GENERAL RECOMMENDATIONS FOR UVB LIGHTING IN AMPHIBIAN ENCLOSURES
A. For open top enclosures or when there is no material between the bulb and the animal:
1 Use a T8 2–6% bulb at distances up to 15 inches between the bulb and the animal; for distances over 15 inches, a T8 10–12% or T5 6% bulb may be required.
2 Provide a UVB and heat gradient so animals are not constantly exposed to UVB light.
3 Turn UVB light on for 2–4 hours daily to every other day, especially for cryptic or fossorial species that are naturally exposed to low levels of UVB.
For enclosures with a screen/mesh between the bulb and the animal:
1 Use a T8 6–12% bulb at distances up to 15 inches between the bulb and the animal; for distances over 15 inches, a T8 12% or T5 6% bulb may be required.
2 Provide a UVB and heat gradient so animals are not constantly exposed to UVB light.
3 Turn UVB light on for 2–4 hours daily to every other day, especially for cryptic or fossorial species that are naturally exposed to low levels of UVB.
Note: depending on the type of mesh, there may be a 30–50% reduction in UVB, which must be taken into consideration when selecting the bulb. The use of a UVB radiometer is more critical when the bulb is placed above a mesh in order to determine the actual UVB exposure.
Suggested Reading
1 Acierno MJ, Mitchell MA, Zachariah TT, Roundtree MK, Kirchgessner MS, Guzman D. Effects of ultraviolet radiation on plasma 25‐hydroxyvitamin D3 concentrations in corn snakes (Elaphe guttata). Am J Vet Res 2008; 69(2):294–297.
2 Burger RM, Gehrmann WH, Ferguson GW. Evaluation of UVB reduction by materials commonly used in reptile husbandry. Zoo Biol 2007; 26:417–423.
Abscesses
DEFINITION/OVERVIEW
Abscesses are non‐fluctuating hard masses of variable size, formed by concentric layers of purulent material in which the outermost layer has the most liquid consistency. All purulent material is contained in a fibrous capsule. Coloration ranges from brown to yellow. Adhesions occasionally occur with adjacent tissues. There are no general symptoms if the abscess does not result from a systemic infection (salmonellosis, pseudomonas, microsporidiosis, etc.). Dermal abscesses in reptiles evolve from external wounds, ectoparasites or contamination by direct contact with feces or water with a high bacterial population, all of which may be exacerbated by immunosuppression.
ETIOLOGY/PATHOPHYSIOLOGY
Can be a result of local or systemic infections.
Local infections typically isolated to the skin—contamination of wounds with environmental, fecal, or normal flora leading to abscess formation.
Existence of local infections in the skin is very frequent.
Cultures show a high causative flora, including bacteria, fungi, and viruses.
Systemic infections may also lead to abscess formation particularly in internal organs.
Some local abscesses may spread and become systemic if environmental conditions are favorable.
Systemic mycosis has been described by Penicillium griseofulvum in Dypsochelys (Geochelone) gigantea, or sepsis by Serratia marcescens in Gopherus agasizii.
In tortoises, not unusual to find proliferations of fibrous connective tissue, which form hard, subcutaneous, adherent but sometimes mobile structures, comprised of a dense fibrin network that captures inflammatory cells—fibriscess.
Fibriscess grows constantly and becomes fully visible—should not be confused with a fibroid or benign connective tissue neoplasia.
SIGNALMENT/HISTORY
No specific signalment.
Main focus should be on obtaining a thorough history of the husbandry and social interactions of the reptiles.
A history of aggression in a group of reptiles may contribute to the appearance of abscesses.
Poor cleanliness and hygiene of the enclosure can lead to increase environmental bacterial load, which can contribute to skin lesions and abscess formation.
CLINICAL PRESENTATION
Reptiles may present with cutaneous abscesses ranging in size from a few millimeters to centimeters in diameter. These can either be freely moveable or firmly attached to the underlying tissues.
Some abscesses become chronic and expel a malodorous, purulent discharge. The content of the abscess is mostly caseous in nature.
Sometimes abscesses can affect nearby bones, and animals may present with lameness. Dysecdysis may also be observed in association with the abscess or through the animals’ body.
In aquatic chelonians, the most affected parts are the hindquarters and the neck.
Although they can occur throughout the body of the animal, there is a greater frequency of cutaneous abscesses in the parotid, maxillary, interdigital, limbs, neck, and costal wall.
RISK FACTORS
Husbandry
Poor hygiene and overpopulation can lead to increased bacterial load in the enclosure and possibly stress and immunosuppression.
Rough substrate or surfaces in the terrarium can lead to cuts or abrasions that may become infected.
Inappropriate diet and/or UVB exposure may also lead to a weakened immune status.
Others
N/A
DIFFERENTIAL DIAGNOSIS
Chronic dysecdysis
Blister disease
Limb fractures can occur with symptoms similar to osteolytic abscesses at the same extremities (limb malposition, lameness, etc.).
DIAGNOSTICS
Cytology
Cytology can be used as the first screening tool to identify whether a mass is an abscess either via an aspirate or an impression smear of the material within.
Abscesses usually reveal a large number of leukocytes, cellular detritus, tissue remnants, and desquamation of cells.
Infectious organisms may also be observed, but their absence does not rule out an infection.
Microbiology