The World Small Animal Veterinary Association has issued a statement denouncing a Daily Telegraph / Mail on Sunday story which claimed that 'thousands of dogs are dying or suffering severe allergic reactions' after being treated with Nobivac L4, and that the Association is urging owners not to use the vaccine on puppies less than 12 weeks old.The World Small Animal Veterinary Association has issued a statement denouncing a Daily Telegraph / Mail on Sunday story which claimed that 'thousands of dogs are dying or suffering severe allergic reactions' after being treated with Nobivac L4, and that the Association is urging owners not to use the vaccine on puppies less than 12 weeks old.

The Veterinary Medicines Directorate (VMD) has given VetSurgeon the data on which these stories were based. 

In the 3.5 years since the vaccine was authorised, the incidence of suspected adverse animal reactions has been 0.064%. In other words, for every 10,000 doses sold, the VMD has received reports of 6 suspected adverse reactions. This incidence is considered 'rare', according to the following convention:

  • very common (more than 1 in 10 animals displaying adverse reaction(s) during the course of one treatment)
  • common (more than 1 but less than 10 animals in 100 animals)
  • uncommon (more than 1 but less than 10 animals in 1,000 animals )
  • rare (more than 1 but less than 10 animals in 10,000 animals)
  • very rare (less than 1 animal in 10,000 animals, including isolated reports).

The VMD reports that amongst the 40+ authorised dog vaccines in the UK, the incidence of suspected adverse reactions ranges from 0.002% (classified 'very rare') to 0.3% (classified 'uncommon')

However, the VMD is at pains to stress that suspected adverse reaction reports should not be used to compare the relative safety of products. They are, after all, only 'suspected' adverse reactions. The reliability of suspected adverse reaction reports is further complicated by the fact that vaccination against leptospirosis rarely occurs in isolation, making it very difficult to interpret which adverse reactions are attributable to Leptospira vaccines.

Many vaccines providing protection against leptospirosis also contain components for prevention of other diseases, such as distemper, parainfluenza and parvovirus.  In addition, many dogs are vaccinated concurrently against other diseases, such as kennel cough and/or rabies, and other products (e.g. flea and worm treatments) may be administered at the same visit. Therefore the clinical signs observed may be related to any of the products used or they may be unrelated. 

The VMD says the majority of the most commonly reported suspected adverse reactions to Nobivac L4 are linked to allergic type reactions which are well-recognised potential side effects of any vaccine, and are presented on the product literature. 

As to the newspaper claim that: "The World Small Animal Veterinary Association (WSAVA) is urging owners not to use Nobivac L4 vaccine on puppies under 12 weeks old.", the WSAVA denied this in the strongest possible terms, saying: "This statement is blatantly untrue. The WSAVA would never ‘urge owners’ and would never make recommendations about individual named commercial products."

In a statement issued in response to the newspaper story, MSD said: "Nothing is more important to MSD Animal Health than the safety and efficacy of our products, and the health and well-being of animals. 

"Nobivac L4 was launched in 2013 across Europe to prevent dogs from contracting Leptospirosis which is a serious zoonotic disease. It is one of the most widely used vaccines for dogs with several million doses being used annually to successfully prevent infection in dogs."

"As a responsible animal health company, we take every adverse reaction report seriously and investigate thoroughly. Whenever possible, we work with the pet owner and attending veterinary surgeon to assemble as much clinical information as we can to help determine the cause of a pet’s health issue, and whether or not the product may have been involved .

"We report findings to governing regulatory agencies around the world (based on a country’s respective laws and policies), so that they can make a fully informed, scientific assessment about the safety of the product. We do this so that accurate safety and efficacy information is available for veterinary surgeons prescribing our products." 

In a parting shot, the WSAVA said: "The WSAVA guidelines are publicly available on-line and this journalist has clearly not undertaken adequate research before publishing this article."

See: www.wsava.org/educational/vaccination-guidelines-group

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