# Oral Calcium / Phosphorus Bolus (Calcimust): veterinary dose and monograph

> Oral Calcium / Phosphorus Bolus (Calcimust) is a veterinary drug. Oral calcium + phosphorus + vitamin D3 supplementation for periparturient cows / buffaloes. Indications include periparturient calcium prophylaxis (pre- and post-calving cattle / buffalo); milk fever relapse prevention (after IV calcium); subclinical hypocalcaemia / inappetence post-calving. This monograph lists 4 reference doses for cattle and buffalo, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/calcimust-bolus · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Veterinary drug
- **Also known as:** Calcimust, Calcimust Bolus, Calcium-phosphorus oral bolus
- **Species with doses:** Cattle and Buffalo
- **Routes:** PO
- **Last reviewed:** 1 October 2026

## Indications

- Periparturient calcium prophylaxis (pre- and post-calving cattle / buffalo)
- Milk fever relapse prevention (after IV calcium)
- Subclinical hypocalcaemia / inappetence post-calving
- Phosphorus supplementation in high-production dairy

## Oral Calcium / Phosphorus Bolus (Calcimust) 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.

### Cattle

*Oral Calcium / Phosphorus Bolus (Calcimust) doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Milk fever prophylaxis (gel protocol) | One 300 g bottle PO at each of: 1–24 h pre-calving, at calving, 12 h and 24 h after | PO | 4-bottle schedule | — | Withdrawal NOT established — treat as extra-label |
| Milk fever relapse prevention | One bottle PO immediately after IV calcium, then at 24 h and 48 h | PO | 3-bottle schedule post-IV | — | Withdrawal NOT established — treat as extra-label |
| Daily calcium supplementation (bolus) | 1 bolus PO twice daily | PO | q12h | — | Withdrawal NOT established — treat as extra-label |

- Milk fever prophylaxis (gel protocol): Catalogue: Bottle 1 — 1–24 h before parturition; Bottle 2 — immediately after parturition; Bottle 3 — 12 h post; Bottle 4 — 24 h post. Each 300 g bottle = 1 oral dose.
- Milk fever relapse prevention: Catalogue: After successful IV calcium, give Bottle 1 immediately, Bottle 2 at 24 h, Bottle 3 at 48 h.
- Daily calcium supplementation (bolus): Catalogue: 1 bolus PO BID morning and evening. For teat-crack prevention: start 2 weeks before calving.

### Goats

*Oral Calcium / Phosphorus Bolus (Calcimust) doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: The previous row extrapolated ‘half the cow bolus dose’ with no source. The product is labelled for cattle and buffalo; neither Papich 5e nor Plumb’s covers it.

### Buffalo

*Oral Calcium / Phosphorus Bolus (Calcimust) doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Periparturient milk-fever prophylaxis / relapse prevention | Gel 4-bottle calving schedule, or 1 bolus PO twice daily | PO | gel 4-bottle or bolus schedule | — | Withdrawal NOT established — treat as extra-label |

- Periparturient milk-fever prophylaxis / relapse prevention: Mankind Calcimust labels buffalo with cattle (same protocol). Buffalo are highly milk-fever-prone at calving: gel Bottle 1 pre-calving → 2 post-calving → 3 at 12 h → 4 at 24 h; or 1 bolus PO BID. Recumbent clinical milk fever still needs IV calcium borogluconate FIRST.

## Contraindications

Severe hypercalcaemia. Acute milk fever with recumbency requires IV calcium first — oral products alone are inadequate. Do not over-supplement in dry-period cows on DCAD diets.

## Species-specific warnings

> **Caution:** Cattle: Use as ADJUNCT to IV calcium borogluconate in recumbent milk fever, not as primary therapy. Prophylaxis use 12 h pre-calving is high-value in high-risk cows.

## Adverse effects

- Hypercalcaemia (over-supplementation) — rare
- Soft-stool with prolonged use (high phosphorus load)

## Pregnancy and lactation

Safe in pregnant cows / buffaloes at recommended doses — primary use is prophylaxis in the periparturient window.

## Monitoring

- Clinical milk fever signs — calcium gel is supportive, not curative for recumbent cows
- Serum total calcium ideally; in field practice, clinical response (rises, eats, milks) is the marker
- Body condition score and recurrence pattern across lactations — habitual relapsers benefit from prophylactic gel protocol

## Clinical pearls

- High-risk cow (previous milk fever, ≥4th lactation, high producer): give Bottle 1 of Calcimust Gel 12 h pre-calving — single biggest prevention win in Indian dairy
- Post-IV calcium relapse prevention: gel immediately + 24 h + 48 h prevents most relapses (~70% of cows that relapse do so within 48 h)
- Bolus form for daily pre-calving supplementation 2 weeks before calving: maintains calcium reserves and reduces teat oedema / cracks
- Calcium gel is NOT a substitute for IV calcium in a down cow — give IV first, then oral supportive
- Always verify cow can swallow before drenching gel — recumbent / depressed cows are aspiration risks

