August 2022
Sheep Abortion Vaccination Supply Issue in September
Almost all farms have evidence of exposure to Toxoplasmosis and two thirds of farms have been exposed to enzootic abortion. These common infectious causes of abortion can cause abortion storms with up to 20% of ewe’s aborting. They also present a human health concern as the infections can be passed onto humans. If you experienced more than 2% of your ewes aborting or barren in the 2021 tupping cycle, your flock will likely have experienced an infectious abortion.
Toxoplasmosis and enzootic abortion can be prevented by a single vaccination prior to tupping. Both vaccines can be given on the same day, at separate sites, at least four weeks before the tup goes out. A single vaccination will last a commercial ewe’s lifetime!
Planning is important with abortion vaccination due to the timing of vaccination, purchase of replacements and remembering that Toxovax is made to order, so must be ordered about 2 weeks before you would like to use it. Toxovax also has a short shelf life so you must be prepared to use it when it is ready for collection.
Please note there will be no deliveries of Toxovax between Thursday the 25th of August and Tuesday the 20th of September. For dispatch on the 25th of August, we advise you place your order by Friday the 19th of August at the latest, although we can place the order for that date anytime from now. Please note that the manufacturers may close orders when there is high demand, so order early to avoid disappointment. Remember that Toxovax has a very short shelf life and the effectiveness of the vaccine cannot be guaranteed beyond this date so only order if you are able to use within a week of delivery.
Mycoplasma in Cattle
Calf with drooped ear due to mycoplasma otitis
We are seeing a greater prevalence of Mycoplasma on farms (both beef and dairy). This disease can create significant challenges for farmers.
Mycoplasma are very small bacteria that belong to a class called mollicutes. They lack a cell wall meaning that certain widely used antibiotics are not effective. It also can evade the cow’s immune response.
Clinical signs of mycoplasma for calves include increased respiratory disease, ear infections (otitis media showing a typical head tilt shown below), arthritis and joint infections. Adult cattle can rarely get pneumonia and mastitis.
Clinically affected calves shed large numbers of organisms via saliva and other respiratory secretions (coughing). This means milk feeders and troughs are likely to be highly contaminated. Avoid feeding whole milk if possible. Disinfection in between batches is essential to control disease.
Diagnosis of positive animals is achieved using nasopharyngeal swabs or bloods. Animals ideally should be isolated from the rest of the group to reduce spread.
Prompt treatment is essential for control and prognosis for calves. Isolation, antibiotic and anti-inflammatory treatment as well as disinfecting between batches is essential to control the disease.
Biosecurity is critical to prevent Mycoplasma entering your herd. If you are a closed herd, then isolate new purchases or source stock from clean herds. If calf rearing, then keep batches and age groups separate and ideally in different air spaces. We have started vaccination in calves and cows with an imported vaccine on some of our farms where mycoplasma is an issue and has been diagnosed. The response has been good. Contact the surgery for more information.