How Much Medicine Should You Give Your Dog?

When we talk about the dosage of pharmaceuticals, knowing how much medicine to administer to our pets is fundamental. Today, we'll explain how to calculate how much medicine you should give your dog.
How Much Medicine Should You Give Your Dog?
Juan Pedro Vazquez Espeso

Written and verified by the vet Juan Pedro Vazquez Espeso.

Last update: 26 October, 2022

Posology is a branch of pharmacology that’s responsible for studying dosages of medicine that a patient should receive to reach the therapeutic amount and minimize side effects. In the case of veterinary medicine, knowing how much medicine to give your dog is crucial. That’s because animals come in all shapes and sizes.

Any time your dog suffers from some condition that requires medication, you need to know how to calculate the correct amount. Today, we’ll tell you everything you need to know.

Posology in medications

Without a doubt, the last time your doctor prescribed you medication, he or she wasn’t thinking about your weight. This is generally because adult humans tend to fall into a general size and weight range. Therefore, doctors usually don’t need to make precise calculations in order to prescribe the right amount.

However, when it comes to dogs, veterinarians work with several weight ranges. These vary from between just a few pounds up to 150 pounds or more. Therefore, knowing how to calculate the exact amount is vitally important in order to guarantee proper treatment. Just think–the largest of dogs can be over 70 times larger than the smallest.

A pill for a mastiff is almost as large as a chihuahua’s head.

A veterinarian preparing medicine for a small dog.

How much medicine should you give your dog?

In general, except for cancer treatments that depend on body surface, most pharmaceutical dosages depend on a dog’s total weight. Therefore, knowing approximately how much your dog weighs will be fundamental when it comes to any sort of treatment.

On occasions, it may seem easy to guess it. However, in dogs with long and voluminous hair, or those that are robust and muscular, your guess may be far off. Therefore, and as a means of protocol, your vet will want to weigh your dog on a regular basis.

Once you know how much your dog weighs, you just need to see what dosage corresponds to said weight. You can usually calculate the amount of medicine you should give your dog by looking at the package insert. For example, let’s say the total dose of a medication is 0.1 mg/lb. So, if your dog weighs 9 pounds, you’ll have to give it 0.9 milligrams. But, if your dog weighs 65 pounds, you’ll have to administer 6.5 milligrams.

How many times per day?

The number of times your need to administer medication per day will also appear on the package insert. Many times, you’ll encounter the following abbreviations

  • SID or QD: From the Latin semel in die or quaque die, meaning once per day.
  • BID: Bis in die, or twice a day.
  • TID: Ter in die, which, as you may have guessed, means three times a day.

There are more abbreviations, but most medication requires between one and three doses per day.

How to divide medication

This answer is actually very simple. Most manufacturers of medicine for animals are aware of these particularities. Therefore, many medications already come in small, medium, and large versions.

This size variety in pills makes it much easier when the time comes to administering medicine. After all, it’s not merely a question of knowing how much medicine to give your dog, but also administering it correctly. Having pills that are just the right size for a dog makes a veterinarian’s job much easier .

However, on some occasions, the medicine a dog needs doesn’t come in a veterinary version. In these cases, it’s time to turn to human pharmaceuticals.

At this point, things get a little more complicated. You may find it tedious to have to cut a pill into 24 pieces for your 5-pound dog… But practice makes perfect…

A scared pug looking at a pill.

We’re sure that the above information will be helpful when it comes to knowing just how much medicine you should give your dog. Remember, being careful in this regard is crucial when it comes to your dog’s health and well-being.

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The contents of My Animals are written for informational purposes. They can't replace the diagnosis, advice, or treatment from a professional. In the case of any doubt, it's best to consult a trusted specialist.