Toldimfos sodium (Organic Phosphorus): veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Tonophosphan

Species with doses

Dogs, Cats, Cattle, Horses, Goats and Pigs

Routes

IV, IM

Last reviewed

1 October 2026

Indications

• Metabolic disorders — milk fever support (alongside calcium)
• Downer cow syndrome (adjunct)
• Transit tetany
• Repeat-breeder cow — uterine and ovarian tonic
• Convalescence / post-parturient inappetence
• Convalescence after surgery / chronic disease in companion animals

Toldimfos sodium (Organic Phosphorus) dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Convalescence / metabolic support: Product catalogue (Tonophosphan 200 mg/mL): 1–3 mL IM in dogs. Use the lower volume for small dogs.

Cats

• Convalescence (extra-label): The catalogue groups cats with dogs (1–3 mL IM) — at the upper volume that is a very large dose for a cat. Use the lowest volume and check the pack insert.

Cattle

• Metabolic / milk fever support: Product catalogue (Tonophosphan 200 mg/mL): 10–20 mL IV alongside calcium borogluconate. Not a substitute for IV calcium in hypocalcaemic milk fever.
• Repeat-breeder / infertility: Product catalogue (Tonophosphan 200 mg/mL): 5–10 mL IM on the day of service.

Horses

• Convalescence / metabolic support: Product catalogue (Tonophosphan 200 mg/mL): 5–20 mL IM/SC.

Goats

• Metabolic support: The product catalogue lists 5–20 mL adjusted to body weight without a goat-specific volume; check the pack insert before dosing a goat.

Sheep

• No reference dose for this species: The previous sheep row (5–15 mg/kg) had no source; the catalogue used for this entry gives no sheep volume.

Pigs

• Convalescence / pre-/post-farrowing: Product catalogue (Tonophosphan 200 mg/mL): 5–20 mL IM in sows.

Buffalo

No buffalo-specific doses are on file, so buffalo are dosed as cattle.

• Metabolic / milk fever support: Product catalogue (Tonophosphan 200 mg/mL): 10–20 mL IV alongside calcium borogluconate. Not a substitute for IV calcium in hypocalcaemic milk fever.
• Repeat-breeder / infertility: Product catalogue (Tonophosphan 200 mg/mL): 5–10 mL IM on the day of service.

Contraindications

Hypersensitivity. Use with caution in severe renal failure. Not as a substitute for IV calcium in true hypocalcaemic milk fever — calcium borogluconate remains the primary therapy.

Species-specific warnings

Cattle: For milk fever support — give IV alongside calcium borogluconate. Repeat-breeder dose 10 mL IM on day of service.

Adverse effects

• Local injection-site reaction (transient swelling)
• Rapid IV can cause mild restlessness — give slowly

Pregnancy and lactation

Safe in pregnant cattle, buffalo, mares and sows at recommended doses. No reported teratogenic effects.

Monitoring

• Clinical response — cow rises within 2–6 h if response is going to occur
• Serum phosphorus before repeat dose if available
• Inflammatory reaction at injection site — rotate sites in chronic use

Clinical pearls

• Down cow with milk fever: 10–20 mL Tonophosphan IV PLUS calcium borogluconate 400–500 mL IV — phosphorus deficit is the #2 cause of downer cow after calcium
• Repeat breeder: 10 mL IM on the day of service is a low-effort intervention with reasonable response in subclinical hypophosphataemia
• Convalescence in horses / pigs: 5–10 mL IM weekly for 2–3 weeks improves appetite and weight gain

Mechanism of action

Provides organically bound phosphorus (P) to support cellular energy metabolism — phosphorus is a cofactor in ATP production and is depleted in milk fever, transit tetany, and high-production dairy stress. Stimulates rumen function, hepatic gluconeogenesis, and ovarian activity by correcting subclinical hypophosphataemia. Better tolerated parenterally than inorganic phosphates.

Formulations and products

• Tonophosphan VET 200 mg/mL injection (MSD, 10 / 30 / 100 mL)
• Tonophosphan VET (MSD Animal Health) — Toldimfos sodium 200 mg/mL, Injectable solution

Storage

Vials 15–25 °C, protected from light. Multidose vial: discard 28 days after broaching.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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Frequently asked questions