The Ministry of Agriculture is investigating almost twice the number of animal welfare complaints it normally gets in winter.
It is linking the increase to feed shortages and the poor condition of livestock in areas recovering from drought.
MAF Investigations Manager, Greg Reid, says instead of about 200 cases, it is dealing with closer to 400 complaints.
He says they range across all types of farming and the ministry's investigations unit has been hard-pressed to cope.
Mr Reid says many of the complaints are coming from areas of Southland, Canterbury, Waikato and Northland where there has been drought.