Plasma concentration of ionized calcium in healthy iguanas

Interpretation of Serum Analytes for Nutritional Evaluation

Serum micronutrient analysis can provide insight into diet and clinical assessment, despite the complicated interplay between micronutrients and species idiosyncrasies. Approach serum nutrient analytes with skepticism, before jumping to alter diets or offering supplementation. Utilize across species but know that some exotics have exceptions to typical ranges, such as calcium in rabbits or iron in reptiles. Make sure you trust that referenced ranges reflect normal and healthy for that species. Micronutrients are integral to every bodily process, so measurement of serum analytes can tell a story that aids in the clinical picture, when one can recognize what stands out.

METASTATIC MINERALIZATION IN A ZOOLOGIC COLLECTION OF SPOT-TAILED EARLESS LIZARDS (HOLBROOKIASPP.)

Vitamin and mineral supplements are commonly used in diets for zoologic and companion animals. Because specific nutrient requirements are often unknown, informed decisions are based on literature for related species. Over 18 mon beginning in November 2017, an entire population of spot-tailed earless lizards (Holbrookia lacerata and Holbrookia subcaudalis) died (N = 33). All but two lizards were submitted for histopathology (94%). All examined cases had mineralization in at least one tissue; 71% (22 of 31) had multisystemic mineral deposits consistent with metastatic mineralization. No underlying causes were detected histologically. The supplement used for dusting the food items fed five to six times per week was inadvertently switched for 2 to 4 mon, and the incorrect supplement was found to contain fourfold the intended vitamin D3 concentration. Thus, hypervitaminosis D was considered the most likely cause. Interestingly, eastern collared lizards (Crotaphytus collaris), also fed prey supplemented five to six times a week, and over 50 other insectivorous reptile and amphibian species possibly receiving the supplement one to seven times a week did not appear affected. During this time, only two other cases of metastatic mineralization were diagnosed in other herpetofauna at this institution. Prior to receiving the incorrect supplement, there were no cases of metastatic mineralization detected in the earless lizard population. These cases highlight species-specific sensitivities, and the deleterious effects of excessive or inappropriate supplementation. It is important to confirm product identification on arrival, regularly conduct chemical analysis of supplements, and educate keepers and owners about adverse effects of inappropriate supplementation.

Conservation of a flagship species: Health assessment of the pink land iguana, Conolophus marthae

The pink land iguana, Conolophus marthae, is one of four species of iguanas (three terrestrial and one marine) in the Galápagos Islands, and the only one listed as critically endangered by the IUCN. The species can only be found on the north-west slopes of the highest volcano on Isabela Island and was first described to science in 2009. As part of a population telemetry study, a health assessment was authorized by the Galápagos National Park. Wild adult iguanas were captured on Wolf Volcano in September 2019 and April 2021 to record morphological and physiological parameters including body temperature, heart rate, intraocular pressures, tear formation, and infrared iris images. Blood samples were also collected and analyzed. An i-STAT portable blood analyzer was used to obtain values for base excess in the extracellular fluid compartment (BEecf), glucose (Glu), hematocrit (HctPCV), hemoglobin (Hb), ionized calcium (iCa), partial pressure of carbon dioxide (pCO₂), partial pressure of oxygen (pO₂)_, percent oxygen saturation (sO₂%), pH, potassium (K), and sodium (Na). When possible, data were compared to previously published and available data for the other Galápagos iguanas. The results reported here provide baseline values that will be useful in detecting changes in health status among pink land iguanas affected by climate change, invasive species, anthropogenic threats, or natural disturbances. The collected data also provide an invaluable resource for conservation scientists planning to implement conservation strategies, like translocations, that may temporarily alter these baseline values.

Clinical Management of Reptile Renal Disease

Renal disease is one of the most common medical conditions encountered in captive reptiles. In most cases, signs of disease are nonspecific and often not present until the condition is advanced. Many factors contribute to the development of renal disease, and the etiology often is multifactorial. Diagnosis of renal disease by traditional methods used in small animals is not as straightforward as in reptiles; often many tests may be needed to reach a firm diagnosis. Prevention is preferred to treatment. Understanding the pathophysiology, potential causes, diagnostic tests available, and treatment options is essential for the reptile veterinarian to manage this condition.

