NEWS: Reports Show UK Dogs Are Dying From Lepto Vaccine


UK dog owners are learning what US dog owners have suspected all along …

…the lepto vaccine is much more dangerous than we’re led to believe.

The Nobivac L4 lepto vaccine, which was rolled out in the UK by Merck’s UK subsidiary, MSD Animal Health, is reportedly causing adverse effects in the dogs receiving it, including epilepsy, swollen glands, blindness and death.

Reports say that since its introduction to the UK in 2014, over 2,000 reports of adverse reactions to Nobivac L4 have been received by the Veterinary Medicines Directorate, which regulates UK animal drugs.

The vaccine is also suspected in the deaths of at least 120 dogs.

The news is such a surprise to UK pet owners that even UK tabloids are carrying the reports.

Maybe the UK government will take this dangerous vaccine more seriously than the government here in the US … because, as you’ll see, nobody seems to be concerned about how dangerous this vaccine really is.

The UK Knew The Dangers Of the Lepto Vaccine

Safety concerns were raised about this vaccine back in 2014 when the L4 vaccine was introduced.

The 2014 European Medicines Agency Veterinary Pharmacovigilance Report investigated the Nobivac L4 vaccine and found:

“Several signals were identified, mainly relating to anaphylaxis and various immune-mediated conditions such as anaemia, thrombocyte-penia and arthritis. The MAH [manufacturer] was advised for the upcoming PSUR to compare the incidence of these adverse events with its other Leptospira product, which contains only two serovars. There are no conclusions yet related to potential causal relationship and regulatory action has not been considered necessary at this stage.”

So basically, they saw evidence of sudden death and autoimmune disease (think cancer, allergies and joint disease, to name a few), and didn’t really think action was necessary.

The UK’s Veterinary Medicines Directorate (VMD) also reviewed the safety of the vaccine and their 2014 Review of Adverse Events Report stated:

“…for the purposes of this report, we have classified core vaccines as those giving protection against any combination of distemper, parvovirus, adenovirus, parainfluenza and/or leptospirosis. We have done this, as in the UK dogs are almost invariably vaccinated against leptospirosis at the same time as the other diseases, which makes it very difficult to determine which vaccine component is responsible for the signs observed.”

In case you didn’t catch that, they decided to bury the adverse events from the L4 vaccine with the other core vaccines.

Despite the signs of safety issues, the RSPCA and World Small Animal Veterinary Association (WSAVA) still recommend pet owners give their dogs the lepto vaccine. The current WSAVA recommendations for the lepto vaccine are:

“…when these non-core vaccines are chosen for an individual dog (on the basis of national or regional knowledge about the prevalence and risks of leptospirosis) they should be given from 8 weeks of age in puppies, with a second dose 2 – 4 weeks later and then an annual booster vaccine.”

So basically, vets can give the lepto vaccine when there’s sufficient risk. So the next question is, what is the risk of lepto in the UK?

Lepto: A Shot In The Dark

MSD defended the promotion of the L4 vaccine in the UK because of “outbreaks” across the country. But when they were asked for evidence of this claim, they admitted it wasn’t based on research, but on anecdotal reporting from vets.

According to Dogs Today writer Hwin-Yi Cohen, the only actual report MSD could provide was a 1991 survey of more than 500 unvaccinated strays in Edinburgh and Glasgow. The study shows that between 23.5% and 27.5% of the stray dogs had antibodies to Leptospirosis (meaning they were exposed to it, got better and moved on with their lives). It also means that 75% of the stray dogs weren’t exposed to lepto at all (assuming there wasn’t a large number of dogs who died from lepto, which is just an assumption since MSD didn’t have those numbers either).

So we only know how many dogs had antibodies to lepto, not how many dogs were actually sick from it.

MSD funded a 2014 project headed by Christopher Ball from the University of Liverpool. A questionnaire was sent out to veterinary practices in the UK for his thesis. Of the 472 questionnaires he sent out, only 89 were returned. Of these, by far the largest response came from vet practices which had seen no lepto cases in the previous twelve months. Only 13 practices reported a case within the last twelve months, of which only five had lepto confirmed by a laboratory test.

A further 29 practices reported having seen a case within the last 15 years. No practice in the study reported seeing two or more suspected (or confirmed) cases in the previous 12 months.

