Scotland's avian flu outbreak could grow more severe in the coming week, it has been warned. 

Around 224,000 domestic birds have been culled in Scotland this year, and the disease was confirmed at six commercial premises and another two non-commercial farms north of the border. 

The infectious disease can have a "devastating effect" on poultry flocks and a single case can lead to the "compulsory slaughter of all the birds in that flock to prevent the disease from spreading further". 

Sheila Voas, the Scottish Government’s chief veterinary officer, said: "This year has been unprecedented in terms of avian flu. That's a word I don't use lightly. 

Scotland's outbreak has so far been significantly smaller than in England, where some 1.67 turkeys and two million chickens have been culled following rising cases of the highly infectious H5N1 strain of the disease.

READ MORE: Public asked to avoid part of Scotland after geese deaths linked to bird flu

Speaking on the "rapidly increasing mortality" caused by avian flu, Ms Voas told a Holyrood committee how quickly the virus caused devastation to chickens.

She said: "In one of our cases, we went from five dead overnight to 19 to 100 to about 3000 in the space of four or five days."

The spread of the deadly H5N1 strain has affected wild birds throughout the summer and has had devastating impacts on some seabird populations. 

Ms Voas confirmed that like Covid-19, the virus may have a worse impact in the winter months.

"Flu viruses generally like cold damp conditions and so they survive much better in the winter and will spread and remain effective for longer than in the summer when ultraviolet sunshine and high temperatures will kill it," she said. 

It has also led to egg shortages in some shops and fears the Christmas turkey market could be affected.

READ MORE: MPs warned of Christmas dinner shortage as turkeys wiped out by bird flu

Speaking to the Rural Affairs, Islands and Natural Environment Committee, Ms Voas added: “We certainly could be behind the curve, and so we’re continuingly monitoring what’s happening so that if we need to take further measures, we can.

“It is possible that in the next few weeks, the picture here will deteriorate, in which case we will need to take further action.”

The UK Government has recently ordered all poultry and captive birds in England to be kept indoors in an effort to curb the virus.

However, because the figures in Scotland are significantly lower, Ms Voas said that the measure is currently not being recommended north of the border as the disease can spread quickly among housed birds.

It comes after an industry chief warned MPs that half of the free range turkeys produced at Christmas in the UK have been culled or died because of bird flu.

Ms Voas said Scotland’s turkey industry is not significant.

She said: “We’ve got a few tens of thousands, they tend to be seasonal producers, people who keep a few 100 turkeys for the local market within Scotland, unlike the commercial turkey production in England.

“England have slaughtered 1.67 million turkeys but in context… that 1.68 million is about disease control. The normal Christmas market is about 10 million, a proportion of which are slaughtered earlier in the year and frozen.

“Turkey may be scarcer but I’m not concerned that there isn’t going to be any turkey around this Christmas.”