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|Cuban Crocodile Medical Management Guidelines|
MEDICAL MANAGEMENT OF CUBAN CROCODILES (Crocodylus rhombifer)
Zoltan S. Gyimesi, DVM
Associate Veterinarian, Louisville Zoo, 1100 Trevilian Way, Louisville KY 40213
This chapter is the result of a literature review as well as a compilation of medical records obtained from facilities that house or have housed Cuban crocodiles. With proper husbandry, this species is hardy and long-lived in captivity and few disease problems have been reported. Most health problems appear to be due to conspecific trauma or husbandry issues (i.e. nutritional issues, access to foreign bodies, exposure to low temperatures).
PRESHIPMENT AND QUARANTINE GUIDELINES
Prior to shipping, there should be good communication between the shipping and receiving institution. Medical history of the specific animal(s) being shipped, medical history of the species at the sending institution, diet history, and housing history should all be reviewed. What is learned from this correspondence may dictate the preshipment testing requested. At a minimum, a visual exam and fecal exam should be performed prior to shipping. Hands-on procedures could include a physical exam, sex confirmation, blood collection (CBC, chemistries, lead, zinc, vitamin E, vitamin A, Mycoplasma alligatoris serology, serum/plasma banking), transponder placement/verification, radiographs (to assess bone density and screen for foreign bodies), and weight and length (total and snout-vent) measurements. In some situations, especially with adult crocodilians, it may not be in the best interests of the animal or personnel to handle the animal repeatedly prior to crating and shipping. The timing and thoroughness of the preshipment evaluation needs to be mutually acceptable to the shipping and receiving institution and will vary from case to case.
Quarantine should last 30 to 90 days (depending on the animal’s history and origin) on an all-in-all-out basis. Every attempt should be made to isolate new animals and their water systems from the rest of the animal collection for the duration of quarantine. The amount of handling and medical testing during quarantine may be impacted by how thorough the preshipment evaluation was. Serial fecal exams to screen for endoparasitism should be performed during quarantine. In many instances, the quarantine period represents a rare opportunity to get a hands-on evaluation of a crocodilian. Veterinarians should maximize this opportunity by obtaining as much baseline data as is reasonably possible (see Preventive Health Guidelines section)
PREVENTIVE HEALTH GUIDELINES
Fecal examinations (flotation and direct) should be performed at least once yearly. Veterinary staff should perform visual exams annually. Hands-on examination of crocodilians, particularly larger animals, is typically done on an opportunistic basis unless there is a medical concern prompting a scheduled exam. Routine hands-on evaluation of Cuban crocodiles should include the following:
Significant findings and remarkable morbidity should be shared with the SSP Veterinary Advisors.
The ability to identify individual crocodiles is crucial for responsible captive management. Identifying animals by their individual unique natural markings and body type/conformation can be very effective. Photographs may support the written descriptions of individuals. In hatchlings, it can be helpful to scan the belly scales with a photocopier as a record. Although generally effective, these strategies are not flawless and should not be the sole manner to identify individuals.
Many crocodile farms utilize digit clipping or tail notching, both of which are not ideal for captive display animals. Also, these procedures are painful, disfiguring, and can potentially lead to localized infections. Tagging crocodilians on the toe webbing or dorsal crest is also utilized by crocodile farms and can be effective, however tags can be lost and head tags in particular are typically unacceptable in a zoo setting.
Implantable transponder chips, microchips, or P.I.T. (passive integrated transponder) tags are a long-term, effective, and cosmetic method of individual identification. These chips are inert and can be placed safely in even hatchling crocodilians. The only disadvantage is that reading of the chips requires close contact with the animal. Although these chips can be placed subcutaneously anywhere along the body, it is helpful if this practice is standardized. For crocodilians, it has become customary to place microchips subcutaneously in the dorsal neck behind the dorsal plate of the head between the post occipital scales and nuchal scales. The Cuban crocodile SSP recommends that all animals in the program be microchipped in this location. Microchips can fail and migrate so it is prudent to check them opportunistically.
Sexing crocodilians can be accomplished via direct visualization or digital palpation/eversion of the clitoris in females or the larger, cartilagenous penis, or phallus, in males. These structures are located in the floor of the cloaca. This is simple and straightforward in sub-adults and adults, however in hatchlings and juveniles, requires some experience. In mature, unanesthetized males, it may not be possible to digitally exteriorize the penis.
