Application for approval to manufacture ESN containing sodium - - PowerPoint PPT Presentation

Application for approval to manufacture ESN containing sodium nitrite and a bait containing sodium nitrite to be used as a

Vertebrate Toxic Agent for the control of

brushtail possums (Trichosurus vulpecula) and feral pigs (Sus scrofa)

Application context

• It is clearly stated in our EPA application that in our opinion

the majority of use for this bait will be for possum control

• Sodium nitrite an additional tool for possum and feral pig

control not an outright replacement for current methods

• Sodium nitrite and PAPP have been developed as new

toxins, both have the same mode of action and the same antidote

• PAPP registered for stoats and feral cats but not toxic to

possums; hence the complementary development of a sodium nitrite bait

Speakers

• Lee Shapiro – Connovation Ltd
• Dr Alastair Fairweather – Department of Conservation
• Nick Hancox – Animal Health Board
• Jack Craw – Auckland Council

Connovation Ltd Background

• Manufacturer of pest control products for 18 years
• Commercial products for controlling vertebrate pest

species: possums, rodents, mustelids (stoats, ferrets and weasels) and wallabies

• A focus on low residue and humane toxins
• Registration of PAPP - a new toxin - for stoat and feral cat

control 2011

Overview

Possums and feral pigs Impacts

• Native biodiversity
• Possums known TB vector
• Pigs implicated transmission of PTA

Limitations current control

• Possums -brodifacoum, 1080, cyanide
• Lack antidote or complex treatment
• Anticoagulant residues
• Anticoagulants low welfare ranking
• Feral pigs - Hunting
• No registered pig toxin

Sodium nitrite

• NaNO2
• Common food preservative
• Cereal paste 100g/kg SN
• Reduces oxygen transport

Benefits

• Non persistent in environment
• Sub-lethal doses rapidly eliminated
• Non persistent in poisoned animals
• Very low risk secondary poisoning
• Effective antidote
• Relatively humane

Impacts of possums and feral pigs

• Possums and feral pigs

Impact and cause damage to:

• Native biodiversity including rare native plants, frogs,

lizards, invertebrates, birds and their eggs

• Pasture, crops and young plantation trees
• Native forest regeneration
• Possums
• Known vector for bovine tuberculosis (Mycobacterium bovis)
• Feral pigs
• Pigs implicated in spreading kauri dieback disease

(Phytophthora taxon agathis)

Limitations of current control

• Possums
• Commonly controlled with anticoagulants, 1080, cyanide and

trapping

• Lack an antidote or complex treatment required for accidental

poisoning

• Anticoagulant residues can accumulate in sub-lethally poisoned

animals and also cause secondary poisoning

• Anticoagulants have highest relative impact on welfare of all VTAs

registered for possum control

• Withholding periods exclude hunters from blocks indefinitely
• 3 years recommended for 2nd generation anticoagulants
• Restrictions on use e.g. brodifacoum not allowed on DoC estate

Limitations of current control

• Feral pigs
• Controlled by hunting with and without dogs and from a helicopter

as well as trapping

• Currently no registered toxin for feral pig control in NZ
• No current method for rapid knock down in the case of a disease
• utbreak e.g. foot and mouth
• Certain areas where hunter access is not permitted or possible for

pig control I. Public spaces where firearms or hunting not permitted II. Areas where risks to certain species e.g. Kiwi from pig dogs III. Areas with sensitive terrain e.g. Sensitive geothermal features IV. Private farms/properties that do not want hunters

The Application

• To manufacture ESN containing sodium nitrite at 950 g/kg and

a bait containing sodium nitrite at 100 g/kg to be used as a Vertebrate Toxic Agent

• Shown to be effective at controlling possums and feral pigs
• Baiting will be in bait stations
• Baits will be coloured green or blue
• Permission needed to use on DoC land

The Application

• Sodium nitrite paste bait will provide a safe, low residue

and humane toxin for possum and feral pig control

• Will provide market choice with another control tool
• Response readiness as no registered feral pig toxin
• Control of possums using sodium nitrite baits will

increase access to certain areas for hunting

Sodium nitrite (NaNO2)

• Common food additive - preservative in bacon, ham and

salami

• Toxic in higher doses
• Reduces the ability of red blood cells to transport oxygen
• Added to a cereal paste bait for possum and feral pig control
• Time to death approx. 1 -2 hours for possums and feral pigs

