Case Study: Staggers in lambs caused by vaccination
On a farm near Mansfield in northeast Victoria, autopsy of two ataxic lambs found abscesses deep within the neck muscle (Figure 1), compressing the cervical spinal cord through the foramina at C1/C2 (Figure 2). Within seconds of starting to run the lambs would collapse in the front legs and summersault.
The lambs were two of 80 that had been injected with Gudair® at lambmarking two months previously with a half-inch long needle “high on the neck below the ear”. Gudair is an oil-based, highly tissue reactive vaccine containing killed mycobacteria used to prevent ovine Johne’s disease.
Microscopic examination found numerous acid-fast bacilli in smears of the pus and Wallerian degeneration in the spinal cord distal to the abscesses. Culture of the pus was negative. These findings support the theory that overly deep administration of the Gudair vaccine was the root cause of the ataxia.
It is recommended that Gudair is administered subcutaneously. This is best achieved in lambs using a self-tenting Sekuris safety vaccinator with a ¼” needle injected at 45o into the mid-side neck.
Written by Dr Tristan Jubb
Bendigo Sheep Vets
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