Owners needed to assess if they had enough feed and water to keep their animals in reasonable condition over winter, according to Equine Veterinarians Australia, a special interest group of the Australian Veterinary Association.
EVA president Dr Barry Smyth said that there had been a series of distressing cases recently in which people kept under-nourished horses for far too long.
"In many parts of southern Australia that have not yet received significant rains, there is likely to be a long winter with no further pasture growth," he said. "Now is the time for horse owners to make the hard decisions about whether or not they can afford to feed horses over the coming winter months.
"Drought plans and budgets need to be carefully calculated and horses should be kept in decent condition until the drought ends.
"Their condition needs to be monitored regularly to ensure they are not over or underfed. Veterinarians can assist with taking objective measurements. In some cases, more feed is required for lactating mares and immature growing horses."
Dr Smyth said that as the condition of animals can deteriorate gradually, horse owners can benefit from expert opinions. "Some horse owners are prone to being highly attached to their animals. However, it does nobody any good to hang on to horses where it adversely affects their welfare.
"At this stage, we may not be able to depend on rain before winter. Horse owners will need to sit down and work out if they have the water, the feed and the funds to continue through the rest of the drought."