Sodium nitrite

• Not persistent in the environment
• Sub-lethal doses quickly eliminated
• Not persistent in poisoned animals
• Very low risk of secondary poisoning
• Effective antidote exists
• Relatively humane

Not persistent in the environment

Sub-lethal doses quickly eliminated

Not persistent in poisoned animals Very low risk of secondary poisoning

Group Compound Half-life values Likely persistence of residues after sub-lethal exposure 1

Cyanide Sodium nitrite 1080 + <60 minutes <11 hours 12-24 hours <12 hours 7 days

2

Pindone 2.1 days 4 weeks

3 Cholecalciferol 10-68 days 3 months 4 Brodifacoum 130-350 days 24 months or longer

+ = No published value but likely to be <12 h based on published information on sodium nitrite Table adapted from Eason et al 2008 Proceedings of 23rd Vertebrate Pest Conference

Effective antidote exists

• Veterinarians are familiar with nitrite or nitrate poisoning in

grazing ruminants

• Active growth of plants after rain following dry or drought

conditions can lead to nitrate or nitrite poisoning

• Symptoms will include cyanosis, ataxia, unconsciousness and

death in untreated animals.

• Animals are treated with an injection of methylene blue and

recover rapidly

• Trials undertaken to determine the efficacy and welfare
• f pigs poisoned with sodium nitrite paste bait
• Poisoned pigs observed by Dr Cristin Dwyer (BVSc) of

Selwyn Rakaia Vet Services

• “ After ingesting sodium nitrite baits pigs became pale

and ataxic” (Lacking motor co-ordination)

• “In my opinion the sodium nitrite caused a rapid death

with little distress signs evident from the pigs”

Relatively humane

Information extracted from Gregory et al (1998), O’Connor et al. (2003 and2007), and Littin et al (2000, 2002, 2009)

Group Compound Symptoms Mean duration symptoms Mean time to death Relative degree

• f suffering

1

Cyanide

Un-coordination, Mild or moderate hyperpnoea, Loss of response to handling (indicator of unconsciousness) Convulsions

6.5 min 17.9 min Low

2

Sodium nitrite Pale nose extremities, vomiting, blue

tongues, lethargy, ataxia, slight tremors collapse and death.

1 hour 1.5 hours Low

3

1080

Changed appearance , Retching, Vomiting Unsteady head movements & walking Minor tremors or spasms , Prolonged lying, prostrate (>2 hours)

9.5 hours 11.5 hours Intermediate

4

Cholecalciferol Reduced activity, Rapid breathing, Reduced

feeding, weight loss, Prostration Mineralisation in organs , Lung pathology Unconsciousness (just prior to death)

7 days 9 days High

5

Brodifacoum

Changed appearance, Reduced feeding Diarrhoea, minor; abnormal breathing, shivering, tremors spasms, un coordination Haemorrhages, Prolonged lying, Loss of response to handling & palpebral reflex

7 days 21 days High

Support for the application

• The Department of Conservation
• The Animal Health Board
• Auckland Council
• Regional Council support:

Northland, Environment Southland, Hawkes Bay, Tasman, Greater Wellington

• Community Landcare groups:

Whangarei Heads Landcare Forum and Whareora Landcare Group

Support from Landcare Groups

• “There is a great need for effective pest control tools

to protect biodiversity, primary production, disease management and the economy.”

• “Sodium nitrite is a leap forward in the development
• f acceptable pesticides.”
• “Feral pigs an indirect but major cause of adult kiwi

deaths through pig hunting dogs. Use of sodium nitrite will allow Northland communities to remove feral pigs from areas with significant kiwi populations and avoid deaths of this nature.”

• Table taken from ‘How humane are our pest control tools’ MAFBNZ

2010

• Numerical scores from 1 – 8 assigned as a combination of welfare

impact scores and the duration of the welfare impact(s)

• The higher the score the higher the overall welfare impact

Species 1080 Cyanide Cholecalciferol Brodifacoum Pindone Phosphorus Zinc Phosphide PAPP

Sodium nitrite Possum

6

4

8 8 7.5 6 6 Rodents 6 7.5 NDD Stoat 6.5 (NT) NDD/NT

5.5

Ferret 6.5 (NT) 7.5 (NT) NDD/NT Feral cat 6.5 7.5 (NT)

5.5

Rabbit 6 8 NDD

Pig

6.5 (NT) 7 5.5

Deer NDD/NT Wallaby 5.5 (NT) NDD