How to Make the Most of Antibiotics for your Dog
Dose and Frequency of Administration
The dose is computed by weighing the dog, then dividing the total daily dose
into equal parts and giving them at prescribed intervals. Other factors that
must be accounted for when computing the daily dose are the severity of the
infection, the age of the dog, her overall health and stamina, and whether the
dog is taking another antibiotic. When the total dose is too low or the
antibiotic is not given often enough, the drug may not be effective.
Antibiotics can destroy the normal flora in the body, which crowds out
pathogens. This allows harmful bacteria to multiply and cause disease.
Furthermore, strains of bacteria may develop that are resistant to antibiotics
and thus cannot be effectively controlled. This is particularly likely to occur
when antibiotics are used:
- For too short a time
- In too low a dosage
- When the antibiotic is not bactericidal
Microorganisms that are resistant to one antibiotic are usually resistant to
other antibiotics of the same class. The development of antibiotic-resistant
bacteria is one of the main reasons why antibiotics should be used exactly as
prescribed and only in situations in which they will clearly benefit the dog.
If antibiotics are given at a lower than effective dose or for a shorter time
period than prescribed, this may select for bacteria that have resistance to
that drug. For example, if five days of treatment would kill all the bacteria
and you administer antibiotics for only four days, the only bacteria left are
those that managed to survive through four days of treatment. The most
resistant bacteria are then left to reproduce.
Antibiotics and Steroids
Steroids are often combined
with antibiotics, particularly in topical preparations for the eyes and ears,
and on the skin. Corticosteroids have
anti-inflammatory effects. By reducing swelling, redness, and tenderness, they
often give the impression that the dog is getting better when actually, she is
Steroids have one other side effect that is undesirable: They depress the
normal immune response. This can impair the dog’s ability to fight the
infection. Antibiotic medications that contain steroids should be used only
under the guidance of a veterinarian.