In over 20 years that I have been employed as an Inspector of Stock in several Pastures Protection Districts of N.S.W., I have often been called by stock owners and others to investigate mortality in stock and, in many cases, the deaths were due to irritant poison. It is my experience that when you reach the property the owner of the affected stock is in an agitated state of mind and invariably he blames "cyanide" as the cause of the mortality. Often as not he states that someone may have come onto the property and laid "cyanide" baits to kill opossums. I can. however, honestly state that in three hundred or more cases investigated and found to be due to irritant poisoning, I have never once been able to blame "cyanide" poisoning as the cause of the trouble.
Most of these poisoning cases are due to the carelessness and indifference of stock owners in allowing their stock access to unfenced sheep dips, railway lines (that have been treated with an arsenical poison to destroy weeds), rubbish heaps (that often include discarded paint tins and other forms of irritant poisons).
It is not unusual upon arrival at the property to discover that the stock owner thinks that, a Stock Inspector, by gazing at a dead animal or even by holding a post mortem on such an animal, can tell the owner immediately what poison it was killed the animal.
As a general rule it is advisable for a Stock Inspector to obtain from the stock owner all the history available prior to the death of such animals before he conducts a post mortem. He should point out to the stock owner that any one of very many irritant poisons may have killed his stock, and that if any specimens were to be submitted to the Research Station for analysis, it was clearly necessary that certain poisons suspected should be named. Just fancy submitting a morbid specimen to the Glenfield Research Station with a memo. stating: "Please examine these specimens for some irritant poison" To put the matter lightly, an Inspector doing this would deserve a severe rap over the knuckles.
I make it a rule when I arrive at a property where a mortality has occurred, due to irritant poisoning, to first obtain from the stock owner complete history of the stock for sometime before death. Then to make a survey of the outbuildings, stock yards, sheep dips, and even enclosed buildings that may have a door open which would allow quiet stock access thereto. If possible, I also obtain footprints of stock leading to such places as unfenced dips, rubbish heaps, etc., and make a search to find any evidence of irritant poisoning, such as arsenic, in any of the places mentioned above. It will give an inspector of stock a line to go on when he eventually conducts his post mortem and submits specimens for examination to the Research Station.
If criminal intent is suspected for poisoning of animals, an inspector should advise the owner to secure a Police Officer before conducting a post mortem. After the Police Officer's arrival at the property, the inspector may proceed with the post mortem. The main reason for this is, that if litigation follows, the Department will not undertake examination of the specimens at the Research Station. Also, it saves involving the Department in such litigation. The specimens obtained from the dead animal should be handed to the police and, if the owner so desires, duplicate specimens may be handed to him as a control. The police officer then takes the matter up with the Government Analyst on behalf of the owner.
To further explain the foregoing information, I herewith give a few examples of irritant poisoning of stock that I have investigated.
One Saturday, all animals at a slaughtering yard were apparently in perfect health, but on the Sunday following, 14 pigs and a dairy cow were found dead. The owner reported the matter to me on the Monday but I was unable to investigate the matter of mortality until the Tuesday.
On arrival at the slaughtering yard, reasonably early on a winter's morning, I found the owner, and two of his assistants, waiting for me to tell them what had killed the pigs and cow, and the owner requested me to examine the carcases straight away. However, I told him that I would not do this until I got some history of the matter, and an examination had been made of old rubbish heaps, discarded tins, etc., around the piggery.
In the course of general conversation he told me that he suspected cyanide poisoning. Promptly I asked the owner if he suspected any person of poisoning his stock, or did he see any dead opossums or baits in the vicinity of where the pigs and cow were found dead. His reply was "No." Ultimately I asked him if there were any other buildings or old yards within the slaughtering paddock, which, I might add, was an area of 500 acres. He replied: "Yes, there is an old building over that hill." "I think we had better make an inspection of that building, I suggested, and he said "Why not examine the dead pigs first."
