What can cause your dog’s vaccinations to fail?

Vaccinating your dog against all of the core transmissible diseases that are considered to be a threat to the canine population of the UK is of course a vital part of keeping your dog safe and protected against the main nasties that can affect our pets, and this is something that all responsible dog owners are well aware of.

The chances of a vaccinated dog getting sick due to one of the conditions that they have been vaccinated against are very low-and even if they do catch such a condition, it is apt to be much milder than it would be in a non-vaccinated dog-however, it can happen, and this is something that not all dog owners know.

Whilst generally you can pretty much forget about your dog’s vaccinations after their annual boosters and rest assured in the knowledge that they are covered for a year, in a small proportion of cases, vaccinations fail, and fail to provide coverage-or provide a lower level of coverage than they should.

Obviously you may well not realise this at the time-or ever, if your dog does not get sick and continues to have successful booster shots each subsequent year-but understanding some of the causes of vaccination failures in dogs is a good idea for dog owners, in order to help to reduce the chances of it happening to your own dog.

In this article, we will look at the various different causes of vaccination failures in dogs, and how they can be avoided. Read on to learn more.

What do we mean by vaccination failure?

Vaccination failure in this context refers to a situation that occurs when a dog is vaccinated as normal, using the appropriate product that has been properly stored, handled and administered, and yet the vaccination either does not take effect at all, or provides a level of protection that is not as high as it should be.

One of the main problems with vaccination failure is that you are unlikely to know that the vaccination has failed unless the dog becomes sick with a condition that they should have been protected against, although unless the vaccination totally failed, it will still offer some level of protection.

Dogs can of course be tested for their antibodies against different conditions, so it is theoretically possible to ask your vet to test your dog after the proper time has elapsed. However, while your vet will of course do this if you are willing to pay, it can be expensive and is usually unnecessary due to the extremely low rate of vaccination failure.

That said, if your dog is known to be at risk of vaccination failure or if your dog has become sick with a condition that they should have been covered for, it may be wise to test them or have them tested after their next set of vaccinations or boosters just to be sure.

Next, we will look at the main causes of vaccination failure in dogs in the UK.

Puppy vaccination problems

Responsible breeders that do not sell or rehome their puppies until they are at least twelve weeks of age will have had their pups vaccinated prior to them going off to their new homes, giving the new owner one less thing to take care of.

However, prior to their first puppy vaccinations, pups receive a level of protection thanks to the antibodies present in their mother’s milk, which also helps to kick-start the pup’s own immune system and begin the process of building and strengthening their immune system for life.

However, the timing of administering puppy vaccines is important, as up until the pup reaches 14-15 weeks of age, they will be suspended in what is known as a “window of susceptibility”-essentially, a time of their life when they are at higher risk of contagious disease than they will be at any other point in their lives. This is because during this stage, their maternal antibodies will be falling and with them, the protection that they offer to the pup, but these antibodies can still potentially compromise the efficacy of the vaccines that are given.

This is why puppies are given their vaccinations in two stages with a gap between them, to counteract this issue, and because adult dogs do not face the same problem, they only need one dose of their boosters.

The younger the pup is when they have their vaccinations, the higher the risk is-which is why pups do not receive their first vaccinations until they are at least eight weeks old.

Dogs with weak immune systems

Dogs that have any form of immune disorder that causes immune suppression may suffer from a heightened propensity to vaccination failure or vaccinations not being as effective as they should. This is because of the way that vaccines work-they are designed to trick the immune system into recognising a threat and so, producing antibodies against it, which then protect the dog against a live strain of the same illness.

However, if the dog is immune-suppressed, their immune system’s response to vaccination will be weaker than it should be, or even absent entirely, which is why special care and consideration should be given when vaccinating immune-compromised dogs to ensure that they are protected.

Ill health or substandard living conditions

Illnesses and substandard living conditions all serve to weaken the dog’s immune system for the duration of the problem, and so vaccination must not be given to a dog that is ill, even if the illness is mild and not causing any real problems-such as a slightly high temperature or a bout of the sniffles. Waiting until the dog is well again can prevent this.

Also, a dog that is malnourished, in poor condition or otherwise suffering due to poor living conditions or care will have a weaker immune system too, which again increases the chances of vaccination failure.

Other issues

Vaccination failure can also occur if the vaccinations are not administered properly, or if they have been stored or handled incorrectly, such as being out of date, not being kept in a fridge or otherwise are improperly cared for.

Avoiding this relies upon the integrity and care standards of the veterinary clinic that buys and gives the vaccine, and the skills of the vet to administer them, and so such situations are vanishingly rare and regarded very seriously by the RCVS should they occur.

Whilst administering a vaccine is in itself fairly simple-a shot to the scruff of the neck (or a nasal spray for kennel cough) things can go wrong during administration, particularly if the dog is a handful and challenging to dose. The most common issue that arises (which again is not really common at all) is for the needle to go through the dog’s scruff and out the other side, so that the dose is not delivered, or for the nasal spray to not fully go up the nostril.

Brachycephalic dogs with particularly flat faces are the main challenge when it comes to administering nasal vaccines, as is the case with the pug, which has both a flat face and small nostrils.

However, such problems are usually obvious when they occur, giving the vet the chance to do it again in order to ensure protection.