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This article was published in 1953
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
Pleuro-Pneumonia Contagiosa
FIEID CONTROL OF A MAJOR OUTBREAK IN 1952
E. SCOTT ROGERS, B.V.Sc., Inspector of Stock, Deniliquin and Jerilderie
PART 1 — RIVERINA
Introduction
The outbreaks of Pleuro-pneumoma in N.S.W in 1952 were so extensive and so serious that they almost brought to a standstill the normal flow of cattle from Queensland through N.S.W. into Victoria. This was not due to any restrictions imposed by the authorities of any State on the movement of cattle other than those directly involved in outbreaks or their contacts, but by the suspicion in which all cattle, particularly Queenslanders, were held by all buyers and landowners generally. The fact that cattle have to remain in N.S.W. for six months prior to entry into Victoria means that agistment has to be obtained for them after entry into this State. After the initial outbreak of P.P.C. this was almost unprocurable although the number of cattle actually quarantined and tied-up was a comparatively small percentage of the normal movement and trading activity. The Victorian Border well might have been closed with the extensive outbreaks along its length but it was most gratifying to know that the Victorian authorities considered that disease control measures in N.S.W. were sufficiently good to warrant leaving the Border open and thus allowing normal trade to continue. Victoria is supplied largely with cattle from Riverina Districts and any closure of the Border would have had serious consequences, both to the Riverina and to Victoria.
When pleuro outbreaks occur in the Riverina the normal restrictions placed on the movement of cattle into Victoria become a serious obstacle in dealing with contact and outbreak cattle; and in some cases are anomalous.
Due to the prevalence of the disease in the Deniliquin and Jerilderie Districts, landowners decided to reduce the risk of infection and to dispose of their cattle as rapidly as possible from August onwards; and for the six-monthly period 47,600 cattle entered Victoria compared with last year's figure of 24,600. This must have given Victoria many qualms but their only reaction was a request that Schedule A be issued with greater care and in more detail; and that the history of the cattle should be known for the preceding six months.
By February, 1953, most of the pleuro cattle had been disposed of, all holdings had been released from quarantine and trade was back to normal, with pleuro virtually forgotten.
Field Control
Field control of P.P.C. involves a senes of activities which must be fully co-ordinated; all Veterinary Officers and Inspectors of Stock must work together at maximum capacity and the Department must be prepared to move all available officers to the outbreak areas; leading, of course, to a virtual cessation of normal duties. The first essential step, of necessity, must be the early diagnosis of the disease and this in nearly every case should fall on the Inspector of Stock.
In the Riverina on 1/8/52, McCulloch of the Hume District inspected three steers on the Jingellic-Tumbarumba road these having been dropped from a mob of cattle owned by S. and purchased in the Wagga saleyards on 2nd July. All were showing symptoms of P.P.C. and they were destroyed. On post-mortem this diagnosis was confirmed and specimens were collected and forwarded to Glenfield; an action which must be taken in all cases oi P.P.C. to avoid legal complications. These three steers came from a mob which was paddocked at C.'s and in which subsequently 25 deaths occurred in a mob of 57. The balance of S.'s cattle had moved on to Jingellic, and were dealt with there. In this mob it is interesting to note that the first death occurred fourteen days after vaccination and the last at 130 days.
That early diagnosis started the ball rolling. The D.V.O. was notified immediately, checked the origin of S.'s cattle and found that they had been purchased in the Wagga saleyards on 2nd July; the majority from M. and N. These had come out of a protected area for P.P.C., but seventeen Hereford steers had been purchased from G., and these had crossed into N.S.W. from Queensland on 23rd June, 1951 (note the year). One of the steers destroyed by McCulloch was identified as one from this mob.
From this point most of the details given will refer to the Deniliquin-Jerilderie Districts and should show a typical example of control measures as instituted by the District Veterinary Officer and Inspector of Stock in an outbreak area.
On the 2nd August, one day after the disease had been diagnosed, the D.V.O. notified the writer that a possible pleuro mob of cattle was walking towards Deniliquin for sale on the 5th. These were owned by G., who had owned another mob purchased by M. of Finley. On the same night the agent handling G.'s cattle was instructed to hold them on the stock route north of the river and not to offer them for sale; whilst M. was told to hold his on his property. On 5th August instructions were received to vaccinate and Quarantine both mobs; the necessary vaccine and syringes being forwarded by air freight.
