By Roberta A. Avila-Guevara CVT

 

Disease Process

Nutritional Metabolic Bone Disease is characterized by a decline in skeletal health. It is the product of low calcium levels in blood. The primary problem is a disruption in calcium metabolism that results in low calcium levels over a period of time. The low levels trigger the production of parathyroid hormone. In response to the hormone, the skeletal system releases calcium from its stores, and the kidneys reabsorb calcium while excreting excess phosphorus. Eventually, the mineralization of bone is compromised, causing the bones to become soft; metabolic pathways continue to fade, and calcium levels continue to decline.

Causes of Nutritional Metabolic Bone Disease

Captive reptiles develop NMBD because of husbandry and dietary mismanagement. Herbivorous and insectivorous reptiles such as the Green Iguana and the Leopard Gecko, have a high incidence of the disorder because these reptiles are dependent on UVB radiation, supplementation, and proper diet in order to maintain correct levels of vitamin D and calcium in blood.

Carnivorous reptiles such as snakes and monitor lizards, are able to obtain calcium and vitamin D from the adult prey they eat. Because of this, it is not common for these reptiles to present with NMBD unless they are fed an inappropriate diet of infant to young adult prey who do not have fully calcified bones.

Husbandry Mismanagement

Inappropriate husbandry practices result in anorexia and a decrease in mineral uptake. In most cases this is secondary to stress, therefore, misguidance in pet care has an influence on calcium metabolism.

Tropical and semi-tropical species

Most tropical reptiles are tree climbers. Housing them in an aquarium or other unit that's longer than it is tall doesn't allow them to climb. If these reptiles stay on or near the ground, they won't obtain the appropriate amounts of UV radiation and they will perceive their environment as a consent threat for predators. Humidity levels that are too low cause chronic dehydration and stress, while high levels are a breeding ground for bacteria and other organisms that can cause infection.

Incorrect temperatures cause several problems. If temperature ranges are too low, proper digestion and other metabolic functions will not occur, temperatures too high can burn pets. Lack of appropriate temperature ranges in the environment, or temperature gradients, do not allow reptiles to establish normal ectothermic behaviors.

Lighting systems are a major problem with reptile keeping. Tropical species have specific needs that can not be met with regular household light bulbs. Many reptile bulbs also do not meet the requirements for most of these species. Basking bulbs and most broad spectrum bulbs are designed for the sole purpose of providing heat and light. They do not provide UVA or UVB radiation needed by these reptiles unless they are specifically labeled. The amount of time an animal spends in the sunlight, or the photoperiod, can't be too long or too short, otherwise future medical problems will occur.

Desert and grassland species

Reptiles from desert and grassland habitats that are housed in units that are not tall enough can result in over heating of the enclosure or serious damage from the bulbs. If the unit doesn't have plenty of floor space for moving around, reptiles can't maintain appropriate internal temperatures. Humidity levels don't have to be extreme for these habitats, however, water needs to be accessible and low levels of humidity provided for proper shedding.

Incorrect temperatures, and temperature gradients, for any reptile will affect digestion and other metabolic functions. Regardless of whether the levels are too high or too low, serious consequences result. It shouldn't be assumed that all desert reptiles require high heat; this simply is not the case.

Desert and grassland reptiles can not all be kept on the same light bulbs. Some species require UVA and UVB bulbs, while some only need basking bulbs. Household bulbs are inappropriate as are any bulbs that are not specifically designed for reptile keeping. Household plant bulbs do not provide specific radiation and light needed by certain species. Photoperiods can not be too long or too short, they must be appropriate for the species and the season.

Part 3 will discuss dietary mismanagement, clinical signs of NMBD, diagnostics, and short term medical treatment..

Roberta A. Avila-Guevara CVT is a practising Certified Veterinary Technician and has been published in several veterinary technician journals. 

By Aliza Arzt

We love our reptiles and we (or at least our family members) like the house to look good as well. These two goals can sometimes be in conflict with each other. Tanks scattered throughout the house, unattractive racks, enclosures that need cleaning, shelves cluttered with miscellaneous supplies –before you know it, the lounge resembles a poorly maintained pet shop. Some are lucky enough to have a separate reptile room where we can arrange things as we like without worrying about how it looks to others, but most of us find ourselves sharing public living space with the reptile collection. Gorgeous display enclosures go a long way toward beautifying the space but they are expensive and don't necessarily meet the needs of a mid-sized to large collection where multiple enclosures are required. What follows are some simple suggestions to help maintain an attractive living space with a reptile collection:

• Keep the middle of the room clear: Unless you have a display cage that doubles as a coffee table, keeping random tanks on tables or on the floor in the middle of the room is unattractive and also a safety hazard. Utilize wall space (not in front of the windows, as a rule) for stacking enclosures, installing shelf units or other furniture that can hold cages. If you have access to front-opening enclosures, a shelf unit can hold a cage on each shelf and has the same effect on a room as a bookshelf full of books.
• Organize the wires: Enclosures that require heat and light also generate multiple cords, timers and outlet strips. When these wires are allowed to sit in a big tangle on the floor, they don't look nice, are a safety hazard and can be difficult to sort out when a wiring change is needed. Mount outlet strips and thermostats on the baseboard or on a cabinet. Untangle the wires, coil up the excess in each cord and match plugs to outlets in a logical sequence.
• Use matching enclosures: Wherever possible, use matching enclosures in each area. Even if they are different sizes, cages with the same finish or style are more appealing than random cages made with different materials or colors.
• Build or buy attractive racks: Large reptile collections lend themselves to racks which are fine in utility rooms, but seldom enhance the lounge or the dining room. For best results, choose rack furniture that matches the color scheme of the room or use wood with an attractive grain that can be oiled or otherwise finished. Consider adding nice edging to the rack, or build a rack into an attractive piece of furniture like a wardrobe or a bureau. Keep tub labels standard in size and shape and put them in the same place on each tub.
• Keep supplies hidden: Reptile keeping generates random containers, bags and boxes. Keep these in closed containers rather than strewing them all over your public living space.
• Keep the cages clean: As reptile keepers we get used to the smell that our animals and their feeders and caging generate. Visitors to our home do not. If your reptile collection is in public living space, keep the cages clean, be sure to use adequate ventilation and air fresheners if necessary.

Careful attention to what looks nice, and use of simple, practical solutions to keeping multiple cages and supplies in public space can turn the home from an eyesore to a fascinating destination and comfortable environment.

 

Aliza Arzt is an editor for Gecko Time (www.geckotime.com) and has been and avid keeper of reptiles foir many years.