Background on the condition
Dropped hock syndrome is not an exotic disease and is currently believed to be nutritional or genetic in origin. Farmers who suspect a cow has the condition should contact a veterinarian.
Most cases occur in:
- rising 3-year-olds (occasionally rising 2-year-olds)
- Jersey or Jersey-cross breeds
- often poorly-grown animals in mid-late pregnancy.
Possible causes such as transmissible spongiform encephalopathies (TSEs), other exotic, and previously-described endemic causes of this condition (like trauma) have been ruled out.
Cases have occurred in the main dairying areas of New Zealand – on both the North and South Islands.
From 2011 until 2018, the Ministry for Primary Industries (MPI) collected information from veterinarians on dropped hock syndrome. Our involvement on this study with Massey University has now ended, but research by Massey University continues.
Video – cows with dropped hock syndrome (1:31)
This video shows several cows with dropped hock syndrome struggling to walk in a paddock.
No words relevant to the topic are spoken.
The animals are suffering from muscle weakness of the legs (paraperesis).
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Know the signs
Animals affected by this condition can initially present with shortened gait. This can progress rapidly to severe sinking of the hocks and result in cows that are unable to walk. Early cases can present as a 'mincing' or 'short-stepping' gait in a number of cows, with a smaller number developing the full condition.
In some cases, 'flying scapulas' are seen together or separately from dropped hocks.
Clinical signs are always bi-lateral, although they may be less marked on one side. Specific veterinary information, including on sampling and reporting is available in our update.
Keren Dittmer at the School of Veterinary Science, Massey University is researching dropped hock syndrome.
Contact Keren if you:
- have seen cattle with some of the signs of dropped hock syndrome, or
- are planning to euthanise an affected animal.