On the same day the D.V.O. had sent out a preliminary but comprehensive report to the C.D.A.I., D.V.R. and all Inspectors involved. This gave the movements and brief history of G.'s cattle prior to the Wagga sale. As additional information was collected further reports were submitted and all Inspectors were duly notified of the over-all developments. At the same time, Inspectors were submitting detailed reports of their own outbreaks to the D.V.O., both by 'phone and letter. A complete list of all sold and unsold cattle ex Wagga sale was supplied and from this list each Inspector was able to extract the details relating to the cattle which had entered his District.
In passing it might be mentioned that the quoting of prices is a great help, as in very many cases the purchasers can pick cattle better on price than on description.
To revert to G.'s cattle walking towards Deniliquin, these were held up four miles north of that town, on reasonable feed and good water. They had walked the last 50 miles in under 5 days and this probably aggravated the subsequent incidence of the disease. They were inspected with a representative of the owner and it seemed highly probable that quite a number of active cases of P.P.C. were present in the mob. One beast showing typical symptoms was shot, and on post-mortem showed equally typical lesions. It was then necessary to collect as much information ar possible. The drover was interviewed and it was fortunate that his off-sider had kept a list of all the cattle which had been dropped, with a reasonable description of each, and was able to account for his numbers. He had left Wagga on 11th July with 149 head of G.'s cattle and 174 head of B.'s were boxed with them. Of the total of 323, he reached Deniliquin with 300. Of the 23 dropped en route, 7 were left at Jerilderie and all were destroyed subsequently with P.P.C. Some were dropped at Urana and boxed with the Common cattle; involving a complicated round-up. There was one report of a possible contact along the route about which a lot of conflicting evidence was obtained later, and this involved 222 cattle. One heifer was boxed with the mob for a day but as the owner was unknown and she had a broken leg she was destroyed by me as soon as possible.
It is interesting to note that in the journey to both Jingellic and Deniliquin no cattle on holdings along the route became infested despite the possible contacts. Nevertheless, as a precautionary measure owners were warned that a pleuro mob had passed through; and to watch their cattle carefully. Up to the 8th August 15 head of cattle were destroyed on the route, following the daily inspections to pick up clinical cases, and on this date the vaccine arrived.
Facilities were few and far between and it was decided to take the risk and bring the mob through the town to the rodeo yards on the opposite side of the river. The route and roads were cleared by the herdsman and a clearance of 100 yards was demanded. With a little publicity this was not difficult to obtain, and the mob was given a very wide berth. They were vaccinated near or in the tip of the tail and a broad green stripe was painted down the back. This proved a very useful identification mark for any cattle which strayed. The cattle were returned to their original camp but agistment still could not be obtained and the immediate destination of the mob had become a major problem.
During the next five days 22 more cattle were destroyed and the lungs of each one was examined. This may be done quite simply in many cases by removing one foreleg and slitting between the ribs. Disposal of carcases was a problem as wood was scarce so close to town, but fortunately we were able to buy five tons of old rubber tyres, which did a very good job as fuel but proved expensive. Agistment was obtained eventually by offering 5/- per head all round and the cattle were safely paddocked where periodic inspections could be made. Up to the 13th August only two out of the 37 head destroyed belonged to B.; the first clinical case being found 30 days after contact.
During the period of agistment a lot of the country flooded and the cattle started to break out on to the neighbouring properties. It became necessary then to camp a man permanently with the cattle and to round them up twice daily and keep a tally.
At the subsequent visits to this property, which was 23 miles from town, another 23 head were destroyed; and the total was reduced to 240. Half of these 23 belonged to B. The agistment ran out by 18th November, but by then the owners had made the necessary arrangements with the Department to take over the cattle at Deniliquin at local valuation. For this purpose the cattle were brought into town and drafted into lines as if for sale, with each owner's separate. A value was placed on them by the owners and if not approved by me, and many of these were considered too high, it was referred to an independent valuer who had been requested to be present and who was acceptable to the owners as an arbitrator. After valuation each pen was divided into lots and two equal and similar consignments were made up-one for Homebush and the other for Goulburn, where certain butchers had agreed to take over all cattle at a certain price per 100 lbs. They were floated to Finley and railed to their destination.
