Organic arsenicals Flashcards
(25 cards)
Use?
- Feed additives to improve wt. gain and feed efficiency and to control enteric infections in swine and poultry
- Arsanilic acid mainly used in swine
- Roxarsone mainly used in poultry
Sources?
- Overdosage or prolonged use
- Recommended concentrations in debilitated, dehydrated, or sick animals
T/F: Organic arsenicals are phenylarsonic acid (benzenearsonic acid) derivatives
TRUE
What state is organic arsenic in?
Pentavalent oxidation state
T/F: Organic pentavalent arsenicals are more toxic than inorganic arsenic
FALSE–organic pentavalent arsenicals are less toxic
What is the recommended concentration of arsanilic acid in swine and poultry?
Recommended concentration as growth promoter is 50-100ppm
What is the recommended concentration to control swine dysentery?
250-400 for 5-6 days
What level causes toxicosis in swine?
500ppm for 7-10 days
Recommended concentration of roxarsone as a growth promoter?
Poultry = 25-50ppm
Swine = 25-37.5ppm
Recommended concentration of roxarsone to control swine dysentery?
200ppm for 5-6 days
What levels of roxarsone causes toxicosis in swine?
250ppm for 7-10 days
What enhances toxicity of organic arsenicals?
Dehydration, water deprivation, and renal insufficiency
Absorbance, distribution, and excretion of organic arsenicals?
- Small amount is absorbed from GI tract
- Distributed throughout body
- Excreted unchanged in urine
What is the mechanism of action?
Unknown
Peripheral nerve demyelination and axonal damage very similar to vitamin B deficiency
Clinical signs of arsanilic acid toxicosis in swine?
- Onset of acute toxicosis is 3-5 days
- Signs are incoordination, ataxia, then partial paralysis but they still have a good appetite
- Blindness may develop with arsanilic acid but not with roxarsone
- May be erythema with sensitivity to sunlight
- In chronic toxicosis, gradual onset of blindness and partial paralysis but pigs still eat and drink
Clinical signs of arsanilic acid in poultry?
Anorexia, depression, coma and death
Clinical signs of roxarsone toxicity in swine?
- Sudden onset
- Marked hyperexcitability
- Tremors
- Collapse
- Coma
- Possible death
- No blindness
Clinical signs of roxarsone toxicity in poultry?
Incoordination and ataxia
What lesions are seen in swine?
- Possible erythema in light-skinned pigs
- May be muscle atrophy in chronic cases
- Microscopically: peripheral nerve and optic nerve degeneration, demyelination, and gliosis
What specimens are used for chemical analysis?
Suspected feed, liver, and kidney
Diagnosis?
- History of exposure to organic arsenicals
- Clinical signs
- No gross lesions
- Microscopic peripheral nerve demyelination
- Chemical analysis
DDx for arsanilic acid toxicosis in swine?
- Subacute selenium toxicosis (paralysis w/o blindness)
- Organic mercury (seizure)
- Vitamin B complex deficiency
- Infectious diseases
DDx for roxarsone toxicosis in swine?
- Pesticides
- Water deprivation/Na ion toxicosis
Treatment?
- No specific antidote
- W/drawal of organic arsenicals
- Supportive therapy
- Plenty of water or fluid therapy
- Multiple vitamins
- Antibiotics to prevent bac. infections
