Dr Berhe Gebreegziabher, in his latest report to the World Organisation for Animal Health (OIE) on September 19, said there were still 15 outbreaks unresolved.
"It is not possible to declare this event resolved until these individual outbreaks are resolved," he said of the disease, which is carried by midges.
Across 15 villages, a total of 4000 cases have been reported, of which 2185 have died.
The report says about 46,500 horses, mules and donkeys are suspectible in the outbreak, which began late in March.
In the village of Didu, with 5000 horses, mules and donkeys, 500 animals have so far been affected by the disease, of which half died.
In the village of Adile, 215 of the 250 equines which came down with AHS have died.
Similar numbers have been recorded in other villages, such as Saylem, with 300 deaths from 500 cases; and Gawata, with 200 deaths from 300 cases. Bita Genet had 222 deaths from 500 cases.
Authorities have vaccinated nearly 24,000 horses in a bid to control the outbreak.
The cases are confined to the western region of the country.
Epidemiological investigation is continuing.
Dr Gebreegziabher said previous outbreaks of the disease in Ethiopia were due to serotypes 9 and 6. "The current outbreak has affected equines vaccinated against serotype 9," he said.
African horse sickness is endemic in Africa but has spread north into parts of Europe.
It is closely related to the Bluetongue virus that affects sheeps and cattle, and is also in Europe. Both are transmitted by Culicoides species midges. In some outbreaks, up to 90% of horses die.
Authorities in Britain fear an outbreak on its shores, which would have huge economic consequences for equine-related industries.
Plans are in place for the slaughter of infected animals, destruction of the carcasses, and the establishment of a protection zone of at least 100km radius around infected premises.
This, together with a surveillance zone of at least a further 50km, would likely remain in force for at least 12 months. The scale of the zone is because virus movement over long distances by windborne infected midges is possible.