1. TOXAEMIC JAUNDICE FOLLOWING THE USE OF A BLUESTONE FOOT-BATH
Investigation of a reported mortality in sheep brought out the following points:—
The losses occurred in a flock of 350 first cross Dorset Horn ewes, 2-3 years old, following the use of a 10% bluestone solution as a foot-bath for the treatment of Footrot. Post-mortem examination of three carcases showed that all deaths were due to Toxaemic Jaundice; salient features of the picture at autopsy being generalised icterus, rapid decomposition after death and methaemaglobinuria.
The sheep had been running on an ordinary "slope" pasture which had been improved by the sowing down of mid-season subterranean clover. There had not been any previous cases of Toxaemic Jaundice on this property.
Footrot appeared in the flock and the owner put the ewes through a foot-bath containing the bluestone solution; to which salt had been added on the advice of a neighbour, and at the rate of about ½ lb. to the gallon.
[When asked why the salt had been added to the bath the author stated that he did not know; but it appeared that when a neighbour had been told of the losses he said that deaths should have been expected—since the sheep had not been given any salt for several months. In any case, perhaps the method of administration had just as much merit as the "diagnosis."]
The sheep were put through the bath three times in eight days. They were held for treatment of fly-strike daily: and had been so held for about six weeks—weather permitting. After the second bath the first death occurred; two died the following day; and deaths continued at an average rate of two each day for the next seven days.
When Formalin was substituted for Bluestone the deaths ceased; although all other factors remained constant.
It would appear, therefore, that the subject sheep had a subcritical copper status, so that the ingestion of even a small amount of additional copper proved rapidly fatal.
[It was suggested some three or four years ago that Toxaemic Jaundice had followed the use of a blues'one foot-bath on a property in the Molong District. In that case the bluestone bath was used over an extended period until the Footrot was eliminated from the property. In the case now reported it would appear that the much more rapid action resulted from what actually was induced ingestion.]
2. SUGGESTED TOXAEMIC JAUNDICE FOLLOWED REPEATED DRENCHING WITH BLUESTONE AND NICOTINE.
Of a flock of 550, two (2) one-year-old Corriedale weaners are known to have died of Toxaemic Jaundice.
This flock was running on improved pasture and had been drenched with a Bluestone-Nicotine preparation monthly for a period of seven months. During that period 10 sheep died and the deaths were ascribed to Haemonchosis: but in the two cases it which a positive diagnosis was possible. Toxaemic Jaundice was confirmed as the cause of death. The pasture over the period under review corrprised stubble, sub. clover, rye and trefoil; with a few native grasses.
3. ENTERO-TOXAEMIA AND HAIR WORM INFESTATION.
1,200 crossbred weaners were running on country fronting the Murrumbidgee River. Severe floods occurred and much of the fencing was damaged, and following the recession of the flood-waters and the advent of good feed an outbreak of Entero-toxaemia was experienced. Inoculataon with a single-dose vaccine steadied the losses at about 40 in a period of one month: but at the end of that period mortality continued and several sheep examined were noted to have died from Entero-toxaemia.
The history suggested that a few of the later deaths may have been due to Trichostrongylosis. The flock was given a second dose of vaccine, and although losses diminished they did not cease until the mob had been drenched twice with Phenothiazine. Total losses amounted to 120 over a period of three months.
It would appear that a moderate to heavy infestation with Trichostrongyle can impair immunity to Entero-toxaemia.