Drugs FA Flashcards
1
Q
Thiabendazole
A
- Thiabendazole is a broad spectrum antihelmintic agent used predominantly in treatment of intestinal pinworm and strongyloides infection, which recently has been replaced by better tolerated agents.
- Thiabendazole therapy has been shown to cause clinically apparent cholestatic liver injury which is rare, but can be severe.
2
Q
Moxidectin
A
- Trade name: Cydectin
- Moxidectin is an anthelmintic drug used in animals to prevent or control parasitic worms (helminths), such as heartworm and intestinal worms, in dogs, cats, horses, cattle and sheep
- Cydectin® Pour-On is approved for use on beef cattle and dairy cattle (including lactating dairy cattle) for the treatment of infections and infestation of internal and external parasites.
- Cattle: Horn Flies, Lice, Mites, Worms
- Brown stomach worm for 28 days
Lungworm for 42 days
Nodular worm for 28 days
Barber pole worm for 14 days
3
Q
Ivermectin
(Clear Drench)
A
- Ivermectin is a member of the macrocyclic lactone class of endectocides which have a unique mode of action.
- Compounds of the class bind selectively and with high affinity to glutamate-gated chloride ion channels which occur in invertebrate nerve and muscle cells
- Kills: Roundworms (including Brown Stomach Worm), Lungworms, Grubs, Sucking Lice, Biting Lice, Mange Mites, Horn Flies
- GIT Roundworms: Ostertagia ostertagi (including inhibited stage) (adults and L4), Haemonchus placei (adults and L4), Trichostrongylus axei (adults and L4), T. colubriformis (adults and L4), Cooperia oncophora (adults and L4), Cooperia punctata (adults and L4), Cooperia surnabada (adults and L4), Strongyloides papillosus (adults), Oesophagostomum radiatum (adults and L4), Trichuris spp (adults)
- Lungworms: Dictyocaulus viviparus (adults and L4)
- Cattle Grubs: (parasitic stages) Hypoderma bovis, H. lineatum
- Mites: Sarcoptes scabiei var. Bovis
- Lice: Linognathus vituli, Haematopinus eurysternus, Damalinia bovis, Solenopotes capillatus
- Horn Flies: Haematobia irritans
4
Q
Organophosphates
A
- All organophosphates are veteran antiparasitics
- Many organophosphates have a broad spectrum of activity, i.e. they act against a large number of external parasites of different groups: insects (e.g. flies, mosquitoes, fleas, lice, etc.), ticks, mites, etc. They may be effective against both adult and immature stages (larvae, nymphs, etc.)
- They were vastly used as drenches or even injectables in the 1950’s to 1970’s, before the discovery of better and safer anthelmintics
- Effects can be potentiated by phenothiazines
- can lead to toxicity! - seizures
- BUT is now the the mainstay of sheep scab in the UK (Psoroptic mange)
5
Q
Imidocarb
A
- Antiprotozoal
- Only for the treatment and prevention of bovine babesiosis in cattle
6
Q
Bleeding abomasal ulcers (sometimes called type 2 ulcers) have been diagnosed in a 2-year old dairy cow with melena and anemia. What treatment is contraindicated?
A
Flunixin meglumine
- This drug (aka Banamine) is a non-steroidal anti-inflammatory drug (NSAID) and will only promote more ulceration because NSAIDs decrease mucosal blood flow.
- Blood transfusions are sometimes given if the bleeding is severe.
- Omeprazole (a hydrogen pump blocker) and ranitidine can be beneficial in calves and raise the abomasal pH, but not useful orally in adults.
- In adults, IV ranitidine can be used but is very expensive and reserved for high-value animals.
7
Q
Ranitidine
A
Zantac
can be used in cats, dogs, horses, cattle
- Ranitidine is used in horses to treat and prevent the recurrence of gastric ulcers
- Used for: Stomach ulceration, esophageal ulceration, increasing food transit through the GI tract
8
Q
Bovine Trichomoniasis
in a bull?
in a cow?
A
- Trichomoniasis, caused by the protozoan Tritrichomonas foetus, is typically a temporary infection in the female. She characteristically eliminates the infection in 2-4 months.
- The bull, however, becomes a chronic carrier as he ages, since aging is associated with increased depth of epithelial crypts of a bull’s glans penis and prepuce, thus increasing the availability of the “niche” where the organism thrives
- The mature bull is commonly the reservoir of infection for a herd
- Once infected, a cow typically clears the infection from the reproductive tract in 2-4 months and regains her fertility.
- Young bulls are rarely infected chronically, probably because they have shallow penile and preputial crypts, which are thought to provide poor niches for chronic infection.
- Trichomoniasis typically manifests no visible signs in either the male or female.
9
Q
Ceftiofur Sodium
A
- Ceftiofur is a third-generation cephalosporin
- Ceftiofur or Naxcel used as labelled has a 4 day withdrawal time in meat.
- It has zero withdrawal time for milk
10
Q
Chloramphenicol
A
- broad spectrum AB
- Chloramphenicol use is not allowed in food animals!!
11
Q
Withdrawal time of oxytetracycline (from meat)?
Penicillin G?
Sulfadimethoxine?
A
- Oxytetracline (LA200) has a 28 day meat withdrawal time
- Sulfadimethoxine has a meat withdrawal time of 7 days.
- Penicillin G has a meat withdrawal time of 10 days.
12
Q
Treatment for acute lead poisoning in cattle?
A
chelation therapy
Calcium EDTA
Calcium EDTA given IV is safe and effective for lead chelation therapy. The calcium salt avoids depleting serum calcium.
13
Q
2PAM
(Pralidoxime)
A
- Pralidoxime relieves both the nicotinic and muscarine effects of organophosphate poisoning by regenerating acetylcholinesterase and can reduce both the bronchial secretions and the muscle weakness associated with poisoning
- 2 PAM is used to treat organophosphate toxicity it is an anticholinesterase
14
Q
Lasalocid
A
- Lasalocid is an antibacterial agent and a coccidiostat, which is produced by strains of Streptomyces lasaliensis.
- can be used daily to prevent coccidiosis in young ruminants; as there is no vaccine
- other coccidiostats: monensin, amprolium, decoquinate, diclazuril and toltrazuril
15
Q
Fipronil
A
- Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole chemical family.
- Fipronil disrupts the insect central nervous system by blocking GABA-gated chloride channels and glutamate-gated chloride (GluCl) channels.
- This causes hyperexcitation of contaminated insects’ nerves and muscles.
17
Q
Fluoride Toxicity in Young Cattle
A
- affects teeth and bones!
- Fluoride toxicity results in ameloblasts prematurely reducing in size (cells present during tooth development that lay down enamel).
- Eventually, the enamel epithelium forms an irregular matrix which does not calcify normally.
- Fluoride toxicity will cause bone lesions.
- Interestingly, the first palpable lesions are seen on the medial surface of the proximal third of the metatarsal bones.
- A key thing to know is that articular surfaces are not affected with osteofluorosis so this may help rule it in or out from other diseases such as osteomyelitis, septic arthritis, and osteoarthritis
