General principles and basic equipment
No single hospital environment can meet the needs of every exotic animal. Caging systems must be tailored to meet the specific needs of each patient (Fig 1), however there are caging requirements that remain constant among exotic animals:
- First, the space used to house prey species (such as rabbits and guinea pigs) must be quiet. Select an area away from the sight and sound of predator species like cats, dogs, and ferrets (Mustela putorius furo).
- Install dimmers in the room(s) that will house exotics. Lowering light levels can calm a nervous prey species or facilitate restraint.
- Select caging that is easy to clean and well ventilated. The cage setup should also physically block the view of one animal from another.
- Cage floor substrate will vary with the species; however, a stack of newspaper or butcher paper can meet the needs of many hospitalized patients.
- Many exotics will also benefit from some form of visual security. Drape a towel over part of the incubator or tape newspaper or some other opaque paper over part of a treatment cage door. Place a cardboard box or a plastic hide box within the cage.
- Commercially available incubators and intensive care or treatment cages (e.g. Lyon Technologies, Synder Manufacturing Company) are a great way to provide warmth, oxygen, and nebulization. Whenever possible, test the unit before purchase to identify potential problems such as overheating or difficulty cleaning. Assess the unit’s ability to vary humidity as well as its durability. Ideally the treatment cage should also be large enough to hold a standard birdcage. Should the need arise, this will allow you to provide supplemental heat and/or oxygen without touching your debilitated patient. Maintain one more treatment cage than needed to accommodate typical patient caseload. This allows back-up in the event a treatment cage fails, an extra one to move patients so a dirty cage can be cleaned, and it provides added hospitalization capability on busy days.
- Heat may also be provided by under tank heaters such as insulated heat strips or a heating mat. An alternative or supplemental source of warmth is an overhead or radiant heat source, such as a ceramic heat lamp or lightless infrared heat projector (i.e. Mega-Ray HP 60 watt heat projector). Make sure the patient cannot contact this overhead heat source.
- A small “warm room” can also be a useful way to house sick birds and reptiles. Maintaining an ambient room temperature of 80°F (27°C) makes it much easier to heat individual cages. Use a radiator to heat the “warm” room, and make sure this is controlled by an external thermostat. The temperature controls of radiators often fail with long-term use and many have strict warnings that they are not to be left unsupervised. The coils of many space heaters are Teflon coated. When superheated, Teflon can release polytetrafluoroethylene (PTFE) gas, causing potentially fatal respiratory disease in birds.
Provide supplemental heat to small mammals cautiously, and monitor the animal closely for signs of overheating. The thick, dense coat of the chinchilla means this animal is at particular risk of overheating at temperatures above 75°F (24°C). The long, lean ferret is not only capable of overheating easily, but it cools down rapidly as well.
Whenever a cage is heated, use thermometers to regulate temperature. Place digital thermometers at both ends of the enclosure or use an infrared thermometer to monitor the temperature gradient. Heat sources should ideally be connected to a thermostat with alarms that signal deviations outside the preferred temperature ranges of the patients.
House fluffed and ruffled birds at a minimum temperature of 80-85°F (27-29°C). A range of 85-95°F (29-35°C) may be needed for some birds. Monitor the patient for signs of overheating and use particular caution in overweight birds. It is particularly important to provide a temperature range for reptiles so they can behaviorally thermoregulate. For many reptiles, the hot spot in the cage should be 90-95°F (32-35°C) with the cold spot no lower than 75-80°F (24-26°C).
Although not a basic requirement, it is important to consider what will you do when faced with an exotic animal that is highly contagious. Plan for an exotics isolation room away from regular housing. Ideally the isolation room’s air pressure should be negative to hallway pressure to prevent air from easily flowing from this room.
Depending on the species involved, exotic small mammals may be housed in a variety of habitats ranging from stainless steel hospital cages or wire cages to aquariums and Plexiglas pet cages with snap-on lids. Traditional clear polycarbonate laboratory cages for rats, mice, and guinea pigs also work well and are much more durable than glass or Plexiglas cages.
