Why Did My Dog Get A Large, Swollen, Hard Lump After Receiving Vaccination Shots On His Upper Back By His Neck?

First of all, I must point out I am not a medical or veterinary expert so if you are really concerned about your dog's well being take him to a vet as soon as possible. This is because you also give no other details about your dog such as other symptoms he may be suffering from, his age and what breed of dog he is. Also you give no indication of any previous health problems he has, so by taking him to your local family vet, they will have the added knowledge and expertise to advise you accordingly.

Based on opinions from other pet owners and comments posted on online forums, there could be a number of explanations for the lumps your dog has developed.

These may include the following:

• A reaction to the injection that has caused a lump to develop. If it keeps growing, starts turning red or it is obvious your dog is in pain- please seek medical attention for him.
• Sometimes an infection can be caused by needles that have not been cleaned properly. If the lump has started to get bigger and is very red, go back to the vet as soon as possible.
• Some vaccines that contain immune system stimulatory additives are known to cause a lump in the area where the injection was administered. This lump is generally found under the skin and can also be moved around. Some lumps of this type can reach the size of a marble and can stay on the skin for up to six weeks. If you are concerned or unsure though, ask for help.

Not normal exactly but it happens. Can happen from things like playing with other pups as well. If the vet gave the vaccine it is extremely unlikely a handling issue (but could be with someone else if unaware of protocol) but more likely something got into the tiny puncture (dust, bacteria ect.). Try warm compress several times a day for a couple of days. If it gets bigger or there is no change in a couple of days, opens, or you see any signs your pup isn't feeling well or acting normal or anything you should call your vet.