Photo by Dr. Wendy Smith Wilson

The ritual of regular vaccinations for pets, especially cats, is disrupted in the United Kingdom as manufacturers report shortages of a number of vaccines. As a result, some products are being rationed, and practitioners are prioritizing younger animals while recommending older pets with a solid history of vaccinations wait a little longer than usual for their boosters.

Veterinarians in the United Kingdom are having to ration vaccines that protect cats and dogs from a range of deadly diseases amid a national supply squeeze that is expected to last for months.

Some vaccine manufacturers are pinning the shortage on a surge in demand caused by a pandemic pet boom and the clearing of a backlog of appointments following an easing of lockdowns.

The pet vaccine shortage also comes as the U.K.'s recent exit from the European Union worsens supply-chain bottlenecks that are disrupting the transportation of everything from gasoline to chicken meat.

Moreover, materials used to manufacture and package vaccines, such as plastic chambers and glass vials, are in high demand as governments rush to immunize their human populations from COVID-19.

Three of the world's biggest animal health-care companies — Zoetis, Boehringer Ingelheim and MSD Animal Health — confirmed separately to the VIN News Service that they are experiencing, or expect to experience, a shortage of certain shots in the U.K.

None indicated the problem was occurring elsewhere, although one said "unprecedented demand" for pet vaccines is being seen also on the European mainland, without naming countries.

The affected products include vaccines that protect pets against a range of pathogens, such as feline and canine parvovirus and feline leukemia virus.

The manufacturers each said the shortage is far more pronounced for cat vaccines. But one said it has imposed order caps on certain in-demand dog vaccines, too, as a precaution to prevent panic buying.

Zoetis, the world's biggest animal health-care company by sales, is "currently anticipating a shortage in supply" of its Versifel line of cat vaccines in the U.K., according to its senior director of international communication, Anne-France Quentric.

In an emailed response to questions from VIN News, she attributed the shortage to "delays in the manufacturing process" and "current challenges being faced in the U.K. market," without being more specific.

The Versifel vaccines protect cats from pathogens that include feline parvovirus, feline calicivirus, feline herpesvirus type 1 and feline leukemia virus.

At least one vaccine vendor has been showing on its website in recent days that Versifel CVR solution is unavailable, "likely because of a manufacturing delay."

Quentric from Zoetis said: "Our global manufacturing and supply organization is exploring solutions to limit supply disruption for our customers to take care of their animals, and we are working to minimize the impact to customers as much as we can to ensure reliable supply of our core vaccines."

MSD Animal Health has placed some vaccines on "allocation," meaning orders have been capped based on the size of customers' previous orders, according to its U.K. communication and external relations manager, Vicky Bewer.

MSD Animal Health, which is owned by pharmaceutical giant Merck, issued a communiqué to veterinarians confirming that the rationing applies to certain products in its Nobivac range — for dogs as well as for cats.

"Across Europe and the U.K. we continue to see unprecedented demand for cat vaccines," MSD's letter reads, adding that demand for dog vaccines also is increasing, prompting it to ration those, too. "At this stage, we anticipate more stock being available in January 2022."

A third big manufacturer, Boehringer Ingelheim, also has put some vaccines on allocation, spokesperson Nora Aji said, without disclosing which specific products are affected. The German company manufactures the Purevax range of vaccines for cats, according to its U.K. website.

(Elanco Animal Health, the world's second-biggest animal health-care company behind Zoetis, does not manufacture or distribute any vaccines in the U.K.)

Many veterinarians are prioritizing for vaccination animals that are potentially more vulnerable, such as kittens needing their initial course, according to a statement released by Britain's National Office of Animal Health, a lobby group for animal health-care companies.

"Producing vaccines is a precise, regulated process with many checks to ensure full safety, quality and efficacy of every batch," NOAH stated. "Vaccine manufacturers continue to operate at full capacity to increase supply to the market."

The Wylie Veterinary Centre in Upminster, England, is among clinics that are prioritizing pets — in its case, puppies, kittens and animals who need first-year boosters. "For the moment, we are delaying booster vaccinations by three months from their due date," the practice said on its Facebook page.

Dr. John Blackwell, a veterinarian based in Shropshire, England, said other cats subject to higher infection risks, such as those going into a cattery from multi-cat households, might also be given priority.

"Arguably, cats who have had year-on-year boosters, do not have any other disease challenges or aren't exposed to higher risk should be able to demonstrate a good immunity to allow their booster interval to be extended to around 15 months, from the normal 12 months," he said. "This hopefully will allow the profession to manage supply issues in the short term."

In the meantime, veterinarians in the U.K. wonder how much the various demand and supply pressures are contributing to the vaccine shortage — and how long it might last.

"At the moment, it seems like only cat vaccines are affected, and they are saying it will be sorted by the New Year," said Dr. Cat Henstridge, a locum veterinarian in Sheffield, who recently talked to a representative at Zoetis. "But I do wonder if we are being eased in gently to a crisis."