Advances in Exotic Animal Clinical Pathology

Over the last 10 years, exotic animal clinical pathology has been evolving, improving health assessment in avian, mammal, fish, reptile, and amphibian patients. These advances are reviewed in this article. Species-specific reference intervals for blood parameters are becoming more available (eg, for ionized calcium, endocrine panels, and vitamin D plasmatic concentrations). In addition, new technologies are being developed to facilitate targeted metabolite detection and result acquisition by veterinarians. Novel techniques, biomarkers, and clinical changes related to disease have been described in avian, mammal, fish, reptile and amphibian species. The use of mobile applications may also be helpful.

Health assessment of Conolophus subcristatus, Conolophus pallidus, and C. subcristatus X Amblyrhynchus cristatus hybrid (Galápagos land iguanas)

The land iguanas, Conolophus pallidus and Conolophus subcristatu are large and charismatic lizards endemic to the Galápagos archipelago, but little information exists on their normal health parameters. The former is restricted to Santa Fe island, while C. subcristatus inhabits the islands of the central and western region of the archipelago. Both species are classified as vulnerable by the IUCN Red List of Threatened Species. As part of a population health assessment authorized by the Galápagos National Park, wild adult iguanas from three islands (North Seymour, South Plazas, and Santa Fe) were captured in July 2018. Data from a single C. subcristatus X Amblyrhynchus cristatus hybrid captured on South Plazas is also included. We analyzed blood samples drawn from 52 healthy wild adult land iguanas captured on three islands. An iSTAT portable blood analyzer was used to obtain values for pH, lactate, pO2, pCO2, HCO3-, sO2%, hematocrit, packed cell volume (PCV), hemoglobin Na, K, iCa, and glucose. Standard laboratory hematology techniques were employed for PCV determination; resulting values were also compared to the hematocrit values generated by the iSTAT. Body temperature, heart rate, respiratory rate, and body measurements were also recorded and compared to previously published data for the marine iguana (Amblyrhynchus cristatus), which shares a common ancestor with the land iguana. The data reported here provide preliminary baseline values that may be useful in comparisons between captive and wild populations, between wild populations, and in detecting changes in health status among Galápagos land iguanas affected by anthropogenic threats, climate change, or natural disturbances.

Haematology and biochemistry of the San Cristóbal Lava Lizard (Microlophus bivittatus)

The San Cristóbal lava lizard, Microlophus bivittatus, is one of nine species of lava lizards endemic to the Galápagos Islands of Ecuador. No information presently exists about baseline health parameters for any of these species. We analysed blood samples drawn from 47 lizards (25 males and 22 females) captured at two locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for total CO₂, lactate, sodium, potassium, ionized calcium, glucose and haemoglobin. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination. Body temperature, heart rate and body measurements were also recorded. We found significant differences in haematocrit values between males and females. The values reported in this study provide baseline data that may be useful in detecting changes in health status among lava lizards affected by natural disturbances or anthropogenic threats. Our findings might also be helpful in future efforts to demonstrate associations between specific biochemical or haematological parameters and disease. Because there are several related species on different islands in the Galápagos archipelago, comparisons between populations and species will be of interest. Lay Summary:Haematology and biochemistry values of the San Cristóbal lava lizard Microlophus bivittatus, along with several other health parameters (morphometrics and temperature), are reported for the first time.

HEALTH SURVEY INCLUDING SELECTED BLOOD PARAMETERS IN THE AFRICAN SLENDER SNOUTED CROCODILE (MECISTOPS CATAPHRACTUS) AT THE ABIDJAN ZOO IN CÔTE D'IVOIRE

The Zoo National d'Abidjan (Abidjan Zoo) in Côte d'Ivoire, West Africa, holds the world's largest captive population of African slender-snouted crocodiles (Mecistops cataphractus, formerly Crocodylus cataphractus), at 36 adults, 16 yearlings, and 23 hatchlings. Twelve yearling and 12 adult slender-snouted crocodiles at the Abidjan Zoo were restrained for physical exam, body condition scoring, and venipuncture in September 2015. Blood samples collected from the supravertebral venous sinus were analyzed using a handheld blood analyzer (Abaxis® I-stat, Abaxis, Inc., Union City, California 94587, USA) with Chem8+ cartridges (CLIAwaived, Inc., San Diego, California 92130, USA). The adult crocodiles appeared in good general health and demonstrated blood values similar to those of other reptiles. The yearlings had low, ionized calcium values and low hematocrit and hemoglobin levels compared with the adult crocodiles and to other crocodile reference ranges. These findings may dramatically improve the health of the crocodiles and help to ensure a thriving captive population of this critically endangered species.

