“Lumpy Jaw”—Another Perspective
American Association of Zoo Veterinarians Conference 2002
D.A. Fagan1, DDS; J.E. Oosterhuis2, DVM
1The Colyer Institute, San Diego, CA, USA; 2San Diego Wild Animal Park, Escondido, CA, USA

The term “lumpy jaw” has been utilized in Veterinary Medicine for many years as a catch all phrase to describe a diverse assortment of clinical ailments involving the facial bones of a wide variety of animals. Most often it seems to have been used as a pseudonym for chronic actinomycosis, commonly seen in domestic sheep and cattle or associated with various macropods. As a result of these associations, many clinicians have come to believe that any and all “lumpy jaw” lesions are de facto actinomycosis, to be opened, drained, flushed, and left to heal on their own. The authors have individually and collectively treated a substantial variety (see Appendix A) of these so called “lumpy jaw” lesions during the past 25+ years and have come to see them as something much more specific. The purpose of this presentation is to share some of our observations and, hopefully, shed some much-needed light on the exact nature of this all-too-common facial lesion.

It is important to establish the fact that the term “lumpy jaw” is not an actual disease or a recognized morphologic diagnosis. It is merely a colloquialism—“an expression or form of speech of the type used in informal conversation”. “Lumpy jaw” is an informal term commonly used to identify the presence of an anatomical abnormality associated with the facial bones of various animals. This is an important distinction because this chronic, expansive, bony lesion is actually the first visual manifestation of chronic alveolar osteomyelitis involving the animal’s dentition, and is usually associated with an overlaying, diffuse, soft-tissue cellulitis.

The term “chronic alveolar osteomyelitis” is the morphologic diagnosis for this common anatomical abnormality. Consequently, this lesion can be described in greater detail in terms of its etiology, pathogenesis, and treatment alternatives.

The etiology of this common bony lesion remains complex and incompletely understood. It is, however, clear that one or more of the following four common clinical ailments can form the focus of infection, which eventually results in the expansive infection of the alveolar bone. These are:

1.  Any aggressive periapical abscess

2.  Any chronic periodontal abscess

3.  A localized traumatic injury to the face

4.  A genetic or developmental defect (example: enamel dysplasia)

These can and often do occur in combination. For example, a localized periodontal abscess can progress into a peri­apical abscess. An enamel or dentin dysplasia like the dens in dente, can (and often does) result in an irreversible pulpitis with peri-apical abscess, which then eventually develops into a chronic alveolar osteomyelitis. A traumatic blow to the lower border of the mandible often results in a localized inflammatory injury, which can then easily become infected and develop into an osteomyelitis. It is important to note that all these etiological factors (1) occur with regularity; (2) involve the animal’s dentition; (3) are difficult to detect without a detailed intra-oral examination including specific dental radiography; and (4) eventually all of them will result in a chronic, expansive, alveolar osteomyelitis. No doubt, there are additional etiological factors, and/or combinations of factors, as yet unidentified, which contribute to the formation of this lesion as well.

An understanding of the pathogenesis of these lesions is important because the clinical management and treatment of this chronic bony infection depends upon the interruption of this progressive sequence. “Alveolar osteomyelitis” typically develops in the following sequence. Secondary to one of the factors listed above (i.e., abscessation, trauma, or a developmental abnormality with secondary infection), inflammation of the alveolar bone occurs. If the lesion was not infected initially, sooner or later, infection of the site will follow. This infection is generally of mixed-microbial growth and it develops within the body of the bone. The animal’s immune system will respond and attempt to “wall off” and contain the infection with fibroplasia, which eventually results in the formation of a cystic cavity. Bacterial growth (particularly anaerobic), however, continues within the cystic cavity. Intermittently but regularly, the pressure within the cystic cavity exceeds the surrounding local capillary bed pressure, and the lesion will expand with more active inflammation and fibroplasia. Eventually, this partially contained expansion erodes into the nutrient canals in the adjacent cortical layer of bone, and diffuse cellulitis results. It is only at this time that outwardly demonstrable “lumpy jaw” is evident.

