Nursing care of exotic mammals (Proceedings)

Providing veterinary care to exotic pets is challenging and rewarding, offering the veterinary technician the chance to work with a wide variety of species. There is an inherent challenge for those working with these pets given the large variety of species presented for care. Often the standard organization of a veterinary hospital is not ideal for exotic pets and special accommodations must be made. More time may be required to perform the physical assessment and diagnostic evaluation of exotic pets due to the need to obtain an in-depth history and the sometimes fragile state of these patients. Critical care is an integral part of disease management in zoological species and a high mortality rate is inherent in exotic animal emergency medicine. The nature of these species and the fact that they are fairly recently domesticated dictates that they hide their illness until they have decompensated. Owners need to be aware that their pet is in serious condition but by providing nursing care, you provide them with the best chance for their pet's recovery. Additionally, admission and support staff must be knowledgeable about exotic pet care and should receive training regarding their handling and husbandry to optimize an exotic animal practice. 

Preparedness

Many exotic pets requiring hospitalization and nursing care are presented in critical condition. As in domesticated species, the time to prepare for emergencies is before the emergency occurs. Work with your care staff to create a plan to respond to medical emergencies. Most of the supplies and equipment used for emergency care of traditional pets can be used to care for zoological species, but some additional supplies will be needed. Prepare a space in your facility that is ready to care for exotics. Include small gauge needles and small syringes, small endotracheal tubes, and drug doses for exotic species in your crash cart. Organize and hold training sessions to practice emergency techniques on exotic species, using cadavers or models to hone your skills and those of your support staff. Every good team has members that know their role in an emergency and are prepared to perform it. Make sure your team members are ready.

Triage examination

Patient assessment is part of any good triage examination whether the patient has just arrived for an emergency or it is being evaluated after a night of hospitalization and care. It is important to visually assess the patient prior to an actual physical exam. Many zoological species are stressed when in unusual situations and are intolerant to handling and the stress it induces. As animals in critical condition may decompensate from a simple physical examination, decisions must be made as to how much the animal can tolerate at any given time during therapy. It may be necessary to perform diagnostic testing and treatment administration is a staggered fashion, allowing the patient recuperation time between handling periods. Some animals benefit from sedation or anesthesia to minimize perceived stress.

Basics of nursing care

Supplemental heat is critical for patients that have lost or do not have the ability to thermo-regulate their own body temperature. This is especially true of avian and reptilian species. Providing an external heat source reduces the physiological stress on the animal during hospitalization care. This can be done with the use of pediatric or veterinary incubators. Often, used pediatric incubators in good working order may be obtained from human hospital surplus stores. Alternatively, radiant heating lamps may be attached to cage doors or placed over aquaria to provide ambient heating when an incubator is unavailable. In this instance, it is important to be cognoscente that the patient and potentially flammable materials are not in direct contact with the lamp as burns and fires are possible. Heating pads and heating discs are good alternatives for providing supplemental heat for patients that are ambulatory and do not need constant thermo-regulation. Temporary heat may also be provided with hot water bottles or rice filled socks that area heated in the microwave. This is especially useful post anesthesia or surgery. A non-ambulatory animal should never be left on a focal heat source without constant monitoring as they may become hyperthermic and not be able to move away from the source to cool down. Additionally, caution must be used when using heating pads for rodent species as they may chew on the power cord leading to electric shock. 

Nutritional support must be provided to hospitalized patients, especially those with high metabolic rates where anorexia rapidly results in cachexia. The caloric requirements of the patients must be calculated and those requirements met on a daily basis through self or supplemental feeding. As in domestic species, metabolic rates are measured in kilocalories per day (kcal/day). The basal metabolic rate (BMR), or metabolic rate at complete rest, equals the patient's weight measure in kilograms multiplied to the 0.75 power times a species coefficient (K). The species coefficient takes into account the type of animal's metabolic rate. Once the BMR is calculated, the maintenance energy requirement (MER), the metabolic rate based on activity), can be determined by multiplying the BMR by the activity level of the patient (1-2, 1.5 for convalescing animals, 2 for growth).

• BMR kcal/day = K x Weight kg (0.75)

• MER kcal/day = 1.5 x BMR

• K values (passerines-129, non-passerines-78, reptiles-32, placental mammals-70)

Once the number of kilocalories needed for MER are determined, the amount of food needed to meet that requirement can be calculated and divided over the day's feedings. The best way to determine if a patient is receiving appropriate nutrition is to weigh the patient daily on an accurate gram scale. Supplemental feeding can then be adjusted as appropriate.

Nursing care of ferrets

Ferrets are very resilient and can generally recover well from critical situations. Caution is warranted as even the nicest ferret will bite when uncomfortable or ill. Public health protocols developed for domestic canines should be implemented in response to bites from ferrets. Aggressive or uncooperative ferrets may be restrained for short procedures by providing anesthesia by mask. Isoflurane or sevoflurane are most commonly used.

Hospitalization Considerations 

A regular hospital cage is appropriate for ferrets and a litter box should be provided. A towel or hide box is also appreciated as these animals will burrow. Water should be provided in a bowl or sipper bottle, depending on what the ferret is accustomed to, and a high quality kitten food or ferret food should also be provided. Have the owner provide the food that the ferret is used to as some are finicky eaters. If the ferret is not eating on its own, syringe feed a gruel carnivore diet (Eukanuba Recovery, Science Diet A/D, chicken baby food, Oxbow Critical Care for Carnivores, Lafeber Carnivore diet) at a rate of 12-20 ml every 4-6 hours. Syringe feeding may be enhanced by scruffing the ferret and placing the catheter tip at the corner of the mouth to administer small amounts of food at a time.

