Reptiles: History and Physical Examination Study Notes
Reptiles: History and Physical Examination
Client Education
Provide educational materials: Discuss the materials with clients, ensuring they understand the primary care requirements, and send them home for further reference to reinforce key concepts.
Diary: Encourage clients to maintain a detailed diary to track relevant information about their reptiles, which is crucial for identifying trends and potential health issues.
Feeding schedule: Detailed log of what specific food items, their quantity, and when the reptile is fed (e.g., prey type and size for carnivores, specific vegetables/fruits for herbivores). Note any refusals or changes in appetite.
Weight: Regular weight checks (e.g., weekly or bi-weekly for growing reptiles, monthly for adults) to monitor hydration status, growth, and overall health. Significant weight loss or gain can indicate underlying issues.
Stool production: Keep track of frequency, consistency (e.g., firm, soft, watery), color, and presence of any undigested food or foreign bodies in feces and urates. Changes can signal digestive problems or parasites.
Ecdysis: Document shedding events (frequency, completeness of shed, presence of retained spectacle or skin) for signs of health. Incomplete or difficult sheds (dysecdysis) can indicate husbandry problems or systemic disease.
Fecal sample: Necessary for parasitological analysis (e.g., flotation, direct smear) to detect internal parasites such as nematodes, cestodes, trematodes, and protozoa, which are common in reptiles and can cause significant health problems.
Water sample: Collect to assess water quality for contaminants like nitrates, nitrites, ammonia, chlorine, chloramines, and pH levels, especially for aquatic and semi-aquatic species, as poor water quality can lead to skin infections and respiratory issues.
History
Signalment
Age: Important for assessing normal behaviors, growth rates, and age-related health issues (e.g., metabolic bone disease in young, organ degeneration in older individuals). Knowing the exact hatch date or estimated age is crucial.
Species: Essential as different species have vastly varying physiological needs, dietary requirements, environmental parameters (temperature, humidity, lighting), and common disease presentations. Misidentification can lead to inappropriate care.
Sex: Crucial for health care plans, especially regarding reproductive health, potential for egg binding, and sex-specific behaviors. Methods of determination vary significantly between species.
Species Identification
Photos and studies, such as those by Tim Howes, can help accurately identify specific reptile species, which is foundational for providing appropriate care, as care requirements are highly species-specific.
Age Assessment
Example: A 3-year-old slider turtle kept in a captive environment, provided with an aquarium and a pelleted diet can develop health issues if not properly monitored or if husbandry is inadequate.
An adequate diet and environment (including proper thermal gradients, UVB lighting, filtration, and enrichment) are critical for captive reptiles to prevent conditions like metabolic bone disease, hypovitaminosis A, shell rot, and respiratory infections.
Sex Determination
Methods for determination include:
Femorales/Riugs (Femoral Pores/Plugs): In many lizards (e.g., iguanas, geckos), males possess prominent, often waxy or solid, femoral pores along the inner thigh that are absent or much smaller in females. These release pheromones for territorial marking.
Fat pockets: Indicator of sexual maturity and reproductive readiness, especially in turtles where males may have larger fat reserves in certain areas.
Jowls: Enlarged jowls can be a secondary sexual characteristic in some male lizards (e.g., Gila monsters, some iguanas), used in display.
Sexing probe: A highly accurate method for snakes and some lizards, where a lubricated blunt probe is gently inserted into the cloaca and directed caudally. The depth of insertion indicates sex: females typically have no more than 1-3 subcaudal scales covered by the probe, while males have 9-15 subcaudal scales covered, as they possess paired hemipenes within the tail base.
Hemipenes are a distinguishing feature in males; these paired copulatory organs are inverted and stored in pockets at the base of the tail. Males will have a prominent bulging pocket for hemipenes, often resulting in a thicker tail base compared to females.
Resources: Refer to external sources like RepticZone.com and papers such as Joe Laszlo's research on probing techniques for detailed, species-specific guidance.
History Taking
Background Information
Important factors to discuss:
Where was the reptile acquired? Understanding its origin (wild-caught, captive-bred, pet store, breeder) can hint at potential past stresses, exposure to parasites, specific pathogen risk, or acclimation challenges.
Length of Ownership: Indicates the owner’s experience and familiarity with species requirements. Recent acquisition might mean the reptile is still adjusting or manifesting pre-existing issues.
Other pets: Other reptilian or non-reptilian pets (e.g., dogs, cats) may affect the reptile’s health through direct interaction (stress, injury), indirect transmission of pathogens, or competition for resources.
Interaction time: Helps gauge bonding and stress levels. Lack of interaction might mean problems go unnoticed, while excessive or improper handling can cause chronic stress.
Environmental Conditions
Assess critical factors for proper husbandry:
Temperature: Ideal ranges are species-specific and should include a thermal gradient (a hot spot for basking, a cool end for retreat) to allow the reptile to thermoregulate behaviorally. Day and night temperatures are also important.