Here in the US, there are also no official statistics for the prevalence of lepto, only haphazard and anecdotal reporting. And as you’ll see, what reporting we do have in the US also shows lepto isn’t all that common.

But Merck and MSD continue to push the lepto vaccine, arguing that it doesn’t matter how prevalent lepto is – because lepto can lead to a horrible death for dogs.

But how true is this?

What Really Happens When Dogs Get Lepto

Just like the stray dogs in the UK, healthy dogs who come in contact with lepto may never show any symptoms.

In affected dogs, symptoms can include fever, vomiting, diarrhea, muscle pain, blood in the urine, lack of appetite and lethargy. In more serious cases, jaundice—a yellowing most easily seen in the whites of the eyes—can occur as the kidneys are affected.

And in most cases, leptospirosis is highly treatable when recognized early. Conventional treatment with antibiotics (typically Doxycycline) usually gives fast, good results and homeopathy is also very successful in treating lepto.

There is a terrible peracute (very sudden) form of the disease where animals go into rapid shock and die; and that’s the lepto we’re all led to fear.

What Is Leptospirosis?

Leptospirosis is caused by the Leptospira bacteria, a type of motile bacteria called a spirochete. The bacteria occur in the urine of animals that have the disease. They survive in water such as streams, ponds and puddles, especially during warmer, rainy seasons. They are also more common in tropical climates where there’s likelihood of standing water or flooding. Rat infestations in densely populated urban areas can also be a factor.


In the US, leptospirosis is most common in Hawaii, California, Oregon, Washington, the upper Midwest, Texas, Colorado and the mid-Atlantic coastal region as well as the southeastern US.

How Lepto Is Transmitted

Dogs, farm animals and wild animals such as raccoons, skunks and rodents can all carry the bacteria.

A dog can become infected when he comes in contact with water contaminated with infected urine. The spirochetes enter the body through the mucous membranes of his mouth, eyes, or nose.

Humans can also contact leptospirosis through contact with the urine of an infected animal or drinking contaminated water. This is so rare (100 to 200 cases a year) that the CDC (Centers for Disease Control and Prevention) doesn’t even consider it a reportable disease. There are 30 US states that do report human cases and Hawaii is where the disease is most prevalent in humans.

Leptospirosis Symptoms

Signs of leptospirosis infection are often vague and non-specific and may include:

  • Fever
  • Lethargy
  • Muscle soreness
  • Appetite loss
  • Vomiting
  • Diarrhea
  • Jaundice

Leptospira organisms can cause severe damage to the liver and kidneys, so veterinarians should suspect leptospirosis in dogs with signs of kidney or liver failure. Other symptoms include uveitis, pulmonary hemorrhage, acute febrile illness or abortion.

Dogs suffering from the peracute form of the disease may show severe symptoms such as:

  • Rapid breathing
  • Rapid, irregular pulse
  • Coughing up blood
  • Tarry feces
  • Nosebleed
  • Red or purple spots on the skin (known as petechial hemorrhage)
  • Reluctance to move
  • Very sensitive to pain or touch
  • Enlarged lymph nodes

Unfortunately the peracute form of the disease is very hard to treat, even with intensive care.
Many healthy dogs (and humans) exposed to Leptospira may not show any symptoms or become ill.

The Nobivac L4 Vaccine

The Nobivac L4 Vaccine is the most recent Leptospirosis vaccine that covers four different strains of Leptospira bacteria:

  • interrogans serogroup Canicola serovar Canicola
  • interrogans serogroup Icterohaemorrhagiae serovar Copenhageni
  • interrogans serogroup Australis serovar Bratislava
  • kirschneri serogroup Grippotyphosa serovar Bananal/Lianguang

The manufacturer recommends giving it at 9 weeks of age, followed by a second shot four weeks later.  Immunization lasts for one year.

But just how many cases of lepto are the low-grade, treatable form and how many dogs actually die?

Nobody is telling us that either and nobody is really keeping track on a large scale.

So I looked at one of the states where lepto is most commonly found – California. And they claimed again that the cases of lepto have been rising in the past few years.

But after a little digging, I found that in 2014, only five dogs in all of Los Angeles County were actually confirmed to have lepto.


