development by interfering with electron transport
-wide safety margin
-should not be used in laying hens, breeding animals, lactating animals

Question 21

What are the characteristics of aromatic diamidines?

Answer 21

-used in dogs, cats, horses, sheep
-targets Babesia spp., Hepatozoon canis, Cytauxzoon felis
-IM or SC injection
-denatures DNA
-adverse effects include injection pain, mild cholinergic signs, possible kidney and liver necrosis

Question 22

What are the characteristics of hydroxynaphthoquinone?

Answer 22

-used in dogs and cats
-targets Babesia, Hepatozoon, Cytauxzoon, Toxoplasma
-oral suspension
-causes nucleic acid inhibition
-adverse effects include nausea, vomiting, diarrhea, hypoglycemia, anemia, neutropenia

Question 23

What are the characteristics of triazines?

Answer 23

-used in horses, poultry, cattle, swine, sheep, dogs, cats, reptiles, camelids, rabbits, falcons
-targets Sarcocystis and coccidia
-oral paste, medicated feed, or pellet
-disrupts ability of protozoa to reproduce
-not for use in pregnant/lactating animals
-can cause loose stool, blisters on mouth, rash/hives in horses

Question 24

Which drugs are used to treat canine and feline giardiasis?

Answer 24

-fenbendazole
-metronidazole
-febantel

Question 25

What are the recommendations for giardia treatment in dogs and cats?

Answer 25

-5-10 days of fenbendazole; 50 mg/kg SID or
-fenbendazole at 50 mg/kg SID and metronidazole for 5 days at 25 m/kg BID
-repeat combo treatment for another 5 days if originally fails
-remember to bathe animals, clean environment, etc.

Question 26

What is the justification for using fenbendazole and metronidazole together?

Answer 26

-different MOAs can increase activity against metronidazole-resistant strains; may cause synergy
-both medications are generally safe and inexpensive
-fenbendazole will also eliminate any present nematodes

Question 27

What are the characteristics of metronidazole?

Answer 27

-not for use in food animals
-ELU in dogs and cats
-adverse effects include neuro. signs, teratogenic, vomiting, diarrhea, ataxia, carcinogenic in cats
-not for use in pregnant/lactating animals

Question 28

Which drugs are used for coccidia treatment in dogs and cats?

Answer 28

-sulfadimethoxine (+/- ormetoprim)
-sulfaguanidine
-furazolidone
-trimethoprim-sulfa
-quinacrine
-amprolium (+/- sulfadimethoxine)
-ponazuril