– urinary excretion.
Toxicity
Highly toxic – clinical signs observed at doses as low as 0.25 mg/kg.
Toxic effects may vary by dose with some clinical signs observed more often at higher doses.
Systems Affected
Neurological – anxiety, ataxia, tremors, muscle fasciculations.
Cardiovascular – tachycardia, arrhythmias (including VT), increases in MAP, SAP, DAP.
Gastrointestinal – colic.
Renal – hematuria.
Risk Factors
Iatrogenic administration.
Exposure to cobalt salts intended for other species (e.g., goats).
Historical Findings
Iatrogenic administration.
Owners or trainers may be reluctant to admit administration due to regulations.
Incidental exposure to cobalt salt intended for another animal.
Location and Circumstances of Poisoning
Worldwide problem, especially in racehorses.
Often intentional exposure in horse racing due to perceived increased erythropoietic effects.
Unintentional exposure by placement of cobalt salts, especially when co‐mingling of horses in pasture with animals requiring cobalt supplementation.
Variable by dose received.
Common signs include agitation, ataxia, muscle fasciculations, tachycardia, arrhythmias, hematuria, colic.
Colic of other etiology.
UTI or bladder stone for hematuria
Rhabdomyolysis.
HYPP.
WNV.
WEE, VEE, EEE.
Rabies.
CBC/Serum Chemistry/Urinalysis
Routine laboratory work including serum chemistry and urinalysis.
Transient increase RBC for 1 hour post‐administration.
Mild increase in lactate and glucose within 1 hour of administration.
RBCs and urinary epithelial cells in urine.
± hypocalcemia.
Specialized testing for elevated cTnI within 24–48 hours of administration.
Other Diagnostic Tests
ECG as needed for tachycardia and cardiac effects.
Presence in serum and urine:No rapid, commercially available urine tests.ICP‐MS useful for diagnosis, but the time delay would hinder therapeutics.
Pathological Findings
No specific lesions reported in horses.
The goal of therapy is to provide supportive care.
Detoxification
Large ingestions – gastric lavage or reflux with large‐bore tube.
Supportive care if symptomatic.
Appropriate Health Care
Most can be treated in the field.
Most clinical parameters return to baseline within 2 hours.
Antidote
No specific antidote.
Drugs of Choice
IV fluids as needed for dehydration and volume expansion; may be helpful to increase elimination.
Agitation:Acepromazine 0.01–0.05 mg/kg IV, IM, SC prn.Adrenergic agonist: detomidine 10–40 μg/kg IM, IV or xylazine 0.5–1 mg/kg IV.
GI protectants:Omeprazole 2–4 mg/kg PO q24h.
Tremors, twitching:Acepromazine 0.01–0.05 mg/kg IV, IM, SC prn/Methocarbamol 4.4–22.2 mg/kg IV to effect. Administer half estimated dose and pause until the horse has relaxed. Administer the remainder of the dose to effect. Repeat as needed but do not exceed 330 mg/kg/day.
Precautions/Interactions
Protection to the head and limbs may be necessary in severely agitated horses.
Client Education