## Mechanism of action

Calcium carbonate / tribasic calcium phosphate dissolves in the rumen acid environment, releasing ionised Ca²⁺ for intestinal absorption. Vitamin D3 (cholecalciferol) is bio-converted to 1,25-dihydroxy-vitamin D in the kidney, upregulating intestinal calcium absorption and bone mobilisation. The herbal / mineral co-factors in the proprietary formula contribute to gut motility and absorption efficacy. Oral calcium is best used pre-calving to prime the calcium-handling pathway and post-IV-calcium to maintain serum levels above the relapse threshold.

## Formulations and products

- Calcimust Bolus (Mankind) — Calcium 2 g + Phosphorus 1 g + Vit D3 20 000 IU + Vit A 50 000 IU per bolus
- Calcimust Gel (Mankind) — Calcium 19.8 g + Phosphorus 10.2 g + Vit D3 96 000 IU per 300 g bottle
- Calcimust Bolus (Mankind Veticura) — Calcium 2 g + Phosphorus 1 g + Vit D3 20 000 IU + Vit A 50 000 IU + Vit E 100 mg + B12 100 µg per bolus, Oral bolus
- Calcimust Gel (Mankind Veticura) — Calcium 19.8 g + Phosphorus 10.2 g + Vit D3 96 000 IU + Vit B12 1200 µg per 300 g bottle, Oral gel — drench bottle
- Microcal 4G (Micro Animal Health Care (Micro Labs group), Bengaluru) — Calcium 4000 mg + Phosphorus 2500 mg + Vitamin D3 16000 IU + Vitamin B12 200 mcg + Carbohydrate 28000 mg per 100 mL, Oral calcium suspension
- Calsure-Gold Advance Gel (Assure Biotech, Jagadhri (HR)) — Ionic calcium 10000 mg + Phosphorus 5000 mg + Vitamin D3 32000 IU per 100 g, with Pueraria mirifica and herbal extracts, Oral calcium gel
- Lactica HG (VetMed Pvt Ltd, Kolkata) — Calcium 3.256 g + Phosphorus 1.67 g + Vitamin D3 18000 IU + Vitamin B12 200 mcg per 100 mL, with herbal galactagogue, Oral calcium syrup

## Storage

Tablets / boluses: 15–25 °C, dry, protected from light. Gel bottles: 15–25 °C — shake before use.

## Before you use this dose

> **Caution:** 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

### What is the dose of Oral Calcium / Phosphorus Bolus (Calcimust) for cattle?

Reference doses for Oral Calcium / Phosphorus Bolus (Calcimust) in cattle: One 300 g bottle PO at each of: 1–24 h pre-calving, at calving, 12 h and 24 h after PO 4-bottle schedule (Milk fever prophylaxis (gel protocol)); One bottle PO immediately after IV calcium, then at 24 h and 48 h PO 3-bottle schedule post-IV (Milk fever relapse prevention); 1 bolus PO twice daily PO q12h (Daily calcium supplementation (bolus)). Confirm against the label and the patient before use.

### Can Oral Calcium / Phosphorus Bolus (Calcimust) be given to goats?

Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species (No reference dose for this species).

### What is the dose of Oral Calcium / Phosphorus Bolus (Calcimust) for buffalo?

Reference doses for Oral Calcium / Phosphorus Bolus (Calcimust) in buffalo: Gel 4-bottle calving schedule, or 1 bolus PO twice daily PO gel 4-bottle or bolus schedule (Periparturient milk-fever prophylaxis / relapse prevention). Confirm against the label and the patient before use.

### What is the withdrawal period for Oral Calcium / Phosphorus Bolus (Calcimust)?

Cattle, PO (Milk fever prophylaxis (gel protocol)): Withdrawal NOT established — treat as extra-label; Cattle, PO (Milk fever relapse prevention): Withdrawal NOT established — treat as extra-label; Cattle, PO (Daily calcium supplementation (bolus)): Withdrawal NOT established — treat as extra-label; Buffalo, PO (Periparturient milk-fever prophylaxis / relapse prevention): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Oral Calcium / Phosphorus Bolus (Calcimust) not be used?

Severe hypercalcaemia. Acute milk fever with recumbency requires IV calcium first — oral products alone are inadequate. Do not over-supplement in dry-period cows on DCAD diets.

### What are the side effects of Oral Calcium / Phosphorus Bolus (Calcimust) in animals?

Hypercalcaemia (over-supplementation) — rare; Soft-stool with prolonged use (high phosphorus load).

## Sources

- Mankind Veticura PIB 2022 — Calcimust Bolus p. 3, Calcimust Gel p. 4–5
- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.