Reptiles 2: Clinical Techniques and Therapeutics Flashcards
Safety and Precautions for reptile handling
- Always get back up for large and potentially dangerous reptiles
- Wear gloves for large aggressive reptiles
- Wear gloves or wash hands thoroughly after handling! ZOONOTIC risk with Salmonella
Non-Venomous Snakes
- how to handle
- constrictors
- snake defecation
- speed
- large snakes
- Grasp firmly but gently behind the head
- Support and control the body with your second hand
- Do NOT place constrictor species around your head or neck
- Some snakes will defecate or produce foul-smelling secretions from scent glands when handled
- Some species can strike VERY fast, often with no warning
- 1 person/meter for large snakes
venomous snakes - should we handle?
- tools?
- Do NOT handle
- Special training is required
> Snake hooks
> Snake tubes
lizard handling
- how to hold
- tail?
- eyelids
- dangers
- tools
- Grasp firmly but gently at the neck/thoracic girdle
- With the second hand, hold the hind legs into the body at the pelvis/base of the tail to prevent the legs and tail from thrashing
- Do NOT pick up by tail may accidentally come off or be shed in an escape mechanism (tail autotomy) in some species (e.g., iguana, skink, and gecko species)
- Gentle pressure over the eyelids causes a vaso-vagal response and can help with handling for radiographs
- Can bite, scratch with toenails, and whip tail
- Can use a towel
large lizard dangers when handling
- Monitor lizards, iguanas, and tegus need to be approached with caution
- Have a VERY powerful bite, strong and sharp claws, and can whip their tail
Chelonians
- how to hold
- dangers
- examination problem
- Hold across the middle of the shell or the edge of the carapace and plastron with both hands
- Can bite and scratch with their beak and toenails (turtles > tortoises)
- Will retract head and limbs making examination difficult
reptile history taking
- acute vs chronic problems?
- what issues usually involved in issues?
- Remember that most reptile problems are not acute problems
<><> - Husbandry issues are almost always involved (See Reptile 1 lecture)
- Enclosure
- Temperature gradient
- Humidity
- UVB lighting
- Diet (supplements)
History Taking
- signalment > what to know
Signalment
* Species, subspecies
> Also gives idea of biotope of origin
* Age
* Sex (if known)
* Duration in owner’s care/captivity
* Origin (captive bred, wild caught, importation date)
History Taking
- what to know about husbandry?
Enclosure
* Size, type, hiding spots
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Temperature:
* Gradient: maximum, minimum, basking area
* Night temperature
* Temperature control and monitoring
* Heating equipment
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Humidity
* % humidity, humidity gradient, humidity boxes
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UVB lighting
* Type and position, when last changed?
* Presence of a screen between the source and animal
* Any time outdoors in summer
History Taking
- what to ask about diet?
- What is the diet?
- When and how often is it fed?
- How is food prepared?
- Amount or size offered?
- How much is actually eaten?
- Treats/supplements used?
> Especially calcium and vitamins - How is water provided?
History Taking
- other important questions aside from signalment, hisbandry, diet
- Breeding details, if any
- Other animals in the enclosure?
- Disease history
- Quarantine protocol
History Taking
- what to ask about current problem
- Reason for presentation
- Clinical signs
- Duration of illness
Physical Examination
- how to start
- Start by an overall visual assessment prior to restraint
> Attitude, mentation - Always obtain weight (gram scale needed for most of these patients)
Physical Examination should be thorough and routinw, and progress from
head to toe
Physical Examination
- head
> what to look at, tools
- Eyes, ears (not for snakes and chameleons)
- Open mouth with credit card or soft spatula
> Look at choana, glottis, teeth, gum, Jacobson’s organ
Physical Examination
* Coelomic cavity palpation
> what can we feel? in diff animals?
* what else to palapte?
* examine what structures?
Coelomic cavity palpation
* Snakes – can usually palpate the heart, sometimes
gallbladder, look for masses or impacted GI tract
* Lizards – kidneys can be palpated via rectal exam if large (sit in the pelvic girdle), look for masses and impacted GI tract, bilateral fat pads caudoventrally
* Chelonians – one or two fingers placed in the inguinal area between the hindlimbs and shell – cystic calculi, foreign bodies, neoplasia, potential eggs
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* Palpation of the extremities and tail
* Examine cloaca
* Examine the shell of chelonians
Physical Examination
- heart rate > auscultate?