It is interesting to note that of 120 sent to Goulburn 40 were reported to show lesions of P.P.C., all being chronic; whilst of the 120 sent to Homebush only four showed lesions. Yet the consignments were a fair division and appeared to be identical.
After the 1st September compensation was paid on all cattle destroyed, so it was necessary to value the cattle before destruction, and in the company of some competent person who was accepted as being a representative of the owners. Since leaving Wagga, G. had lost 69 head out of 149 but was paid compensation on about a dozen only; the earlier deaths occurring before the Cattle Compensation Act, 1951, came into force.
In dealing with the G.-B. mob it was a comparatively simple case of an outbreak mob caught on the route hundreds of miles from home and with no destination other than the saleyards; but of more interest and far greater difficulty was the case of M.'s cattle; also purchased in Wagga on the same date as the others. He purchased 70 steers from G. and 67 head from other owners and immediately transported the lot to Finley, where he boxed them with 30 other cattle on his holding on the edge of the town. This owner was interviewed on 6th August and stated that 164 of the 167 head had been offered in the Finley saleyards on 9th July; with 1,400 other cattle. 96 had been sold and scattered far and wide. The unsold 66 were offered again in Finley on 23rd July (with 8OO other cattle) but none was sold.
The most urgent necessity was to deal with the cattle from Wagga. which by now were known to include P.P.C. cattle. Of the 96 sold, 35 went to C., Jerilderie, and the balance to Victoria; while of the unsold cattle 35 were retained on the holding and 24 sent to Newmarket, where they were sold and railed back into the Deniliquin district. All these became outbreak mobs and will be mentioned later. The Victorian Inspectors of Stock were given the details of the cattle which had entered that State, and also the name of the agent handling C.'s cattle.
With considerable personal knowledge of the agents, owners.etc., in one's own District it is possible to tie up stock temporarily without a paper war. The necessary Forms 8 and 6 can be completed at a later date; after more urgent matters have received attention. Despite the number of contacts it was hoped that the Department could handle the job before widespread outbreaks occurred but assistance was required urgently in this area. Two Veterinary Officers from Orange and Goulburn were posted to check up the contacts further east and to inoculate the Finley contact cattle, whilst the writer handled the outbreak mobs and Deniliquin contacts. It was found after the full disposal lists had been obtained from the two Finley sales that there were 39 contact mobs of cattle in the Jerilderie District, besides those in Corowa and Deniliquin; and the outbreak mobs. All of them had to be vaccinated but facilities in this area are primitive for handling cattle, except in the saleyards and trucking yards.
It was found that 700 and 300 cattle from the sales on the 9th and 23rd July respectively had entered Victoria and full lists of these were supplied to the Chief Veterinary Inspector of that State. Following further checking at Wagga it was found that G.'s cattle included Hereford steers and Shorthorns only, and it appeared likely that outbreaks in the first instance would be limited to this class. The disposal of these was to C., P. and J.; and returned unsold to M. This estimation was later borne out, as P.P.C. occurred in each mob of these and nowhere else. All Victorian contact cattle were sent into abattoirs and compensation paid at purchase price plus freight to destination and agistment value, but not one case of P.P.C. was found on post-mortem except in the G. mob which went to Cobram (J.'s). Of the 35 head owned by M., including 7 contact Jersey heifers, all were bled and vaccinated; and the clinical cases were destroyed immediately they were found. In all 17 head were killed, and of these only one was not from the original Wagga mob; and this was a doubtful case. The last death occurred on 19th September. This owner was unwilling to send his cattle to Homebush for slaughter owing to the low prices being offered and preferred quarantine.