Offer food in shallow dishes, lids, or appropriately sized plastic or ceramic bowls. Always ask the owner if their pet drinks from a water bottle or bowl, and maintain a collection of water bottles of various sizes. Provide burrowing material, such as facial tissue or recycled paper bedding, in the hide box for small patients like mice, gerbils, and hamsters.
Burrowing is also a must for the hospitalized ferret (Fig 2). Many owners will bring something from home in which the ferret may burrow, but you may also provide toweling, an old scrub top, or a pillowcase. If the ferret is attached to tubing due to intravenous and/or urethral catheter placement offer something small, like a surgical towel, to satisfy the ferret’s need while minimizing the risk of the line becoming entangled.
Ferrets can be housed in standard stainless steel cages as long as the bar spacing is not large enough for the ferret to squeeze through. Provide a small, shallow litter pan, and offer food and water in heavy ceramic bowls to prevent these active creatures from knocking over the dishes.
Rabbits may be housed on newspaper or butcher paper, however there is always a risk of leg or back injury when rabbits are kept on a slippery surface. At least a portion of the cage should offer more traction by lining the floor and hide box with a rubber bath mat topped with shredded paper or a large, thick towel. Alternatively, the rabbit may be placed on a mat or a grate (e.g. PVC coated grill floor, Shor-line). Monitor the patient for chewing on the towel or mat, and offer a litter pan lined with recycled paper product or shredded paper. Hay or straw can serve as good alternative bedding for healthy, curious rabbits.
Depending on the species involved, the hospitalized bird may be housed in a stainless steel cage, a smooth-sided enclosure with a snap-on lid, an incubator (Fig 3), or an intensive care or treatment cage. Of course birdcages may also be used, however it can be relatively difficult to retrieve an uncooperative patient from such an enclosure. Some treatment cages offer the advantage of a porthole, which allows you to insert your arm into the cage without the worry of bird escapes. Stainless steel caging is an inexpensive option that can be used to house medium to large-sized birds. Strategically arrange door mount brackets to allow suspension of food and water dishes, toys, and foraging devices. Unfortunately these cold, shiny, often noisy metal cages are not well received by all avian patients. And while the majority of the cage is easy to clean, some parrots can extensively soil the cage doors. One solution is to replace the standard bars with Plexiglas® doors that contain ventilation holes.
All but the weakest perching birds will be much more comfortable if provided with perch material. Perches are available commercially or may be constructed from PVC piping. Purchase a variety of PVC pipes cut to variable lengths, then attach joints and caps. Wrap the PVC with adhesive bandage material (Vetrap, 3M) or white tape to provide traction and for ease of cleaning (Fig 4). Place perches on the cage floor or elevate perches only slightly to minimize the risk of falls. For patients housed in stainless steel cages, perches are commercially available that may be screwed onto the cage door with wingnuts and washers.
Although PVC perches may be offered to wild birds, natural tree branches are often accepted best (Fig 5). See Plants & branches for your bird for advice on branch selection. For birds of prey, create perches of various sizes from large PVC pipe covered with artificial turf or use large, sturdy branches.
Birds often perch on their food and water dishes in a hospital setting. Standard metal hospital dishes are often not heavy enough to support the bird’s weight so provide heavy ceramic or plastic dishes of appropriate size instead.
When birds are very weak or suffering from neurologic deficits, it can also help to elevate food and water dishes. Once dishes are elevated, the patient no longer needs to lean over to eat and drink. Therefore this practice can increases the intake of food while minimizing the risk of falls, particularly falls into the water bowl. This also allows the use of relatively shallow dishes, which reduces food wastage.
Food items placed into bowls may not be well accepted by free-ranging birds used to foraging on the ground. Scatter food on the cage floor instead and when bowls are offered, select a shallow ceramic dish or a plastic lid.
The primary goal when housing songbirds is to prevent escape while minimizing patient stress. If the songbird is only going to be hospitalized short-term, a small Plexiglas pet cage will facilitate easy capture because of the porthole in the snap-top lid. Keep enclosures within a room that will allow for easy capture if your patient does escape.