> how to take?
> where to find for snakes, chelonians, lizards
Cannot auscultate most of the time > use Doppler
> Where to place the Doppler?
* Snakes – approximately the end of the last third of the body
* Chelonians – on the neck over the carotid artery or in the
thoracic inlet
* Lizards – between forelimbs or axillary region; a monitor lizards’ heart is more caudal
consideration for taking retile resp rate?
Remember: reptiles can hold their breath for long periods of time
TPR for reptiles - can we do it?
- normal values?
- TPR: no temperature and no palpable pulses
- Normal physiologic values > Extremely variable – depends on ambient temperature, age, species, health status
reptile BCS - scale? how to take?
Body condition scoring
* Range 1 (emaciated) to 5 (grossly obese)
> Look at: the palpability of ribs, pectoral/pelvic girdles, the girth of the tail, the muscle mass of forelimbs and hind limbs
Physical Examination
- what about animals about to shed? how to tell?
> why should we care?
Avoid handling animals about to shed if possible – appear dull, blue-tinged, or opaque in color
* May be more aggressive
* Underlying skin is not fully developed
> handling may cause damage to newly developed skin
Physical Examination
* Assessing dehydration
- MM
- skin
- CRT
- eyes
- Mucous membranes – should
be pink and moist
> Common sign of dehydration in reptiles – dry or tacky mucous membranes with saliva strands
<> - Skin – may lack normal elasticity and appear wrinkled
> Can tent skin in many species
<> - Capillary refill time – should be about 1-2 seconds
<> - Eyes – dehydrated reptiles appear to have sunken eyes
Physical Examination
- sexing
> in snakes, how to
Snakes – use a well-lubricated, clean metal probe or rubber feeding tube > insert into the lateral portion of the cloaca (left or right), directed caudally > stop once resistance is met
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- can probe far deeper in male cloaca
Physical Examination
- sexing lizards, how to for various types
- Hemipenis bulges caudal to cloaca
- Enlarged femoral pores in most male lizards
- Precloacal pores in geckos (more prominent in male)
- Sexual dimorphism
> Male iguanas – large dewlap, taller dorsal spines, larger opercular scales, large and well-developed femoral pores
Physical Examination
* Sexing Chelonians
- how to
- Males have longer tails than females
- Males often have a concave plastron, and females tend to be flat
- Males have longer nails than females (especially freshwater turtles)
- Male cloaca protrudes beyond the edge of the plastron (for females it is within the margin of the plastron)
Venipuncture puncture in snakes
- where?
- Ventral coccygeal
- Heart
Venipuncture in lizards
- where?
- Ventral coccygeal
- Jugular
- Lateral tail vein (iguanas, large lizards)
Venipuncture in chelonians
- where?
- Jugular
- Brachial
- Dorsal coccygeal
- Subcarapacial plexus - not reccomended
Lymph Dilution
- what is this concern for blood sampling?
- when to suspect
- what it can alter
- Lymph dilution is a concern – any sample with clear fluid or a watery appearance may have lymph dilution (or it may appear grossly normal!)
- Can reduce all parameters, but most severely affected are
> CBC parameters
> Total protein
> Potassium
Hematology for reptiles
- ref ranges
- all techniques are automatic or manual?
- extrapolation?
- unique cells?
- husbandry considerations?
- Reference ranges are available for some species, but not all
- Like birds, all hematological techniques are manual
- Difficult to extrapolate among species
<><> - Unique cells on CBC – azurophil, heterophil
> Heterophil: - > Function similar to a neutrophil, but lacks the enzyme myeloperoxidase > therefore, purulent material is thick and not liquified
Azurophil (mainly seen in snakes and lizards) - > Behaves like a heterophil in snakes
- > Behaves like a monocyte in all other reptiles
<><> - Appearance of cells varies by species
- Hematologic response heavily influenced by captive husbandry
Biochemistry for reptiles
- similar interpretation to what other animals?
> urea
> liver panel
> best parameter for renal disease??
- electrolytes?
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- differences between sexes
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- seasonal effects
- husbandry
Similar overall interpretation as birds with a few exceptions
* Some species produce urea in a significant proportion (most
chelonians, but aquatic chelonians in particular)
* Liver panel is not very sensitive
* Ca:P ratio is the most sensitive parameter to detect renal disease
* Can withstand drastic changes in electrolytes
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Effect of sex
* Females – higher cholesterol, total calcium, total protein, albumin
> Protein electrophoresis also required for albumin/globulins
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* Seasonal effects – brumation
* Affected by captive husbandry
Diagnostic Imaging for reptiles
- how to radiograph
> views and positioning
- Always collect at least 2 views (3 in chelonians) = orthogonal!