HEALTH AND NUTRITIONAL ASSESSMENT OF FREE-RANGING EASTERN INDIGO SNAKES (DRYMARCHON COUPERI) IN GEORGIA, UNITED STATES

Clinical pathology and nutritional parameters are useful in evaluating and monitoring threatened and endangered wildlife populations, but reference ranges for most snake species are lacking. From 2001 to 2005, health assessments were performed on 58 eastern indigo snakes (EIS) (Drymarchon couperi) captured in the wild in southeastern Georgia, United States. Health and nutritional assessments performed included hematology, serum biochemistry, fat-soluble vitamins, heavy metals, pesticide contaminants, parasitology, and surveys of other pathogens. Significant differences in total solids, packed cell volume, glucose, blood urea nitrogen, albumin : globulin ratio, amylase, triglycerides, and bile acids between males and females were observed. Additionally, there was a significant difference between liver and kidney concentrations for vitamins A and E. As previously noted in captive EIS, total Ca was elevated in comparison to concentrations reported in other snake species. Parasitism was a common finding in sampled EIS, but the overall health status of this free-ranging population appeared good. A winter-time dermatitis was found in most snakes, which resolved in the summer months. This study represents the first health and nutritional assessment of free-ranging EIS, and provides needed data to guide monitoring and conservation efforts.

Reptile Critical Care and Common Emergencies

Reptile emergencies are an important part of exotic animal critical care, both true emergencies and those perceived as emergencies by owners. The most common presentations for reptile emergencies are addressed here, with information on differential diagnoses, helpful diagnostics, and approach to treatment. In many cases, reptile emergencies are actually acute presentations originating from a chronic problem, and the treatment plan must include both clinical treatment and addressing husbandry and dietary deficiencies at home. Accurate owner expectations must be set in order to have owner compliance to long-term treatment plans.

Blood gases, biochemistry and haematology of Galápagos marine iguanas (Amblyrhynchus cristatus)

The marine iguana, Amblyrhynchus cristatus, is an iconic lizard endemic to the Galápagos Islands of Ecuador, but surprisingly little information exists on baseline health parameters for this species. We analysed blood samples drawn from 35 marine iguanas captured at three locations on San Cristóbal Island. A portable blood analyser (iSTAT) was used to obtain near-immediate field results for pH, lactate, partial pressure of O2, partial pressure of CO2, bicarbonate (HCO3 (-)), percentage O2 saturation, haematocrit, haemoglobin, sodium, potassium, ionized calcium and glucose. Parameter values affected by temperature were auto-corrected by the iSTAT. Standard laboratory haematology techniques were employed for differential white blood cell counts and haematocrit determination; resulting values were also compared with the haematocrit values generated by the iSTAT. Body temperature, heart rate, respiratory rate and body measurements were also recorded. Body length was positively correlated with several blood chemistry values (HCO3 (-) and glucose) and two haematology parameters (haemoglobin and manually determined haematocrit). A notable finding was the unusually high blood sodium level; the mean value of 178 mg/dl is among the highest known for any reptile. This value is likely to be a conservative estimate because some samples exceeded the maximal value the iSTAT can detect. For haematocrit determination, the iSTAT blood analyser yielded results significantly lower than those obtained with high-speed centrifugation. The values reported in this study provide baseline data that may be useful in comparisons among populations and in detecting changes in health status among marine iguanas affected by natural disturbances or anthropogenic threats. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease.

Update on common nutritional disorders of captive reptiles

Nutritional disorders of captive reptiles remain very common despite the increasing knowledge about reptile husbandry and nutrition. Many nutritional disorders are diagnosed late in the disease process; often secondary complications, such as pathologic fractures in reptiles suffering from nutritional secondary hyperparathyroidism have occurred. Therefore, every attempt should be made to educate reptile owners and keepers about the proper care and dietary needs of reptiles under their care because all nutritional disorders seen in captive reptiles are preventable.