Offer swans, geese, and ducks large water bowls or buckets; ideally the bird should be able to completely submerge its head. To maintain waterproofing, allow these birds to swim in a large hospital tub or a kids’ pool regularly (Fig 6). If the bird cannot submerse itself in water for medical reasons, it should be misted heavily with water on at least a daily basis in an effort to promote preening. House waterfowl on rubber mats or grates to keep the enclosure from getting too wet. To prevent the development of pododermatitis in birds hospitalized for more than a brief period, these large bodied birds also require some cushion in their floor substrate.
Each reptile species has a preferred optimal temperature zone (POTZ) at which its physiology functions optimally. When ill or injured, the reptile’s ability to heal and recover is also most efficient within this POTZ. Place indoor/outdoor digital thermometers with remote probes at both ends of the enclosure to monitor cage temperature. The target temperature at one end of the enclosure should be the low end of the POTZ, while the other end of the cage should reach the high end of the recommended temperature gradient. Some species also require a basking spot, which reaches a higher temperature. For instance the bearded dragon (Pogona vitticeps) has a POTZ of 80-88°F (27-31°C), but its basking spot should reach 95-105°F (35-40°C). Basking spots for arboreal lizards are reached as the animal climbs higher and gets closer to the radiant heat source. Only reptiles of adequate strength and normal bone quality should be offered vertical space for climbing, and the reptile should never be able to contact the overhead heat source. If reptiles are seen regularly in your practice, post a reference chart that lists recommended temperature ranges (Table 1) to help caretakers prepare hospital cages.
Table 1. Recommended indoor temperature or preferred optimum temperature zone (POTZ) of selected reptile species. Don’t see your species of interest here? For many reptiles, a temperature range of 75-85°F (24-29°C) will serve as a good target until the specific needs of your species can be determined.POTZ: Preferred optimal temperature zone at which a which a reptile’s physiology functions optimally
|Common name||Scientific name||POTZ °F (°C)||Basking spot °F (°C)||Nighttime low °F (°C)|
|African spurred tortoise (see Sulcata below)|
|Anole||Genus Anolis||75-80 (24-27)||85-90 (29-32)||65-75 (18-24)|
|Ball python||Python regius||80-85 (27-29)||90 (32)||70-75 (21-24)|
|Bearded dragon||Pogona vitticeps||80-88 (27-31)||92-95 (33-35)||60-70 (16-21)|
|Blue-tongue skink||Tiliqua spp., Cyclodomorphus spp||75-88 (24-31)||90-95 (32-35)||Low to mid 70s (21-24)|
|Boa constrictor||Boa constrictor||80-90 (27-32)||90 (32)||70-75 (21-24)|
|Box turtle, Eastern||Terrapene carolina||70-80 (21-27)||85–90 (29-32)||70-75 (21-24)|
|Corn snake||Elaphe guttata||75-85 (24-29)||90 (32)||65-72 (18-22)|
|Desert tortoise||Gopherus agassizii||80-85 (27-29)||95 (35)||65-70 (18-21)|
|Gopher tortoise||Gopherus polyphemus||75-85 (24-29)||88-94 (31-34)||70s (21-26)|
|Green iguana||Iguana iguana||80-88 (27-31)||92-95 (33-35)||70-75 (21-24)|
|Hermann’s Tortoise||Testudo hermanni||78-85 (26-29)||90 (32)||70-75 (21-24)|
|Jackson’s chameleon||Chamaeleo jacksonii||70-80 (21-27)||82-85 (28-29)||Low to mid 70s (21-24)|
|King snake||Genus Lampropeltis||76-86 (24-30)||88-93 (31-32)||Low 70s (21-23)|
|Leopard gecko||Eublepharis macularius||70-80 (21-27)||90 (32)||Low 70s (21-23)|
|Leopard tortoise||Geochelone pardalis||72-86 (22-30)||90 (32)||70 (21)|
|Milk snake||Genus Lampropeltis||76-86 (24-30)||88-93 (31-32)||Low 70s (21-23)|
|Painted turtle||Chrysemys picta||72-82 (22-28)1||85–90 (29-32)||High 60s to low 70s (20-23)|
|Panther chameleon||Furcifer pardalis||75-90 (24-32)||95 (35)||65-70 (18-21)|
