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Considerations for the Use of Antibiotics in Dogs and Cats

Antibiotics are commonly used in both dogs and cats. They are used primarily to either treat an existing bacterial infection or to prevent a bacterial infection from occurring. However, when it comes to using antibiotics in dogs and cats, there are several important things you should consider.

Read on to learn more.

Considerations for the Use of Antibiotics in Dogs and Cats

Antibiotics are NOT NEEDED for All Sick Dogs and Cats

The first step in considering which antibiotic is appropriate for a dog or cat is determining whether the pet actually needs an antibiotic.

Antibiotics are not needed by all dogs or cats that are ill.

Antibiotics should be used only in animals that are likely to benefit from their usage.

  • In most cases, antibiotics are used for a pet that is suffering from a bacterial infection.
  • In some cases, antibiotics are used to prevent the development of bacterial infections in a situation where the health of the dog or cat makes secondary bacterial infections likely.
  • For other still rarer situations, some antibiotics have other properties for which they may be chosen. For instance, tetracycline and metronidazole both have anti-inflammatory properties and may be used to control inflammation.

In situations where there is no clear benefit for the dog or cat in using an antibiotic, antibiotics should not be used.

The indiscriminate or inappropriate use of antibiotics can lead to antibiotic resistance and the development of resistant forms of bacteria.

This can affect not only the individual dog or cat in question but the entire population of dogs, cats, people, and other animals.

Choosing the Ideal Antibiotic for a Dog or Cat

Once it has been established that an individual dog or cat can actually benefit from the use of an antibiotic, an appropriate antibiotic needs to be chosen.

Ideally, the choice of antibiotic should be based on the results of a culture and sensitivity test.

The culture allows the identification of the infecting bacteria. The sensitivity test determines which antibiotic is most capable of killing or controlling the bacteria causing the infection.

Other Factors to Consider

In reality, doing a culture and sensitivity test may not be practical or possible in each individual pet’s situation.

In addition, it may not be desirable to wait several days until the results of the testing are obtained before beginning to administer antibiotics to the dog or cat.

As a result, choosing an antibiotic often becomes an exercise in determining which antibiotic is most likely to have the desired effects with the least chance of undesired side effects caused by the antibiotic.

Choosing the BEST Antibiotic

There are many factors that a veterinarian must consider in deciding which antibiotic is the best antibiotic for your individual dog or cat.

There are many different antibiotics available and each has a specific range of specificity.

Some antibiotics are more effective against one type of bacteria than another.

If a culture and sensitivity test result is not available, an educated guess must be used to determine which bacteria are most likely to be involved in the infection and which antibiotic is most likely to be able to treat that particular type or category.

The antibiotic chosen must reach an effective concentration in the body system where the antibiotic is needed.

For instance, if the infection is in the central nervous system, the antibiotic must be capable of crossing the blood-brain barrier in a concentration that is great enough to kill or control the infecting bacteria.

The potential side effects caused by the antibiotic must be considered.

All antibiotics have the potential to cause allergic reactions and/or adverse reactions.

Choosing the antibiotic that is least likely to cause undesirable side effects is an important part of deciding which antibiotic to use.

The overall health of the individual dog or cat needs to be taken into consideration.

For instance, some antibiotics are metabolized by the kidneys.

If the pet suffers from kidney disease and one of these antibiotics is being considered, it may be necessary to either adjust the dosage of the antibiotic or even consider using a different antibiotic.

Other medications that the pet is receiving must also be determined.

Some antibiotics may be contraindicated in the presence of specific types of medications. This is because of the increased risk of side effects caused by the two medications being given concurrently.

In other cases, medication may work synergistically with an antibiotic. This means it may necessitate a change in the dosage when the medications are used together.

Top 5 Antibiotics for Dogs

Antibiotics are an essential part of treating and preventing infectious diseases in dogs.

While there is no one-size-fits-all antibiotic regimen for every sickness, there are five most commonly prescribed antibiotics for dogs.

These include Amoxicillin/Clavulanate, Gentamicin, Chloramphenicol, Enrofloxacin, and Metronidazole.


Amoxicillin/Clavulanate is related to Penicillin and can be used as a broad-spectrum antibiotic. It is useful to treat skin infections, respiratory infections, gastrointestinal infections, and genitourinary infections in dogs.


Gentamicin is frequently prescribed for eye infections, ear infections, and pneumonia. Additionally, it’s often paired with an anti-inflammatory drug to help reduce redness and swelling.


Chloramphenicol has a pH level that’s safe enough for the medication to completely pass through your dog’s body. This means it can be used to treat bacterial infections in the organs with fewer side effects than some other antibiotics.


Enrofloxacin is usually prescribed to treat urinary tract infections or soft tissue infections such as acne.


Metronidazole is commonly used and will help with inflammation caused by an infection within the gastrointestinal tract.

Top 5 Antibiotics for Cats

The top 5 antibiotics prescribed for cats are Amoxicillin, Cephalexin, Clindamycin, Enrofloxacin, and Metronidazole.


Amoxicillin is a very popular antibiotic prescribed by veterinarians to treat bacterial infections in cats. It is effective against skin infections, urinary tract, gastrointestinal and respiratory infections, making it a potent broad-spectrum antibiotic.

The side effects of treatment with amoxicillin are usually minimal, meaning cats will likely suffer only minor consequences as a result of taking it.


Cephalexin is another popular broad-range antibiotic for cats. It can be used to treat urinary tract infections, skin and soft tissue bacterial infections, bone inflammation, and respiratory tract infections.


Clindamycin is an antibiotic that vets sometimes prescribe for toxoplasmosis but it’s also a top pick for treating skin and soft tissue bacterial infections in cats, as well as mouth or bone infections.

It is also an excellent choice when handling acute or long-standing bacterial infections in cats.

This particular antibiotic is effective against toxoplasmosis but can also be used to address bacterial activity on a cat’s skin, teeth, or bones.

Like other antibiotics, it may cause discomfort to the cat, such as vomiting or diarrhea, but this is rare when dosed correctly.


Enrofloxacin is a good option for tackling complicated urinary tract infections in cats. It is also used for respiratory and soft tissue infections.

It is a powerful antibiotic that can provide quick relief. However, it should be used with caution due to its potential to cause kidney or liver damage.


Metronidazole is a commonly prescribed antibiotic for cats experiencing digestive issues or diarrhea. It can be administered to the cat in tablet or liquid form, or by infusion performed by a veterinarian.

In Conclusion

Antibiotics can be an important part of treatment and maintaining the health and well-being of your pet. As with any medication, there are potential risks associated with the use of antibiotics in dogs and cats.

Each dog or cat presents a different situation. Therefore, an antibiotic must be chosen carefully, based on consideration of many different factors.

It is essential that you consult a veterinarian before administering any antibiotic to your pet. They will be able to assess your pet’s condition and prescribe the most appropriate medication.

Debbie P

Friday 27th of November 2020

They should only be taken if really necessary. Thanks for the article.

Debbie P

Friday 27th of November 2020

Thanks for this informative article. Dogs taking them is kind of like people taking the. Only when you really have to.

Debbie P

Friday 27th of November 2020

Dogs taking antibiotics is kind of like people taking them, only when really really needed. Thanks for this informative article.

Jeanine Bevacqua

Tuesday 25th of February 2020

Antibiotics are just as bad for pets as they are for humans. It stands to reason that we need to be cautious about using them unnecessarily.

Mary Gardner

Saturday 8th of December 2018

Thankfully we have only had to give our dog antibiotics once. Thanks for the information.

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