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Dog Reaction to the Lepto Vaccine

Lepto Vaccine for Dogs

A dog reaction to the lepto vaccine is something that needs attention. Leptospirosis is a serious medical condition in dogs but a dog reaction to the lepto vaccine can be something scary to witness as well. Fortunately, most cases of dog reactions to the lepto vaccine are self-limited, with the symptoms subsiding generally within 72 hours; however, there are always risks for anaphylactic shock after a vaccination, so it's imperative to keep an eye on the dog for some time so to ensure this does not happen. Vaccine reactions should always be reported to the vet, so the vet can record the event in the dog's medical records and take preventive measures for future vaccinations.

Dog Reaction to the Lepto Vaccine 

Parvo is part of the five in one vaccine for dogs

Report dog reaction to the lepto vaccine to your vet.

At times, some dogs may develop vaccine reactions to the lepto shot. There are two types of reactions that may occur: serious anaphylactic reactions and mild reactions.

Usually, the most serious (yet rare!) reactions tend to occur within several minutes to an hour after the vaccine. Dogs typically develop swelling around the eyes, mouth or there may be "hives" on the dog's body. Some dog may start vomiting and having diarrhea.

Usually dogs are still at the vet or on the way home when the first signs happen. The reaction can be life threatening just similar to what happens to people with a peanut allergy after consuming peanuts, points out veterinarian Dr. Fiona.

Most vaccine reactions in dogs are fortunately mild and delayed, presenting hours to several days after vaccination. Typically, these dogs develop a mild fever, lethargy, reduced appetite and vomiting, explains veterinarian Dr. Scott.

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Affected dogs may feel better when given plain Benadryl. Dogs who are vomiting instead may benefit from Pepcid for dog vomiting or fasting followed by a bland diet. Consult with your vet for dosing instructions. Your vet may want you to pick up a stronger prescription drugs (like short-acting steroids or an anti-histamine injection if the reaction warrants it).

Particularly predisposed to vaccine reactions are young, small-breed dogs who received multiple vaccines per office visit. Generally, these dogs develop symptoms within 72 hours after vaccination.

If your dog is suffering from a vaccine reaction, it's always best to contact the vet. With this sort of thing it is always a gamble. To make sure you are doing the right thing it's always best to have vet check over your dog without delay.


Dogs Who are Sore

It's not unusual for some dogs to be a bit sore at the vaccination site after a lepto vaccine. Affected dogs may act in pain after some hours following the shot. They may resent being picked up, touched or being near other dogs. However, after 3 to 4 days affected dogs should be back to normal, points out Dr. Matt. 

Something you can do to help your dog feel better is to alternate warm and cool compresses over the area the lepto shot was given (usually the left shoulder). Alternating helps because, on one hand, the coolness helps sooth the pain, while on the other hand, the warmth increases blood flow to the area, which ultimately speeds up healing, points out veterinarian Dr. Altman.

You can also call your vet and ask whether giving some plain Benadryl (diphenhydramine) to help reduce the side effects from the injection is worth a try. Some dogs may also need pain medications or steroids if their symptoms are severe or long lasting. Consult with your vet if you suspect a dog reaction to the lepto vaccine.

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How Risky is it Really? 

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There is still a prevailing belief that the lepto vaccine has a high rate for causing vaccine reactions. A 2010 ACVIM Consensus Statement on leptospirosis revealed that a study was dedicated on observing acute vaccine reactions in dogs.

The study found that the lepto vaccine was no more likely to cause problems than the other vaccines. "The leptospirosis vaccine is a killed vaccine and is no more risky than a rabies vaccine," points out Dr. DeBess. Dr. Bess currently recommends that all dogs should be vaccinated against this disease and that includes dogs who have contracted the disease once they are healthy again and off the antibiotics.

And what about future vaccines? If your dog had a mild reaction to the lepto vaccine and your dog lives in an area where the disease is prevalent, then your vet can "pre-treat" your dog to prevent a future reaction. This means your vet can give your dog some Benadryl or an anti-inflammatory drug like dexamethasone before the lepto vaccine. This pre-treatment helps prevent allergic reactions before they have a chance to start and generally take care of the problem, further adds Dr. Fiona.

dog lepto vaccine reaction

To Vaccinate or Not?

"Should I vaccinate my small house dog against lepto?" Many dog owners wonder whether they should vaccinate or not their dogs against lepto, especially after a dog reaction to the lepto vaccine.

This is ultimately something that only the vet can determine based on location and the dog's lifestyle. Vaccines should be given when a dog is likely to be exposed to a disease in question.

Lepto is a disease of world-wide importance that is particularly prominent in places with wet climates. The leptospira bacteria are carried in the urine of domestic and wild animals. Any dog that comes in contact with other dogs, raccoons, rodents or other animals that act as reservoirs for infection, should be vaccinated against lepto, points out veterinarian Dr. Drew.

In farms, animals that act as primary reservoirs of infection in dogs are mainly pigs and cattle, while in suburban areas, wildlife animals such as rodents, deer, raccoons, possum and other common wildlife act as important reservoirs. Exposure to urine-contaminated water, can also cause disease.

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Living in the city is not without risks considering that rats function as reservoir as well, explains Dr. Kenneth R. Harkin, a veterinarian specializing in internal medicine. Rat urine can be easily found on city sidewalks. So, yes, those small dogs living in apartments in a city like Portland, Oregon can be at risk for lepto as well!

Deciding whether to vaccinate or not a dog for lepto is therefore based on potential for exposure. With lepto being a potentially deadly disease, the risks associated with giving the vaccine are usually much lower than the risks of the disease itself. Dog owners should consult with the vet for guidance.

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  • DVM360: Canine leptospirosis (Proceedings)
  • DVM360: Not your grandpa's canine leptospirosis cases
  • DVM360: The changing face of canine leptospirosis
  • Sykes JE, Hartmann K, Lunn KF, et al. 2010 ACVIM small animal consensus statement on leptospirosis: diagnosis, epidemiology, treatment, and prevention. J Vet Intern Med 2011;25:1-13

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