Hematology and clinical chemistry values of free-ranging basilisk lizards (Basiliscus plumifrons) in Costa Rica

Twenty-three lizards were captured for this study, both males and females (12 males, 10 females, 1 undetermined), with a large range in body weights (40-286 g) appeared to be healthy based on activity level, physical examinations, and body condition scores. Heparinized blood samples from 20 free-ranging basilisk lizards (Basiliscus plumifrons) in Costa Rica were used for determining complete blood cell counts, plasma, and heparinized whole blood biochemical analysis. This information will serve as baseline reference data for future health assessment studies of free-ranging and captive basilisk lizards, as well as epidemiologic, conservation, and captive-breeding studies. A point-of-care analyzer was useful for this field study, and clinical chemistry values from heparinized whole blood samples were similar to values from plasma, which indicates that separation of plasma may not be necessary to process blood samples on site in remote areas. To the authors' knowledge, this is the first report of hematologic and plasma biochemical data from free-ranging B. plumnifrons.

Metabolic and respiratory derangements associated with death in cold-stunned Kemp's ridley turtles (Lepidochelys kempii): 32 cases (2005-2009)

OBJECTIVE

To assess selected clinicopathologic variables at hospital admission (day 1) for cold-stunned Kemp's ridley turtles (Lepidochelys kempii) that died during the first 3 days after admission (nonsurvivors) and turtles that survived (survivors) and to determine the percentage change of each variable from day 1 to day of death (nonsurvivors) or to day 2 or 3 of hospitalization (survivors).

DESIGN

Retrospective case-control study. Animals-64 stranded, cold-stunned Kemp's ridley turtles hospitalized from October 2005 through December 2009.

PROCEDURES

Blood gas, pH, Hct, and selected biochemical values in blood samples determined on day 1 and day of death (nonsurvivors; n = 32) or day 2 or 3 of hospitalization (survivors; 32) were obtained from medical records. For each variable, initial values and percentage changes (from initial values to values at the day of death or day 2 or 3 of hospitalization) were compared between survivors and nonsurvivors.

RESULTS

Compared with blood analysis findings for survivors, nonsurvivors initially had significantly higher potassium concentration and Pco(2) and significantly lower Po(2), pH, and bicarbonate concentration than did survivors. For the first 2 or 3 days of hospitalization, percentage changes in potassium, lactate, and ionized calcium concentrations were significantly higher and percentage changes in pH and plasma glucose and bicarbonate concentrations were significantly lower in nonsurvivors.

CONCLUSIONS AND CLINICAL RELEVANCE

At hospital admission, cold-stunned Kemp's ridley turtles were affected by metabolic and respiratory derangements; severe derangements were associated with death. Evaluation of blood gas, pH, Hct, and selected clinicopathologic variables provided useful clinical and prognostic information during rehabilitation of cold-stunned Kemp's ridley turtles.

A fresh look at metabolic bone diseases in reptiles and amphibians

Metabolic bone diseases (MBDs) are a common presenting complaint in reptiles and amphibians to veterinarians; however, understanding of the causes and diagnostic and treatment options is often extrapolated from human or other mammalian medicine models. Although the roles of UV-B, calcium, phosphorus, and cholecalciferol are better understood in some MBDs, there remain many X factors that are not. Likewise, quantitative diagnosis of MBDs has been difficult not only in terms of staging a disease but also regarding whether or not a condition is present. Treatment options also present challenges in corrective husbandry and diet modifications, medication/modality selection, and dosing/regimen parameters.

Comparison of total calcium, ionised calcium and albumin concentrations in the plasma of captive tortoises (Testudo species)

Plasma total calcium, ionised calcium and albumin levels in Hermann's tortoises (Testudo hermanni), spur-thighed tortoises (Testudo graeca), marginated tortoises (Testudo marginata) and Horsfield's tortoises (Testudo horsfieldi) were investigated. The animals were captive adults maintained under natural unfiltered sunlight in the UK with no dietary sources of cholecalciferol. Analysis of total calcium data showed statistically significant seasonal elevations in females in August compared with March (P=0.003), and statistically significant elevations in females compared with males at all sampling points (March P=0.036, June P=0.003 and August P<0.0001). These differences in values became more prominent as the summer progressed. Albumin values did not appear significantly affected by season. However, males had significantly higher albumin levels than females in the August samples. A correlation between total calcium and ionised calcium was confirmed but there was no correlation between total calcium and albumin values. Total calcium levels were a poor indication of ionised calcium levels, which constituted between 18 and 57 per cent of the total calcium value.

