Local Anaesthetic & Numnuts
The Pain Relief
Numnuts uses fast-acting local anaesthetic addresses the immediate acute pain that follows ring marking.
Caused by the initial restriction of blood circulation (‘ischemia’), this reaches a peak at around 15 minutes after ring application. Studies show that lambs experience the most intense pain 15-45 minutes after ring application, when the initial restriction of the blood supply causes pain to rise to its peak level.
Why Local Anaesthetic?
30 years of veterinary research carried out in New Zealand, Australia and the UK has identified injectable local anaesthetic as the preferred solution for pain relief during castration and tail docking with rings. It provides fast acting pain relief in the first 45 minutes, when lambs experience the most acute pain caused by the loss of blood flow.
Local anaesthetics are very fast acting and block this pain.
Not all pain medications are the same. The majority of pain relief products are analgesics (NSAIDs), in the same family as the human medication ibuprofen. These address the secondary, chronic inflammatory pain. Injected or given orally, these only start working after 20-30 minutes and reach full potency at one hour. It is, however, possible to use local anaesthetic in a combined approach with an analgesic, meeting industry guidelines for best practice.
Local Anaesthetic effectively blocks nerve signals during the acute pain period in the first hour after marking. After this time, the ring has largely disabled nerve function, and the lamb’s pain decreases. This is when the chronic inflammatory response begins.
Local Anaesthetic Legislation
The rules around using local anaesthetics for castration and tail docking vary around the UK.
Farmers in Scotland can legally use Numnuts for castrating or tail docking lambs up to 12 weeks old, provided an anaesthetic is administered.
This innovative method minimises the pain and distress typically associated with traditional rubber ringing procedures. Scottish legislation allows this practice up to 3 months, ensuring adherence to animal welfare standards and providing a compassionate alternative to older methods. Read more here
Unfortunately, the current legislation in England and Wales is more restrictive, with rubber rings for castration or tail docking being prohibited on lambs older than 7 days. We understand this is under review by Defra, along with potentially removing the ban on using lignocaine on UK sheep by the VMD.
We have asked Defra for a timescale for harmonising legislation across the UK; Defra cannot provide this. They are currently consulting on the issues. Read more here
Buying Local Anaesthetic
Local anaesthetics are classified as POM-V medicines (prescription only veterinary medicines)
and must be bought directly from your vet.
Your Veterinarian will be able to supply you with local anaesthetic in 100 mL bottles. There are currently 2 types of local anaesthetic registered for sheep in the UK:
- Procamidor Duo (Richter Pharma)
- Pronestesic (Fatro S.p.A)
A standard 100 mL bottle of either of these will fit the Numnuts Bottle Mount. Numnuts dispenses a calibrated 1.5 mL dose, therefore each 100 mL bottle dispenses 65 doses.
If your vet is a Numnuts stockist, they can also supply you with Numnuts hardware and spares. If you are a vet and would like to become Numnuts stockist, register here.
Please keep in mind: a vet requires a bona fide professional relationship with you to be able to prescribe local anaesthetic for your flock.