Fluid Administration

The cephalic vein is most often used for IV catheterization. A 24 gauge catheter can be placed in the cephalic vein of most ferrets unless dehydration is pronounced. The skin over the vein should be nicked prior to placement to avoid barbing the catheter as ferret skin is very tough. The catheter is then secured using tape and vetwrap. IO catheter placement is best performed in the proximal femur using an appropriately sized hypodermic or spinal needle. The skin is shaved and aseptically prepared in a routine manner. It is best to anesthetize the ferret prior to this method. Heparinized saline should be used to keep the catheter patent. Fluids can be administered by SQ, IV, or IO routes. SQ fluids are administered in the intra-scapular area. A large gauge needle should be used as ferrets find this route to be uncomfortable and rapid infusion of warmed fluids is preferred. Fluid requirements are 60-70 ml/kg/day. Fluid therapy instituted for treatment of shock should follow protocols developed for domestic felines.

Drug Administration 

The injection sites for drug administration are similar to those used in domestic pet care. Subcutaneous injections are generally administered in the intra-scapular area; intramuscular injections are administered in the quadriceps muscle mass on the cranial thigh. Oral administration of drugs follows the same technique used to syringe feed a ferret.

Nursing care of rabbits and rodents

These species are exquisitely sensitive to stress. Even when therapy seems to be progressing well, these animals can become compromised quickly. As such, supportive care is critical to their management. When stressed or in pain, rabbits and some rodents (guinea pigs, chinchillas) will not eat, leading to gastrointestinal problems (stasis, etc.). These problems can often be more critical than the presenting problem. Rabbits and some rodents (guinea pigs, chinchillas, hamsters, degus) have hind gut fermentative digestion which makes them extremely sensitive to certain antibiotics. Avoid using any beta-lactam (penicillins, cephalosporins), tetracycline or macrolide antibiotics with oral administration. Isoflurane anesthetic restraint can be administered by mask if immobilization is required for a brief period of time. Be sure to monitor respiration and heart rate while anesthetized. 

Hospitalization Considerations

A normal hospital cage or aquarium with lid is used when hospitalizing rabbits and rodents depending on the size and species of the patient. Newspaper or towel bedding is appropriate. Hide boxes are appreciated by many of the small rodent species. Litter boxes should be provided to rabbits. Food and water should be made available at all times. Water should be provided in either a bowl or bottle depending on which the animal is used to. Most small mammals are sensitive to heat, thus heating pads can be used for supplemental heat under a towel but be sure the animal can move away from the heat source should they becomes over-heated. Supplemental heat is not necessary unless the patient is hypothermic. Pellets, hay, and fresh salad greens may be used to tempt the anorexic rabbit or large rodent to eat. Seed mixes and pellets are generally offered to small rodents. Do not give seeds to large rodents or rabbits. If the patient is not self-feeding, syringe feeding should be implemented using herbivore gruel diets (Oxbow Critical Care for Herbivores, blenderized pellets, canned pumpkin, vegetable baby food). Small mammals are fed 50 ml/kg/day divided into feedings every 6 hours. Syringe feeding of rabbits and large rodents (guinea pigs, chinchillas) is facilitated by placing the patient on a flat surface wrapped in a towel “burrito”. A small syringe (1-3 ml) filled with gruel is introduced into the mouth caudal to the incisor teeth. This gap between the incisors and cheek teeth (diastema) is an area through with the syringe can safely pass. The food is then expressed into the caudal oral cavity, allowing the animal to chew and swallow before the process is repeated.

Fluid Administration

A 24 gauge IV catheter can be placed in the cephalic veins of rabbits, chinchillas, and some guinea pigs. Additionally, IV catheters can be placed in the marginal ear vein of rabbits. For small rodents and patients where IV access is compromised, IO catheter placement is indicated. IO catheter placement in rabbits, guinea pigs, and chinchillas performed using the proximal tibia. IO catheter placement in small rodent species is most easily accomplished using the proximal femur. IO catheters may be left in for 3-5 days. IO catheter placement should be performed with the patient sedated or anesthetized.

Fluids can be provided by SQ, IV, or IO routes. Maintenance fluid requirements for most small mammals range between 60-100 ml/kg/day, with the average rate being 70 ml/kg/day. Shock fluid rates are 90-100 ml/kg/hr as needed. These fluids can either be given as constant rate infusion or as intermittent boluses. A syringe pump is extremely useful in fluid therapy administration for small mammals.

Drug Administration

SQ injections are given in the intra-scapular area. Use caution to avoid injecting into the cheek pouches which may extend into the intra-scapular area in some rodents (hamsters). Guinea pigs and rats typically object to subcutaneous fluid administration. Intramuscular injections are administered into the quadriceps muscles on the cranial thigh or the semimembranosis-semitendinosis muscle mass on the caudal thigh. Oral drug administration is performed in the same manner as syringe feeding.

Resources

A Technician's Guide to Exotic Animal Care. Tully T.N. and Mitchell M.A., eds. 2001. AAHA Press, Lakewood, CO.

Exotic Animal Medicine for the Veterinary Technician. Ballard B. and Cheek R., eds. 2003. Iowa State Press, Ames, IA.