Close this window to return to IVIS www.ivis.org Proceedings of the Southern European Veterinary Conference - SEVC - Sep. 30-Oct. 3, 2010, Barcelona, Spain Next SEVC Conference: Sep. 30-Oct. 2, 2011 - Barcelona, Spain Reprinted in the IVIS website with the permission of the SEVC - AVEPA www.ivis.org
Emergency mergency/c /Critical care Critical care techniques in small exotic mammals Douglas Mader, MS, DVM, DABVP Marathon Veterinary Hospital, Marathon, FL USA Small mammals will present for emergent care for all the same reasons that are seen in dog and cat medicine. Perhaps the two broadest categories that are seen are metabollic collapse and trauma. Trauma is a frequent cause for visits to the veterinarian by small animal owners. Not uncommonly, these pets are owned by small children, and it is not an infrequent occurrence for these little pets to get dropped, stepped on or bitten by dogs and cats. The approach should be no different than for any trauma victim. Treat lifethreatening emergencies first. Follow the ABC's, Airway, Breathing and Circulation. Metabolic collapse, in small mammals, can be related to physical and organic disturbanceds. A familiarity with the most common diseases seen in these patients will better prepare the clinician in the event of an emergency situation. This presentation will help prepare the clinician to recognize the common problems and subsequently stabilize the patient for the first 24 hours. Preparation There are literally hundreds of different types of Pocket pets on the market. However, in reality, there may be only a dozen or so that will present to the ER on emergency. Most of these pets will range in size from the house mouse to a large rabbit. As such, it is imperative that the ER is prepared to handle and house these animals. Most importantly, understanding the unique physiological needs of these relatively tiny patents will help in developing the necessary protocols to handle the special needs patients. The majority of these patients have relatively high metabolic rates compared to the more common dog and cat patients. In addition, because of their small size, and hence, relative large surface area to volume ratio, heat loss and subsequent hypothermia is a big problem. Incubators or some method of warming these patients are essential for proper emergent care. Examination tables should be covered with a clean (preferable warm) towel prior to placing the patient on the table. Stainless steel tables, although easy to sanitize, act as a heat sink and can cool an already hypothermic patient rapidly. It is preferable have a room designated for exotics. That way, specialty items such as gram scales, hard plastic oral specula, small otoscope cones, and the like will always be available. When an obtunded patient presents you will not have to go searching for the needed items.
Fluids and venous access There is an old adage, if the mouth works, use it. This holds true in dog and cat medicine, and also works wonders with exotics. There is some weird unwritten rule that states if you are going to be an exotic veterinarian, you MUST use intraosseous (IO) catheters. In actuality, if you are going to be a GOOD exotic animal veterinarian, you should evaluate your patient first, decide if fluids are necessary, and then decide on the best route of administration. For some trauma patients some type of venous access may be necessary. Unless the patient is critical, very small, severely dehydrated, hypothermic and has no accessible veins, an IO catheter should be the last choice for fluid administration. Remember another old adage, above all, do no harm. IO catheters are painful, can cause severe damage and if not placed properly, with strict adherence to asepsis, can cause osteomyelitis. Fluid choices will depend on the need. Again, follow the guidelines used for dogs and cats. Let the laboratory analysis be the determining factor. If cost is an issue and blood work is declined, then a balanced electrolyte will suffice. Published dosages range from 30 90 ml/kg in the first hour. Maintenance rates will be the same as those for dogs and cats 60 ml/kg/day with compensation for special losses. Whole blood can be transfused in any of the Pocket pets as needed, pending the availability of appropriate whole blood. Blood should be transfused from like species to like species (i.e. rat to rat, not rat to mouse). Blood typing does not appear to be necessary for most small mammals, and transfusion reactions are rare. Pre-medication with diphenhydramine at 1 mg/kg, either IV or IM may be of some benefit. There have been anecdotal reports of successful use of hemoglobin substitutes, such as Oxyglobin. However, substantiated research as to its effectiveness and safety has not been published. Using synthetic hemoglobin substitutes may be warranted but the owner needs to be appraised of the novelty of the procedure