Furosemide: what the FDA reviewed for dog products
4 Freedom of Information summaries from the FDA Center for Veterinary Medicine for products containing Furosemide, as typed records: every value below is followed by the verbatim passage it was taken from. Species as stated by each summary: Cattle, horses, dogs and cats; Dogs; Dogs and Cats.
Products
- Furosemide Injection 5% (NADA/ANADA 200-293)
- Furosemide Syrup 1% (NADA/ANADA 200-373)
- Furosemide Syrup 1% (NADA/ANADA 200-382)
- Furosemide Tablets (NADA/ANADA 200-759)
Furosemide Injection 5% NADA 200-293, Original approval, December 18, 2001; sponsor Elanco US Inc.; species: Cattle, horses, dogs and cats; foi_id 1045; FDA PDF
Indication
Diuretic-saluretic for prompt relief of edema (edema associated with cardiac insufficiency, acute noninflammatory tissue edema, physiological parturient edema of the mammary gland).
Dose regimen
1/4 to ½ mL per 10 lb body weight (dogs and cats), intramuscular or intravenous, BID or SID, Horses 5 to 10 mL BID or SID; cattle 5 mL BID or 10 mL SID.
Dog and cat-1/4 to ½ mL/10 lbs BID or SID
Extraction notes: Generic ANADA (pioneer Lasix 5% Injection, NADA 034-478). Waiver from in vivo bioequivalence granted September 29, 1997 (same active and inactive ingredients, injectable solution); no safety, effectiveness, PK or adverse reaction data in the summary. Dose figures in mg are not given; the solution is 50 mg/mL per General Information.
Furosemide Tablets NADA 200-759, Original approval, July 18, 2025; sponsor ZyVet Animal Health, Inc.; species: Dogs and Cats; foi_id 17256; FDA PDF
Indication
Treatment of edema (pulmonary congestion, ascites) associated with cardiac insufficiency and acute noninflammatory tissue edema in dogs and cats.
Dose regimen
1 to 2 mg/lb body weight (approximately 2.5 to 5 mg/kg), oral (12.5 mg or 50 mg tablets), once or twice daily at 6 to 8 hour intervals, Lower dosage suggested for cats; in severe or refractory cases the dose may be doubled or increased by 1 mg/lb increments; intermittent schedules (every other day or 2 to 4 consecutive days weekly) for mobilizing edema.
The usual dosage of furosemide is 1 to 2 mg/lb body weight (approximately 2.5 to 5 mg/kg).
Pharmacokinetics
| Parameter | Value | Conditions | Quote |
|---|---|---|---|
| auc | 5268 (generic) vs 5273 (RLNAD) ng/mL*hour (geometric means); ratio 1.00 (CI 0.95, 1.05) | 50 mg tablet, single oral dose, fasted male Beagles, n=28, four-period crossover; row order: parameter, sWR, generic mean, RLNAD mean, ratio, 95% upper bound, 90% CI | AUC (ng/mL) *hour 0.157 5268 † 5273 † 1.00 NE (0.95, 1.05) |
| cmax | 2265 (generic) vs 2571 (RLNAD) ng/mL (geometric means); ratio 0.89 | 50 mg tablet, single oral dose, fasted dogs, n=28; reference-scaled ABE (sWR 0.307) | CMAX (ng/mL) 0.307 2265 † 2571 † 0.89 -0.011 NE |
| tmax | 0.91 (0.41) h generic vs 1.02 (0.50) h RLNAD (arithmetic mean (SD)) | 50 mg tablet, fasted dogs, n=28 | TMAX (hours) (SD) ‡ NE 0.91 (0.41) ‡ 1.02 (0.50) ‡ NE NE NE |
| auc | 5544.71 (generic) vs 6108.89 (RLNAD) ng/mL*hour (geometric means); ratio 0.91 | cats: 12.5 mg tablet, single oral dose, fasted neutered males, n=28, four-period crossover; RSABE (sWR 0.3130) | AUC (ng/mL)*hour 0.3130 5544.71† 6108.89† 0.91 -0.03 |
| cmax | 1056.17 (generic) vs 1214.40 (RLNAD) ng/mL (geometric means); ratio 0.87 | cats: 12.5 mg tablet, fasted, n=28; RSABE (sWR 0.5817) | CMAX (ng/mL) 0.5817 1056.17† 1214.40† 0.87 -0.12 |
| tmax | 3.00 (1.92) h generic vs 2.74 (1.77) h RLNAD (arithmetic mean (SD)) | cats: 12.5 mg tablet, fasted, n=28 | TMAX (hours) (SD)‡ NE 3.00 (1.92)‡ 2.74 (1.77)‡ NE NE |