On the other hand, C. purchased 35 head of G.'s cattle from M. on 9th July, and when mustered on 7th August following a report of P.P.C., only thirty head could be counted. When inspected on 11th August four more were destroyed with typical lesions on post-mortem; the remaining 26 head being bled and vaccinated. When results came to hand, fourteen out of twenty-six were positive; which meant that only 12 out of 35 were negative P.P.C. cases on clinical examination and C.F. test. The owner decided to cut his losses and consigned all but the clinical cases to Homebush. In all, 22 cattle were forwarded and 15 were positive on post-mortem; only seven out of 35 being negative when the cattle were finally cleaned up. This owner received a nett return of about £80 for 22 head of cattle consigned to Homebush; £600 being paid for the original 35 head.
It was later found that 4 steers had been boxed with the 35 from Finley in a transport and later run with 120 bullocks. All were vaccinated and the steers bled twice at about a month's interval; with negative results in each case.
A "Break-down"
One serious temporary break-down did occur in control measures but this was due to an oversight by the Victorian authorities, who had been notified on 6th August that 24 head of pleuro suspect steers had been consigned to Newmarket. Nothing was heard of these cattle till 19th August, when the Newmarket purchaser, who has a holding in N.S.W., informed me that six of his cattle were sick; and that his agents had just notified him that they were probably pleuro contacts. The property was visited and six head immediately were destroyed; with typical symptoms of P.P.C. Twenty head which were thought to include the rest of G.'s cattle (18 head) were drafted off, bled and vaccinated. In addition, another 54 head were vaccinated and paddocked separately. The result of the C.F. test revealed that four positive reactors were present. These were destroyed and showed obvious lesions.
In this outbreak fourteen more deaths occurred up to 24th October, the date of the last death, and it might be noted that after contact with G.'s cattle for 3 weeks eleven deaths occurred in 52 contact cattle, with 15 out of 26 in the actual G. cattle; whereas in M.'s outbreak, after contact with G.'s cattle for 7 weeks, no cases occurred in the cattle which had been running originally on the holding. The only difference was that clinical cases were destroyed as soon as seen in the latter, but had reached the dying stage in the former before destruction commenced.
It is interesting to note that ten cattle belonging to a neighbour were boxed with the above cattle for one week and were returned to their own mob of 170 prior to my visit. All these were vaccinated and seven weeks later one beast became very sick with symptoms very like P.P.C. On post-mortem, typical lesions were found but this diagnosis was not confirmed by Glenfield and the cattle had to be released from quarantine 3 months from vaccination and 5 weeks after this death.
General Features and Conclusions
In most of the outbreaks the incidence was extremely high in the G. cattle, but generally low to negligible in the contact cattle, with the above exception. In fact, it seems that the incidence was very high in the original outbreak mobs but almost negligible in the contact cattle when handled quickly.
For the Finley saleyard contacts, which were vaccinated, a Quarantine of 3 months was imposed from the date of vaccination. These cattle were not released until inspected and were not eligible to enter Victoria for 6 months from the date of contact. The Quarantine period was reduced to two months following vaccination provided it was three months from the original contact with the pleuro cattle. For the outbreak mobs, quarantine for three months was imposed from the last death, and thereafter surveillance for nine months; the cattle being ineligible to enter Victoria whilst under surveillance. The surveillance was lifted after six months from the last death if the cattle gave a negative reaction to the C.F. test. This test is not conclusive as some advanced cases do not react and a negative reaction is not necessarily free from P.P.C.; but it does pick out some subclinical cases.
From experience it was found that small steers can be bled fairly easily in a crush or by throwing them, but cows and bullocks give a great deal of trouble unless excellent facilities are available. With a crush only it probably would take 6 hours to bleed 50 head with a team of men; whereas it is easy to vaccinate 100 per hour. Without good facilities bullocks can be bled more easily from the tail than from the jugular vein.
In the course of these outbreaks several interesting facts came to light. The first was that some of the cattle affected with P.P.C. were only 12 months old, and in some of these the lesions were old and encapsulated and were breaking out afresh. It was obvious, therefore, that these young cattle had had the disease previously in N.S.W., probably whilst on agistment in Urana, and few if any deaths occurred; although these may have been masked by the natural increase. This outbreak was not known to the owner of the cattle or of the property.
