Reptile Medicine Flashcards
Key aspects of clinical examination
- Husbandry
- Demeanour
- Respiration
- Responses to stimuli
- Faecal analysis - fresh smear + flotation technique
Pinworms
- Oxyurids common in most species (species-specific)
- Rarely significant in low no.
- Treat if CS present - weight loss, poor growth, diarrhoea, anorexia
- Tx - Fenbendazole 20 mg/kg/d for five doses
- Beware concurrent disease
- Avoid ivermectin in all chelonia + green tree pythons - associated neurotoxicity
Coccidia
- Isospora amphiboluri common in agamids (lizards)
- Pathogenic - bearded dragons
- 30 mg/kg TMPS for 5 d
- 10mg/kg toltrazuril (Baycox) for 2 d
Ascarids
- Common in tortoises
- Pathogenic - impaction, ill thrift and death reported
- Tx - Fenbendazole effective
Protozoa
- Tortoise faeces carry a wide variety of motile protozoa
- Few pathogenic
- Txt only if CS suggest pathology
- Protozoa in carnivorous species are abnormal flora
- Tx = Metronidazole at 50 mg/kg q 2 d
Cryptosporidium
- Cause of SI epithelial hyperplasia in leopard geckos + some monitor species
- Gastric hyperplasia in snakes
- Leads to rapid weight loss -> growth reduction + regurgitation (uncommon in
geckos); regurgitation + gastric dilation common in
snakes; asymptomatic dormant state common - Dx - organism detection: acid-fast faecal/gastric flush preparations + histopathology, biopsies of intestinal tract - identify oocysts in villi, hard to see in=house, v small
Cryptosporidium Tx
- Potentiated sulphonamides slow progression
- Paromomycin + hyperimmune bovine
colostrum have shown experimental promise - Not readily available
- HIBC no benefit in small intestinal infection
- No reliable therapy
- Advanced cases should be euthanased
- In contacts should be considered infected
Salmonella
- Zoonotic - from aquatic terrapins, kids < 5 y/o at risk, should not have access + wash hands
- Captive reptiles frequently carry Salmonella as part of
their GI flora - Wild reptiles do not
- Tx not recommended due to potential for inducing antibiotic resistance
- Good hygiene practice will prevent human infection
Ectoparasites
- Ophionyssus nactricis mites
- Pterygosomid mites
Ophionyssus nactricis mites
- Snakes and lizards
- High burdens can lead to anaemia
- Vector of disease
- Tx - Fipronil (Frontline), 2 mL/kg (used with care due to toxicity of alcohol-based solvent)
- Ivermectin - don’t use with Green tree pythons or near tortoises
Pterygosomid mites
- Unusual in UK reptiles, occasionally seen in imported animals
- Tx - Fipronil (Frontline), 2 mL/kg (used with care due to toxicity of alcohol-based solvent)
- Ivermectin - don’t use with Green tree pythons or near tortoises
Blood sampling - tortoise
- Jugular vein runs superficially from the tympanum to thoracic inlet
- Supcarapacial sinus - decent vol
- Dorsal tail vein samples are frequently lymph-contaminated, advance until hit bone + draw back -> small vols
Blood sampling - lizard
Ventral tail vein
- Proximal tail contains
hemipenes in males - if too proximal will cause trauma
- Insert needle midline
- Advance until vertebral contact occurs
- Withdraw slightly
- Easy to sample in most species
- Avoid in geckos and juvenile iguanas - will tail drop
Jugular vein
- Runs along a line drawn from the mandibular ramus to the shoulder
- Difficult to access blind
Ventral abdominal vein
- Haemostasis v difficult - once withdraw needle - nothing to apply pressure to, risk of haematoma, don’t risk it
Blood sampling - snakes
Ventral tail vein
Palatine vessel
- Possible in large, anaesthetised snakes
Cardiac
- Visualise heart on ventral body wall, smaller snakes; use doppler in larger
- Immobilise the heart by placing a thumb proximally
- Insert needle from caudal aspect
Biochemistry sample
- Serum/heparinised plasma suitable
- Machines run profile in 0.1 mL serum (6-8% blood vol collected)
Hepatic dysfunc
- Hepatic lipidosis - anorexia
- Very common syndrome with non-specific symptoms
- Enzymes (AST, GGT, ALT) non-specific
- AST elevation with normal CK supports hepatocellular
damage, rather than generalised ST damage - Low albumin and uric acid, elevated urea
- Bile acids most reliable marker - single point measurement, insensitive with focal/mild hepatopathy
- Imaging may identify hepatomegaly - endoscopic or surgical biopsy is required for definitive diagnosis
- Accompany w/ US scan - look for enlargement, abscessation + focal masses
Renal dysfunc
- Urinalysis limited as urine is modified in the lower
intestine - Urinary GGT, NAG and AST indicate renal tissue
damage - Blood AST non-specific
- Elevated uric acid can indicate compromise
- Concurrent urea measurement helps with differentiating renal and pre-renal disease
- Hypocalcaemia and hyperphosphataemia seen in
renal disease (RSHP, Renal Secondary Hyper parathyroidism)
Calcium
- Total calcium not a reliable marker of calcium homeostasis
- Ionised calcium much more reliable but requires
greater sample vol - Phosphate elevation with low ionised calcium consistent with secondary hyperparathyroidism
