Drug resistance in pets


It has become quite common these days for dogs and cats to develop resistance to drugs like antibiotics and antimicrobial medications. Some factors include the characteristics of the bacteria they are fighting, the choice of antibiotic and, of course, the underlying health of your dog or cat. Drug resistance is a major concern for both people and their pets, especially when fighting Staphylococcus aureus MRSA infections.

Below is a list of factors that play a significant role in creating drug resistance:

• The underlying health of your dog or cat

• Certain problems with the drug or antibiotic itself

• When a specific bacteria develops a resistance to antibiotics or other antimicrobial drugs

• Damaged internal organs or tissues

• The inability of infected organs and tissues to receive proper blood flow

• When the infected area fails to remove fluids and pus before using antibiotics

• Suppressing the immune system through therapies while simultaneously using antibiotics

The effectiveness of any antibiotic treatment will depend on the health of your dog or cat. Sometimes problems can arise when the drug or antibiotic used to fight the infection or stop the bacteria from growing ends up being killed by your pet’s immune system.


Inappropriate choices of antibiotics can cause drug resistance and further complications. Here are some things to be aware of:

• Improper frequency or dosage given to your dog or cat

• Discontinuing the antibiotic before the full amount has been given to your pet

• Choosing the wrong antibiotic to fight the organism or bacteria

• Foods or other medications that can prevent the absorption of the antibiotic, or interfere with the body metabolizing the antibiotic


Many types of bacteria have their own built-in defense mechanisms that kick in and render an antibiotic or antimicrobial drug ineffective. Some bacteria produce specific enzymes that can make antibiotics unsuccessful or useless, while other types of bacteria can produce a coating or film that protect against any antibiotic (and prevent it from working). Genetic changes within groups of bacteria may be passed on from generation to generation, making the antibiotics and other drugs futile and ineffective. Sometimes bacteria can reduce the amount of antibiotic that enters, so it never reaches effective levels to fight infections.

Your veterinarian knows how important it is to select the right dosage and frequency of an antibiotic to achieve the best results. As pet parents, we all need to follow any instructions given by our vets, including giving the full course of antibiotics to avoid drug resistance. This lets the medicine do its job – kill the infection.

When it comes to antimicrobial drugs, careful consideration to recommendations, selection and dosage are needed to protect both pets and their people. Some antibiotic-resistant bacteria may develop from exposure to antimicrobial drugs used in the agriculture industry. Be aware that pet parents may be at risk themselves when their dog or cat is treated with antimicrobial drugs. Talk to your veterinarian for safety precautions.


Reviewed and Approved by Dr. David L. Roberts, DVM

Photo:  Courtesy of Victor Bezrukov via Flickr (CC by 2.0)

Sherry is a Nutritionist, Writer, National Speaker, Ghostwriter of books for Natural Medicine Doctors and an Author of 2 healthy cookbooks. She is a Nationally Certified Fitness Instructor and Personal Trainer in Pilates, Yoga, Body Pump, STEP and Aerobics with over 20 years experience. She served as the On-Air Nutritionist for QVC television in the United States and the UK and hosted her own weekly “Healthy Living” segments for PBS. Sherry is passionate about helping animals and worked with “Helping All Animals” in Palm Springs, CA. in their rescue efforts, and is a member of the ASPCA and the Humane Society of the United States. Her experience working as a Veterinarian’s Assistant for many years’ aids in her passion for helping animals lead healthy and happy lives. For more information on Sherry, visit www.sgtotalhealth.com or write to Sherry at sgfit12@aol.com - call 517.899.1451