Effectiveness
Blood-level bioequivalence study in dogs (Study 20C505Q1G197; GLP): masked, randomized, four-period, two-sequence, single-dose crossover of generic 50 mg vs Salix 50 mg furosemide tablets in 28 fasted healthy intact male Beagles (1.6-2.3 years, 8.6-12.4 kg) with an 8-day washout; average BE for AUC and reference-scaled ABE for Cmax.; n = 28; primary endpoint: Cmax and AUC (0 to last quantifiable concentration); bioequivalence limits 0.80-1.25; result: Bioequivalence demonstrated: AUC ratio 1.00 (90% CI 0.95-1.05), Cmax ratio 0.89 with 95% upper bound -0.011 (<0); generic 50 mg tablets bioequivalent to RLNAD in dogs. A parallel study in 28 cats showed bioequivalence of the 12.5 mg tablets; biowaivers granted for the other strengths on dissolution similarity (f2 54.6-89.4).
The laboratory study was conducted as a randomized, masked. four-period, two- sequence, two-treatment, single-dose crossover design using 28 dogs with an 8-day washout between periods.
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| No serious adverse events (bioequivalence studies) | There were no serious adverse events reported during the study. |
Extraction notes: Generic ANADA (RLNAD Salix tablets, NADA 034-621). 'Effectiveness' here is the in vivo blood-level bioequivalence study in dogs, not a clinical effectiveness study; no target animal safety study. PK values are from Tables II.1 (cats) and II.2 (dogs), quoted as flattened rows with dagger footnote markers attached to geometric means; the dog table row order is parameter, sWR, generic mean, RLNAD mean, ratio, 95% upper bound, 90% CI (NE = not estimated).
Furosemide Syrup 1% NADA 200-382, Original approval, November 18, 2004; sponsor Cronus Pharma Specialities India Private Ltd.; species: Dogs; foi_id 1133; FDA PDF
Indication
Oral diuretic-saluretic, alone or with furosemide injection, for edema (pulmonary congestion, ascites) associated with cardiac insufficiency and acute noninflammatory tissue edema in dogs.
Dose regimen
1 to 2 mL (10-20 mg) per 10 lb body weight, oral (syrup, 10 mg/mL, calibrated dropper), once or twice daily at 6 to 8 hour intervals
Dog: 1 to 2 mL (10-20 mg) Furosemide Syrup 1% for each 10 lb. body weight. Administer once or twice daily at 6 to 8 hour intervals.
Extraction notes: Generic ANADA (pioneer LASIX Syrup 1%, NADA 102-380; sponsor Phoenix Scientific at approval, marketed as AMTECH). Biowaiver granted based on formulation; no safety, effectiveness, PK or adverse reaction data in the summary.
Furosemide Syrup 1% NADA 200-373, Original approval, November 18, 2005; sponsor First Priority, Inc.; species: Dogs; foi_id 1124; FDA PDF
Indication
Oral diuretic-saluretic, alone or with furosemide injection, for edema (pulmonary congestion, ascites) associated with cardiac insufficiency and acute noninflammatory tissue edema in dogs.
Dose regimen
1 to 2 mL (10-20 mg) per 10 lb body weight, oral (syrup, 10 mg/mL, calibrated dropper), once or twice daily at 6 to 8 hour intervals
Dog: 1 to 2 mL (10-20 mg) Furosemide Syrup 1% for each 10 lb. body weight. Administer once or twice daily at 6 to 8 hour intervals.
Extraction notes: Generic ANADA (pioneer LASIX Syrup 1%, NADA 102-380). Biowaiver granted based on formulation (oral solution, same active ingredient and concentration); no safety, effectiveness, PK or adverse reaction data in the summary.
Reproduce: foi_structured_search(query="Furosemide") and foi_summary_get(foi_id=...) in dog-geroscience-mcp; dataset foi-summaries-dog (config structured).