Introduction

The patient must be seen as a whole, not merely the sum of his or her many disparate body parts. Balzac* observed that ‘There are conflicts between diseases and physicians…of which physicians alone have any knowledge and whose reward in cases of success is never found in the paltry price of their labours nor, indeed, under the patient’s roof but in the sweet gratification…bestowed upon true artists by the satisfaction they feel…in having acomplished a worthy work.’ Those sentiments were as germane to veterinary surgeons as they were to human physicians and barber surgeons; and they are as appropriate today as they were well over a century-and-a-half ago (perhaps even more so) because today the healing arts have at their disposal so many more means for arriving at an accurate diagnosis and novel methods for treating diseases. Only after carefully assembling a history, keenly observing the patient’s physical signs and conducting specialised investigations can a list of differential diagnoses be constructed; then, like kernels of grain, that list must be winnowed gradually until only one or, at most, a very few possibilities remain. From these, a prognosis is formulated; only then can a rational course of therapy or corrective surgery be established and carried out. Because of economic considerations, valuable clinical laboratory investigations may not always be executed, but most of these cases will not be diminished if enough required information has been gathered from the client and if the patient has been examined meticulously. By completing each task conscientiously and consistently, the probability of success is enhanced. In this self-assessment guide we have provided sufficient explicit information from which to formulate differential diagnoses, decide upon treatment plans and arrive at prognoses. The clues to the solution of clinical puzzles are often subtle. When examining radiographs and electrocardiograms, you may find surprises lurking, ready to snag the unwary. In some instances, the diagnosis is obvious, but the prognosis or treatment might not be so clear. This approach was taken because in real life situations the diagnosis and treatment of patients are not always trouble-free or easily achieved. We have systematically decreased the number of provisional diagnoses by proposing various

clients tell the whole truth; some may not actually lie about their animals, but also they may not always volunteer details that might be vitally important to the final diagnosis and outcome of their particular case; others may, for their own reasons, conceal facts that might be germane. As mentioned before, economics often plays a major role in how an animal responds to treatment – or whether it is even examined and treated professionally – particularly if the definitive diagnosis relies upon expensive tests or procedures. We have selected cases which are instructive and probably would/could be seen in clinical practice. The majority are common everyday cases; a few are exotic and may have been observed only once. For those readers who have never observed even a single example of one of the common everyday cases, the purchase of this text is justified; the rarer cases are included to whet the intellectual appetites of the more experienced of our readers. Perhaps, just perhaps, a similar puzzling case will arrive on your doorstep one day; having experienced the question and answer vicariously in the pages of this guide may make your case all the more memorable! The popularity of certain reptiles as pets or study animals is reflected in the selection of cases for this book; it is for this reason that so many iguanas are included as representatives of reptilian disease. Some people who possess large, showy and expressive lizards are often willing and able to incur the considerable expense of having their pets properly diagnosed and treated; others who own another species of herbivorous lizard perceived as being of less value may elect not to have it examined and evaluated. However, we are confident that information regarding the physiological responses to disease in iguanas is sufficiently similar to disease processes in other herbivorous lizards. Bacterial infections, parasitism and many metabolic disorders in North American chelonians closely mimic the same conditions observed in European, African or Asian turtles, terrapins and tortoises and vice versa. We have included more than a single case of some particular conditions (but each has differed somewhat) because we believe that repeating the discussion of these common, but significant, conditions is important due to their ramifications; in these instances we have endeavoured to include special features that will maintain your interest. We wish to enunciate one caveat: ‘normal’ values are only rarely cited in this guide. Unlike humans and domestic animals, from which thousands of data have been collected and collated, reptiles and especially captive reptiles (1) may or may not be normal (or even healthy) when their body fluids are sampled, and (2) the very nature of captivity and the stress incurred during restraint in order to obtain the samples introduce variables that are reflected in the laboratory results. We recognise these shortcomings and urge the reader to consider these undeniable facts when judging whether a laboratory finding is meaningful or out of ‘normal’ range. (We used only the most current ‘accurate’ values available, but advise you to keep your sceptic’s salt-shaker at the ready!)

Fredric L Frye David L Williams January 1995