The Scottish SPCA is appealing for information after a young female Staffordshire bull terrier was discovered in water near Overtown Road in the North Lanarkshire town.
A post-mortem revealed the dog had been struck on the head, neck and body.
The dog had been weighed down with two large slab-like stones before being dumped in the water.
The animal was found on Friday May 15.
Inspector Heather Lawson said, “The dog had been in the water for 24 to 48 hours before she was discovered. Although the trauma to her head and neck was significant it would have been unlikely to be the cause of death, which is unexplained at this stage.
“It is not yet known if she was still breathing when she entered the water.
“The dog had been weighed down with two large, slab-like stones which had been tied to her lead.
“She was a young brown female Staffordshire bull terrier type and other than her injuries was in good bodily condition.
“She was a very unusual colour for this breed as this shade of brown is more commonly seen in Patterdale terriers or chocolate Labradors.
“We would appeal to anyone who recognises the description of this dog and knows who may have done this to her to contact us on 03000 999 999.”