So let’s do the math. There are an estimated 1,131,392 households in Los Angeles County that own an average of 1.48 dogs. This means there are an estimated 1,674,460 dogs in Los Angeles County.

And out of those 1,674,460 dogs, only five showed signs of lepto.

Here are the cases of lepto in Los Angeles County for the last ten years.

Graph of cases of lepto in Los Angeles County for the last ten years

So one out of every 334,892 dogs in an apparently endemic area tested positive for lepto antibodies in 2014.

Is this really an issue we should be concerned about?

(NOTE: Want to know exactly how many unnecessary vaccines your dog gets? Click Here to grab our free Vaccine Guide and our handy chart will tell you instantly)

We’re Afraid Of The Wrong Thing Here

So why are so many people trying to make dog owners vaccinate against lepto?

Well … there used to be some clues on this lepto vaccine manufacturer’s web page called Lepto Info. But strangely, the page has magically disappeared. It looks like they’ve completely removed it, as we can’t find their lepto information any more (see if you can find it on their site!).

Fortunately we copied some of the information before they took it down. The headlines were very compelling and were clearly meant to scare dog owners into vaccinating for lepto.

lepto vaccine-2DNM

The number of seropositive dogs in the US has increased over 600% in 7 years

lepto vaccine-3DNM

Surely if this disease was as dangerous and prevalent as this website claimed, somebody would be keeping track of the actual numbers of dogs dying from lepto?

But if you read down further, you’ll see this:

lepto vaccine-4DNM


lepto vaccine-5DNM

Now read right down at the bottom – the bit in fine print that nobody looks at …

lepto vaccine-6DNM

There’s the rub … neatly hidden way down at the bottom of the page.

Most of the lepto scare is being perpetuated by the people who stand to profit from vaccines.

Lepto is a zoonotic disease – which means it can be passed from animals to humans like rabies can. Yet here in North America, we don’t use a human lepto vaccine.

Despite its apparent epidemic proportions, only 100 to 200 people get lepto in the US each year. So few that the CDC doesn’t consider it a reportable disease.

So while the government makes sure dogs and cats are vaccinated for rabies to protect us humans, when it comes to lepto, their involvement is a big old Meh.

So why are we being pushed hard to vaccinate our dogs for a problem that’s really not all that common? And how big of a problem is lepto if your dog comes across it?

The Facts About The Lepto Vaccine

Here’s what you probably don’t know about the lepto vaccine.

The vaccine doesn’t really work all that well

The American Veterinary Medicine Association (AVMA) actually warns that 30% of dogs don’t respond to the vaccine at all.

The American Veterinary Medicine Association (AVMA) actually warns that 30% of dogs don't respond to the lepto vaccine at all

Animal Medical Center Chief of Medicine Dr Richard Goldstein commented that the vaccine “appears” to work but, admits this is based on data provided by the company that makes the vaccine. He also says the vaccine provides a year’s worth of protection but this again is based on drug company data.

The vaccine can actually cause lepto

We’ve been informed of many cases of dogs contracting lepto after getting the vaccine. And in the Canine Health Concern vaccine survey, 100% of dogs with leptospirosis contracted it just after being vaccinated against it.

The vaccine only protects against a few serovars

There are about 300 different serovars for lepto. And the vaccine only covers four of them: Leptospira Canicola, Grippotyphosa, Icterohaemorrhagiae and Pomona Bacterin.

Oh and those dogs in Los Angeles County with lepto? The most common serovar found in those dogs was Automnalis,  which isn’t covered by the lepto vaccine.

The vaccine isn’t very safe!

Most veterinary experts agree the lepto vaccine is the one that’s most likely to cause serious adverse events. Events such as sudden death and autoimmune disease that the European Medicines Agency had already reported. The WSAVA even claims that leptospirosis vaccines “can be associated with adverse reactions” and are “associated with as many or more adverse reactions than occur for any other” optional vaccine on the market.

But MSD defends the safety of their vaccine, saying:

“We appreciate that, on rare occasions, vaccination may adversely affect canine health. Our pharmacovigilance monitoring does demonstrate that adverse reactions such as transient malaise, lumps at the site of injection or even anaphylaxis can occur rarely. These rare outcomes however must be weighed up against the risks of the animal not being vaccinated and thus be left vulnerable to disease.”