Emergency care of reptiles

Most reptile emergencies are the result of improper husbandry and nutrition. Reptiles are good at masking disease, and owners, failing to recognize early signs of illness, only seek veterinary assistance when issues are advanced and near terminal. The veterinarian should be familiar with reptile species-specific husbandry and nutritional requirements and basic clinical techniques. The same principles and techniques used in small animal medicine can be applied to reptile emergencies. This article reviews general emergency principles that apply to the reptilian patient and common emergency presentations. The main areas of discussion focus on cardiopulmonary resuscitation, fluid therapy, and analgesia.

Plasma concentrations of 25-hydroxycholecalciferol in 22 captive tortoises (Testudo species)

The plasma concentration of 25-hydroxycholecalciferol was measured in 13 adult Hermann's tortoises (Testudo hermanni), seven adult spur-thighed tortoises (Testudo graeca) and two adult marginated tortoises (Testudo marginata) during 2004. They were healthy, of both sexes, and kept in captivity under natural unfiltered sunlight in southern England with no dietary sources of cholecalciferol. Blood samples were taken in March, June and August, and the concentration of 25-hydroxycholecalciferol did not vary significantly with the seasons. However, the concentrations in the female tortoises were always significantly lower than in the males.

Biochemical reference intervals and intestinal microflora of free-ranging Ricord's iguanas (Cyclura ricordii)

Caribbean iguanas, including the Ricord's iguana (Cyclura ricordii) are ranked as critically endangered on the International Union of the Conservation of Nature (IUCN) Red List. The taxon is endemic to Hispaniola, where it inhabits xeric lowlands and is found in a very limited range in two subpopulations in the southwestern area of the island. The goals of this study were to obtain and analyze plasma biochemical and intestinal microbiological data from Ricord's iguanas in the subpopulation of the Neiba Valley, on Cabritos Island National Park, Dominican Republic, and to establish biochemical reference intervals. A total of 23 blood samples from clinically healthy iguanas (16 males, 7 females) and 14 fecal samples from clinically healthy iguanas were analyzed. Adult female iguanas had higher concentrations of cholesterol, phosphorus, triglycerides, urea, uric acid, and aspartate transaminase activity compared with male iguanas, although the difference was not statistically significant. Seventeen bacterial isolates were obtained, including: Salmonella sp. (serogroup B; serogroup D negative) Escherichia coli, Brevibacterium sp., Enterobacter cloacae, and Enterococcus durans. These data will help contribute to the management and recovery of Ricord's iguana populations.

Hematologic and plasma biochemical analysis of juvenile head-started northern red-bellied cooters (Pseudemys rubriventris)

The Massachusetts population of the northern red-bellied cooter (Pseudemys rubriventris) is listed as federally endangered due to its extremely restricted geographic range and low population. A captive rearing program has been used since 1984 to augment the population. Blood from 30 juvenile specimens from three rearing institutions was collected prior to release, and hematologic and plasma biochemical data were analyzed. Results were generally consistent with previously published data for other species of the family Emydidae. Basophils were the most numerous type of leucocyte. Results for some values varied significantly between institutions, possibly due to unrecognized differences in husbandry at each facility.

Metabolic and respiratory status of cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii)

"Cold-stunning" of sea turtles has been reported as a naturally occurring stressor for many years; however, the physiologic status of cold-stunned turtles has only been partially described. This study investigated initial and convalescent venous blood gas, acid-base, and critical plasma biochemical data for 26 naturally cold-stunned Kemp's ridley sea turtles (Lepidochelys kempii) from Cape Cod, MA, USA. Samples were analyzed for pH, pCO(2), pO(2), bicarbonate, plasma osmolality, sodium, potassium, chloride, ionized calcium, ionized magnesium, glucose, lactate, and blood urea nitrogen using a clinical point-of-care analyzer. Data were corrected for the patient's body temperature using both species-specific and more general correction methods. In general, venous blood gas, acid-base, and plasma biochemical data obtained for surviving cold-stunned Kemp's ridley sea turtles were consistent with previously documented data for sea turtles exposed to a wide range of temperatures and physiologic stressors. Data indicated that turtles were initially affected by metabolic and respiratory acidosis. Initial pH-corrected ionized calcium concentrations were lower than convalescent concentrations, and initial pH-corrected ionized magnesium concentrations were higher than convalescent concentrations.

