What is antibiotic resistance?
Antibiotics are important medications. It would be difficult to overstate the benefits of penicillin and other antibiotics in treating bacterial infections, preventing the spread of disease, and reducing serious complications of disease.
But some medications that used to be standard treatments for bacterial infections are now less effective or don't work at all. When an antibiotic no longer has an effect on a certain strain of bacteria, those bacteria are said to be antibiotic resistant. Antibiotic resistance is one of the world's most pressing health problems. It is estimated that 100 to 150 million dogs, cats, and other pets are given antibiotics each year - each of these with the potential to cause resistant strains of bacteria.
Urinary tract disease, respiratory disease, and skin infections in pets are commonly treated with oral antibiotics. The misuse, improper use, and overuse of these drugs can and does lead to antibiotic resistance which can lead to life-threatening infections. According to the Centers for Disease Control and Prevention, up to one-third to one-half of antibiotic use in humans is unnecessary or inappropriate. Members of the AVMA's Task Force For Antimicrobial Stewardship in Companion Animals said it "seems likely" that the amount of inappropriate use of antibiotics in companion animal settings is close to the most recent estimates in human medicine—50%.
How are antibiotics misused?
Antibiotics are used to kill bacteria; they have no effect against viral infections. Many times veterinarians or doctors will prescribe antibiotics without proof that bacterial infection is present. Any time an antibiotic is prescribed, the antibiotic will attack all bacteria in the body - bacteria that are either beneficial or at least not causing disease. This misdirected treatment can then promote antibiotic-resistant properties in harmless bacteria that can be shared with other bacteria, or create an opportunity for potentially harmful bacteria to replace the harmless ones.
Another type of misuse occurs when the wrong antibiotic is chosen. Many times infections can be cleared using first-line antibiotics (simpler antibiotics with a narrow scope of treatment) rather than starting with second or third-line antibiotics that should be reserved for resistant infections. For instance, many bacterial infections may respond to amoxicillin, but veterinarians immediately reach for a second-generation cephalosporin or fluoroquinolone antibiotic.
Misuse can also occur when:
- clinicians prescribe antibiotics before test results confirm a bacterial infection
- pet owners pressure the veterinarian for an antibiotic prescription
- pet owners give antibiotics they have purchased for another pet after self-diagnosing a bacterial illness
- pet owners give antibiotics left over from a previous prescription
What are some examples of infections that are contributing to antibiotic misuse?
1. Skin infections
Superficial bacterial folliculitis (skin infection or pyoderma) is usually caused by Staphylococcus pseudintermedius; it is routinely treated with systemic (oral) antibiotics. Infection occurs due to reduced immunity associated with alterations of the skin barrier and underlying diseases that may be difficult to diagnose and resolve (Cushing's, hypothyroidism, diabetes, allergies, and others); because of this, pyoderma is frequently recurrent and repeated treatment is necessary.
Bacterial infection should be confirmed by cytology (examining a swab from the skin under a microscope using special stains). If bacteria are present in large numbers, bacterial culture and sensitivity testing should be performed to determine the correct antibiotic needed to treat the infection.
The emergence of multi-resistant bacteria, particularly methicillin-resistant S. pseudintermedius, has focused attention on the need for optimal management of skin infections. Ways to treat skin infection without the use of oral antibiotics may include:
- Bathing with anti-bacterial shampoos that do not contain antibiotics
- Bathing with specialized bathing systems to remove bacteria and dead skin
- Applying anti-bacterial sprays that do not contain antibiotics
- Supporting the immune system with colostrum, probiotics, and herbs
- Decrease inflammation by feeding coconut oil and fish oil to nourish skin
- Use Manuka honey with a high UMF as a natural antibacterial agent
- Use French green clay on oozing or irritated skin
2. Urinary tract disease
Any time a cat urinates outside the litter box or a dog urinates in the house, passes blood in the urine, or strains to urinate, a urinary tract infection (UTI) may be the underlying problem. However, other causes may include:
- behavioral issues
- inflammation without infection (sterile cystitis)
- urinary tract stones
- diabetes mellitus
- medication side effects
- kidney failure
- diabetes insipidus
- urinary tract cancer
- spinal disease
Clinical signs are nonspecific and should not be used alone for diagnosis of UTI. However, the presence of clinical abnormalities should indicate the need for further testing, including blood and urine analysis.