If that’s true, then shouldn’t somebody actually start showing evidence of the risks of not vaccinating?

Chris Bradley, the Veterinary Adviser for MSD claims:

“Yes, there is the odd case that may have a possible link to (L4) vaccines but the incidence is so low, it’s not considered significant. Our pharmacovigilance database has had no recorded incidence of anaphylactic shock in dogs, from our vaccine and very little record of other reactions.”

But wait … shouldn’t we know exactly how many dogs are harmed by the lepto vaccine so we can make our own decisions on what level of risk is significant for our own dogs?

Pet owners in the UK are finding out the risk is pretty significant. But if you want to know just how many dogs have been harmed by the vaccine here in the US … well, you’ll never know.

In fact, the government doesn’t even know.

How Vaccine Makers Bury Their Adverse Reports

In order for a vaccine reaction to be reported, a veterinarian would have to first recognize it as a vaccine reaction. Usually, unless the dog’s head swells to the size of a football while he’s still in the clinic after his shot, vets don’t ever consider vaccine reactions as a cause of illness in dogs.

Once the dog leaves the clinic, his owner would need to be smart enough to recognize that kidney disease, allergies or cancer could be caused by the lepto vaccine, even when they appear days after the vaccine.

And if the dog owner is smart enough to know this, then he has to convince his veterinarian to be just as smart and to actually file an adverse report.

And if that report did get filed, it wouldn’t go to the government – it would go to the vaccine manufacturer.

The CVB (the Center for Veterinary Biologics), is a division of the USDA (United States Department of Agriculture) and the CVB is responsible for approving and labelling veterinary vaccines, and for tracking adverse events.

But they only receive 10% of the reports. The rest go to the vaccine manufacturers. And the vaccine manufacturers don’t send them to the CVB unless they’re requested.

And apparently, that’s a rare event.

Here’s how good a job the CVB does at monitoring vaccine safety.

In September 2013, veterinarian Ron Hines received two letters from dog owners whose dogs had died after receiving the lepto vaccine.  So he called the veterinarian’s inquiry line at the CVB and was informed that adverse reactions wouldn’t be discussed with him – that they were “proprietary” and property of the vaccine manufacturers.


Think about it. What this means is that unlike pet foods and drugs, there’s no place where vets, or even you and I, can find reports on vaccine safety.

Think about the thousands of dogs and cats that died from melamine poisoning a few years back. Now imagine that happening without any reporting to the FDA and without pet owners having a place to find the reports on what foods were poisoning pets.

This is what is happening now with vaccines. We have nowhere to go to find out about their safety and nobody seems to care.

So when Dr Hines didn’t have access to the adverse reports for those lepto vaccines, he asked the CVB to view the initial safety studies on them. The CVB again refused to share that information.

“You can see all bad reaction reports on the vaccines humans take anytime – they are posted online.” says Hines. “But you are not allowed to see the same information when it comes to your pet.”

So Dr Hines filed a Freedom of Information Request and although the CVB told him it wasn’t possible, in December of 2013, he was finally able to see the adverse reports involving lepto vaccines.

But neither of the two dogs who died were in those reports.

How could that be?

Well, the only time the CVB receives adverse reports from the vaccine manufacturers is if they request them. And from what Dr Hines learned, that’s a rare occurrence.

So we really have no way of knowing whether the lepto vaccine is safe or not.

According to the Telegraph, a spokeswoman for MSD said: “It is important to critically examine the facts relating to adverse events vs anecdotes that are not substantiated by science and medical evidence. A report does not mean causation.”

Well, right back at you MSD! The entire reason the lepto vaccine is being pushed so hard is because of apparently anecdotal claims of just how prevalent lepto really is.

If you really want to know how prevalent lepto is in your area, you can research this through your local public health department.

But the recent deaths and illness of the dogs in the UK are showing us that the lepto vaccine isn’t as safe as the vaccine manufacturers would have us believe.

The Canine Health Concern’s Catherine O’Driscoll concludes, “The fact that it is dangerous and practically useless, and fighting a disease that is barely a problem, doesn’t much matter to them.”

And that’s the real reason dogs are suffering in the UK.

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