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.

Have pet health questions? For any medical concerns, we always recommend you consult your veterinarian. However, for non-emergency questions, you can contact Dr. Dym directly using our Ask the Vet form.

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  1. hi karen. frankie is doing okay, but i wondered if you could help me with some things. he was dx with CHF jan 27th and is still on all those same meds. when he first came home from the hospital he was l.5 pounds lighter from them getting rid of the fluid. prior to that visit and now 🙁 he seems fuller and kind of grunts when i pick him up. respirations are great, but he seems sluggish alot. he also gets kind of “slurpy” with his tongue and nose and i dont know if that could be his tummy upset or what. the specialist doesnt really have answers, but i thought i would ask you since you have a same size dog that has the same dx. thanks for your help. i appreciate your time and hope your dog is doing well.

  2. also, what mg. of each is she taking? you can feel free to contact my email directly if you want.

  3. Dr. Michael Dym, VMD veterinarianMarch 27, 2014 at 10:27 pm

    Hi Teri. I did not see first part of your email, but cornerstone of treating CHF in dogs typically involves drugs like vetmedin, diuretics like furosemide, and in later stages spironolactone, as well as ACE inhibiters like enalopril or benazopril. I also like to use supplements on these pets like Coenzyme Q 10 as well as hawthorne herb.

  4. Dr. Michael Dym, VMD veterinarianMarch 27, 2014 at 10:30 pm

    I dont see a problem with these two meds, however you should be under care of local vet while using these meds.

  5. Hi I have a 4 year old Doxie who has recently been prescibed Metacam once a day for back pain. I took him to the vet because I suspected an ear infection and our vet gave him Primor 240mg for 10 days. Are these drugs ok together? He weighs 20 pounds. Thank you very much for your reply and God bless.

  6. I forgot to mention that my 4 year old Doxie is also taking a pill to protect his stomach before taking Metacam. He was also given a topical ointment for his infected ear. Thank you again.

  7. Dr. Michael Dym, VMD veterinarianMarch 29, 2014 at 3:42 pm

    Hi Jennifer. There should be no problem with these drugs, although always best to have liver/kidney blood work done first before going on drugs like these just to make sure no underlying pre existing issues.

  8. Dr. Michael Dym, VMD veterinarianMarch 29, 2014 at 3:43 pm

    Got it.

  9. I hope you can help. My dog recently got a carpal sprain. The vet did blood work to check her liver/kidney functions as well as her sugar and protein levels. Everything was good. I ended going to an orthopedic specialist for a 2nd opinion. He agreed about the sprain. He said to continue the previcox but now has added Gabapentin. I gave her the first dose of the Gabapentin yesterday, now this morning it seems as if she may have a UTI (she had a few in the past and acted the same way, wants to go out every little while and just pee’s a little bit). I’m calling the vet as soon as they open but I’m very concerned about these medications. Do you have any suggestions? I’m so worried. Thank you so much!

  10. Dr. Michael Dym, VMD veterinarianApril 4, 2014 at 5:50 pm

    HI Kelly. Gabapentin and Previcox are fine. Likely separate urinary tract infection from the history you mention. See vet for exam and urine analysis, as she may need antibiotics, etc

  11. can anything natural take the place of lasix, theophylline and ciprofloxin for a large dog with cancer in the lungs and breathing problems from that. our dog Sam was yesterday diagnosed with cancer nodules in the lungs and extra fluid (and possibly cander on ribs as well?) She was having very labored breathing and is now breathing better but very lethargic after on day on meds described above. She wont make the effort to drink water and when presented sometimes will and sometimes won’t. She hasn’t wanted to eat anything at all since yesterday. I want to know if there is anyway to keep her comfortable and breathing and hopefully eating and help with the extra fluid on her lungs without all those harsh meds??? Thanks for advice.

  12. Dear Dr. Dym,

    My 7 pound 13 month old Yorkshire Terrier name Lucy was spayed about 4 days ago. Less than 24 hours post surgery she began having diarrhea & vomiting & refused to eat or drink so I calked my Vet. Upon exam the Vet stated she was slightly dehydrated so they injected a subcutaneous hydration pack under her skin as well as a shot for her nausea. She was also prescribed Centrine (1/2 tablet) every 12 hours until stool reformed, which it has after only 1 round of the Centrine. In addition the Vet. put her on Baytril 22.1 mg. 1 X/day because she was suspected of having a Urinary Tract Infection. Since the return visit she has improved tremendously & is now eating chicken & rice as well as drinking appropriately.

    Now that I’ve given you her short term health history, my question is this: Lucy has started licking me excessively. Licking my hands, fingers, arms, neck, etc. last night I awoke many times to her lying beside my licking my arms & hands nonstop… Could this be a side effect of any of the drugs she was given or is still taking? Should I be concerned about this behavior being a sign of some other health issue? I realize it’s only licking but it’s out of character for her & quite annoying as well. While she has always been a \llicker\ & loves to give kisses when she’s excited or first seeing you she has never just sat & licked me non-stop or as much as I will letter her lick me like this!

    Thanks so much for your help!


