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Chronogest Sponges
Pack of 25 sponges

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  • Applicator £13.00
  • Pack of 25 sponges £85.49

Selection of 2 products from

£13.00 to £85.49


This is a prescription hormonal treatment used to control the time of ovulation in farm animals.

The sponges are often used in conjunction with a PMSG injection available from VioVet. (Click on the link to see it.)

Need help or advice? Contact us:

  • Landline: 01582 842096
  • Mon - Fri: 8:30am - 5:00pm
  • Sat: 9:00am - 1:00pm (Collections only)
  • Email: [email protected]

All prices include VAT where applicable.

Medication Datasheets

Pack of 25 sponges

Chronogest CR 20 mg controlled release vaginal sponge for sheep

Qualitative and quantitative composition

Each polyester polyurethane sponge contains

Active substance(s)

Flugestone acetate, 20 mg.

List of excipients

Excipients qsp 1 sponge.

For a full list of excipients, see section “Pharmaceutical Particulars”.

Pharmaceutical form

Vaginal sponge.

White cylindrical polyester polyurethane foam equipped with string.

Clinical particulars

Target species

Sheep (ewes and ewe-lambs)

Indications for use

In ewes and ewe lambs, in combination with PMSG (Pregnant Mare Serum Gonadotrophin)


Please refer to sections “Use during pregnancy” and ”Interactions” below.

Special warnings for each target species


Special precautions for use

Special precautions for use in animals

Operator warnings:

Adverse reactions

A muco-purulent discharge may occasionally be observed at sponge removal. It is not associated with clinical signs and does not alter fertility.

Use during pregnancy, lactation or lay

Can be used during lactation.

The use is not recommended during gestation.


The sponges should not be used in conjunction with alcohols, cresols, phenols, sheep dips or similar disinfectants.

Amounts to be administered and administration route

The dose is one sponge per animal irrespective of body weight, breed, type (dairy or meat) and season.

The sponge is inserted intra-vaginally using an applicator.

Duration of sponge residence is 14 days. At the end of the administration period, the sponge is gently removed by pulling on its string.

To obtain an optimal synchronization of ovulation, an intra-muscular injection of PMSG (range 300-700 IU) is recommended (i.m.) at the time of sponge removal.

In case fixed time artificial insemination is applied, it is recommended to perform it 55 h after sponge removal.


A five time overdose of flugestone acetate (100 mg/sponge) did not result in observable side effects.

Withdrawal periods

Meat: 2 days after withdrawal of sponges.

Milk: zero hours, including the treatment time.

Pharmacological particulars

Pharmacotherapeutic group: progestagen

ATC vet code: QG03D.

Pharmacodynamic properties

Flugestone acetate is a synthetic analogue of progesterone. It is approximately 20 fold more potent than progesterone and displays progestational activity but no anti-progestational, anti-androgenic or androgenic properties together with a low glucocorticoid activity.

Owing to its binding to the progesterone receptors, flugestone acetate acts by negative feedback on the hypothalamo-pituitary axis, suppressing pituitary release of gonadotrophins and therefore terminal follicular growth and ovulation.

Pharmacokinetic properties

Flugestone acetate is readily absorbed during the 12-14 days period of intra-vaginal administration. Tmax ranges between 8 and 24 h, whereas Cmax varies between 1.4 and 3.7 ng/ml. Steady state is reached quickly following onset of the treatment. Plasma cronolone concentrations are relatively constant throughout treatment. One day after removal of the Chronogest CR, flugestone acetate concentrations have dropped below the limit of quantification (LOQ = 0.04 ng/ml).

Flugestone acetate is metabolised into hydroxylated metabolites, which are excreted in faeces and urine.

Pharmaceutical particulars


Hydroxypropyl cellulose, 20 mg.

Polyethylene glycol, 20 mg.

Major incompatibilities

None known.

Shelf life

Shelf life of the veterinary medicinal product as packaged for sale: 36 months.

Special precautions for storage

Store below 25 °C in a dry place.

Store the product in its original immediate packaging.

Once packaging is opened, any unused product should be discarded.

Immediate packaging

Bags made of polyester/ aluminium/ polyethylene containing 10 sponges, 25 sponges or 50 sponges.

Not all pack sizes may be marketed.


Any unused veterinary medicinal product or waste materials derived from such veterinary medicinal products should be disposed of in accordance with local/national requirements.

Marketing Authorisation Holder (if different from distributor)

Intervet International BV, The Netherlands

Marketing Authorisation Number

Vm 06376/4042

Date of the first authorisation or date of renewal

21 June 2005

Date of revision of the text

August 2014.

Any other information

For animal treatment only. Keep out of the sight and reach of children.

Legal category

Delivery Information

How quickly do you deliver?

Under almost all products on our website is an Estimated dispatch time, check this for a delivery prediction specific to the item you are looking to purchase. These badges are updated live based on the stock levels we have and also those of our suppliers - so are usually very accurate, but cannot be guaranteed. In more general terms, we aim to dispatch all orders within 1 working day of receiving payment (and a prescription if required). If we cannot do so within 3 working days we will contact you by email.

What do you charge for delivery?

For UK delivery, we charge the following:

Order Total Weight Delivery
£0-£28.99 Under 2kg £2.99
2kg+ £4.99
£29-£38.99 Under 2kg Free
2kg+ £4.99
£39+ Under 2kg Free
2kg+ Free

Prices quoted are for delivery to all parts of mainland UK except certain Scottish postcodes (where the price is higher for items sent by courier. Delivery of food abroad (including Channel Islands, N. Ireland and other islands around the UK) is charged at a higher price and free delivery is not available. Temperature controlled products are also not always subject to the standard and/or free delivery options.

For full information on our delivery charges, including prices on heavy deliveries to Scotland and abroad, see our delivery information page.

We can deliver most items to all around the world, but prices do vary. To find the exact cost of shipping your item, and to see all options available, follow these steps:

  1. Put the items you wish to order in your basket
  2. Proceed to checkout and enter your delivery address, including country
  3. Delivery information including price will automatically update to what is available to you

Delivery of aerosols

Due to restrictions aerosols can't be sent by Royal Mail. We appreciate your understanding.

Delivery of temperature controlled items

Some products, such as non-ambient items and frozen food, need to be delivered in insulated packaging to prevent them from getting too warm (or too cold) during transit from us to you. Purchasing any of these items in your order will result in a £1.99 charge being added to the total to cover the high cost of the insulated packaging materials. You only pay the £1.99 once per order, regardless of how many temperature controlled items you purchase in that order.

How do I cancel or return an order?

Please call us as soon as possible if you need to amend or cancel an order on 01582 842096. If your order has been processed for dispatch we will be unable to cancel or amend the order. You will however be able to return your product for a full refund*.

To return an item, you must contact us by phone or email to arrange this BEFORE posting any product back to us. We will explain the process at this stage for you.

*For full details on returns, see our terms and conditions page.


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