reptile - Articles
Abscesses
Synonym(s): Infected wound, Granuloma, Fibriscess
Introduction
- Cause: local collection of inflammatory product consisting of leukocytes, purulent and liquefied tissue enclosed within a capsule. The contents range in consistency from liquid (rare in reptiles) to a more solid pasty material. May be sterile (rarely - foreign body reaction, particularly drug injection sites) or associated with a wide variety of possible etiological agents (bacterial, fungal, parasitic, viral).
- Many types of bacteria have been described, including Aeromonas spp, Citrobacter spp, Corynebacterium spp, Enterobacter spp, Morganella spp, Neisseria spp, Proteus spp, Pseudomonas spp, Salmonella spp, Serratia spp; and anaerobic species (Bacteroides spp, Fusobacterium spp, Clostridium spp and Peptostreptococcus spp.
- Mycobacterium and Nocardia spp have been found.
- Various fungi may be associated with abscesses, eg Candida, Aspergillus, Fusarium spp.
- Protozoal spp, especially Trichomonas spp, have been associated with subspectacular abscesses.
- Microsporidia may be associated with abscesses (especially bearded dragons).
- Signs: dependent on location of the abscess.
- Diagnosis: history and oral/physical examination; imaging; bacterial culture and sensitivity.
- Treatment: drain/reduce/resect/remove abscess; antimicrobial therapy.
- Prognosis: depends on location and extent of the abscess, system involved, etiologic agent and chronicity of the infection.
Presenting signs
- Depends on location of the abscess.
- Generally, the reptile is behaving normally; may be lethargic.
- Appetite may be reduced if abscess is within the body cavity. May have lost weight, be in poor body condition or regurgitating. Lumps may be palpably obvious in snakes or lizards; usually not painful.
- If oral, swelling of the gingivae, subglottal swelling may occur
, and rarely, generalized swelling of the head. - If cutaneous or subcutaneous
, lumps will be visible/palpable. - Subspectacular abscesses, collection of purulent material beneath the spectacle.
- Aural abscesses are visible as distension of the tympanic scute in chelonia, possibly extending rostrally and ventrally, or as plugs of purulent material visible orally in the oropharynx, especially with pressure on the tympanic scute
. - Tail base swelling (hemipene pockets
, cloacal glands).
Acute presentation
- Rare.
- Abscesses are usually chronic in nature in reptiles.
Geographic incidence
- Worldwide.
Age predisposition
- Any.
Public health considerations
- Bacterial abscesses; risk of spread to other reptiles sharing same enclosure, water bowl.
- Zoonotic risk, particularly Salmonella spp, Mycobacteria spp and some fungal species.
- Clinicians and staff working with reptiles with abscesses should ensure appropriate biosecurity measures: wearing gloves; disinfecting instruments, surfaces, enclosures, cage furniture, water bowls and feeding equipment.
Cost considerations
- Diagnostics.
- Medications.
- Imaging.
- Surgery.
Special risks
- Coelomic abscesses in snakes may be attached to vital structures such as major blood vessels, gut and gall bladder, making surgical removal or resection difficult.
Pathogenesis
Etiology
- Local collection of inflammatory product consisting of leukocytes, purulent and liquefied tissue enclosed within a capsule secondary to tissue damage/infection.
- The contents are usually solid or pasty material (rarely liquid in reptiles), and difficult to drain.
- Many types of bacteria have been described, including Aeromonas spp, Citrobacter spp, Corynebacterium spp, Enterobacter spp, Morganella spp, Neisseria spp, Proteus spp, Pseudomonas spp, Salmonella spp, Serratia spp; and anaerobic species (Bacteroides spp, Fusobacterium spp, Clostridium spp and Peptostreptococcus spp.
- Mixed infections are found in oral abscesses.
- Can occur in multiple systems and signs vary according to location of the abscess.
- Subspectacular abscess in snakes will present as a collection of purulent material beneath the spectacle. Infection may originate from the oral cavity and travel via the nasolacrimal duct; from penetrating wounds or bacteremia. Often associated with flagellates Flagellate/ciliate infection (microscopy of purulent material essential).
- Gastrointestinal abscesses may occur due to migrating ascarid larvae.
- In pythons, abscesses are common in the intestine at the level of the gall bladder.
- Aural abscesses in chelonians are discrete spherical abscesses ventral and rostral to the tympanic membrane.
- In snakes and lizards, stomatitis may lead to abscessation.
- Abscess may also occur in the caudal cloaca or hemipene region.
- Trauma from bite wounds may result in abscessation in lizards.
- Bacteremia may result in abscessation anywhere in the body.
Predisposing factors
General
- Suboptimal husbandry Chelonia husbandry Lizard husbandry Snake husbandry.
- Poor parasite control Chelonia parasitology overview Lizard parasitology overview Snake parasitology overview.
Specific
- Inadequate sterilization of feeding equipment, water bowls.
- Poor tank management and water quality in aquatic chelonians.
- Group housing (fighting/mating wounds).
- Hypovitaminosis A.
- Stress.
Pathophysiology
- Abscesses usually occur due to bacteremia, a wound or a penetrating foreign body, eg ascarid larvae, plant material.
- Oral abscesses in snakes are usually secondary to stomatitis which may initially occur due to poor husbandry and the build-up of pathogenic bacteria in the substrate or drinking water.
- Trauma suffered by snakes during prehension of food may also cause gingival wounds or periodontal damage resulting in infection.
- A fibrous capsule forms around the purulent material, which is difficult to drain.
Timecourse
- Abscesses in reptiles usually form slowly and are chronic in nature.
- The time period from infection to diagnosis is difficult to determine in most cases.
Epidemiology
- Any reptile can be susceptible to abscessation.
- If housed in groups, some species may fight and inflict wounds, eg male lizards with rivals or mates.
Diagnosis
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Treatment
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Prevention
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Outcomes
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Further Reading
Publications
Refereed papers
- Recent references from PubMed and VetMedResource.
- Huchzermeyer F W & Cooper J E (2000) Fibriscess, not abscess, resulting from a localised inflammatory response to infection in reptiles and birds. Vet Rec 147 (18), 515-517 PubMed.
Other sources of information
- Chitty J & Raftery A (2013) Soft Tissue Masses. In: Essentials of Tortoise Medicine and Surgery. Wiley-Blackwell, UK. pp 231-234.
- Jacobson E R (2007) Bacterial Diseases of Reptiles. In: Infectious Diseases and Pathology of Reptiles. Ed: Jacobson E R. Taylor & Francis Group, USA. pp 461-526.
- Mader D R (2006) Abscesses. In: Reptile Medicine and Surgery. Saunders-Elsevier, USA. pp 715-719.
- Murray M J (2006) Aural Abscesses. In: Reptile Medicine and Surgery. Ed: Mader D R Saunders-Elsevier, USA. pp 742-746.
- Pare J A, Sigler L, Rosenthal K L & Mader D R (2006) Microbiology: Fungal and Bacterial Diseases of Reptiles. In: Reptile Medicine and Surgery. Ed: Mader D R. Saunders-Elseveier, USA. pp 217-226.
Organisation(s)
- Association of Reptile and Amphibian Veterinarians. Website: www.arav.org.