Very interesting review of 1080 from South Africa - why NOT to use this poison by a poison specialist. Vitally the misconception about water is discussed below. 1080 Burns et al (1991) recorded decrease in intake of meat with 1080 by golden eagles (Aquila chrysaetos) and skunk (Mephitis mephitis), and increased intake in clean meat. Sminthopsis crassicaudata (an Australian marsupial) were conditioned to feed freely on meat in the laboratory, but when they were offered meat poisoned with 1080 their intake was significantly reduced and they vomited. Some of them refused to eat meat altogether even when a choice of poisoned and non-poisoned meat was provided (Sinclair & Bird 1984). Deer mice avoided eating grain with 1080 after sub-lethal dosing (Howard et al 1977). Some animals thus clearly can detect the presence of 1080 in bait and it can be assumed that jackal will be able to as well. STABILITY OF WATERY SOLUTIONS There seem to be a misconception about the stability of the poison in watery solution. This may come from authors like Atzert (1971) and Kramer (1987) with statements that 1080 degrades in watery solution. This is a very slow degradation mainly due to micro-organisms. The standard way of applying 1080 to bait in the USA as well in Australia is by dissolving the 1080 in water and injecting meat baits with hypodermic needle from the stock solution. The baits remain poisonous for months and millions of coyotes and rabbits and thousands of dingoes and feral dogs have been poisoned in this way. Toxic collars are also filled by watery solution and under different testing situations, no weakening of the poison was found for more than a year (Robinson 1948, Green 1951; Rudd & Genelly 1956; Meldrum et al 1957; Rowley 1960; Atzert 1971; McBride 1978; Connolly 1980; Hone & Pederson 1980; Sinclair & Bird 1984; McIlroy 1986; Boddicker ??; Burns et al 1988; Connolly & Burns 1990; Green 1992;). What is worrying actually is the long lifetime of the poison that remains in nature. If the bait dries out it will remain poisonous indefinitely. The intensive research by McIlroy in Australia and the relative good results are mainly because the “pests” are exotics with a relatively low resistance to 1080. The indigenous animals, however co-evolved with 1080 bearing plants and developed a high resistance to 1080 (McIlroy 1992). In South Africa, however the “pests” has a high resistance. McIlroy et al (1986) came up with various reasons why success with the capture of feral dog was better by gin trap rather than with 1080. Another big drawback of 1080 is the fact that there is no dependable antidote. This may have serious consequences for humans and non-target animals. SYMPTOMS OF POISONING Statements have been made about the symptoms of 1080 poisoning in dogs than resemble heart failure. The literature and research by Nature Conservation contradicts this statement. Symptoms differ through taxonomic groups. In general it seems like herbivores die as if in heart failure. Primates, pigs and cats show symptoms of the effect of the poison on the heart, but also severe convulsions. Dogs, however die from only the convulsions, and death is attributed to asphyxiation when the dog cannot breath due to the convulsions (Clarke et al 1981; Timm 1983) Another important aspect of 1080 poisoning is the vomiting that that poses a threat to small non-target animals. Various substances have been tested unsuccessfully to prevent vomiting. O’Brien et al (1986) found metocloprimide did not affect the frequency, although the volume of vomitus decreased in feral pigs. Rathore reported success with the same chemical but it did not prevent vomiting in coyotes (Green 1992). Boddicker? “Relative to strychnine, 1080 takes longer and coyotes experience longer periods of discomfort...” Insight in this aspect can be gained by transcription of part of one of the data pages of Grafton & Van Rensburg 1962-1964: Jackal 0.7mg/kg: took poison 14:00. 16.03 Vomited; 16.20 Vomited, reactions acute & very nervous; 16.30 Salivating very heavily; 16.35 Vomited; 16.37 Nervous spasms; 16.50 Heavy breathing and salivating 16.55 Standing erect, very weak & foaming at the mouth; 17.45 Vomited & started shivering; 17.46 Severe convulsions – leapt into air & struck the top of the cage (1.8m) and fell on its right side – extreme convulsions. Try to rise, legs crossing very stiff & shaking – eyes staring – unable to stand. Convulsions of the very worst degree, muscular tremors over entire body – apparent no control over reactions; 17.55 Breathing stopped, stiffening of limbs. Slight convulsions – slow deep breathing commencing; 17.56 Convulsions, unable to rise, limbs stiffening, breathing stopped. Slight muscular tremors; 17.57 Only head and shoulders jerking; 18.00 Very slight tremors, deep breath, stiffening, release & shivering 18.07 Convulsions & breathing stops. Head & shoulders contractions of muscles; 18.08 Deep breaths – convulsions for a few seconds then lying still as if dead; 18.09 No breathing 18.10 Slow breaths – at intervals tightening of muscles hackles rising, lying as if dead. “Greens” can cause problems – we do not need lies about symptoms and humaneness. LETHAL DOSE (LD) & DEGRADATION OF 1080 IN THE FIELD LD Figures quoted is for overseas animals like coyotes and dingoes. However a small series of tests have been done in South Africa and a summery of the results are given in the table below. Southern African animals, like the jackal developed along with 1080 containing plants and have a resistance against the poison resulting in a significantly higher dose necessary to kill them than their overseas counterparts. On the other hand figures quoted for vultures are the opposite. American vultures or condors (Cathartidae) have LDs above 15mg/kg, (Timm ed 1983) but is in a different family than the South African vultures (Accipitridae) Our vultures and almost all the other raptors belong to the Accipitridae. Our vultures are thus closer related to our eagles than to American vultures. Further the other American raptors also belong to the Accipitridae and we share some genera like Buteo and Circus for which the LD is above 10mg/kg. However we also share the genus Aquila, (America A.chrysaetos, Australië A.audax and South Africa A.rapax, A.nipalensis, A.wahlbergi and more), for which the LD is given as 1.25mg/kg. THE EXTRAPOLATION OF LD VALUES F0R RELATED GROUPS THUS CANNOT BE ACCURATE! Toxicity of 1080 was found to differ with temperature and situation (from 1.78mg/kg to 2.3mg/kg for magpies) Burns & Connolly (1992). The most extreme found to date comes from Oliver & King (1983) who found a five times higher LD for the house mouse (Mus musculus) at 24°C than at 12°C. The authors found that extremes of temperature caused the animals to be much more susceptible to the poison. This has huge implications for non-target animals as most of the poisoning will be done at very low temperatures. McIlroy (1981) demonstrated the effect of stress on LD for 1080 and concluded that some animals are to nervous in captivity for LD tests and to obtain valid figures the animals would have to be radio collard and released in free situation for proper determination of LDs. ENDS
Posted on: Fri, 16 Jan 2015 03:36:37 +0000
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