Sodium Iodide / Potassium Iodide
Sodium Iodide, Potassium Iodide
Also known as: SSKI · Iodoject · Pima · Thyrosafe · Iosat · Potassium Iodide · Sodium Iodide · Ethylenediamine dihydroiodide · EDDI
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Sporotrichosis | 40 mg/kg PO q8h | PO | q8h | at least 60 days | 🌎 NA |
| Sporotrichosis | 40 mg/kg PO q12h | PO | q12h | — | 🌎 NA |
- Sporotrichosis: Using SSKI
- Sporotrichosis: Using SSKI; give with food. Itraconazole is less likely to have adverse effects.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Sporotrichosis | 20 mg/kg PO q12-24h | PO | q12-24h | at least 60 days | 🌎 NA |
| Sporotrichosis | 20 mg/kg PO q12-24h | PO | q12-24h | — | 🌎 NA |
- Sporotrichosis: Using SSKI; give with food. Itraconazole is less likely to cause adverse effects.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Sporotrichosis | 20-40 mg/kg PO daily | PO | q24h | several weeks | 🌎 NA |
| Sporotrichosis | Loading dose of sodium iodide at 20-40 mg/kg IV for 2-5 days, then 20-40 mg/kg PO once daily | IV, PO | q24h | at least 3 weeks after all clinical lesions disappear | 🌎 NA |
| Conidiobolomycosis | 20% sodium iodide at 44 mg/kg IV for 7 days, then ethylenediamine dihydroiodide at 1.3 mg/kg PO q12h for 4 months, then q24h for 1 year, then once per week | IV, PO | Variable | Over 1 year | 🌎 NA |
- Sporotrichosis: Sodium iodide
- Sporotrichosis: May administer via oral syringe or mixed in sweet feed. Topical hot packs of 20% sodium iodide may be used on open wounds.
- Conidiobolomycosis: Excessive lacrimation occasionally noted, but resolved if the drug was held for one day.
Cattle
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Actinobacillosis (woody tongue) | 70 mg/kg IV given as a 10% or 20% solution | IV | repeat at least one more time at a 7-10 day interval | — | 🌎 NA |
- Actinobacillosis (woody tongue): Refractory cases may require more frequent (2-3 day intervals) treatment. Severe cases may require adjunctive antibiotics.
Sheep
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Actinobacillosis | 70 mg/kg IV given as a 10% or 20% solution | IV | repeat at least one more time at a 7-10 day interval | — | 🌎 NA |
- Actinobacillosis: Refractory cases may require more frequent (2-3 day intervals) treatment.
Goats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Actinobacillosis | 70 mg/kg IV given as a 10% or 20% solution | IV | repeat at least one more time at a 7-10 day interval | — | 🌎 NA |
- Actinobacillosis: Refractory cases may require more frequent (2-3 day intervals) treatment.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Iodides (Sodium Iodide and Potassium Iodide) are primarily utilized in veterinary medicine for their effects against specific granulomatous infections.
Key indications include:
- Actinobacillosis (woody tongue) and Actinomycosis (lumpy jaw) in cattle and other ruminants.
- Sporotrichosis (a deep fungal infection) in horses, dogs, and cats.
- Occasionally used as an expectorant or as a supplement for iodine deficiency disorders.
Clinical Pearl: Use in cats is controversial as they are highly susceptible to iodide toxicity (iodism). Alternative antifungal therapies like itraconazole are often preferred for feline sporotrichosis.
Mechanism of action
The exact mechanism of action for treating actinobacillosis and sporotrichosis is unknown.
- Iodides possess little to no direct in vitro antimicrobial or antifungal activity.
- They are believed to act by modifying the granulomatous inflammatory process.
- Proposed mechanism: Iodides may enhance phagocytosis by macrophages or alter the immune response within granulomas, facilitating the breakdown of granulomatous tissue and allowing the body's immune system to clear the infection.