  13. Dr. Michael Dym, VMD veterinarianApril 6, 2014 at 10:00 pm

    Hi Terri. Conventional/traditional medicine really does not have answer or reason for this common clinical complaint of of animal guardians, except to call it some type of obsessive/compulsive disorder, and not due to any of the drugs. I have seen this licking behavior sometimes come up within a few weeks or months of a rabies vaccination, so curious when that last shot was. If sign persists or worsens, then may be worthwhile consulting with a homeopathic veterinarian. To learn more about homeopathy, go to http://www.beyondflatearth.com as well as my website http://www.doctordym.com Many homeopathic vets do offer phone consultations.

  14. Dr. Michael Dym, VMD veterinarianApril 6, 2014 at 10:05 pm

    Hi Bobbi. Always need close monitoring when on the combination of theophylline and cipro, as sometimes elevated theophylline blood levels are seen with this combination. As for other options, I would recommend consulting with a holistic veterinarian in your area. To learn more and to find a homeopathic vet in your area go to http://www.drpitcairn.com

  15. Thanks, you help is appreciated. I quit giving her the meds last night, all three and so far she is feeling and acting so much better. Have not seen any more breathing difficulties, but will monitor her closely and look to see if there is a holistic vet near here. I don’t know where this will go but while giving the meds she simply had no quality of life. Interestingly enough, most humans put up with ingesting this kind of chemicals and medicines all the time and putting up with the side effects and wondering why they are still so sick.

  16. Hi Dr. Dym,

    Thank you for the answer to my question although as you say it’s very strange as it literally started overnight & exactly after receiving the medications I mentioned in my email. The day before she was not doing any of this licking behavior.

    I believe her a Rabies shot was in November of 2013, so it’s been about 4 1/2 to 5 months. Does that fit within any timelines of people reporting this sudden licking behavior? If she doesn’t stop the licking then I will contact a homeopathic Vet. for assistance as I don’t want to let this continue so much that she develops it into a habit.

    Thanks so much for your help!


  17. hi i have a senior male english springer who is on proin. one of his feet has recently gotten irritated near an old sore. i think it may be allergy related as the world has just greened up here and the grass has started growing again. i was thinking of giving him benadryl, but am not sure of the interaction with the proin.

  18. I have a 75 lb American bulldog that s on hydroxyrine 50 mg and Temarl p I can not get her allegry rash under control is there anything else I can do for her?

  19. Dr. Michael Dym, VMD veterinarianApril 7, 2014 at 5:39 pm

    Temaril p may need dosing up, as well as oral antibiotics may be needed in case like this

  20. Dr. Michael Dym, VMD veterinarianApril 7, 2014 at 5:40 pm

    I don’t think these will have much of an interaction but check with your local vet who knows your dog’s history for best advice.

  21. Dr. Michael Dym, VMD veterinarianApril 7, 2014 at 6:00 pm

    HI Terri. Yes I do see in the coming months post rabies vaccination these types of compulsive behaviors. Sometimes what the drugs do is suppress the body’s life force or immune system, allowing these hidden underling tendencies to come out, but are not direct cause/effect. I think homeopathic consultations would be wonderful. Many like myself consult with clients nationwide over the phone, but I would learn more about the chronic process first before scheduling a consultation with any homeopathic vet. Also make sure homeopathic vet is following normal standards of care like I do, as a lot of homeopaths out there not doing service to clients. The guidelines I follow are gone over on http://www.drpitcairn.com My website tells you more about my practice, as I was trained by Dr Pitcairn http://www.doctordym.com

  22. Dr. Michael Dym, VMD veterinarianApril 7, 2014 at 6:08 pm

    Let me know how things proceed. Thanks for the update. Remember many vets like myself do offer phone consultations nationwide http://www.doctordym.com

  23. Hi there, I adopted a dog in December and knew she was “light positive” for heart worms. She was placed on heart guard starting in July of 2013. She was taken to the vet and he didn’t believe light positive results existed. Short story they ran blood work on two brands of the rapid test and one was a barely distinguishable line and the other strong positive. I am refusing to do arsenic based injections. My rescue shelter, foster mom, and many others have had success using a modified slow kill. Ivermectin 1x per week 0.33cc and antibiotics cycles. On one month, off 2, on 1,off 2, etc for at least 6 months. Doxycline is no longer free and they wanted $450 for 90 pills. That’s outrageous. The foster mom, whom I trust very much, said you can use cephalexin. I know a vet can’t tell me to do slow kill. But ive heard successful stories. Dogs heartworm free in 6 mos to a year. She is a 32 lb beagle/ridgeback. She is 22 mos old. Thank you.

  24. My 12 yr old mixed lab has a tumor in the bladder. She is taking piroxicam 5 mg daily for the last 5 months. In the last 4 – 6 wks Her stools have become yellowish and more watery than normal.
    Could this be a reaction to the meds. Initially she was also taking a pepcid ac daily but didn’t seem to have any problem with the piroxicam so I took her off the pepcid per the vets instructions after a month on the meds. The meds are quite costly since they have to purchased from a compounding pharmacy. I was wondering if there was a generic of some type.

  25. I have a 7 yr old Shar Pei that weighs 61 Lbs. He is currently on Phenobarbital for seizures and lately has begun peeing in the house at night. The dog door is opened all evening until we go to bed. We reading a bit about Proin. Would this possibly help and can it be taken with the Phenobarbital? Thanks!

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