METABOLIC BONE DISEASE IN JUVENILE HUMBOLDT PENGUINS (SPHENISCUS HUMBOLDTI): INVESTIGATION OF IONIZED CALCIUM, PARATHYROID HORMONE, AND VITAMIN D3AS DIAGNOSTIC PARAMETERS

Three cases of metabolic bone disease (MBD) were identified in juvenile Humboldt penguins (Spheniscus humboldti) in a zoological collection. Diagnosis, monitoring, and treatment were challenging, in part because radiographs and traditional serum biochemistries did not provide adequate information to guide appropriate clinical management. Normal values for ionized calcium (iCa), 25-hydroxyvitamin D3 [25-(OH) D3], and parathyroid hormone (PTH) have not been reported for any species in the order Sphenisciformes. This study aimed to establish reference ranges for these parameters to provide a method for assessing clinical cases of MBD and other disease processes. iCa was measured in 33 healthy adult birds from two zoological collections by using a portable clinical analyzer. iCa also was measured from 14 of these birds at a commercial laboratory. Mean and standard deviation were determined to be 1.21 +/- 0.09 and 1.29 +/- 0.10 mmol/L, respectively. Limited data exist on iCa in avian species, but these results are consistent with other reports and provide a useful clinical parameter. Analysis of PTH and 25-(OH) D3 was performed at a commercial laboratory on samples from 14 healthy adult penguins in one collection. Means and standard deviations for PTH and 25-(OH) D3 were 0.8 +/- 0.3 pmol/L and 3.7 +/- 2.4 nmol/L, respectively. These results are near the minimal functional detectable limits of the assays; raising uncertainty about the validity and usefulness of currently available PTH and 25-(OH) D3 tests in this species.

Renal diseases of reptiles

Renal disease is one of the most common problems in reptilian medicine. Herbivorous species seem to be more susceptible than carnivores. The causation may be multifactorial, and the signs are often nonspecific. Prevention is preferred to treatment, and a comprehensive health program, which includes quarantine, routine health screens during annual examinations, and necropsy examinations of all animals that die, is desirable.

RENAL EVALUATION IN THE HEALTHY GREEN IGUANA (IGUANA IGUANA): ASSESSMENT OF PLASMA BIOCHEMISTRY, GLOMERULAR FILTRATION RATE, AND ENDOSCOPIC BIOPSY

Plasma biochemistry, iohexol clearance, endoscopic renal evaluation, and biopsy were performed in 23 clinically healthy 2-yr-old green iguanas (Iguana iguana). Mean (+/- SD) values for packed cell volume (30 +/- 3%), total protein (62 +/- 7 g/L, 6.2 +/- 0.7 g/dl), albumin (25 +/- 2 g/L, 2.5 +/- 0.2 g/dl), globulin (37 +/- 6 g/L, 3.7 +/- 0.6 g/ dl), total calcium (3.0 +/- 0.2 mmol/L, 12.0 +/- 0.7 mg/dl), ionized calcium (1.38 +/- 0.1 mmol/L), phosphorus (1.32 +/- 0.28 mmol/L, 4.1 +/- 0.9 mg/dl), uric acid (222 +/- 100 micromol/L, 3.8 +/- 1.7 mg/dl), sodium (148 +/- 3 mmol/L or mEq/ L), and potassium (2.6 +/- 0.4 mmol/L or mEq/L) were considered within normal limits. Values for urea were low (< 1.4 mmol/L, < 4 mg/dl) with 70% of samples below the detectable analyzer range. After the i.v. injection of 75 mg/ kg iohexol into the caudal (ventral coccygeal or tail) vein, serial blood collections were performed over 32 hr. Iohexol assays by high-performance liquid chromatography produced plasma iohexol clearance graphs for each lizard. A three-compartment model was used to fit area under the curve values and to obtain the glomerular filtration rate (GFR) using regression analysis. The mean GFR (SD) was 16.56 +/- 3.90 ml/kg/hr, with a 95% confidence interval of 14.78-18.34 ml/kg/hr. Bilateral endoscopic renal evaluation and biopsy provided tissue samples of excellent diagnostic quality, which correlated with tissue harvested at necropsy and evaluated histologically. None of the 23 animals demonstrated any adverse effects of iohexol clearance or endoscopy. Recommended diagnostics for the evaluation of renal function and disease in the green iguana include plasma biochemical profiles, iohexol clearance, endoscopic examination, and renal biopsy.