Humidity: Must be monitored (using a hygrometer) as it affects the reptile’s skin health (shedding), respiratory system, and hydration. Specific species require different levels (e.g., desert species low humidity, tropical species high humidity), often achieved via misting, humidifiers, or moist hides.
Lighting and Light Cycle: Important for metabolic processes, including vitamin D synthesis (requiring UVB), thermoregulation (basking lights), and circadian rhythms. Full-spectrum UVA/UVB lighting is critical for most diurnal species, with a consistent day/night cycle (e.g., 12 hours on, 12 hours off).
Substrate: Varies according to the species' needs (e.g., newspaper, cypress mulch, sand, coco fiber, artificial turf, specialized soil mixes). Considerations include ease of cleaning, moisture retention, and risk of impaction if ingested.
Cage Furniture: Accessories in the habitat that may influence behavior and health, including basking platforms, climbing branches, hides, water bowls, and enrichment items like artificial plants. These provide psychological and physical stimulation.
Disinfection Protocols: Vital for preventing infections. Details should cover frequency of cleaning, types of disinfectants used (e.g., dilute bleach, chlorhexidine, F10sc), and proper rinsing to remove chemical residues.
Dietary Information
Questions to ask:
Type of food: Species-appropriate diet must be maintained. Ask for specifics: feeder insects, whole prey (frozen/thawed), fresh vegetables, fruits, commercial pelleted diets. Note any recent changes or unusual food items.
Amount Offered: Critical for managing obesity or malnutrition. Relate to the reptile's size and activity level. Ask if food is left uneaten or eagerly consumed.
Frequency and Supplements: Helps to understand proper feeding habits and nutrition. For example, young reptiles typically eat more often than adults. Inquire about calcium supplementation (with/without D) and multivitamin use, as deficiencies are common.
Water Source: Quality and availability matter significantly. Ask about the type of water (tap, filtered, distilled), frequency of changes, and type of water bowl/system (e.g., misting, drip system, large soaking tub).
Reproductive History
Covering aspects such as:
Breeding / Egg-laying habits: Key to understanding life cycle management and potential health aspects. Inquire about frequency, clutch size, presence of a nesting box, signs of egg binding (dystocia), or issues with fertility.
Current Health Status
Eating and Drinking: Evaluate if these are within normal limits (WNL). Look for changes in appetite (anorexia, polydipsia), dysphagia (difficulty swallowing), or regurgitation. Signs of dehydration (sunken eyes, skin turgor loss) are important.
Feces & Urates Inspection: Examine appearance, consistency, and frequency of elimination. Note specific colors (e.g., green urates can indicate liver issues, yellow for dehydration), odors, or the presence of blood or abnormal textures.
Changes: Less urates, thicker, more viscous feces, or complete absence of elimination can indicate dehydration, kidney issues, impaction, or digestive disorders.
Past Medical History: Includes any chronic conditions (e.g., metabolic bone disease, stomatitis, abscesses) or previous treatments, including medications, surgeries, or diagnostic tests performed.
Current Problems: Look for duration and nature of presenting issues for diagnosis. Document specific symptoms like lethargy, lumps, skin lesions, discharge from eyes/nose, lameness, or abnormal breathing.
Initial Diagnostic Work Up
Critical techniques for assessing health include:
Physical Examination: Systematic observation (hands-off and hands-on) of the reptile to assess all major body systems for abnormalities, pain, or discomfort.
CBC (Complete Blood Count): Evaluates blood composition (red blood cells, white blood cells, platelets) to screen for anemia, inflammation, infection, or other systemic diseases.
Biochemistry Panel: Assesses organ function (kidney, liver), electrolyte balance, and metabolic status. Important values include calcium, phosphorus, glucose, and proteins.
Radiographs (X-rays): Imaging techniques for internal assessment of skeletal structures (fractures, metabolic bone disease), presence of eggs/follicles, foreign bodies, organomegaly, or pneumonia. Two views (dorsoventral and lateral) are typically taken.
Fecal Examination: Parasitological and microbial analysis to identify internal parasites, bacterial overgrowth, or abnormal flora. Often includes direct smear, fecal flotation, and occasionally cytology.
Physical Examination
Hands-Off Approach
Initial assessment through observation is key:
Evaluate general disposition (alert, dull, responsive), attitude (aggressive, docile, shy), posture (normal, head tilt, dropped jaw), and behavior of the reptile before physical contact. Observe its breathing pattern, presence of tremors, or inability to move normally.
Look for musculoskeletal issues (swelling, asymmetry, lameness), respiratory problems (open-mouth breathing, nasal discharge, bubbles), or gastrointestinal distress (bloating, abnormal stool visible in the enclosure).
Restraint Techniques
Understand how to safely handle reptiles while minimizing stress to both the reptile and the handler:
Snakes: Use fingers around the mandible to secure the head and support the body along its length to prevent striking and provide security. If large, utilize two handlers, one for the head and one to support the rest of the body every 3-4 feet. Check for potential diaphragmatic issues as reptiles do not have a true diaphragm, relying on intercostal musculature for respiration; improper restraint can impede breathing.