- 1,25-Cholecalciferol (vit D) and PTH levels possible in reptilian species but not commercially available
Haemtaology
- Nucleated red blood cells preclude standard
haematology machine use - Manual counts simple to perform in-house - PCV + WBC
- Heterophilia and leucocytosis common in infectious pathology
- Monocytosis in chronic infections
- Leucopaenia with chronic disease, viral infection, sequestration with focal inflammation or chronic immunosuppression with inappropriate husbandry
- Blood smear evaluation - differential count + assessment of morphology
Toxic heterophil presence, regenerative erythrocyte respone
Nutritional Secondary Hyperparathyroidism (Metabolic Bone Disease)
- Affects all reptiles
- breakdown of calcium homeostasis
- Calcium metabolism requires several factors: calcium; vitamin D (dietary or UVB provision); appropriate heating - so vit D can be converted into active form; renal and hepatic function
- Husbandry deficiencies common
Nutritional Secondary Hyperparathyroidism (Metabolic Bone Disease) - importance of calcium homeostasis
- Keep calcium within a narrow range
- Reduced availability leads to hypocalcaemia
- Parathyroid hormone secretion increases
- Osteoclast activity increases
- Blood calcium normalises
- Bone is demineralised
Nutritional Secondary Hyperparathyroidism (Metabolic Bone Disease) - Dx
- Clinical presentation is characteristic
- Blood calcium may be normal
- Blood phosphate is usually elevated
- Radiographs can grade severity - demineralisation, particularly of extremities + bone remodelling
Nutritional Secondary Hyperparathyroidism (Metabolic Bone Disease) - Tx
Correct deficiency
- Intramuscular calcium gluconate
- Oral calcium and Vitamin D medication
Correct husbandry
- UVB lighting
- Supplementation of vit D + calcium
- Correct temperatures
- Apply to all animals in group, not only clinical cases
- Euthanase cases with permanent mobility or feeding compromise
Post-hibernation anorexia
- Primarily tortoises
Causes - Excessive length of hibernation
- Poor health prior to hibernation
- Low white cell count (neutropoenic) = chronic stress
- Failing to reach POTZ (preferred optimum temperature zone) - compromises immunity, favours pathogens
- Disease or trauma during hibernation
- Poor husbandry and management
Post-hibernation anorexia - when to intervene
- Loss of 10% body weight during hibernation
- Failure to urinate or drink within 4 days
- Failure to eat within one week
- Presence of any clinical signs
- Concurrent runny nose syndrome common
Post-hibernation anorexia - Tx
- Correct dehydration
- Fluid therapy and achieve urination - prior to initiation of feeding
- Increase blood glucose once hydrated
- Optimal environmental conditions
- Appropriate nutrition
- Treat concurrent disease
- Improve long-term care and management
- Oesophagostomy tube
Minimising hibernation problems
Pre-hibernation health check
- Visual exam, faecal exam, further tests if indicated, scan females (any repro issues) - no harm in missing hibernation if tortoise is sick, discuss hibernation length
- Preparation of hibernaculum - esure temperatures are appropriate and stable
- Monitor throughout hibernation - be prepared to act if problems arise
Hibernation preparation
- Mimic late autumnal conditions - dec temperature gradually initially + maintain at consistently low temperatures (< 15 C) + decreasing light and UVB exposure
- Starve for 3 - 4 weeks -> no necrotic food in gut, usually tortoises do this themselves
- Bath regularly to ensure hydration
Hibernation of tortoises
- Hibernate between 3 - 7 C
- Too cold: frost can cause blindness + limb damage, frequently seen in ‘free hibernating’ UK tortoises
- Too warm: energy stores are rapidly used up so tortoises lose weight, dehydrate and accum toxins
- 1% weight loss per month is acceptable
Management during hibernation
- Weight check - q two days
- Signs of activity- urination or significantly disturbed bedding suggests inc temperature + a break in hibernation
- Early hibernation – ensure temperatures low enough
- Mid/late hibernation - stop hibernation
- Monitor ambient temperature at least once daily - auto-monitoring, data-storing thermometer
- Any other signs of illness - predator injury in outbuildings
Hibernation - fridge method
- Stable temps
- Easy monitoring
- Preferable
- Beware of ice formation
Ending hibernation
- Outdoor hibernated tortoises will naturally awake in late spring
- Prolonged hibernation is the most common factor in post-
hibernation anorexia - utilisation of all energy stores, lack of time to re-accumulate stores before next hibernation + failure to recover from prolonged dormant state - UK tortoises are commonly hibernated for 5 - 6 months, far longer than in their natural climate, 4 - 12 w recommended
- Hibernation should never exceed 16 weeks
Ending hibernation
- Tortoises need temperatures > 15 C to kickstart metabolism
- Warming should occur over several hours
