Top Veterinary Articles of the Week: Medication Side Effects, Coccidia, and more ...

7 Common Side Effects of Pet Medications

Dr. Jennifer Coates

Every time you introduce something into the system that naturally doesn't belong there, there is a consequence. Whether it's an antigen, toxin or a drug, it's something the body has to deal with. Science is working on improving medications to limit these effects but as Jasmine's vet said, something can either be effective or have no side effects. I hope that in the future the medications will become targetted enough not to influence things that you don't want influenced but that day hasn't come yet and it might never come.

How much an infection, toxin or medication is going to mess with the system depends on the individual system and its ability to deal with it. That's why some dogs can encounter an infection and not get sick, and some dogs can take long-term medications and not suffer any serious side effects.

I do believe, however, that it is important to realize the fact that every time you introduce a drug into it that you might be looking at side effects. Sometimes these can be mild and sometimes quite violent. Before medicating my dogs, I always ask what to expect and I also recommend reading the product sheet. Your vet is likely to list the common side effects if you ask, but also just as likely not to cite the rare serious ones. This makes sense. But rare doesn't mean it can't ever happen.

"Deciding to give a pet medication always involves determining if the benefits outweigh the risks." ~Dr. Jennifer Coates

What are the most common side effects? With orally administered medications you're looking at potential vomiting, diarrhea, other GI issues, With injectable medications site reactions. With any medications, there is the potential of allergic reaction, weakness, lethargy, and even liver or kidney damage.

Always discuss the pros and cons with your veterinarian.

Related articles:
Veterinary Visit Checklist: Before You Leave the Office
Our Dog's History of Adverse Drug Reactions

How a nasty little protozoa can make life miserable for your pet

Marty Becker

One of the dilemmas in veterinary medicine is the distinction between exposure to a pathogen and an actual disease. For example, if you run your annual Lyme disease blood test and it comes back positive, what should be done? Should you treat the lab work or should you treat the dog? There is no true consensus on the matter at this time. In the particular case of Lyme disease, there is further testing that can be done to determine what is really going on. But what about the cases where a more accurate determination cannot be made?

With blood tests, what the lab is looking for are antibodies. Antibodies are a reflection of an immune response. What such test result is indicating is that there is or was a presence of a bacteria or a virus and that the immune system built an army to deal with it. It doesn't  tell you whether the defense was successful or not, whether you should be helping the troops or not. It's important to note that such test will also be positive after successful vaccination. It indicates the presence of specialized troops. Nothing more, nothing else.

The line might get even more blurry when rather than antibodies, a test detects the actual pathogen, such as with Coccidia. Unlike with an antibody test, where the pathogen might have long been destroyed and dealt with, positive fecal results mean the little bastards are definitely there, no doubt about it. But what if your dog is not sick?

The answer is actually simple. Treat it. If you find out you have mice in your house, why would you wait until they clean out your pantry? You know they're there, you know they're going to do this, and you know they're going to multiply and spread.

With Coccidia, your dog may or may not have a peace agreement with the invaders, but even if they do, every time your dog poops, the infection can spread to other dogs and puppies who can get very ill or even die.

While you may or may not want to treat positive blood test results, you do want to treat positive fecal results.

Mast Cell Tumors in Dogs – A Common Canine Skin Cancer

Dr. Christopher Byers/CriticalCareDVM

Mast cell tumors are common. Way too common, if you ask me. And they can look like just about anything else. Mast cell tumors don't kill dogs, assumptions do. If caught and addressed early, surgery can be curative.

Read Dr. Byers' overview here.

Related articles:
Don't Wait, Aspirate: JD Grows New Bumps
JD's Mast Cell Tumor Diagnostics, Strategy and Treatment


  1. I liked the post about side effects of medications. I started taking my dog to a holistic vet a few months ago, because I was fed up with the amount of drugs my vet was prescribing. Don't get me wrong, he's an amazing clinician and has helped Red tremendously, but every time there's a problem it's more chemicals her tiny little body has to process. We've gotten her off a couple and onto supplements instead. Of course there are situations when drugs are necessary, but there is such a thing, in my opinion, as an excess. I prefer a more natural approach when possible.

    1. Sometimes it's easy to keep adding drugs to a treatment; granny once got really sick because her doctors kept adding and adding and adding, causing toxicity and severe interactions. Only after being rushed into the hospital they took out over half of the things she was on.

      I think it's important to keep an eye on such development and revisit whether or not all the drugs are needed instead of adding further.

      We are also big on using alternative approaches; herbals and supplements. Else you might end up in a situation that you add a drug to counter effects of another drug, and then another to counter that, and then another to counter that ... it can snowball quite easily even with best intentions.

      A good thing to always as is "do we still need to give this medication?" Should we be adding one instead of removing one?

  2. This is an important topic. I know first hand when dealing with giving medications to my cat (before she passed). I elected to use minimal drugs and mainly holistic solutions. Although my pet died in the end, I know the holistic remedies given to her help her feel more normal and happy vs. vaccines/chemo from the vet.

    1. For most things, there is more than one answer. Minimizing the use of drugs, though, I believe is always an important criteria.

  3. People really need to think hard about giving their pet medications. Sometimes vets are too quick just to write a script. There are lots of options and lots of ways we can help support our pets when they are on medications. Thanks for the post.

    1. Sometimes drugs are called for, sometimes they are not. Sometimes there are alternatives. I am more likely to agree to a drug short-term in an acute situation; much more likely to look into alternatives long-term for chronic or ongoing issues.

  4. Our Sienna had something called 'Suppress' once. The side effect was deep depression and it terrified me so much we threw the tablets away and made attempts to control her flea allergy in other days.

    1. Sorry you had such bad experience; we've had our share of bad drug reactions too. Measure twice, medicate once is my motto.

  5. It's funny, we're so aware of the side effects from human meds, probably due to all the requirements in print & commercial ads, but we tend not to think about them as much for pet meds. It is important to weight out the side effects vs. the severity of the issue before dosing your pet up w/ meds.
    Love & Biscuits,
    Dogs Luv Us and We Luv Them


Post a Comment