Sex in crocodilians is determined by environmental conditions (i.e. temperature) during egg incubation and embryogenesis. Crocodilians lack sex chromosomes and thus at the present time, there is no cytogenetic test available that can determine gender. Other noninvasive methods that may be useful to determine gender in hatchlings and juveniles include ultrasound examination of the gonads or measurement of plasma testosterone concentration. These techniques may be an aid for sexing very young crocodilians but require further investigation.
Separate housing of males and females or destruction of eggs/nests is effective.
No vaccines are currently recommended by the SSP. Although West Nile virus has induced morbidity and mortality in crocodilians housed in high density farming operations, to date there are no reported cases in zoo-housed crocodilians. Therefore vaccination is not indicated at this time.
In crocodilians, blood samples can be collected from the caudal or ventral tail vein, the occipital venous sinus, or the heart. The tail vein, either via a ventral or lateral approach is the preferred site in most cases as it is the least likely to lead to iatrogenic complications. See Lloyd and Morris, 1999, for a more detailed overview of blood collection techniques in crocodilians. Although the authors of this article state that no ill effects have been observed when blood is removed at the maximum rate of 6.0 ml per kg, some crocodilian species are reported to have a lesser blood volume than most reptiles. The total blood volume in 3.5 year old Cuban crocodiles (n=19) was determined to be 4.0 +/- 0.3% of body mass for males and 3.6 +/- 0.2% of body mass for females (Carmena-Suero, et al, 1979). Determination of safe blood collection volumes should be calculated, particularly when bleeding sick crocodiles or hatchlings. To minimize the effects of sample lipemia, crocodiles should be fasted for several days prior to blood collection to a week or longer in larger animals.
See Table 1A, Table 1B, and Table 1C for reported physiologic reference ranges.
Cuban crocodiles will tolerate manual restraint for examinations and diagnostic procedures. Safe and effective manual restraint requires skilled and experienced personnel, as this species is agile, quick, explosive, and aggressive. Once adequately restrained, the jaws should be secured with bandage material. Covering the eyes is typically done to decrease stimuli and minimize stress. An ocular vasovagal response is present in crocodilians so compressing the eyes digitally, or with bandage materials, can provide some light sedation to facilitate handling. The combination of manual restraint and local anesthesia can be very effective for some minor surgical procedures (i.e. wound care, digit amputations, skin biopsies, etc.). Caution should be used when using local anesthetics in small crocodilians as there is a greater risk of overdose. More invasive procedures necessitate general anesthesia.
Crocodilians should be fasted a few days prior to anesthesia to minimize the chance of regurgitation or vomiting with subsequent aspiration. Anesthetic induction should occur in a dry, controlled setting to minimize the chance of drowning, falling, and avoidable trauma. Smaller crocodiles can be captured, manually restrained, and induced with gas anesthesia or injectable agents via hand syringe. Crocodilians can be resistant to anesthetic induction via gas, as they are capable of long periods of breath holding. Larger crocodilians are typically induced via injectable agents given intramuscularly via either dart or pole syringe. Suitable intramuscular injection sites include the tail base and limbs. Larger animals that are trained to enter a restraint chute may be hand injected and even induced via the intravenous route. Crocodiles should have no access to water or direct sun until completely recovered from anesthesia.
The remaining Anesthesia section details some of the anesthetic protocols that have been successfully used in Cuban crocodiles. For a more thorough review of anesthesia in crocodilians, refer to articles by Fleming, 2001 and Lloyd, 1999.
Propofol has been used in small Cuban crocodiles for anesthetic induction at 10 - 15 mg/kg IV. Endotracheal intubation may be accomplished with a lesser dose (Fleming, 2001). This short-acting drug is typically followed by inhalant gas anesthesia. Both isoflurane and sevoflurane have been used safely and effectively in Cuban crocodiles. The use of propofol may be limited in larger crocodiles.