Safety & warnings
Contraindications
- Known iodide hypersensitivity
- Lactating animals (excreted in milk)
- Hyperthyroidism
- Renal failure
- Severe dehydration
- Pregnancy (may cause abortion in cattle)
Adverse effects
- Excessive tearing (epiphora)
- Vomiting and nausea
- Anorexia / inappetence
- Nasal discharge
- Muscle twitching
- Cardiomyopathy
- Scaly haircoats and dandruff
- Hyperthermia
- Decreased milk production
- Decreased weight gain
- Coughing
- Diarrhea
- Goiter (especially in foals from supplemented mares)
- Cardiovascular failure (in severe toxicity)
Precautions
Do NOT inject intramuscularly (IM).
When administering parenterally to horses, give slowly intravenously and with extreme caution, as severe generalized reactions have been reported.
Cats are highly prone to developing iodism (iodide toxicity). Weigh risks versus benefits carefully, especially in pregnant animals, as anecdotal reports suggest it can cause abortion in cattle (FDA Category D in humans).
Drug interactions
Iodides may decrease the efficacy of antithyroid medications.
Iodides may enhance the efficacy of thyroid medications.
Monitoring
- Clinical efficacy (resolution of granulomatous lesions)
- Signs of iodism (excessive tearing, nasal discharge, scaly haircoats/dandruff, hyperthermia, coughing, diarrhea)
- Thyroid function (if used long-term)
Pharmacokinetics
Absorption
Rapidly and nearly completely absorbed from the gastrointestinal tract following oral administration.
Distribution
Widely distributed throughout extracellular fluids. Actively concentrated in the thyroid gland, salivary glands, gastric mucosa, and choroid plexus.
Metabolism
Iodide is not metabolized but is incorporated into thyroid hormones (T3 and T4) in the thyroid gland.
Elimination
Primarily excreted by the kidneys into the urine. Also excreted in milk, saliva, and tears. Therapeutic efficacy of IV sodium iodide for actinobacillosis is rapid, with beneficial effects usually seen within 48 hours.
Overdose
Excessive iodine accumulation leads to a toxic syndrome known as iodism.
- Clinical Signs: Excessive tearing (epiphora), vomiting, anorexia, nasal discharge, muscle twitching, cardiomyopathy, scaly haircoats/dandruff, hyperthermia, decreased milk production and weight gain, coughing, inappetence, and diarrhea.
- Species Sensitivity: Cats are particularly prone to developing iodism. Young animals may be more susceptible than adults. Foals have developed goiter when mares were excessively supplemented.
- Severe Toxicity: Can progress to depression, hypothermia, and cardiovascular failure.
Available products
Formulations
- Injection: 20% (200 mg/mL)
- Oral solution: 1 g/mL (SSKI)
- Oral syrup: 62.5 mg/mL
- Oral tablets: 65 mg, 130 mg
- Oral powder/granules (Ethylenediamine dihydroiodide)
Veterinary
- Sodium Iodide Injection: 20 grams/100 mL (20%; 200 mg/mL) in 250 mL vials
- Oral iodide powders/granules (Active ingredient: ethylenediamine dihydroiodide)
Human-labeled
- Potassium Iodide Solution (SSKI): 1 gram/mL
- Potassium Iodide Oral Syrup (Pima): 62.5 mg/mL
- Potassium Iodide Oral Tablets: 65 mg, 130 mg (Thyrosafe, Iosat)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store veterinary injectable products at room temperature (15-30°C). Store Supersaturated Potassium Iodide (SSKI) solution below 40°C (preferably 15-30°C) in a tight, light-resistant container; protect from freezing. Crystallization can occur at low temperatures; re-warming and shaking will usually redissolve crystals. If the solution turns brownish-yellow (oxidation), discard it. Physically incompatible with vitamins B and C injection.
Client information
Administering this medication can be challenging due to its extremely unpleasant taste.
- Administration: When giving orally to dogs or cats, mix the dose with food or a fatty liquid (like whole milk or ice cream) to improve palatability and reduce the chance of nausea and vomiting.
- Toxicity Monitoring: Watch your pet closely for signs of iodine toxicity (iodism). Contact your veterinarian immediately if you notice excessive tearing, runny nose, coughing, severe dandruff, vomiting, or loss of appetite.
- Food Animals: If treating livestock intended for human consumption, consult your veterinarian regarding appropriate withdrawal times (FARAD guidance recommended).
- Nursing: Do not use in nursing animals unless directed, as the drug passes into milk. Switch to a milk replacer if the mother requires treatment.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.