Secondly, in a mob of cattle out of the Gunnedah saleyards on 15th May, cases of P.P.C. were picked up in Newmarket on post-mortem of cattle which had entered Victoria illegally. Following this report the balance of the cattle were inspected by a Veterinary Officer who reported that all appeared healthy. These were consigned to Homebush and out of 49 head of adult cattle 8 were positive on post-mortem; 6 of them being active. It is obvious, therefore, that pleuro is not always as easy to pick up as is often made out; in this case despite the fact that the officer was looking for the disease.
The third point was that the wholesale slaughter of contact cattle as carried out in Victoria is not at all necessary, but is most desirable in herds in which the outbreak has occurred. For the latter a satisfactory method of disposal should be devised to obviate unnecessary expenditure by the Department from the Compensation Fund, or undue loss by the owner.
Lastly, bleeding of adult cattle without adequate facilities is a soul-destroying occupation and takes up time which could be spent more profitably on other activities associated with the outbreak.
Undoubtedly, trucking the cattle away for slaughter is by far the best method of cleaning up an outbreak mob, but it has some very unsatisfactory features. The first of these is that the butchers will not offer a fair price for any contact stock and this is most important where the Department is not prepared to take over the mob at valuation and leaves it to the owner to dispose of the cattle as best he may. In one case of 150 head of contact cattle in which odd deaths had occurred they were fattened on irrigation pastures and on the expiry of quarantine were transported to Wagga for sale for immediate slaughter. When the restrictions placed on the cattle were announced the prices offered were reported to be 25% below market value, and these had to be accepted.
It would appear necessary for some machinery to be set up to have the beasts killed and the carcases graded and valued on the hook and taken over by the Department for disposal as they think fit; either for export or for the local trade. The present method of making it a compulsory sale or selling the beasts on the hoof at a given price per lb. is playing into the wholesale butchers' hands and making them a gift of cheap beef. The position is even more difficult in the Western Riverina, where the natural outlet for cattle is into Victoria; and they are barred from entering that State even for immediate slaughter.
P.P.C. IN VICTORIA
It may be of interest here to say something of the Victorian picture which resulted from this outbreak in New South Wales during 1952; and for the following information we are indebted to Mr. Grayson, Senior Veterinary Officer of the Department of Agriculture, Victoria.
To maintain the normal turn-off in the beef trade in Victoria, up to 200.000 cattle are imported into Victoria annually from N.S.W. and Queensland. Unfortunately, although P.P.C. has not been endemic in Victoria since 1928. sixty-five (85) outbreaks have occurred since 8/4/52; 54 being referable directly to northern cattle introduced since July of that year. These arose as follows:—
| ex Wagga | 2/7/52 | thence via Finley, Wodonga or Newmarket | 22 outbreaks |
| ex Wagga | 16/7/52 | - | 1 outbreak |
| ex Wagga | 22/8/52 | thence via Wangaratta or Dandenong | 19 outbreaks |
| ex dealer T.N. | - | via Albury, Echuca, Henty or Jerilderie | 12 outbreaks |
| TOTAL | 54 outbreaks |
As at the end of December, 1952, the Victorian position was summarised as:—
| 65 | active outbreaks |
| 870 | contact properties in quarantine; with 47,000 cattle |
| 5,500 | slaughtered |
| At that time it was stated that:— | |
| 24 areas had been freed of P.P.C. | |
| 364 | properties (21,627 cattle) were still in quarantine |
| £63,000 | had been paid in compensation; exclusive of mileage, maintenance, laboratory and field work costs |
The basic approach to P.P.C. in Victoria is eradication rather than control; the methods of handling outbreaks being:—
- Quarantine and slaughter of affected animals.
- Tracing and quarantine of all contacts.
- C.F. testing; with slaughter of all positives.
- Vaccination.
- Regular surveillance.
- Further C.F. testing four (4) months later.
In certain circumstances, such as the proximity of a valuable dairy herd, the practice is to slaughter out all cattle in an outbreak mob. The possibility of this particular spread is of great concern in Victoria; where many fattening properties in the better areas adjoin dairy farming communities.
The final blood test before release is considered to be essential in the Victorian eradication campaign, since such will eliminate a carrier whose clinical symptoms have been masked by vaccination.