The dissociative anesthetic ketamine has been used extensively in Cuban crocodiles, both as a sole induction agent (20 - 40 mg/kg IM) and combined with an alpha-2 agonist (xylazine) or a benzodiazepine (midazolam). The Havana Zoo in Havana, Cuba reports that they have used ketamine alone at 40 mg/kg IM with good sedation within 6 minutes for about 3.5 hours duration. For better immobilization and muscle relaxation in Cuban crocodiles, ketamine (15 - 30 mg/kg) can be combined with midazolam (0.3 - 0.5 mg/kg). Reversing the midazolam component with flumazenil can potentially shorten the recovery time. Negatives to using ketamine and midazolam combinations are expense and the large delivery volume. A similar regime used in Cuban crocodiles with a smaller delivery volume is Telazolâ, a commercial combination of tiletamine and zolazepam. Flumazenil can antagonize the zolazepam component of Telazolâ to shorten the recovery time. Besides being combined with ketamine, benzodiazepines such as diazepam and midazolam can be used alone as sedatives prior to manual restraint or to smooth inductions.
The neuromuscular blocking agents succinylcholine chloride and gallamine triethiodide have been used successfully in numerous crocodilian species, including Cuban crocodiles. These drugs provide no analgesia as the patient is only paralyzed, but fully conscious and aware. These muscle relaxants are only appropriate to facilitate nonpainful procedures such as translocation, examination, radiography, venipuncture, gastroscopy, etc. Gallamine can be administered to Cuban crocodiles with or without hyaluronidase at 0.6 - 1.28 mg/kg IM (Lloyd, et al, 1994). Recovery can be prolonged, but can be shortened with neostigmine (0.03 - 0.25 mg/kg) reversal. Succinylcholine is used less often due to the inability to reverse its affects as well as the associated risks inherent to its use (produces painful depolarization, hyperkalemia, and occasional phallus prolapse). Unfortunately, gallamine is currently unavailable commercially in the United States.
Fecal examinations (flotation and direct) should be performed at least once yearly. However, endoparasitism does not appear to be a significant problem in captive Cuban crocodiles.
Review of medical records reveals that coccidia and pinworms are rare findings. Coccidiosis in crocodilians can be an incidental finding as well as a primary cause of morbidity and mortality (Huchzermeyer, 2003, Mader, 1996). It may be worth attempting to speciate the coccidian when found, as they are host specific and avian and mammalian forms are harmless. Detecting pinworms in a fecal is likely also spurious as it typically represents a rodent parasite passing through a carnivore’s gastrointestinal tract. One Cuban crocodile of unknown origin and not part of the SSP was diagnosed via post mortem histopathology with nephritis associated with trematodiasis.
Due to the apparent low incidence of endoparasitism in captive Cuban crocodiles, routine deworming is likely unnecessary. One institution has prophylactically used levamisole at 6 mg/kg administered intramuscularly with no apparent ill effects. The Cuban crocodile SSP does NOT recommend the use of avermectin anthelminthics (i.e. ivermectin and its relatives) in this species due to reports of toxicity in crocodilians (Dumonceaux and St. Leger, 2004, Huchzermeyer, 2003).
Cuban crocodiles display a highly developed social hierarchy based on physical dominance. Captive conspecific aggression often results in trauma. Cuban crocodiles are less tolerant of conspecifics than many other crocodilian species such as Nile crocodiles (Crocodylus niloticus) and American alligators (Alligator mississippiensis). Trauma due to conspecific aggression is the most common cause of morbidity and mortality in this species. Puncture wounds, lacerations, lameness, cloacal trauma, facial/jaw fractures, and secondary infections/abscessation have all been reported by holding institutions. Animals under constant social stress or those that have been attacked can also suffer from secondary hypoglycemia. Clinically, this can manifest as muscle tremors, stargazing, mydriasis, loss of the righting reflex, and in advanced stages, seizures and death. Removing the crocodile from the stressful housing circumstance, and recognition and treatment of the hypoglycemia is indicated in these cases.
Cuban crocodiles tend to have a pugnacious disposition, particularly during feeding. Individual housing is recommended for this species except in very young hatchlings or in breeding situations. Hatchlings should be separated at a young age as severe injuries have occurred in siblings as young as 7 months old.
When fed fresh whole mammalian vertebrate prey, nutritional problems are uncommon. To insure quality control, knowledge of the source of the whole prey being fed is important. Wild-caught whole prey should be fed with great caution, if at all.
