Parasite drugs 3

Question 1

Melarsomine

Answer 1

Tradename= Immiticide for dogs

-kills Dirofilaria immitis heartworms adult stage

-administered by deep IM injection in lumbar muscle only

-Dangerous- contains arsenic; side effects

Question 2

Closantel (Flukiver)

Answer 2

-oral suspension for sheep and lambs

-decent oral bioavailability, high protein binding, limited tissue distribution

-treatment for Haemonchus contortus (barber pole worm) infection
*not for lactating sheep because long withdrawal time (49days)
-extra label got liver flukes (Fasciola hepatica) in cattle and sheep

Question 3

Antiprotozoal drugs

Answer 3

-main use for coccidia (Isospora and eimeria)
-and other infections (cryptosporidium, giardia, sarcocysts, toxoplasma, babesia, neospora)

**complex life cycles!

Question 4

Antiprotozoal drug classifications

Answer 4

1. Coccidiostat
2. Coccidiocide

Question 5

Coccidiostat

Answer 5

Arrests development of parasites, but do not kill coccidial stages
-used more for prevention

Question 6

Coccidiocide

Answer 6

-kill most coccidial stages in later stages
-used when you have clinical signs

Question 7

3 potential Label claims of coccidia

Answer 7

1. Treatment
   -will work when there are clinical signs
2. Control/prevention
   -coccidiostat
3. Reduction in fecal shedding

Question 8

Coccidiosis therapy drugs

Answer 8

-Monensin (ionophore)
-Sulfonamides
-Amprolium
-Toltrazuril

Question 9

Ionophores

Answer 9

-most common drug class used for coccidiosis
>broilers/turkeys, calves, sheep, rabbits

-generally inhibits activity of coccidial stages (especially early=preventative)
>Punch hole in cell membranes of cardiac and skeletal muscle and disrupt Na/K pump and electrolyte balance

Question 10

Ionophore toxicity

Answer 10

-significant toxicity and death in mammals (HORSES and DOGS)
*targets cardiac and skeletal muscle

Question 11

Reasons for ionophore toxicity

Answer 11

1. ionophore containing feed meant for pigs/poultry, calves is ingested by horses/dogs on the same farm
2. mistaken delivery of ionophore containing feed
3. incorrect ionophore concentration in feed

Question 12

Monensin (Rumensin)

Answer 12

-most common ionophore drug for coccidiosis

Question 13

Other antibiotic indications of monensin

Answer 13

-Antibiotic- kills off gram positive bacteria resulting in:

1. increased propionate and decreased methane production= feed efficiency
2. Decreased bloat in cattle grazing on legume pasture
3. Reduction in fecal shedding in Johne’s herds
4. decreased incidence of rumen lactic acid production after grain overload

Question 14

Monensin indications for dairy cattle

Answer 14

1. aid in prevention of subclinical ketosis in lactating dairy cattle
2. reduced milk fat
3. minimize loss of body condition during lactation in dairy cows
4. improve feed efficiency of milk production in lactating dairy cows

Question 15

Sulfonamides

Answer 15

-antimicrobials and used in coccidiosis

-analogue of PABA which inhibits synthesis of folate in bacteria and coccidia

Question 16

Uses of sulfa drugs

Answer 16

1. Sulfaquinoxaline- oral solution for poultry
2. Sulfamethazine- oral bolus or solution for calves, sheep, poultry

Question 17

Amprolium

Answer 17

-thiamine analogue/antagonist
-prevention of coccidial disease reproduction but not used for clinically affected animals
-oral solution mixed in feed; animals receive daily

Question 18

Amprolium overdose

Answer 18

Can occur if animals given too high doses
-thiamine analogue- coccidia is more sensitive but can affect mammals at high dose
*Leads to Polioencephalomalacia= thiamine deficiency

Question 19

Toltrazuril (Baycox)

Answer 19

-use in piglets, lambs, calves
for prevention of coccidiosis, reduction in shedding in lambs
-timing is extremely important
-expensive
-prolonged withholding time (48-70 days)

Question 20

Forceris

Answer 20

-toltrazuril formulation
-injectable solution with iron for piglets
-IM injection behind ear
-70 day withdrawal time

Question 21

Extra label use of Toltrazuril

Answer 21

1. coccidiosis in puppies and kittens
2. Coccidiosis in poultry

Question 22

Decoquinate (Deccox)

Answer 22

-hydroxyquinolone class
-can be added to milk replacer
-good for goats! Works against Coccidiosis

Question 23

Ponazuril

Answer 23

-toltrazuril metabolite
-reduces severity of Equine Protozoal Myeloencephalitis caused by Sarcocystis neurona in horses

-given 28days; expensive

Question 24

Clindamycin

Answer 24

-lincosamide category of antimicrobials
(wide variety of antibacterial label claims)

-Extralabel: Coccidiosis treatment= clinical toxoplasmosis and neospora in small animals

Question 25

Giardia treatment

Answer 25

1. Benzimidazoles (fenbendazole, febantel, albendazole)
2. Metronidazole
   -banned in food production animals
   -used in humans
   -used in dogs (Eradia oral suspension!)