Crooked calf disease
District Veterinary Officer, Agriculture Victoria
During Spring 2018, calves were born with a distinctive deformity on several properties in the Upper North East of Victoria.
The deformity has been given a number of names, including:
- crooked calves
- acorn calves
- bulldog calves or
- dummy calves.
The deformities were most noticeable in the limbs and included shortening and rotation. Limb deformities were seen with or without doming of the skull and distortion of the spine. The dams of these calves were clinically normal.
The outbreak has primarily affected beef producers. All beef breeds commonly found in these districts have been affected. Deformed calves have been born to cows of all age groups. There is no genetic link between affected properties. A varying percentage of calves with a varying severity of deformities have been reported both on and between affected properties.
Previous similar outbreaks occurred during the springs of 2003 to 2006. In each case the outbreaks have followed adverse seasonal conditions early in the year similar to this year.
Affected property owners have consistently reported that their pregnant cattle were on undulating or hilly granitic country during pregnancy.
Several likely potential causes of the deformity such as plant toxins, farm chemicals and a number of viruses have been ruled out.
The cause of the deformity is likely to be a trace element deficiency. Ongoing work is being carried out to help prove or disprove a manganese deficiency hypothesis.
If manganese deficiency is the cause of the deformity, it is unlikely that this disease is caused by one factor such as a simple lack of supply. It is more likely to be a complex interaction of nutritional imbalances.