However, we walked up over the hill to the old building, and the whole surroundings about this old house were in a state of chaos. I felt quite confident that the cause of mortality was to be found somewhere near this building. The owner and his assistants commenced to pull out old bags, dirty tins, etc., from under the house and from within the house. I made an inspection of a rubbish heap some little distance from the building, and, having a stick in my hand, was involuntarily touching the ground with it. Suddenly, I noticed a smoking material oozing from the point of the stick. I smelt this and immediately detected Phosphorus. On looking about the ground I noticed a tin branded "S.A.P.," also tracks of the pigs and cow around this stained earth. I called the owner and said to him: "How did this tin of S.A.P. get here?" He replied, "I can now tell you the whole story. Two rabbiters were camped in this building with my permission, and I noticed after they left a tin of S.A.P. on that post. Evidently the wind blew the tin onto the ground and the pigs and cow licked the stained phosphorus earth." My post mortem examination of the pigs and cow revealed, of course, phosphorus poisoning.
I take no credit for solving this mortality. I consider that the owner should have been more observant and could have solved the matter for himself, without bringing a Stock Inspector 60 miles from his headquarters to solve the case for him.
On another occasion I investigated a case of mortality in calves. On arrival at my destination, I asked the owner what he suspected had killed the calves. He replied: "I have a neighbour here who is unfriendly towards me and I suspect that he poisoned my calves with "cyanide." We made an examination of the paddock where the calves and their mothers had been running, but, apart from finding some old rubbish, such as discarded paint tins, nothing of a poisonous nature was to be seen.
On making an examination of the calf pen and cow bails I noticed a petrol tin just overhead, hanging above the calf pen. I also noticed some dark material oozing slowly from the bottom of it. Pulling the tin down we found six tins of S.A.P. poison. The S.A.P. tins inside the petrol tin had corroded and the calves that died were just able to lick the bottom of the petrol tin and, of course, were poisoned.
I asked the owner how long the petrol tin had been hanging in that spot and he replied. "About two years." I then said: "Did you know there were tins of S.A.P. poison in it," to which he replied: "I forgot all about them." The writer then said to the owner: "I cannot understand a man milking his cows every day and not being observant enough to make an examination of such an object as a hanging petrol tin just above his head and, further, I cannot understand why you would rashly blame your neighbour for poisoning your calves without first making some preliminary examination of your yards and nearby paddocks."
An owner reported by telephone that one of his cows had died, and another was very ill. He suspected "Pleuro." Questioning him as to whether any Queensland cattle had been in contact with his cows, he replied: "I bred these cows, and have not had any outside cattle on my holding for years."
On arrival at the owners' property. I found one cow very ill, and she no doubt showed some of the symptoms given in text books consistent with "Pleuro." The owner told me that he used to graze his cows in a paddock of about 500 acres adjacent to the bail where he milked them, and that he put them back into this 500 acre paddock immediately afterwards. Also that if the cause of the trouble in his cows was not due to "Pleuro" he thought it must have been a case of "cyanide" poisoning.
I asked him if he had been treating any timber with arsenical preparation in the paddock referred to, or was there any old arsenic mines or rubbish heaps in that paddock, to which he replied "No." I then said to him: "Get two horses and we will ride that paddock." He sent his son away to get the horses, but during his son's absence we walked towards the shearing shed, and I noticed the gate leading into the yards was open. On looking on the ground, I noticed the tracks of cattle entering the yards. Walking down to the bottom of the yard and following the track, I found the earth stained a yellowish colour, also there was a circular hole in the earth where something had been licking.
I asked the owner "How did that earth get stained?" and he replied: "I was drenching some sheep here a few days ago with an arsenical drench. I discarded the drench that I did not require for the sheep in these yards." I told him I was now quite satisfied that the cows had been poisoned with an arsenical preparation, and I further said to him, "I thought you milked your cows and put them straight back into that 500 acre paddock." "Oh!" he said, "I forgot to tell you that I bring the cows and their calves down each night and take the calves off the cows and place them in their pens, and let the cows remain in the small paddock where these yards are." So his first statement was conflicting.
Many other similar cases have been investigated.