Rickets, a juvenile form of metabolic bone disease or nutritional secondary hyperparathyroidism can occur in young hatchlings if not fed a diet that meets calcium, phosphorus, and vitamin D3 needs. Manifestation of rickets can include long bone bowing, scoliosis, lameness, and pathologic fractures. Plain radiographs are useful in detecting osteopenia and other skeletal abnormalities. Due to the risk of rickets, feeding hatchlings whole vertebrate prey or a balanced commercial carnivore diet, as opposed to unfortified insects, is desirable. Growing crocodilians do not appear to require exposure to ultraviolet light to meet their vitamin D3 and calcium needs. However exposure to UV light is ideal and chronic deprivation may carry long-term deleterious consequences.
Hypovitaminosis E leading to steatitis has been documented in young Cuban crocodiles fed freshwater fish, and headless and eviscerated marine fish (Moliner, et al, 2000). Hypovitaminosis E as a cause of steatitis and low egg fertility and hatchability is documented in other crocodilian species fed fish exclusively (Lance, et al, 1983, Hunt, 1980, Wallach and Hoessle, 1968). Animals fed unsupplemented, thawed frozen fish are particularly susceptible to hypovitaminosis E. Therefore if fish make up a significant component of a ration, it is generally recommended to supplement 100 IU of vitamin E per kg of fish fed (wet basis) (Bernard and Allen, 1997). Opportunistic measurement of serum/plasma vitamin E concentration in collection animals is advised, regardless of whether fish are fed. Feeding fish exclusively or as a major component also predisposes piscivores to thiamin deficiency. Like vitamin E, thiamine can be rapidly degraded in killed, stored fish. It is recommended to supplement 25-30 mg thiamine per kg of fish fed (wet basis) (Bernard and Allen, 1997). A combination of hypovitaminosis A and E is believed to have lead to significant tooth loss in a large captive collection of Crocodylus sp. (Heard, et al, 2004). The hypovitaminosis was determined to be due to the feeding of eviscerated nutria.
Overfeeding of crocodilians is discouraged at any life stage. Overfeeding juveniles leads to rapid, unnatural growth and may predispose to gout. Captive crocodilians have a sedentary lifestyle and overfeeding adults can lead to obesity. Fat animals can be riskier anesthesia patients and in the case of males, can be reluctant breeders. Obese crocodilians have a bulging tail base, large fat-filled abdomen, and excessive subcutaneous ventral cervical fat stores (prominent jowls).
Foreign Body Ingestion and Heavy Metal Toxicosis
Crocodiles in nature and in captivity have a propensity to ingest foreign objects. These foreign bodies are likely either harmlessly voided or sequestered indefinitely within the stomach. However, sharp or pointed objects risk ulceration and/or perforation of the stomach wall inducing a coelomitis. Other objects can cause gastritis, indigestion, and/or gastrointestinal obstructions. Masses of packed hair or feathers from prey items have been reported to cause a problem in the rare crocodilian, however in the normal, healthy animal, this material is regurgitated as a pellet. Heavy metal toxicosis can occur from ingestion of lead (dietary contaminant) or zinc (coins, hardware). Some free-ranging crocodilian species have been found to bioaccumulate environmental mercury and other contaminants in tissues, however this is not a recognized problem in the captive Cuban crocodile population.
Gastric foreign bodies are typically diagnosed via radiography or gastroscopy. Clinical signs may manifest as lethargy, anorexia, or weight loss. Determination of blood lead and serum zinc levels is indicated if metallic structures are observed. Treatment of gastric foreign bodies can be via manual removal, gastric lavage, endoscopic removal, or gastrotomy. Chelation therapy may be indicated in some cases of metal toxicosis.
An elevated lead level (247 µg/dl) was observed in a captive Cuban crocodile that was being fed urban feral pigeons (Cook, et al, 1989). That crocodile, as well as others in that collection with high blood lead levels, was asymptomatic. Another Cuban crocodile at a second institution had a blood lead level of 47 µg/dL. This animal was ill, but had concomitant zinc toxicosis. Crocodilians appear to have a tolerance for high lead burdens. In birds, blood lead levels above 15 to 20 µg/dL are suggestive of lead poisoning and are often associated with clinical signs.
