PAPP bait; much more humane than the RSPCA - less humane than a bullet in the chest

August 3, 2017

Oh dear. Things are not going great for the Threatened Species Commissioner and his plan to kill two million cats by 2020.

Firstly, the Australian government’s cat population estimates out by tens of millions, meaning there may not even be two million cats to kill. Even on a good day.

While his beloved cat poison, Para-amino-propiophenone (short name ‘PAPP’), seems to be causing him nothing but headaches (or is that the 1080 tea?).

“PAPP isn’t a ‘toxic’ chemical like mercury, lead, dioxins or banned poisonous pesticides" ~ Gregory Andrews: Threatened Species Commissioner

There were two main selling points for Curiosity® cat bait;

1) Addressing growing public concern about animal welfare about 1080’s use, with the RSPCA calling the poison “inhumane” it promised a "humane" alternative, and...

2) With well-known issues of pets and working dogs being killed by the baits, and with the TSC promising this bait would be so safe it could be thrown "off the backs of Toyota LandCruisers" in peri-urban areas, the promise of an antidote was presented as a huge benefit to this new lethal, drug to keep it only killing the animals it was supposed to and not people's pets.

How did the antidote work out?

The manufacturers reassured us that in event of accidental poisoning, that we can simply use the antidote - Methylene Blue - with “... full recovery usually occurring within 1hr”.

In addition the IA-CRC is working to supply an injectable antidote of methylene blue, to be called “BLUE HEALER®” which can recover a working dog even if near death. 

However, even at the start, veterinary literature was not so rosy about the chances of success.

“... Decontamination of the gastrointestinal tract is unlikely to be effective given the rapid absorption of PAPP. Supplemental oxygen is recommended. Methylene blue is the first line antidote, but should be used with caution, if at all; many consider this therapy unsuitable for cats. Whole blood transfusion is recommended. Prognosis in accidentally poisoned domestic species is likely to be ‘guarded’.”

Pets who ingest this poison either accidentally, or through foul play are at extreme risk of death. If the pet is a cat, it is almost certainly dead.

And that was rapidly reflected the literature;

We feel that, given the initial publicity around the antidote and a widely held conception that it was cheap, readily available and effective, that it is necessary to better explain the strengths and weakness, now that we have a better understanding of the IA-CRC work and the implications from the testing results.
Animal Control Technologies website

In that mostly, it doesn't work.

But at least PAPP is humane, right?

The ‘humaneness’ of a pest animal control method refers to the overall welfare impact that the method has on an individual animal. A relatively more humane method will have less impact than a relatively less humane method.

All humane killing techniques end up with an animal being you know - killed to death - but at least it's humane, right.... right?

A model for assessing the relative humaneness of pest animal control methods (Sharp and Saunders, 2008) has been developed under the Australian Animal Welfare Strategy (AAWS). This model has been used to assess the humaneness of a variety of methods used to control pest animal species in Australia.

Lovely. Let's go!

On the Y-axis is "welfare impact prior to death" and on the X-axis is "mode of death".

Being shot in the head is pretty "humane" (2,A)

While getting shot in the chest (which I dunno, seems not that humane, but science!) is a (2,B)

1080 - a known horrific suffering death - is a respectable 1,D... ok... a sliding E

Understood. Okay, so we're ready for some PAPP humaneness.

Okies - some things have changed a little here.

Shooting a cat in the head is more humane than the baseline standard. Somehow. (1,A)

Shooting a cat in the chest is also more humane, somehow (C, 1)

(At this point do you have to ask, are cats not animals? Because somehow this "science" says they suffer less as compared to the baseline standard of being killed)

Being shot in a trap - unsurprisingly - is extremely traumatic with medium levels of suffering at death (4,B)

(Which should probably highlight what practically every trapping-killing non-urban council is currently doing as extremely inhumane)

While being captured in a trap, transported and being issued a lethal injection is basically the most inhumane option for a cat, according to this research (5,D or bright, bright red!)

(Oh, hello! You can find the RSPCA, who's primary cat management technique is trap, hold and "humane" injection "joining forces" with the Threatened Species Commissioner here. So that's turned out well then. Reap, sow, karma)

So now we know what isn't "humane" according to the poison manufacturing, cat killing, for profit, government funded Pest-Smart scientists. What is "humane" then?

Curiosity® of course! 1,C... sliding D

Well that's ok then. Except, that the new Curiosity bait is struggling to outperform 1080 for "humaneness". And we know 1080 is horrendous, so its a pretty freaking low bar.

How do cats poisoned with PAPP actually die?

