The Dangers of Lyme Disease Vaccines for Dogs
Vaccination against Lyme disease in dogs is only usually suggested by veterinarians for dogs living in Lyme-endemic areas or those who are travelling to such areas. This is due to the fact that the Lyme vaccine is not 100% effective and problems may occur with over-vaccination of dogs. There has been suspicion of the vaccine causing glomerulonephritis in some cases, but such associations are few and far between, to the extent that no published studies appear to be available to support such a theory. Glomerulonephritis is a kidney condition which commonly causes such symptoms as weight loss in a dog, apathy, decreased appetite, vomiting, and increased drinking and urination. Laboratory testing of the urine usually finds an increase of blood urea nitrogen, creatinine, cholesterol, amylase, and phosphorus in cases of glomerulonephritis and the dogs often develop anaemia as red blood cell counts lower, along with total protein, and albumin.
However, the testing of a vaccine usually only involves monitoring for any potential side-effects for a few days prior to the vaccine being deemed safe for use. It is then the responsibility of any physician, or in this case, veterinarian, to report any adverse effects of the vaccine in patients receiving the new intervention. It is thought that some dogs vaccinated against Lyme disease do go on to develop the disease, although it is difficult to detect whether this is connected to the vaccination, or to natural exposure to the Borrelia bacteria.
In cases where no actual Lyme disease bacteria were used in the vaccination, such as Merial’s Vaccine, it is impossible for the dog to develop Lyme disease from the vaccination itself but other effects of the vaccination may mimic Lyme disease symptoms causing confusion over diagnosis. The inactivity of the dead bacteria used in the other two types of Lyme disease vaccine for dogs also make it extremely unlikely that any later incidence of the disease is due to the vaccine itself.
Is Your Dog at Risk of Lyme Disease?
It is important to remember that in some areas 60% of dogs are infected with Lyme disease, whilst only a small number, say 3-5% actually develop the disease. In the majority of areas then, the risks associated with hypersensitivity reactions to the Lyme disease vaccine for dogs is deemed greater than the need to vaccinate, especially when comparing vaccine-related adverse events to problems with short-course antibiotic treatment should your dog develop Lyme disease.
Reports have also emerged since the introduction of the Lyme disease vaccine for dogs in the 1990s of dogs developing symptoms indicative of Lyme disease following vaccination but without evidence of infection by the Borrelia bacteria themselves. In such cases it is difficult to determine the cause of such symptoms as arthritis, lameness, and lethargy but could be due to immune-system dysregulation induced by the vaccine in those dogs predisposed to autoimmune system problems. The increasing number of adverse reactions reported to the vaccine is making many people question the desirability of the vaccine when most dogs could be treated with a simple course of doxycycline should they contract Lyme disease.
How Effective is the Lyme Disease Vaccine for Dogs?
The Lyme disease vaccine for dogs is only thought to be about 60-70% effective, with some dogs going on to develop Lyme disease even after vaccination. This may be due to the rapid rate of hybridization that occurs in the bacteria that cause the disease. Originally thought to be just one particular bacterium, the Borrelia burgdorferi sensu stricto, it is now thought that there are more than 37 species of Borrelia bacteria, with 12 thought connected to Lyme disease, and a number of genomic variants.
Whilst the bulk of original vaccine research focused on outer surface protein A (OspA) due to its high level of expression in the infectious bacteria, more recent research concentrates on developing vaccines against the ticks’ saliva as this provides an effective way of protecting against a number of different invading organisms rather than just one. Targeting these tick vectors would also help those in states where Rocky Mountain Spotted Fever, tick-associated rash, ehrlichiosis, and babesiosis exist.
Should You Vaccinate your Dog Against Lyme Disease?
Puppies can be vaccinated against Lyme disease as early as twelve weeks of age, although this is considered unnecessary by most veterinarians unless the puppy lives in a Lyme-endemic area and is unable to tolerate antibiotics. Other, older dogs are subject to the same general rule although those dogs travelling in a Lyme-endemic area may be vaccinated in some cases. Booster vaccination is required each year and this can cause some confusion when blood tests show the presence of antibodies to the Borrelia bacteria already present in a dog’s bloodstream. More recently scientists have developed more accurate methods of testing for Lyme disease antibodies which can discriminate between those produces in response to vaccination and those resulting from natural exposure.
Wagner (et al, 2011) found a high degree of sensitivity and specificity in their combined ELISA and Western Blot bead-based multiplex assay developed to detect antibodies to OspA as well as OspC and OspF antigens. Where a dog shows high levels of antibodies against these outer surface proteins it may indicate the presence of an ongoing Lyme disease infection, which would require antibiotic treatment rather than vaccination.
Where levels of antibodies are low or non-existent, and where a dog is thought at risk of infection through tick-bite, vaccination may be considered appropriate. Currently, where a dog tests positive for antibodies to Borrelia bacteria, a secondary (C6) test is usually carried out to determine whether the antibodies are related to previous vaccination. A combined test would make things considerably faster, cheaper, and less troublesome for dogs, their carers, and veterinarians alike.
Natural Immunity to Lyme in Dogs
Detectable titers to Lyme disease (borreliosis) are frequently found in dogs which display no symptoms of the disease and in those dogs which have been vaccinated against Lyme disease. This can make treatment decisions difficult for many veterinarians and standard practice is not to give antibiotics based on a blood test alone but to monitor for symptoms of Lyme disease in dogs instead. Titers may remain positive for a considerable period of time and, in areas where Lyme disease is endemic and risk to dogs is high, many veterinarians will recommend booster shots of the Lyme disease vaccine for dogs even when titers are positive.
Wagner B, Freer H, Rollins A, Erb HN., A fluorescent bead-based multiplex assay for the simultaneous detection of antibodies to B. burgdorferi outer surface proteins in canine serum. Vet Immunol Immunopathol. 2011 Apr 15;140(3-4):190-8. Epub 2010 Dec 10.
LaFleur RL, Dant JC, Wasmoen TL, Callister SM, Jobe DA, Lovrich SD, Warner TF, Abdelmagid O, Schell RF. Bacterin that induces anti-OspA and anti-OspC borreliacidal antibodies provides a high level of protection against canine Lyme disease. Clin Vaccine Immunol. 2009 Feb;16(2):253-9. Epub 2008 Dec 3.
LaFleur RL, Callister SM, Dant JC, Jobe DA, Lovrich SD, Warner TF, Wasmoen TL, Schell RF.
One-year duration of immunity induced by vaccination with a canine Lyme disease bacterin. Clin Vaccine Immunol. 2010 May;17(5):870-4. Epub 2010 Mar 17.