Historically, the treatment for lumpy-jaw-type lesions has been limited to repeated episodes of opening the lesion, flushing and draining the contained debris, and accepting the eventual granulation and closure of the wound; usually followed in time by another recurrent need for treatment. Recognizing this lesion to be a chronic alveolar osteomyelitis associated with one or more tooth-root abscesses as the source of the recurrent infection, enables the clinician to treat and eventually eliminate, this infection. The authors use a combination of clinically proven treatment modalities, which the authors have collectively termed “the beta-infusion technique with compound apicoectomy”.

This two-part treatment protocol is defined by the limits commonly associated with the treatment of any highly excitable and easily injured exotic herbivore.

The first phase of treatment is the surgical fistulation of the lateral wall of the “lump” with placement of a fixed, solid catheter at a location that will eventually provide adequate access to the apical roots of the involved dentition. This requires familiarity with standard apicoectomy surgical access, as well as multiple intra-oral dental radiographs. The objective of this procedure is to convert the chronic osteomyelitis into a contained, externally draining fistulas tract connecting the apical abscess of the associated tooth (teeth) to the exterior of the animal’s face. This requires minimal “hands on” time, and only two or three intermittent follow-up procedures to flush the internal bony site with a sequence of water (H20) to insure an open path, then simultaneously from two separate sources, hydrogen peroxide (H202) and sodium hypochlorite (NaOCl) and, finally, 2% Betadine Solution (Povidone-Iodine U.S.P., 10% with 1% available iodine) functioning as an antiseptic/microbicide, while the animal’s immune system completes the healing process in about six weeks. This procedure enables the animal to remain with its group or with minimal separation ( e.g., during a breeding or gestation period).

The second phase of the protocol is termed the compound apicoectomy, which restores the integrity of both the dentition and the alveolar bony defect with a combination of (1) a traditional dental tooth-root apicoectomy; (2) endodontic therapy with access through the apex of the tooth [teeth]; (3) retro-fill of the apical aspect of the tooth root with a substantial restorative material like a glass ionomer cement; and finally, (4) the restoration of the bony defect with one or more of the commonly accepted particulate synthetic bony grafting materials like Bioglass, and/or CapSet (Bioglass® Consil, Nutramax Laboratories, Inc., Baltimore, MD; a synthetic bone graft particulate material moistened with any of the commonly available broad spectrum antibiotic solutions like enrofloxacin, amikacin, etc.) and (CapSet®, LifeCore Biomedical, Chaska, MN).

In conclusion, a protocol has been presented which seems to provide the concerned clinician with a method to treat, manage, and or eliminate one of the most common clinical dental infections in exotic hoofstock.


The authors would like to thank Dr. Ron Kettenacker at Nutramax Laboratories, Inc., Baltimore, MD, and Mr. Jonathen Benz, at ENDO-Technic, San Diego, CA, for their support of this work.

Appendix A

Following is a list of some of the species treated by the authors, while developing the beta-infusion technique with compound apicoectomy into a practical clinical protocol.

A few photographs of the developing protocol can be found at www.colyerinstitute.org.

Additional general background information concerning these species can be found on the Ultimate Ungulate Web Site at www.ultimateungulate.com/artiodactyla.

Camelus dromedarius: dromedary, Arabian camel
Elaphodus cephalophus: western tufted deer
Muntiacus muntjac: Indian muntjac
Mazama americana: Mexican red brocket
Pudu mephistophiles: northern pudu
Antilocapra americana: pronghorn
Aepyceros melampus: impala
Connochaetes gnou: white-tailed gnu, black wildebeest
Damaliscus pygargus: bontebok
Antidorcas marsupialis: springbok
Gazella Nanger dama: addra gazelle
Gazella dorcas: dorcas gazelle
Gazella leptoceros: slender-horned gazelle
Gazella rufifrons: red-fronted gazelle
Gazella soemmerringi: Soemmerring’s gazelle
Gazella thompsoni: Thomson’s gazelle
Neotragus moschatus: Zulu suni
Tragelaphus eurycerus: bongo
Tragelaphus spekeii: sitatunga
Ammotragus lervia: aoudad, Barbary sheep
Capra caucasica: West Caucasian tur
Capra ibex: alpine ibex
Hemitragus jemlahicus: Himalayan tahr
Ovis aries: mouflon
Ovis canadensis: bighorn sheep
Oryx dammah: scimitar-horned oryx
and an assortment of thoroughbred, standard bred, Morgan, and mixed-breed domestic horses.


Speaker Information
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D.A. Fagan, DDS
The Colyer Institute
San Diego, CA, USA