Ovine Brucellosis - everything you need to know

Technology and good biosecurity practices can protect you from big losses when it comes to Ovine Brucellosis.  Colin Chapman, Professor and Dorset Downs stud breeder leads us through the best ways to tackle and prevent this mostly hidden from view infection. What is Ovine Brucellosis? It’s caused by a bacteria called Brucella Ovus, which is one of several different types of Brucella.  “It lives only in sheep, it doesn’t live on the ground or in the water.  It spends it’s entire life cycle in sheep, which fortunately makes it easier to control because you don’t have to eradicate it in the environment as well” he explains.  Ovine Brucellosis (OB) quite different to Bovine Brucellosis, which causes the cow to become sick and abort their calf.  The cow and calf are both infected with this type of Brucellosis, and it’s also infectious to humans.  Bovine Brucellosis has now been eradicated in Australia. What problems does it cause in sheep? When Brucellosis is in your flock of sheep you don’t notice it.  “The sheep are not unwell What you do notice is that you will have a drop in fertility and the ewes don’t have as many lambs as expected.  A reduction in lambing percentage over time could indicate that it is present in your flock”, says Colin.  Colin goes on to explain that on closer inspection you may find that the rams have lumps and bumps in the testicles, but apart from palpating the testicles of the rams there is nothing to see. It is mostly invisible except for the records which show a reduction in lambing percentage. How does it reduce lambing percentages? OB reduces fertility in the rams by causing a blockage in the tubules from the testes up to the penis.  In the two testicles one side might be blocked but the other side may be open.  So a ram can be partially infertile or totally infertile, which you can’t tell by the palpation.  Once  OB gets into the reproductive tract it stays there.  All rams that are sexually active regardless of age are vulnerable. What about the ewes and wethers? Colin explains that ewes that are mated with infected rams will possibly have the bacteria present in the vagina and uterus for a brief period of time but normally with no adverse affect.  It does not cause any blockage as ewes or wethers don’t have testes.  It may cause local inflammation in a ewe but that will pass.  The ewe is not a carrier Colin assures.  The presence of the bacteria in a ewe will be resolved usually in a day or two.  So unless there is more than one ram around the same ewe in a short period of time the bacteria would not be passed from the ewe to another ram.  This would be considered an unlikely way for it to be transmitted, it is usually ram to ram transmission through homosexual activity. OB comes onto a property when someone buys a new ram that is infected and puts it in with their ram flock.  Doing this without prior quarantine and testing can infect a whole flock of rams within days or weeks.Teasers can in theory be at risk or a source of infection, as they still have the testes in tact.    How do I check my flock for Brucellosis? If you have had a reduction in lambing percentage then the next step would be for your rams to be checked.  This involves palpating the testes to feel for lumps and bumps.  If there is any on the testes or around the tubes, pea size or bigger, then that would prompt a further investigation.  The next step would be to take a blood test which tells us if that ram has ever been expoSupport the showWant more! Want to show us some sheep love? Sign up for extra content via our sheep supporters tab !https://www.buzzsprout.com/954910/supporters/new