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Positioning - Dorsoventral
- Lateral – horizontal beam
- Craniocaudal – horizontal beam (only in chelonians)
Diagnostic Imaging
- can we ultrasound?
> what do we need?
> A-fast for what?
- Need to get a lot of gel and alcohol between scales to get a good image
- A-fast to check for fluids, masses, and eggs
are CT-scans good for reptiles
- Extremely useful in reptiles
Fecal Floatation in reptiles
- importance?
- parasite pathogenicity?
Routine fecal exams important
* Especially important with wild caught reptiles
* Lost of common intestinal parasites in pet reptiles
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Pathogenicity of various parasites varies by species
* Flagellates are commonly seen on wet mount, but most are non-pathogenic
Intramuscular Injections for reptiles
- where?
- how to insert needle?
- what drugs go cranial? why?
- Typically, in the limbs (epaxial muscles in snakes)
- Insert needle between scales
- Cranial half of the body for drugs with hepatic metabolism (e.g., dexmedetomidine)
> Historically, it was thought that the renal portal system may increase the elimination of drugs given in the caudal half
> We now know that there is a hepatic first-pass effect when given in the caudal half
Subcutaneous Injectionsin reptiles
- character of SQ space? what this means?
- skin tent?
- location for snakes, lizards, chelonians
- technique
- Small subcutaneous space with limited vascularity – absorption of medications and fluids variable
<> - No need to tent skin in reptiles
<> - Location:
- Snakes – lateral body wall
- Lizards – lateral body wall, inguinal space
- Chelonians – axillary and inguinal space
<> - Technique: insert needle parallel to body wall in between scales
should we give intracelomic injections
- No longer recommended
are oral injections a good choice?
- Absorption and efficacy are questionable – consult research
IV injections for reptiles
- where in snakes, lizards, chelonians
- Snakes – challenging, palatal veins in large snakes
- Lizards – ventral coccygeal
- Chelonians – jugular
do we always have to treat iintestinal parasites in reptiles?
- generally not a problem > just because we find on fecal doesnt mean we need to worry
Intraosseous injections
- easier than what other option?
- where in snakes, lizards, chelonians
(easier than IV catheterization)
* Snakes – not possible
* Lizards – distal femur, proximal tibia
* Chelonians – humerus, femur, shell (bridges) also but not great
can we inject stuff up the reptile cloaca?
its possible
where to put catheter for reptiles
- jugular (can be difficult, need them asleep), tail
- can be intraosseous
Nutritional Support
* Force Feeding
> strategy for lizards, snakes, chelonians
- Lizards – usually take food from a syringe
- Snakes – least commonly needed; hold upright and use a red rubber feeding tube
- Chelonians – difficult
Nutritional Support
* Esophagostomy tubes in chelonians
- is this useful?
- Easy to place
- Can be kept long-term
Fluid Therapy for reptiles
- principles
- environment
- methods of rehydration
- crystalloids
- types of fluids to give
- Same principles as for other species
- Correct underlying environmental problems
- Methods of rehydration:
> Soaking (NOT in the bathtub)
> SC
> IV/IO - Crystalloid fluids: 10-30 mL/kg/day
- Types of fluids
> Consult normal osmolality
> LRS or Plasmalyte-A in most species or for IV
> For SC in chelonians: 2/3 LRS, 1/3 NaCl 0.45%
drugs in reptiles
- are they well studied?
- doses vs mammals?
- admin route
- Abx
- Antiparasitics
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- other, pain
- Few pharmacokinetic studies
- Doses and frequencies are typically lower than mammals
- Parenteral administration is common in reptiles
<><> - Antibiotics:
- Ceftazidime or long-lasting ceftiofur crystallin-free; IM/SC q2-5 days
- Enrofloxacin oral or SC diluted in fluids, NOT IM
- TMS – 1st tier
- Metronidazole
<><> - Antiparasitics:
- Ivermectin – NOT IN CHELONIANS
- Fenbendazole
- Ponazuril
<><> - Others:
- Meloxicam
- Hydromorphone, methadone, morphine, tramadol