Clinical zinc toxicosis has been diagnosed in at least two Cuban crocodiles at two different institutions. Signs included anorexia, weight loss, and depression and gastric biopsies from one of the animals revealed gastritis and mucosal necrosis. Serum zinc levels in these animals were 45.3 and 32.4 ppm. Both cases were secondary to coin ingestion and treatment consisted of coin removal and chelation with CaEDTA via a series of intramuscular injections. Serum zinc levels in both cases decreased with treatment. One asymptomatic Cuban crocodile was measured to have a serum zinc level of 2.7 ppm secondary to a single penny found sequestered in the gastrointestinal tract on x-ray. Based on the housing history, the penny was believed to have been in the crocodile for at least 9 years. Due to the history and absence of clinical signs, no treatment was elected in this case. Serum zinc levels above 2 to 10 ppm are seen in birds with zinc toxicosis. Due to the potential for zinc toxicosis from coin ingestion, Cuban crocodiles should be housed in a manner that eliminates, or at least minimizes this risk (i.e. glass or mesh separating the crocodiles from the public).
Crocodilians have open-rooted, conical teeth that are attached via connective tissue within alveolar bone sockets. These teeth are periodically shed and replaced throughout life, however tooth turnover tends to decrease with age. Developing replacement teeth promote resorption of the base of "in wear” teeth until the crown breaks free and is sloughed. Cuban crocodiles possess 66-68 teeth (10 pre-maxillary, 26-28 maxillary, 30 mandibular).
Some captive Cuban crocodiles exhibit "bad bite” or malocclusion. In these instances, the teeth from one arcade may lead to gingival trauma and secondary infection to the opposing arcade. Protruding lower jaws (underbite) commonly occurs in Australian freshwater crocodile hatchlings (Crocodylus johnsoni) and is believed to be caused by high-temperature incubation (Webb and Manolis, 1998). Although only speculative, malocclusion in long-term captive animals may also be related to chronic lack of ultraviolet light exposure and/or lack of physiologic jaw loading (eating soft or small food items) during the early growing years. A captive adult female Cuban crocodile was euthanatized due to severe, chronic, maxillary and mandibular osteomyelitis. This crocodile had a history of chronic gingivitis and periodontitis. Whether the bone infection was an extension of dental/gingival disease is unclear.
As discussed in the Nutritional Problems section, abnormal tooth loss has been reported in a large crocodilian collection due to hypovitaminosis A and E from feeding eviscerated nutria (Heard, et al, 2004).
PATHOLOGY AND GENETIC SAMPLING
Although death due to traumatic injuries have been most common in the captive population, other post mortem diagnoses have included steatitis, bacterial sepsis, osteomyelitis, pneumonia, visceral and articular gout, coelomitis, edema, myopathy, dystocia, hepatitis, myocarditis, nephritis, and disseminated sarcoma. A benign osteoma arising from the orbital margin was diagnosed via excisional biopsy in one aged male Cuban crocodile.
Like fish, amphibians, and other aquatic reptiles, crocodilians seem to autolyze rapidly post mortem. Carcasses should be transferred to coolers and gross necropsies performed as soon as possible after death. Weight, total length, and snout-vent length should be measured. Skull radiographs should be obtained. The use of digital photography is an excellent way to document lesions and share findings observed at necropsy. Please contact one of the Veterinary Advisors if you anticipate the death or euthanasia of a Cuban crocodile.
The following tissues should be saved in duplicate in 10% neutral buffered formalin:
Dead-in-shell embryos should also be necropsied, at least representative egg(s) from a clutch. Gross and histologic evaluation of even autolyzed eggs can sometimes reveal valuable information on the cause of embryonic death.
A set of formalin-fixed tissues should be submitted to a veterinary pathologist with experience in reptile pathology for microscopic examination. Deaths should be reported to the SSP Coordinator and final copies of pathology reports should be forwarded to the Veterinary Advisors.
Several grams of each of the following tissues should be saved frozen, ideally in an ultralow (-80 C) freezer:
These items can be archived and may be valuable for genetics studies as well as for determination of quantitative tissue metal or vitamin concentrations.
