Why you need to ask your vet about pet drug interactions & side effects

Discuss potential medication side effects with your vet

In the middle of a busy veterinary practice, many veterinarians may overlook an opportunity to discuss the possibilities of drug interactions and pet medication side effects. For example, many commonly prescribed nonsteroidal anti-inflammatory medications (NSAIDs) can sometimes cause digestive upset and/or liver/kidney problems in some sensitive pets. Corticosteroids like Prednisone can cause similar problems in some pets, as well as predispose pets to diabetes with prolonged use.

While a topic of debate, these risks are increased if Prednisone and nonsteroidal anti-inflammatory drugs are used together.

While potentially lifesaving, antibiotics can also cause allergic reactions from digestive upset to skin irritation. Some pets are sensitive to topical flea and tick medications, and in my practice I always administer topical flea and tick medication on a separate day from heartworm preventative medication or vaccinations, in order to lessen the burden on a pet’s immune system.

Whenever multiple drugs are prescribed it is always important for pet owners to ask questions, because veterinarians not only prescribe pet medication but are also dispensing these medications in private practice.

Do you have a question on potential pet medication interactions or side effects? Leave a comment below. 

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  1. HI Melissa. No specific reactions of hydroxyzine, doxycycline and thyroid medication. However, thyroid levels shoud be monitored periodically to make sure doses/blood levels of med are adequate and/or not too high. Also pet should have periodic followup with vet who prescribed the doxycycline and hydroxyzine

  2. HI Kim. Not sure about the antiemetic drug being given every 4 days for the cough, but I think it may be cerenia, a drug more commonly used for nausea/vomiting, but which also has been used off label for pain and/or inflammation of airways. May help as adjunct in case like this, but what this dog may need is low dose prednisone type medication such as temaril p, which is my favorite in these dogs, which has cough suppressant as well as antihistamine and/or low dose pred in it but not high enough to cause bad side effects. You would have to work with a homeopathic vet like myself if you wanted more individualized care in that area. To learn more see http://www.doctordym.com . Many homeopathic vets do offer phone consultations

  3. Hi Dr Dym. Is there much evidence that nitenpyram can be used safely with metronidazole? We have a young dog who would really like some nitenpyram ASAP. I am afraid to administer this due to her being on metronidazole and being a sensitive dog in general.

  4. Hi Jeremy. I know of no problems using apoquel and metronidazole together.

  5. HI Jennifer. So sorry to hear about your dog’s possible deafness reaction to the dermavet product. I would return to vet and of course NOT use such products like that containing neomycin or gentamycin again, as on occasion topical antibiotics of this class “may” affect hearing, especially if the ear drum is not intact when it is applied. That is why important for dog with ear issues to be under a vet’s care. ALso report “possible” reaction to drug company.

  6. HI David. I am not familiar with any specific interactions between nitrenpyram and metronidazole.

  7. Good morning. I am wondering if I can apply Advantage 2 to my cat who is on prednisolone and clyndaguard. Any help you can give is greatly appreciated.

  8. Hello,
    I was wondering if its okay to give my cat Dramamine and use feliway spray for car travel? Just want to make sure there isn’t any bad interaction between the two

  9. Puppies had diarrhea, no worms or parasites found. Diarrhea is bloody, they’ve been given Metronidazole and Diphenoxylate.
    Is there a bad interaction between the two because they still have bloody diarrhea.

  10. HI Samantha. I dont see a problem with the Advantage 2, however check with your local vet who prescribed the prednisolone as he or she will be more familiar with the medical history of your cat and is most properly able to give you the thumbs up to proceed with the product

  11. HI Caitlin. Dose of dramamine in cat is typically 12.5 mg given 1 to 2 hours before desired effect. Typical dose is at most once daily. No problem in using at same time as feliaway

  12. HI Mr or Ms Smith. I would use broad spectrum wormer like panacure for 5 or 6 days, as there are hidden worms . i.e like Giardia, etc that often dont show up on routine fecal flotations at vet offices. Further courses of metronidazole and/or other antibiotics like Tylosin may be needed as well, in addition to prescription gastrointestinal foods.

  13. Hi
    I give my dog tramadol as needed for her arthritis pain. yesterday I got hydrocodone oral dose since she’s been coughing a lot due to a progressive collapsing trachea. Tonight I saw her limping and I gave her half of the tramadol 25 mg, and then realized I had given her the hydrocodone 30 minutes prior. How bad is the reaction that can happen ?

    Thank you

  14. My dog has epilepsy and is on Zonisamide 100mg, Levetiracetam 750mg and phenobarbital 97.2mg. He is also on Denomarin after the results of his LDDS test came back. He’s been diagnosed with Cushing’s disease and will need a treatment plan. I want to try and give him a natural herb, like Cushex Drops-S. Will this interfere with the other traditional medications?

  15. HI Aileen. There should not be a problem with the inadvertent giving of tramadol and hydrocodone. Dont worry about this one extra dose of the meds around the same time

  16. Hello I was wondering if it would be safe to give my dog both Bravecto chewable for flea prevention and Heartgard chewable for heart worm prevention. I just wanted to make sure there wasn’t any drug interaction that could be bad before giving them both.

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