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Dr. Kara
Dr. Kara, Board Certified Veterinarian
Category: Veterinary
Satisfied Customers: 16885
Experience:  Over 20 years of experience as a veterinarian.
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My 4.5 month old Brittany just received his Leptospirosis shot..

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My 4.5 month old Brittany just received his Leptospirosis shot.. His first one about 3 hours ago.. It appears swollen at the injection site and when i apply mild pressure to it he whines. It appears to be painfull to him when laying on that side.

Hello, I'm Dr. Kara. I have over 20 years of experience as a veterinarian and I'd like to help with your concerns about Cooper.

I'm sorry to hear that he is uncomfortable and it may be that he is having a mild reaction to the vaccine.

You can apply a cold compress to the area to reduce swelling.

In case he is having a mild allergic reaction you can give him Benadryl (diphenhydramine only, don't use the combination products with decongestants or acetaminophen as they can be toxic to dogs) at 1mg to 2mg per pound or one 25mg capsule per 25 pounds of dog orally every 8 hours for 72 hours.

Be aware that antihistamines can cause sleepiness or hyperactivity in some dogs. These side effects do wear off with repeated use.

Things to watch for that indicate he needs emergency veterinary care are vomiting and diarrhea, facial swelling or difficulty breathing.

If he is still uncomfortable by tomorrow then call and describe his situation to your veterinarian, they will likely either want to recheck him or prescribe an anti-inflammatory to make him more comfortable.

Please let me know if you have any further questions.

Dr. Kara and other Veterinary Specialists are ready to help you
Customer: replied 4 years ago.

He has been passing gas a few times and I am assuming he is not asking to go outside right now, due to the rain. Should I be concerned with regards XXXXX XXXXX stomach? Also with regards XXXXX XXXXX on palpation. Is this normal? He stood up and just stood there and attempted to not put pressure on that leg. Thanks for your help.

As long as he isn't actively vomiting I wouldn't be too worried.

This is one vaccine that we can see a fair amount of secondary inflammation from unfortunately, and probably one that we see more reactions to compared to other vaccines we give. While it isn't "normal" for him to have inflammation and pain they are side effects that are seen with some frequency.

I would definitely let your veterinarian know about his reaction and in the future you may want to consider his risk for the disease in relation to the side effects that he experiences. If he's a hunting dog or a country dog that is exposed to wildlife or a city dog where the rat population is very high then it may be worth continuing to vaccinate him. But I would use antihistamines prophylactically and put him on an anti-inflammatory to mitigate side effects. If he has a very low risk of contracting the disease you may not want to vaccinate him any more.

If you believe his stomach is upset you may want to feed him a bland diet of 1/3 boiled hamburger (or white skinless chicken), all fats and juices drained off mixed with 2/3 boiled, plain white rice. Feed several small meals a day for the next few days. Once he feels better start mixing in his regular dog food very slowly. Less bland more regular with each day. It should take a week or so to convert him back.

Please let me know if you have any further questions.

Customer: replied 4 years ago.

Thank you very much Dr. Kara. Cooper lives between New York City and the North Shore of Long Island. I do not think I will be continuing these shots as I feel his risk of contracting this disease is low. Thanks again.

You are very welcome. His risk of coming in contact with the disease sounds pretty minimal but your veterinarian should have better statistics as far as risks of contracting the disease and I would ask about it.

Just keep a close eye on him tonight. Watch him for pale gums or incoordination, vomiting or difficulty breathing. Those symptoms signify that he is in trouble and needs emergency care.

I just wanted to check in on Cooper and make sure that he is feeling a little better today. If he is still very uncomfortable I would call your veterinarian ask if they will prescribe an anti-inflammatory for him to make him more comfortable.

Let me know if you have any further questions.

Customer: replied 4 years ago.

Hi Dr. kara,


Thank you very much for checking in on Cooper. He slept it off and is feeling a lot better. The site of the injection is no longer swollen. We called the Vet and she told us the same things you had told us. She said we can give him Benadryl now and prophylatically for the second booster, if we choose to continue with the vaccine. My wife and I are considering against continuing the vaccination. Again thank you so very much for your concern.





Davin, thanks for the update on Cooper. I'm glad to hear that he is feeling better today. I always worry a little bit about these reactions as they can progress to a dangerous situation and I wanted to make sure that didn't occur with him. I appreciate you taking the time to let me know he is fine, take care and best of luck with your fellow, Dr. Kara


As an aside in the future I would separate his vaccines, never giving more than one at a time as a precaution against over-stimulating his immune system. I would also recommend vaccinating him early in the day so if something does occur your veterinarian, who know him best, is available for treatment.