|Prehensile-tailed skink||Corucia zebrata||75-86 (24-30)||86-92 (30-33)||Low to mid 70s (21-24)|
|Red-eared slider||Trachemys scripta||75-82 (24-28)1||90-95 (32-35)||70-75 (21-24)|
|Red-footed tortoise||Geochelone carbonaria||78-85 (26-29)||90 (32)||High 60s to low 70s (20-23)|
|Rosy boa||Lichanura trivigata||73-83 (23-28)||78-85 (26-29)||70-75 (21-24)|
|Russian tortoise||Testudo (Agrionemys) horsfieldii||78-85 (26-29)||90-95 (32-35)||60-75 (16-24)|
|Savannah monitor||Varanus exanthematicus||84-92 (29-33)||94-100 (34-38)||75 (24)|
|Sulcata tortoise||Geochelone sulcata||70-90 (21-32)||95 (35)||70s (21-26 C)|
|Uromastyx||Genus Uromastyx||88-104 (31-40)||110-120 (43-49)||60-70 (16-21)|
|Veiled chameleon||Chamaeleo calyptratus||70-85 (21-29)||90-95 (32-35)3||60-65 (16-18)|
|Water dragon, Chinese or Thai||Physignathus cocincinus||84-90 (29-32)||92-97 (33-36)||75-78 (24-26)|
A humidity gauge or hygrometer comes in handy when housing many exotic species, but it is a requirement for reptile patients. Most reptiles do well at a relative humidity of 50-70%. Desert tortoises require 30-50% humidity, while subtropical species should be housed at 60-80% and tropical species at 80-90%.
- To increase cage humidity, provide a water tub large enough for the patient to submerge. The water bowl should be shallow enough for easy access.
- To increase cage humidity, place the water pan underneath a radiant heat source, and/or mist the cage regularly using a water spray bottle.
- Placing a bowl of roll cotton soaked in water in the cage beneath the radiant heat source can also raise humidity.
- Humidity levels may be particularly difficult to increase in some incubators and treatment cages. In these enclosures it can also help to add a bowl with a water-soaked sponge, towel, or roll cotton.
Most reptiles are not hospitalized long enough that ultraviolet (UV) lighting is necessary, however full- spectrum UV lighting may still provide physiologic benefits.
Most terrestrial turtles do not climb well; therefore they can be kept in cages with tall sides and no top. Keep aquatic and semi-aquatic species in aquaria. Some aquatic turtle species are agile climbers, so be sure to include a screen top to prevent escape.
As long as turtles are strong enough to swim, provide hatchling painted turtles (Chrysemys picta) and red-eared sliders (Trachemys scripta) with 3-6 inches (7.5-15 cm) of tap water. Large juvenile and adults of these species will need between 10-30 inches (20-60 cm) of water. Monitor water temperature, which should be maintained between 82-85°F (28-29°C), with the help of a submersible aquarium heater, and perform frequent 50-100% water changes to maintain sanitary conditions.
Provide a dry haul-out area at one end of the enclosure using hardwood, pieces of cork, or a flat rock resting on submerged bricks or cinder block. Create enough of an incline so the turtle can climb out easily, and position an overhead light over one corner of the haul-out area to provide a basking spot. The basking spot should reach 90-95° F (32-35°C).
Sick chameleons may initially need to be housed in an incubator or a heated hospital cage. When the chameleon is able to perch and climb, provide a vertical enclosure such as a wire birdcage or a plastic-coated wire-welded mesh cage with multiple branches or twigs (Fig 6), an overhead radiant heat source, and artificial plants. Provide water either by misting the plants every 4-8 hours, with a commercial reptile water dripper, or rig a makeshift drip system using a medical IV bag or a plastic cup with a pinhole in its bottom.
Most amphibians are easily housed in a Plexiglas pet cage with a tight-fitting, ventilated lid and smooth, clear sides. A plastic food storage container with ventilation holes in the lid or sides can also serve as a temporary enclosure. Be sure to make the ventilation holes from the inside out to prevent patient exposure to rough edges.