Small Lizards: Grasp head firmly at the back of the skull to prevent biting, and hold the body securely without gripping the tail which can be autotomized (dropped) by some species as a defense mechanism.
Large Lizards: Use a forearm or two hands to support the body, as they need a large surface area to feel secure and prevent thrashing. Secure the head and base of the tail to prevent bites and whipping.
Crocodilians and Chelonians: Securely grasping the mouth (preferably with tape or a snare for crocodilians), tail (to prevent whipping), and carapace (for chelonians) is essential. Multiple personnel are usually needed to prevent injury to staff and potential escape.
Restraining Specific Species
Crocodiles: Must secure both mouth and tail. Specialized restraint techniques using ropes, pole snares, or even tranquilizers might be necessary for larger, more aggressive individuals. Prioritize safety of personnel.
Chelonians (Turtles/Tortoises): Secure adult reptiles using multiple personnel due to their size, strength, and defensive behaviors (biting, retracting limbs). Can be difficult to examine fully when withdrawn into their shell; gentle coaxing or waiting for them to emerge is often best.
Physical Examination Documentation
Employ detailed forms with diagrams to note various metrics and findings:
Morphometrics and External Abnormalities: Helps develop a health baseline. Includes snout-vent length (SVL), total length (TL), tail length, and circumference measurements. Document any skin lesions, wounds, swellings, color changes, or external parasites.
Weight monitoring: Serial weights, recorded accurately, can indicate hydration status, nutritional changes, and the progression or resolution of disease. Body Condition Score (BCS) can be assigned based on muscle mass and fat stores.
Enclosure size: Assessment of spatial needs according to the species and current size of the reptile. Inadequate enclosure size can lead to stress, physical deformities, and poorer health.
Respiratory System Assessment
Significant differences between species:
Crocodilians have diaphragmatic control due to the presence of a muscular diaphragm, allowing for more efficient negative-pressure breathing. Whereas other reptiles do not; instead, they use intercostal muscles and limb pumping (coelomic pump) to inflate and deflate the lungs, creating a pseudo-diaphragm effect.
The glottis (opening to the trachea) is positioned differently based on species – rostrally (at the base of the tongue, often visible) in snakes and lizards, while more caudally (deeper in the oral cavity) in chelonians. This affects observation and intubation.
Common respiratory issues include pneumonia, stomatitis, and nasal discharge, often indicated by open-mouth breathing, bubbling at the nares, or lethargy.
Circulatory System Overview
Heart Anatomy:
Most reptiles have a three-chambered heart with two atria and one ventricle, allowing for some physiological shunting of blood. Crocodilians are unique among reptiles, possessing a four-chambered heart similar to mammals and birds, but with a foramen of Panizza. This specialized opening between the left and right aortas allows for shunting of blood away from the pulmonary circulation during breath-holding, aiding in prolonged diving.
Vein identification includes common carotid, jugular, and various arches (e.g., caudal vena cava, ventral tail vein in snakes, jugular in chelonians) for blood flow and venipuncture. Blood can often be drawn from the caudal tail vein, jugular vein, or cardiac puncture (in very small or deceased animals).
Conclusions on Ophthalmic Examination
Cover aspects of examination specific to reptile anatomy:
Many lizards (e.g., geckos) have a fused transparent spectacle covering the eye instead of movable eyelids; snakes also possess a spectacle, which sheds with their skin. Other reptiles, like turtles and some lizards, have typical eyelids.
Movement control varies; some species have good eye movement, while others (like chameleons) have independently moving turret-like eyes. The absence of a consensual pupillary light reflex (PLR) is normal in most reptiles, meaning shining a light in one eye does not cause the pupil in the other eye to constrict.
Oral Examination Techniques
Tools used must be safe for the reptile's oral cavity, ensuring minimal stress and restraint. This includes non-traumatic speculums (e.g., plastic spatulas, tongue depressors, credit cards for small species) which should be gently inserted to visualize the oral mucosa, glottis, and choana. Lubrication helps prevent injury.
Gastrointestinal Function & Adaptations
Important distinctions and modifications within the reptilian anatomy:
Tongue structure varies across species, influencing feeding strategies. Snakes have bifurcated tongues for chemoreception (smell), chameleons have long projectile tongues for insect capture, and herbivorous lizards have broad, muscular tongues for manipulating plant matter.
Teeth types classified as thecodont (teeth set in bony sockets, like crocodilians), pleurodont (teeth fused to the inner surface of the jawbone, common in many lizards and snakes), and acrodont (teeth fused to the top of the jawbone, without sockets, like chameleons and bearded dragons), affecting feeding and shedding. Acrodont teeth are not replaced if lost.
The cloaca is a single opening for digestive, urinary, and reproductive tracts. Common GI issues include impaction, parasite infestations, and stomatitis (mouth rot).
Integumentary System Overview
Layers of skin and functions of scales:
Stratified structure with a protective outer epidermis (keratinized scales) and an underlying dermis. Specialized functions include moisture retention (preventing desiccation), protection from physical injury and pathogens, camouflage, and locomotion. Ecdysis (shedding) of