I went out last week to investigate the sudden death overnight of some lambs on an oat crop. They were going well and due to be sold the next day, when all of a sudden - six dead in the one morning.
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The stock owner was obviously concerned, but after he told me they had not had a clostridial vaccine booster since they had arrived on his property earlier in the year I immediately considered pulpy kidney.
Post mortem findings on one of the dead animals was certainly consistent, and lab investigation confirmed pulpy kidney was the cause.
So just a reminder - now is a good time to be giving last year's lambs a booster vaccination if they haven't had one in the previous three months!
Pulpy kidney is caused by an overgrowth of a specific clostridial bacteria, Clostridium perfringens Type D. This bacteria is naturally present in a healthy sheep's gut as part of normal gut flora. It produces a toxin which doesn't cause a problem at low levels.
However, when the animal is on energy-rich feed these bacteria can multiply really quickly, resulting in very large amounts of toxin being produced. The toxin is absorbed into the animal's blood stream which then causes significant damage affecting multiple body organs.
This results in death - very, very sudden death in unvaccinated animals, often following terminal convulsions. In lambs with some immunity from previous vaccination, illness may be slightly more drawn out, but there is no treatment and affected animals will die.
Pulpy kidney is easily and cheaply prevented by effective clostridial vaccination. An initial two vaccinations are required four to six weeks apart for effective protection, but timely boosters are crucial, and may be necessary up to every three months while on high risk feed.
The lush crops in the district at the moment are certainly considered high risk. The better your lambs are doing the more imperative it is to give a booster - pulpy kidney strikes the best lambs.
As an aside, we also did a worm test on this mob of lambs under our worm test project (which has now finished). They had been drenched with a triple active product four weeks ago and yet their worm egg count was still well over 2000 epg. Larval culture grew a mix of barber's pole and scour worms.
It is most likely that the count reflects new pick up from a contaminated paddock rather than resistance. Remember that it takes up to six months for the majority of worms to die out on pasture, and this year you would be well advised to monitor worm egg counts monthly!
If you have any questions about any of this you can get in contact with us by calling the Central West Local Land Services Forbes Office on 6850 1600.
