Antimicrobial Therapy for Veterinary Dental and Oral Surgical Procedures

The use of antimicrobial drug (AMD) therapy by veterinarians after oral/dental procedures is very common practice. In most cases this use is not necessary. A major concern is the emergence, spread and high prevalence of multidrug-resistant (MDR) pathogens. This is believed to be associated with the frequent use of AMDs(1). The use of AMDs provides selective pressure on MDR pathogens to evolve. The excessive and frequent use of AMDs in companion animals may be a risk factor for MDR zoonotic infections in people including veterinary hospital personnel(1). Stewardship practices for AMD use in companion animals is needed to slow the emergence and spread of MDR bacteria among humans and animals(1). It is recommended that every veterinary medical record include a justification for AMD use in an animal(2).

Important General Principles for AMD use for Veterinary Dentistry and Oral Surgery:

1. Plaque is a biofilm. It must be remembered that for most oral infections (especially periodontal disease) you are dealing with organisms in a biofilm environment and not in their planktonic forms. The biofilm protects organisms from AMD attack. Concentrations of antibiotics may have to be up to 1000 higher to be effective against biofilms. There are multiple, separate biofilm environments within the oral cavity. The supragingival and subgingival environments harbor differing biofilms. Due to the biofilm environment and to the number and variety of oral organisms, culture and sensitivity testing are usually unreliable and not feasible.
2. AMDs should never be used as a monotherapy. Although periodontal disease is caused by bacteria, AMDs should not be the primary treatment strategy(3). Therefore, the mechanical disruption of plaque (dental scaling/polishing) prior to local or systemic AMD delivery is needed to obtain effective results. To do otherwise is an inappropriate use of AMDs and selective pressure for MDR is increased. The days of “pulse antibiotic” therapy are over. This is an inappropriate use of antibiotics.
3. Systemic antibiotics (Ab) enter periodontal pockets via crevicular fluid flow and oral infection sites via secretion in the saliva. These are round-about means of delivery. Crevicular fluid exchange is 40X/hour and is increased when inflammation exists. Therefore, the Ab contact time is markedly limited.
4. The “gold standard” for prevention and control of periodontal disease remains professional supragingival and subgingival dental scaling followed by daily toothbrushing. Oral hygiene at home may be enhanced by utilizing special diets, chew objects and antiseptic rinses; however, these methods are not as effective as toothbrushing and are not designed to replace toothbrushing.
5. The long held belief that oral infections (particularly endodontically treated teeth) result in systemic illness or cause disease processes in distant locations, does not have scientific merit(4). This concept often drives recommendations for systemic AMD use. Therefore, most prophylactic AMD use in dentistry has no scientific basis.
6. Because of the excellent blood supply, wound healing in the oral cavity is rapid and uncomplicated. Therefore, infectious complications are uncommon.
7. Antibiotics are recommended for patients with existing medical conditions (EMC). Patients with compromised immune systems may be at higher risk for anticipated bacteremias progressing to overwhelming septicemias. These patients include patients undergoing chemotherapy, have FIV and/or FeLV infections, have poorly controlled diabetes or have other debilitating diseases(4,5).
8. Oral surgery cannot be considered sterile. Most oral surgeries are either clean-contaminated or contaminated (dirty).
9. Minor lacerations rarely require AMDs. Deeper and/or more heavily contaminated wounds may benefit from AMDs.
10. Antibiotics are indicated for most patients with local and systemic signs of established infection (i.e. pain, swelling, pus formation, lymphadenopathy and elevated WBC).
11. There is currently no scientific support for the previously held belief that there is an association between bacterial endocarditis and either dental/oral surgical procedures or oral infections in dogs(5).
12. The American Heart Association only recommends antibiotic prophylaxis for dental procedures as being reasonable for patients with prosthetic cardiac valves, previous infectious endocarditis and some forms of repaired congenital heart diseases(6).
13. Postoperative oral antibiotics are not routinely recommended for patients undergoing extractions. A perioperative dose may be considered for patients requiring multiple surgical extractions with osectomy, those with severe, generalized periodontitis, and/or patients with medical conditions which might impair their ability to clear anticipated bacteremia(5).
14. In some patients with severe periodontitis, antibiotic use for a few days prior to the procedure may be indicated to reduce periodontal inflammation(5).
15. Unless there are indications because a patient has EMC, there is no justification for using prophylactic antibiotics for patients undergoing periodontal surgery(5).
16. Locally delivered AMDs may be very beneficial. 0.12% chlorhexidine gluconate is considered the “gold standard” of topical AMDs. This agent binds to teeth, oral mucosa, pellicle and saliva (high substantivity). It binds to and damages bacterial cell membranes (bacteriocidal).

References:

1. Baker, S.A., Van-Balen, J., et al. Antimicrobial drug use in dogs prior to admission to a veterinary teaching hospital. JAVMA, 2012;241.
2. AVMA website. Guidelines of veterinary prescription drugs.
3. Radice, M., Reiter, A. Evaluation of Subgingival Bacteria in the Dog and Susceptibility to commonly used Antibiotics. J. Vet. Dent, 2006;23.
4. Tong, Darryl C. Antibiotic Prophylaxis in Dentistry. J. Am. Dental Assoc. 2000;131.
5. Verstraete, Frank JM. & Lommer, Milinda J. (editors). Oral and Maxillofacial Surgery in Dogs and Cats: Antibiotic use in oral surgery. Saunders-Elsevier 2012.
6. Wilson, W., et al. Prevention of Infective Endocarditis: Guidelines from the American Heart Association. 2007;116.