Sediment analysis alone is inadequate for diagnosis of infection. Blood and protein are often present with a UTI, but they are nonspecific and may be caused by noninfectious conditions. The presence of white blood cells and bacteria does, however, provide supporting evidence of a UTI. Complete urinalysis, including urine specific gravity, urine glucose level determination, and examination of the sediment for crystals and bacteria is considered a minimum database for evaluation of a suspected UTI.
Bacterial culture and susceptibility testing should be performed in all cases in order to:
- confirm the presence of bacterial infection
- identify the presence of resistant bacteria that may not respond to initial therapy
- help differentiate reinfection from relapse if the UTI returns
Cystocentesis (obtaining a sterile urine sample by extraction from the bladder with a needle and syringe) should be used for sample collection.
Underlying medical problems listed above that may be contributing to urinary tract infection should be treated if detected.
Natural therapies that can help deter urinary tract infections include:
- Probiotics to establish good bacteria in the body
- Cranberry supplements to reduce bacterial adhesion to the bladder wall
- Glucosamine supplements to reduce irritation in the bladder wall
- Omega 3 fatty acids provide natural relief of inflammation and support kidney health
- Herbal remedies can help clear inflammation from the bladder
- Dietary therapy with high-moisture, species-appropriate diets can decrease crystal formation in the bladder
- Monitor urine at home for signs of blood
3. Respiratory Tract Infections
Respiratory tract infections in dogs and cats can affect the bronchi, trachea, throat, and nasal cavities and are common, especially in pets with compromised immune systems. Bacterial, viral, and fungal infections can occur. Other diseases that may have similar symptoms to infection include:
- allergic bronchitis
- allergies or irritation to fragrances used in the home
- collapsing trachea
- laryngeal paralysis
- heart disease
- parasites - heartworm, lungworm, roundworm migration
Pets spending time in crowded areas such as boarding, daycare, or grooming centers are more likely to contract bacterial or viral respiratory infections.
Symptoms of respiratory tract infections may include:
- Nasal discharge
- Eye discharge
- Coughing, snorting, and wheezing
- Gagging or retching
- Dry nose
- Drooling or foaming at the mouth
- Ulcers of the mouth or nose
- Loss of appetite
- Weight loss
- Exercise intolerance
Before treating with antibiotics for these symptoms, it is important to confirm presence of a bacterial infection. An elevated white blood cell count may help in making the diagnosis, along with radiographs, and culture of nasal discharge. Thick, yellow or green, nasal or eye discharge is often seen in the presence of bacteria, while clear discharge is less likely to signify bacterial infection.
Natural ways to prevent and treat upper respiratory infections can include:
- Probiotics to strengthen the immune system
- Essential oils to strengthen the immune system
- Colostrum to supply immunoglobulins for the immune system
- Manuka honey as a natural cough suppressant and antibacterial agent
- Feed lung - like treats like from a TCVM standpoint
- Give N-acetylcysteine to break up mucous and phlegm
- Give vitamin C to help combat viral and bacterial infections
- Ensure your pet's vitamin D levels are normal through testing
- Provide immune support with herbs and mushrooms
Potential Side Effects From Antibiotic Use in Addition to Resistance
While there is a huge upside to using antibiotics in the face of significant bacterial infection, there are also many potential side effects that may include:
- skin rash
- joint pain
- autoimmune disease
- behavioral changes
- abnormal bone or tooth growth
- kidney failure
- liver failure
- bone marrow suppression
- neuromuscular toxicosis
- anaphylaxis (severe allergic reaction)
- bacterial resistance
To minimize the risk of bacterial resistance, keep these tips in mind:
- Take antibiotics only for bacterial infections. It’s a good idea to let milder illnesses (especially those thought to be caused by viruses) run their course. This helps prevent antibiotic-resistant germs from developing. But leave it to your veterinarian to decide if an illness is “mild” or not.
- Seek advice and ask questions. Ask your veterinarian about whether your pet’s illness is bacterial or viral, and discuss the risks and benefits of antibiotics. If it’s a virus, ask about ways to treat symptoms. Don’t pressure the doctor to prescribe antibiotics. Don't accept antibiotics unless there is a clear indication they are necessary.