For the development of living cell lines, the Frozen Zoo, maintained at the Zoological Society of San Diego, is interested in fresh genetic material. Although the genetic material of founder animals is most valuable for this purpose, due to a small captive population, the Cuban crocodile SSP encourages that all animals be sampled and included. Harvesting of genetic material can occur antemortem opportunistically via skin biopsy. This typically involves a pea-sized plug of full-thickness skin obtained from the toe webbing. A 6 mm skin biopsy punch works well for this purpose. Before obtaining samples, contact Marlys Houck to obtain the appropriate collection vials and more specific harvesting instructions:
Marlys L. Houck, CLSp(CG)
Associate Researcher, Genetics
CRES – Conservation and Research for Endangered Species
Zoological Society of San Diego
Arnold and Mabel Beckman Center for Conservation Research
15600 San Pasqual Valley Road
Escondido, CA 92027
[contact prior to shipping to coordinate, 760-291-5454, email@example.com]
We thank the following individuals and institutions that have contributed data to this chapter - Black Hills Reptile Gardens, Bronx Zoo, Ellen Trout Zoo, Gladys Porter Zoo, Havana Zoo (Cuba), Darryl Heard, Louisville Zoological Garden, Bill McMahan, Memphis Zoo, Miami Metrozoo, Municipal Zoological Garden of Sea Coast (Poland), National Zoo, Roger Williams Park Zoo, Saint Louis Zoo, Bruce Shwedick, Silver Springs, Staten Island Zoo, St. Augustine Alligator Farm, The Toledo Zoo, and Zoologicka Garden and Chateau Zlin-Les (Czech Republic).
Bernard JB, Allen ME. 1997. Feeding captive piscivorous animals: Nutritional aspects of fish as food. Nutritional Advisory Group Handbook, Fact Sheet 005, 1-11.
Carmena-Suero A, Siret JR, Callejas J, Carmena D. 1979. Blood volume and hematological values of crocodile (Crocodylus rhombifer Cuvier). Comp Biochem Physiol, 64A: 597-600.
Cook RA, Behler J, Brazaitis P. 1989. Elevated heavy metal concentrations in captive crocodilians – 2 cases. Proc Am Assoc Zoo Vet, 151.
Dumonceaux GA, St. Leger J. 2004. Ivermectin toxicity in a group of Nile crocodiles (Crocodylus niloticus). Proc Assoc Rept Amphib Vet, 155-157.
Fleming GJ. 2001. Crocodilian anesthesia. Vet Clin N Am: Exotic Anim Pract Analg Anesth, 4(1): 119-145.
Heard DJ, Terrell S, Wellehan J, Scott K, Hall J, Hill R. 2004. Abnormal tooth loss in a captive crocodilian collection. Proc Am Assoc Zoo Vet, 274.
Huchzermeyer FW. 2003. Crocodiles: Biology, Husbandry, and Diseases. Onderstepoort Veterinary Institute, South Africa, CABI Publishing, Wallingford, Oxon, UK, 337 pgs.
Hunt RH. 1980. Propagation of Morelet’s crocodile. In: Murphy JB, Collins JT (eds.). Reproductive Biology and Diseases of Captive Reptiles. Society for the Study of Amphibians and Reptiles, Lawrence, KS, 161-165.
Lance V, Joanen T, McNease L. 1983. Selenium, vitamin E, and trace elements in the plasma of wild and farm-reared alligators during the reproductive cycle. Can J Zool, 61: 1744-1751.
Lloyd ML. 1999. Crocodilian anesthesia. In: Fowler ME, Miller RE (eds). Zoo and Wild Animal Medicine. WB Saunders Co, Philadelphia PA, 205-216.
Lloyd M, Morris PJ. 1999. Phlebotomy techniques in crocodilians. Bull Assoc Rep Amphib Vet, 9(3): 12-14.
Lloyd ML, Reichard T, Odum RA. 1994. Gallamine reversal in Cuban crocodiles (Crocodylus rhombifer) using neostigmine alone versus neostigmine with hyaluronidase. Proc Am Assoc Zoo Vet, 117-120.
Mader DR. 1996. Reptile Medicine and Surgery. W.B. Saunders Company, Philadelphia, Pennsylvania, 512 pgs.