and the potential risks prior to starting the administration. Venipuncture, IV and IO access can be obtained as follows: (commonly used sites) Ferrets Catheters: cephalic, saphenous and jugular veins. Tibial crest for IO catheters. The vena cava and subclavian veins can be used for venipuncture. Rabbits Catheters: cephalic, saphenous and jugular veins. Tibial crest for IO catheters. Note: The older literature suggests using the ear veins for catheters, however, phlebitis is common and sloughing of the ear tip may occur. These veins are suitable for venipuncture. In addition, the cephalic and saphenous veins work well for venipuncture. If you are planning on placing a catheter, then save the cepahlic vein and use the sapehenous for bleeding. Rats, mice, hamsters, gerbils, sugar gliders etc. Catheters: tail veins (rats), jugular veins in all. In general, IV catheters in rats and mice are not commonly performed in clinical practice (although, common in research). Tibial crest for IO catheters. Venipuncture: femoral vein. Not recommended: orbital sinus or cardiocentesis for pet rats and mice. Guinea Pigs Catheters: jugular vein. Tibial crest for IO catheters. Venipuncture can be accomplished using the jugular and saphenous veins. Not recommended for pet vena cava. Hedgehog (Anesthesia almost always necessary) Catheters: jugular. IO in the tibial crest. Bleeding from the jugular, saphenous and (in males) penile vein. Therapy
There are several published articles with dosages for commonly used medications (see Carpenter, et. al.). In general, most drugs that are used in small animal medicine can be used in small exotic pets. There are exceptions and the ER practitioner will need to take the time to learn these. Common emergency drugs include fluids, steroids, antibiotics, diuretics and laxatives. Fluids, as mentioned, should be based on patient need. If in doubt, balanced electrolytes are a good starting solution. Common emergency antibiotics include enrofloxacin, trimethoprim-sulfa and chloramphenicol. All of these antibiotics can be safely used in all pocket pet species without fear of causing gastrointestinal upset or stasis. Dexamethosone sodium phosphate and prednisolone sodium succinate are freqently used in shock. These medications should be used judiciously as side effects seen in small mammal medicine are also encountered with pocket pets. Lactulose, simethicone and bulk laxatives may be needed to assist patients with hepatic disorders and gastrointestinal blockages. Intestinal motility drugs, such as cisapride and metaclopramide, are used but proper patient assessment is mandatory. Specific Problems The clinician needs to be familiar with the most common problems seen in small mammals. The most important thing is to stabilize the patient.. It is usually NOT critical to make the diagnosis immediately rather, it is critical to keep the patient alive with appropriate fluid support, thermotherapy, calorie replacement, etc. Another extremely important point it is entirely possible to kill a small exotic patient by trying to do too much eg. feeling it necessary to collect all the standard data base laboratory samples within the first few minutes of the patient s arrival. In most instances, the collection of laboratory samples can wait until the patient is stabilized. For example if a ferret presents obtunded and you feel that it is critical to get a blood glucose, but the patient is so weak and debilitated that the manipulation may add undue stress and potentially kill it, DON T DO IT! Place the patient in an incubator, administer fluids with glucose (either orally or IV), give oxygen and let it stabilize. You can do the detective work once the patient is stabile. Lacerations and hemorrhage usually require immediate attention. Most rodents, rabbits and ferrets are adept at chewing out sutures. Stainless steel staples or stainless steel sutures are recommended. Bandages are usually poorly tolerated by these little patients and are not recommended. Fractures and other orthopedic problems rarely need emergency repair. These conditions should be stabilized and sent to the family veterinarian for treatment. SUMMARY The approach to pocket pet emergencies should be no different than that for dog and cats. Attention should be paid to the unique needs of the exotic pets. If these guidelines are followed the ER doctor will have no problems treating exotic species. REFERENCES
1 Ferrets, Rabbits and Rodents. Quesenberry and Carpenter. W.B. Saunders. 2003 Excellent quick reference for the common pocket pets. 2 Manual of Exotic Pets. Meredith and John-Delaney. BSAVA Manual. 2010. Covers many different species of exotic pets. 3 Radiology of Rodents, Rabbits and Ferrets: An Atlas of Normal Anatomy and Positioning. Silverman and Tell. Elsevier. 2005. This is the most current reference for evaluating radiographs in exotic small mammals.