Doses - DIGOXIN
Dogs: 
a) 0.22 mg/m2 of body surface area bid (Note: body surface area from weight conversionchart may be found in the appnedix) (Kittleson and Knowlen 1986) b) Oral maintenance dose: 0.01 - 0.02 mg/kg divided bid, monitor and adjust dosage prn.
Rapid oral digitalization: 0.02 - 0.06 mg/kg divided bid the first day and then a maintenance dose. (Kittleson 1985b)
c) Rapid intravenous digitalization for atrial arrhythmias: 0.01 - 0.02 mg/kg divided; give1/2 of above dose IV and wait for 30-60 minutes and give 1/4th the dose IV; waitanother 30-60 minutes and give the remainder if necessary. (Miller 1985)
d) Elixir: 0.005 - 0.008 mg/kg PO bid; Tablets: 0.005 - 0.01 mg/kg PO bid (Moses 1988)
e) Elixir: 0.18 mg/m2 PO bid; Tablet dose same as "a" above (Kittleson 1985a)
f) For canine dilated cardiomyopathy: 0.01 - 0.02 mg/kg PO divided bid; maintain serumlevels between 1-2 ng/ml. (Ogburn 1988)
Cats: (Note: cats dislike the taste of the elixir)
a) Elixir: 0.003 - 0.004 mg/kg PO bid (Moses 1988)
b) Tablets: 0.005 - 0.008 mg/kg/day PO divided bid;alternatively: For cats weighing:2-3 kg = 1/4 of a 0.125 mg tablet every other day.4-5 kg = 1/4 of a 0.125 mg tablet every day.6 kg or > = 1/4 of a 0.125 mg tablet bid (Kittleson 1985a)
c) Oral maintenance 0.007 - 0.015 mg/kg once daily to every other day. Rapid IV: 0.005mg/kg lean body weight divided between three doses (1/2 the dose initially, then 60minutes later another 1/4 of the dose, 60 minutes later the remainder (if necessary) or toeffect. Stop if marked bradycardia, diminished AV conduction, other digoxin relatedarrhythmias or clinical signs of toxicity are present. Begin oral therapy as soon as thelast IV dose is completed. (Miller 1985)
Cattle: 
a) 0.25 mg/100 lbs body weight (not destroyed in rumen), titrate dose to normalize atrialrate; not excreted in milk (McConnell and Hughey 1987)Horses: 
a) 0.022 mg/kg daily orally (maintenance) (McConnell and Hughey 1987) b) 0.06 - 0.08 mg/kg PO q8h for 5-6 doses to digitalize, then 0.01 - 0.02 mg/kg POmaintenance. (Hilwig 1987)
Note: a case report of serious digoxin toxicity in a horse has been reported following 0.035- 0.07 mg/kg/day for 5 days; digitalize with caution.
Birds:a) Using 0.5 mg/ml elixir, 4 drops in 2oz of water as the sole water source, change daily)(McConnell and Hughey 1987)
Monitoring Parameters -
Because of the significant interpatient pharmacokinetic variation seen with this drug and its narrow therapeutic index, it is strongly recommended to monitor serum levels to help guide therapy. Unless the patient received an initial loading dose, at least 6 days should pass after beginning therapy to monitor serum levels as to allow levels to approach steady-state. Suggested therapeutic serum levels in the dog are 0.9 - 3.0 ng/ml and 0.9 - 2.0 ng/ml in cat (Neff-Davis 1985). For other species, values from 0.5 - 2.0 ng/ml can be used as guidelines. Levels at the higher end of the suggested range may be necessary to treat some atrial arrhythmias, but may also result in higher incidences of adverse effects.
Usually a trough level (just before next dose or at least 8 hours after last dose) is recommended.
Client Information - Contact veterinarian if animal displays changes in behavior, vomits, has diarrhea, lack of appetite, symptoms of colic (horses), becomes lethargic or depressed.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times -
There are bioavailability differences between dosage forms and in tablets produced by differentmanufacturers. It is recommended that tablets be used from a manufacturer that the clinician hasconfidence in and that brands not be routinely interchanged. Should a change in dosage forms bedesired, the following bioavailability differences can be used as guidelines in altering the dose:
Intravenous = 100%, IM » 80%, Oral tablets » 60%, Oral elixir » 75%, Oral capsules » 90-100%.
The bioavailability of digoxin in veterinary species has only been studied in a limited manner. Onestudy in dogs yielded similar values as those above for oral tablets and elixir, but in horses onlyabout 20% of an intragastric dose was bioavailable.
Veterinary-Approved Products:
Digoxin Elixir 0.05 mg/ml 60 ml dropper bottle; Cardoxin® LS (Evsco); (Rx)Digoxin Elixir 0.15 mg/ml in 60 ml dropper bottle; Cardoxin® (Evsco); (Rx)
Digoxin tablets and elixir have been approved for veterinary use, but no species are listed in theindications. There are no drug residue data for meat or milk published and no meat or milkwithdrawal times are available.
Human-Approved Products:
Digoxin for Injection 0.1 mg/ ml in 1 ml amps & 0.25 mg/ml in 2 ml amps, & 1 & 2 ml Tubex;Lanoxin® (Glaxo Wellcome), Digoxin® (Elkins-Sinn) and (Wyeth-Ayerst) (Rx)
Digoxin tablets 0.125 mg, 0.25 mg and 0.5 mg; Lanoxin® (Glaxo Wellcome), generic; (Rx)Digoxin capsules 0.05 mg, 0.1 mg, 0.2 mg; Lanoxicaps® (Glaxo Wellcome); (Rx)
Digoxin Elixir Pediatric 0.05 mg/ml in 60 ml dropper bottle, 50 ml and UD 2.5 & 5 ml;
Lanoxin® (Glaxo Wellcome); (Rx); generic (Rx)