Evaluation of the use of technetium Tc 99m diethylenetriamine pentaacetic acid and technetium Tc 99m dimercaptosuccinic acid for scintigraphic imaging of the kidneys in green iguanas (Iguana iguana)

OBJECTIVE

To evaluate the use of scintigraphy involving technetium Tc 99m diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) or technetium Tc 99m dimercaptosuccinic acid ((99m)Tc-DMSA) for the determination of kidney morphology and function in green iguanas (Iguana iguana).

ANIMALS

10 healthy iguanas weighing >1.6 kg.

PROCEDURE

Renal scintigraphy was performed by use of (99m)Tc-DTPA in 6 of the iguanas and by use of (99m)Tc-DMSA in all 10 iguanas. After the injection of (99m)Tc-DMSA, scans were performed for each iguana at intervals during a 20-hour period. Renal biopsies were performed in all 10 iguanas after the final scintigraphic evaluation.

RESULTS

In iguanas, the use of (99m)Tc-DTPA for renal scintigraphy was nondiagnostic because of serum protein binding and poor renal uptake of the isotope; mean +/- SD (99m)Tc-DTPA bound to serum proteins was 48.9 +/- 9.9%. Renal uptake of (99m)Tc-DMSA produced distinct visualization of both kidneys. Renal uptake and soft tissue clearance of (99m)Tc-DMSA increased over the 20-hour imaging period; mean +/- SD renal uptake of (99m)Tc-DMSA was 11.31 +/- 3.06% at 20 hours. In each of the 10 iguanas, ultrasonographic and histologic examinations of biopsy specimens from both kidneys revealed no abnormalities.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that the kidneys of iguanas can be evaluated scintigraphically by use of (99m)Tc-DMSA; this technique may be potentially useful for the diagnosis of renal failure in iguanas.

Evaluation of a point-of-care blood analyzer and determination of reference ranges for blood parameters in rockfish

OBJECTIVE

To compare values of blood parameters in rockfish obtained by use of a point-of-care portable blood analyzer with values determined by a veterinary diagnostic laboratory, calculate reference ranges for various blood parameters in black rockfish, and compare values of blood parameters in clinically normal fish with those of fish with clinical abnormalities.

DESIGN

Prospective study.

ANIMALS

41 captive adult black rockfish (Sebastes melanops) and 4 captive adult blue rockfish (Sebastes mystinus).

PROCEDURE

Rockfish were anesthetized with tricaine methanesulfonate for collection of blood samples. Heparinized blood samples were immediately analyzed with a point-of-care analyzer. Blood sodium, potassium, chloride, urea nitrogen, and glucose concentrations; Hct; pH; partial pressure of carbon dioxide; total carbon dioxide concentration; bicarbonate concentration; base excess; and hemoglobin concentration were determined. A microhematocrit technique was used to determine PCV, and a refractometer was used to estimate total plasma protein concentration. Paired heparinized blood samples were transported to a veterinary diagnostic laboratory for analyses.

RESULTS

Data obtained with the point-of-care analyzer were reproducible; however, values for most blood parameters were significantly different from those obtained by the veterinary diagnostic laboratory. Fish with poor body condition had several blood parameter values that were lower than corresponding values in clinically normal fish.

CONCLUSIONS AND CLINICAL RELEVANCE

Point-of-care blood analyses may prove useful in rockfish. Point-of-care data for a large number of clinically normal fish must be obtained for reference ranges to be calculated, and further assessments of clinically abnormal fish are necessary to determine the relevance of the data.