Moliner JL, Ramos R, Bello O, Elizalde S. 2000. Valores hematologicos obtenidos en el Crocodylus rhombifer el zoocriadero de la Cienaga de Zapata, Mantanzas, Cuba. Proc Crocodile Specialist Group, IUCN, Varadero, Cuba, 113-117.
Moliner JL, Ramos R, Bello O, Elizalde S. 2000. Consideraciones clinicas y anatomopathologias observadas en la deficiencia de vitamina E (Esteatitis) en el cocodrilo Cubano (Crocodylus rhombifer) del zoocriadero de la Cienaga de Zapata, Mantanzas, Cuba. Proc Crocodile Specialist Group, IUCN, Varadero, Cuba, 118-123.
Wallach JD, Hoessle AA. 1968. Steatitis in captive crocodilians. J Am Vet Med Assoc, 153: 845-847.
Webb GJW, Manolis C. 1998. Crocodiles of Australia. New Holland Publishers, Australia, p. 105.
Table 1A. Physiological data reference values for Cuban crocodiles (Crocodylus rhombifer) per ISIS (International Species Information System, Apple Valley, Minnesota, 2003)
Mean +/- standard deviation Number of samples
Hematocrit (%) 27.1 +/- 4.3 19
Red blood cell count (x 106/mL) 1.11 +/- 0.18 9
White blood cell count (x 103/mL) 7.962 +/- 4.306 16
Heterophils (x 103/mL) 3.050 +/- 1.794 14
Lymphocytes (x 103/mL) 3.785 +/- 2.321 14
Eosinophils (x 103/mL) 0.278 +/- 0.249 10
Basophils (x 103/mL) 0.879 +/- 0.830 12
Azurophils (x 103/mL) 0.689 +/- 0.562 10
Glucose (mg/dL) 75 +/- 21 20
Uric acid (mg/dL) 1.9 +/- 1.2 19
Calcium (mg/dL) 15.4 +/- 7.0 20
Phosphorus (mg/dL) 5.1 +/- 2.2 16
Sodium (mEq/L) 150 +/- 7 18
Potassium (mEq/L) 3.7 +/- 0.5 18
Chloride (mEq/L) 116 +/- 5 15
Cholesterol (mg/dL) 359 +/- 113 13
Triglycerides (mg/dL) 151 +/- 116 11
Total protein (g/dL) 6.6 +/- 1.7 21
Albumin (g/dL) 2.1 +/- 0.5 20
Globulin (g/dL) 4.6 +/- 1.4 20
AST (IU/L) 40 +/- 19 20
ALT (IU/L) 23 +/- 6 12
Bilirubin, Total (mg/dL) 0.3 +/- 0.2 13
Alkaline phosphatase (IU/L) 33 +/- 15 16
LDH (IU/L) 478 +/- 547 15
CPK (IU/L) 1141 +/- 1125 14
Table 1B. Hematology reference values from young (0-2 year old) Cuban crocodiles (Crocodylus rhombifer) housed at a crocodile farm in Cienaga de Zapata, Cuba (Moliner, et al, 2000).
Hematocrit (%) 21.7+/- 4.2 119
Hemoglobin (g/dL) 7.5 +/- 1.1 20
White blood cell count (x 103/mL) 12,151 +/- 6614 119
Heterophils (%) 16.7 +/- 9.1 119
Lymphocytes (%) 82.1 +/- 9.2 119
Table 1C. Hematology reference values from 3.5 year old Cuban crocodiles (Crocodylus rhombifer) housed at a crocodile farm in Cienaga de Zapata, Cuba (Carmena-Suero, et al, 1979).
Hematocrit (%) 25.8 +/- 1.4 23.6 +/- 1.5
Hemoglobin (g/dL) 8.9 +/- 0.5 8.1 +/- 0.3
Red blood cell count (x 106/mL) 2.89 +/- 0.9 2.37 +/- 0.2
Anneke Moresco spent the last year doing post doctoral work at Cincinnati Zoo & Botanical Garden in the Center for Conservation and Research of Endangered Wildlife (CREW). Anneke and colleagues participated in a conservation and reproduction project for the black-footed cat in South Africa. See the spotlight HERE. Photo credit Dr. Alex Sliwa (curator at the Cologne zoo)