Lita Konopore of the Latvian Veterinarians' Association (LVB) said that the dog food contained "substances that definitely shouldn't have been there" but researchers weren't able to identify any particular substance causing megaesophagus, an abnormally enlarged esophagus, in the dog food.
"At the moment there is no chance of it being a coincidence. It's direct causality," said Konopore.
She said that this case has already made its way into the history of veterinary medicine. Latvian scientists cooperated with foreign colleagues during research, which was funded by donations.
The wave of canines falling mysteriously ill has stopped. Konopore said that in April 20 cases of the disease were registered but only two new cases have been identified since then.
The Dogo dog food by Tukuma straume was previously linked with a mysterious canine disease causing vomiting and breathing problems, but state-funded research failed to establish a direct connection.
The company, which is a registered exporter to Russia, has lost half of its Latvian market share since the controversy broke.
A month ago the manufacturer threatened legal action against a variety of individuals and legal entities for suggesting the food might be causing health problems to dogs, and demanded compensation on almost half a million euros .
When the claims first surfaced, Agriculture Minister Janis Duklavs went on the record saying Dogo was perfectly safe and that he would happily feed it to his own hound.
The current state of health of the wet-nosed ministerial companion has not yet been confirmed.