The deaths occurred in the Yaroslavl region and several other Russian regions, with owners linking them to batch No. 20 of the vaccine, according to the regional outlet Yarkub. As of August 17, 20–25 dogs had died in the Yaroslavl region alone, with isolated cases also reported in Kaliningrad, Moscow, Saratov, the Leningrad region, the Moscow suburbs, and Tyumen.
Symptoms appeared two to five days after vaccination: fever, excessive salivation, seizures, vomiting with blood, and diarrhea. Many animals gnawed their paws at the injection site until they bled. Owners described the animals' condition as extremely severe — some died within days, while others could not be saved by veterinarians.
The vaccine's manufacturer, the Moscow company Vetbiohim, said it was recalling the batch potentially linked to the deaths pending an investigation. Later, the company suggested possible interference by unspecified "third parties" and urged against using three more batches of its vaccines. Russia's agricultural watchdog Rosselkhoznadzor said it planned to ask prosecutors to conduct a joint inspection of Vetbiohim.
In the Yaroslavl region, all registered deaths followed vaccinations given between August 6 and 15 with batch No. 20. Use of this batch in the region was halted on August 14. Since the start of August, about 100 animals had been vaccinated with this batch at state and private veterinary clinics and mobile stations, regional media reported.
Veterinarians and authorities have not yet officially linked the deaths to the vaccine. According to veterinarian Pavel Rakhmanin, autopsy results for at least one dead dog are not yet available — examinations take time. Nikita Surkov, chief veterinarian at the Tyumen clinic Kovcheg, also said there is no understanding yet of what caused the deaths.
Sources differ: Yarkub reports 20–25 dead dogs in the Yaroslavl region, while the exact number of affected animals in other regions is not given. Vetbiohim allows for interference by "third parties," while affected owners link the deaths to batch No. 20. Official autopsy results have not yet been published.