A temperature range of 75-80°F (24-27°C) is appropriate for many amphibians, but some common pet species, such as White’s tree frogs (Pelodryas caerulea) and many other tropical frogs and toads, need a basking spot of 85-100°F (29-38°C). Many salamanders need much cooler temperatures and show heat stress if brought above 72°F (22°C). Place a heat mat along the back of the tank or underneath part of the enclosure. Never shine a high wattage heat lamp directly over an amphibian’s cage as this will dry the environment out.
Strive for a minimum relatively humidity of 50%, although 70-90% is preferable for many species. To provide appropriate humidity and keep your patient moist:
- Offer a shallow water dish
- Line the cage bottom with non-bleached paper towels kept wet at all times. Alternatively bubble wrap can serve as a soft, atraumatic, and moist substrate.
- Mist cage walls and plastic plants frequently.
- If humidity levels are still not high enough, loosely place plastic wrap over the top of the cage enclosure.
Monitor temperature and humidity with digital thermometers and hygrometer as described for reptiles, and ensure adequate ventilation.
Never use straight tap water for amphibians because of the presence of chlorine, chloramines, and other dissolved substances like lead. Acceptable water sources include bottled spring water, tap water passed through an active carbon filter, tap water treated with sodium thiosulfate (the active ingredient in commercial dechlorinators), or aged tap water. To age water, place room temperature water in an open container for at least 24 hours to allow chlorine to dissipate.
House aquatic amphibians in an enclosure containing dechlorinated fresh water, ideally of similar pH and temperature to the home tank. Add an aquarium air stone to enhance oxygen diffusion. A makeshift aerator may be used short-term by bubbling oxygen through a small line such as a red rubber catheter. Provide plastic aquarium plants for visual security.
Fish should be transported to the clinic in at least 0.5 gallon of tank water per inch of fish (0.8 L/cm). Lidded coolers make great travel containers as they help maintain a constant water temperature. Upon the fish’s arrival, be prepared to provide aeration of the transport container using a portable air pump and disposable air stone, particularly if the fish is piping or gasping for air at the water’s surface. Also be prepared to increase aeration if the hospital visit is longer than 30 minutes.
If the fish must be hospitalized and the owner did not bring enough water to fill a tank, then it will be up to the clinic to provide a safe source of water (see amphibians above). Ideal water temperature will vary with the species, although most pet fish are tropical and do well between 76-86°F (24-30°C). Use an analysis test kit to check water quality. Dissolved oxygen levels should be 6-10 ppm, and pH should be between 6-8.
If fish are seen even sporadically in your practice, it can be useful to maintain a 10-20 gallon (38-76 L) aquarium with filter capacity, heaters, pumps, and air stones. House fish in a room that is aerosol-free and capable of dim lighting. Keep noise and other vibrations to a minimum.
What to do in a pinch
What if you do not routinely see exotic animals? Non-traditional pets are an ever growing part of clinical practice, and it pays to be prepared for the unexpected. Some of the basic equipment mentioned here such as small pet cages, incubators, and treatment cages can also prove useful in general veterinary practice.
Even if you don’t have much in the way of equipment, there are still things that can be done for a critical exotic patient that cannot be immediately referred. Focus on the ability to provide supplemental heat and oxygen as indicated. Heating pads are not made to have items like a cage or aquarium placed on top of them, but they can help short-term. Place the pad underneath part of the enclosure, select the low setting, and place a towel between the pad and the cage. A makeshift “incubator” may also be created by first covering one side of a cage with a towel. Place a radiant heat source like a ceramic heater close enough to provide heat without creating a hazard, and then monitor this set-up closely.
A wide variety of special species are kept as pets, and meeting the housing needs of these animals can be quite challenging. Caging systems must be tailored to meet the specific needs of each species, however there are basic space, caging, and equipment requirements that must be met (Table 2).
Table 2. Checklist of minimal requirements for housing birds, small mammals, and reptiles in a hospital setting.