Dog owners in Shanghai fear rabies vaccinations required under new licensing rules may be unsafe after an animal rights group reported that at least 11 dogs have died shortly after getting the jabs.

Melissa Chen, a Singaporean dog owner, said her three-year-old chihuahua Rainbow had a spasm two hours after having a rabies shot at a government-designated veterinary clinic on May 28. Vets at a Jing'an animal hospital were unable to resuscitate the dog.

"The vet did not say the rabies injection was the cause of death," Chen told the Global Times. "But Rainbow was a healthy dog and showed no symptoms of illness before the vaccination."

Rainbow and the other dogs died after new dog licensing rules were introduced on May 15, which require dog owners to have their pets vaccinated for rabies at one of 20 designated animal clinics in the city. The vaccination certificate is required for the dog license application.

Marvin Manalac, founder of local non-profit organization Jiaya's Animal Rescue, said he had been told of the 11 deaths and had received dozens more anxious enquiries about the vaccinations from expatriate dog owners.

"It is premature to jump to the conclusion that the rabies shots were contaminated. However, the reported deaths could deter dog owners from following the city's new dog license regulations," Manalac told the Global Times.

More than 60,000 dogs have received rabies vaccination since May 15, with only four dog owners reporting that their pets suffered adverse reactions to the shots, Xu Feng, the spokesman of Shanghai Agriculture Commission's Animal Husbandry and Veterinary Office, told the Global Times.

"All vaccines at assigned animal clinics are produced under strict quality supervision. Each batch of vaccinations are tested to ensure their safety," said Xu.

"It is true that dogs are exposed to certain side effects after the vaccination. But it is also important that dog owners vaccinate their pets as the benefits outweigh the potential risks," Xu added.

Jun Guohua, a vet at government-designated Shanghai Animal Care Veterinary Clinic in Changning district, told the Global Times that one in 10,000 dogs could develop allergic symptoms toward rabies shots, and of these cases only very few would result in death.

There is no allergy test available for dogs before the administration of rabies shots, according to Jun.

"Small-sized dogs are more likely to develop adverse symptoms, as the dose for a 3-kilogram dog is the same as those for a 20-kilogram one," he said.

Dog owners should watch their dogs for at least three hours after the vaccinations, Jun said. If the dog develops swelling around their eyes and faces or loses its appetite, owners should immediately take their pet to the vet for treatment.