During the period from collapse to insensibility, when poisoned animals are incapacitated, they are potentially vulnerable to a range of welfare impacts such as predation, injury, exposure to extremes of temperature and distress resulting from not being able to perform normal behaviours. The longer this period of vulnerability the more severe the welfare impact prior to death.

With PAPP, insensibility only occurs just prior to death and the period from collapse to death can be highly variable.

Read that again for effect

"... insensibility only occurs just prior to death and the period from collapse to death can be highly variable."

Animals are conscious right up until they are finally dead.

And the period from when they are collapsed and immobile (vulnerable and stressed) is "highly variable". How variable?

After a cat has ingested a bait containing PAPP there is a lag period before signs of toxicosis such as head nodding, lethargy, ataxia (uncoordinated movement and difficulty maintaining balance), salivation and sometimes vomiting are observed. As the toxicoses progresses, cats collapse and cannot move voluntarily. They appear unresponsive, but still show signs of awareness until they become unconscious for a short period just before death

The duration of the lag phase, duration and severity of symptoms and time to death can be highly variable. 

In a pen study of 31 feral cats that ingested 78mg PAPP baits, the average time from bait consumption until signs of poisoning was 3 hours 51 minutes (range 43 minutes to 15 hours). 

The average time from onset of symptoms to collapse was 72 mins (range zero to around 5½ hours) and the average time from collapse to death was 107 minutes (range 30 minutes to around 8 hours).

So this bait can go either relatively well, or terribly for the animal involved. Feeling deathly ill, to actual death, can range from 43 minutes to 15 hours.

The period from collapse to insensibility which is identified as a time where an animal is conscious and aware, but unable to defend itself or move voluntarily, can be anything from 30 minutes, to 8 hours.

A poison which leaves an animal immobilised, but conscious and slowly dying for anything up to 8 hours. Super humane you guys!
Suffering – The lag period is likely to be associated with minimal suffering, however after the onset of clinical signs when cats cannot coordinate body movements it is likely that they will experience some distress, confusion and anxiety as they cannot perform normal behaviours (e.g. standing, moving, feeding, drinking, defensive and escape behaviours). Lethargy and weakness are also potential sources of distress. In addition—during the later phase of toxicosis when cats are unable to move but are still conscious—if they were not able to seek appropriate shelter prior to becoming incapacitated, they are at increased risk of predation (e.g. from crows, other predators), aggression (e.g. from dogs, foxes, other cats) and environmental exposure, which could lead to further distress and suffering.

And we know how it feels to suffer these fatal symptoms directly, thanks to the same symptoms being seen in humans...

- Methaemoglobinaemia is the state of excessive methaemoglobin in the blood

- methaemoglobin is an altered state of Hb where ferrous ions (Fe2+) of haem are oxidised to the ferric state (Fe3+) and rendered unable to bind O2

- normal level is < 1.5%


- In human cases of methaemoglobinaemia, ‘chocolate brown' blood and clinical cyanosis are seen at methaemoglobin concentrations of 15 to 20%, but there are usually no symptoms at this stage. 

- When concentrations fall between 20 and 45%, dyspnoea, fatigue, lethargy, dizziness, headache and occasionally syncope (fainting) occur. 

- At concentrations between 45 and 55% there is a reduction in the level of consciousness and 

- with concentrations of 55 to 70%, oxygen-carrying capacity is reduced sufficiently to cause major hypoxic symptoms. Circulatory failure, cardiac arrhythmias, seizures and coma may then be seen. 

- With greater than 70% methaemoglobin, there is a high incidence of mortality.

In other words, death by Methaemoglobinaemia sucks. It might be a better death, than death by spasm ala 1080, but it is still a sucky death by any scientific measure of a sucky death.

According to veterinary literature, the symptoms of PAPP poisoning include;

  • nausea & vomiting
  • (behavioural) depression
  • exercise intolerance
  • elevated respiratory rate
  • elevated heart rate
  • incoordination
  • tremors and,
  • haemorrhage from body orifices

Which could roughly described as ‘an animal experiencing the ordeal of being poisoned to death’ and certainly not anything we would want to happen to our own pets. And given what we know about the history of such things, things tend to be deemed less humane over time, with new research and measurement techniques. To start at such a humanely-dubious place for a new poison seems unethical at best.

To declare it "humane" simply because it is less not-humane that the poisons currently used by government now, is absurd. And it is a horrible future to inflict on 2 million animals simply because they're born one species, and not another.


PestSmart Humaneness Assessment

See also on Saving Pets

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