- Once responsive movement is seen move to normal enclosure
- Inc temperatures from 15 C to POTZ over 48 h
- Provide 8 h light with UVB
- Bathe daily - many tortoises require water to stimulate urination, allow hydration via drinking/bladder absorption
- Monitor weight, urination, defaecation + appetite until normal
Post-hibernation exam
- Discuss hibernation protocol used
- Check weight
- Physical examination
- Assess summer management
- Intervention as necessary - further tests e.g. blood profile, FT, pharyngostomy tube placement, specific treatment
Runny nose syndrome
- Any tortoise species, often Testudo sp (mediterranean)
Causes - Viral
- Mycoplasma
- Bacterial
- Fungal
- Hypovitaminosis A
- Poor husbandry
Runny nose syndrome - Dx
- Clinical appearance distinctive
- Identify specific causative factors
- Chelonian herpes PCR
- Geochelone/Stigmochelys species and Hermann’s tortoises appear particularly sensitive, many others may act as carriers
- Mycoplasma PCR
- Chlamydia serology/PCR
- Dietary and husbandry assessment
- Bacterial culture and sensitivity
Runny nose syndrome - Tx
- AB - 2y infections
- Nasal flushing - AB, saline, F10 (antiseptic solution)
- Improve husbandry
- Severe cases - hospitalisation: assist feeding, FT, nebulisation + flushing
Pneumonia
- RNS (runny nose syndrome) in tortoises or stomatitis in snakes
- Viral, bacterial and fungal agents all reported
- Radiography especially useful in tortoises
- Horizontal beam views most rewarding
- Tracheal wash indicated in all reptiles: cytology, culture, PCR
- Lung biopsy/flush can be carried out endoscopically
Pneumonia - Tx
- Antimicrobial therapy based on microbiology
- Nebulisation - 1 : 1250 F10, AB solutions
- Clearing of secretions in snakes - coupage, encourage activity, high humidity
Tortoise trauma
- Common in outdoor
tortoises - lawnmowers, children, dogs, foxes and rat - All wounds should be
considered contaminated - Maintain as open wounds
initially - Soft tissue injuries require
protection to granulate
Shell Fx repair
-1). Wet-to Dry Bandages - gauze and saline +/ chlorhexidine, short-term to clear infection, long-term use traumatises granulation bed
- 2). Vacuum assisted closure - constant negative pressure of ~ 125 mmHg, excellent for chronically infected wounds
- Expensive equipment, not practical in all cases
- 3). Epoxy resin - cannot be used for contaminated wounds
- Can hinder shell growth
- Often used together with screws/wires/plates
- 4). External fixation - cannot replace deficits
- Good positioning of fragments usually achieved
- 5). Platelet Rich Plasma - platelets store + release GFs + chemotactic molecules involved in haemostasis and cell proliferation (clot blood w/ calcium gluconate + place in wound, can be from donor)
- Sodium citrate anticoagulant - add calcium gluconate to trigger clot formation + apply as a gel
- Acts as a barrier and promotes local healing
Shell Fx repair management
- Analgesia
- Antibiotic therapy
- Secure loose fragments
- Sterile dressing changes daily
- Consider patching large defects once confident the area is not infected
- Fibreglass or non-heating resin
Stomatitis
- Inflam of mm of mouth
Causative factors vary: - Herpes virus related in tortoises
- Snout trauma in lizards
- Immunosuppression in snakes
- Paramyxovirus involvement
- Culture, cytology and biopsy can aid specific Dx
- Often broad spectrum antibiotic therapy is initiated
- Topical Tx - F10 flushes, silver ointments for open lesions
- Analgesia necessary
Periodontal disease
- Agamids + chameleons
have acrodont teeth (no root) - housed in an exposed section of the jaw bone, teeth are not shed and replaced - Soft diet or trauma predispose to gingival
inflammation and recession - Osteomyelitis eventually results
Periodontal disease - prevention + Tx
- Feed harder diet (avoid soft fruits)
-Prevent trauma - Tx - Remove plaque
- Debride necrotic tissue and bone
- Administer topical and systemic antibiotics
Neuro disease in snakes - CS
- Loss of righting reflex
- Stargazing
- Paresis
- Tremors
- Seizures
- Aggressive behaviour
Neuro disease - DDx (snake)
- Heat or mechanical trauma
- Metabolic abnormalities
- Renal/hepatic disease
- Hypocalcaemia unusual in snakes
- Toxin exposure
- Nicotine
- Insecticides
- Infectious - permethrin
Neuro disease - infectious causes (snake)
- Paramyxovirus (Ferlavirus), colubrids and elapids, predilection for venomous species
- May cause respiratory or neurological disease
- Difficult to Dx reliably - can have an incubation period of up to 1 y, 1/3 positive cases asymptomatic, 1/5 grossly normal on PME
- Dx by serology - seroconversion takes 6 - 8 w, demonstrate rising titre
- PCR on oral and cloacal swabs can be used
- Lung>intestine>liver>kidney for inclusions on histopa
Inclusion body disease of Boids (IBDB)
- Infection with arenavirus
- Pythons highly susceptible + develop acute neurological symptoms
- Single case report in corn snakes
- Boas can act as subclinical carriers
- Serology and PCR available for ante-mortem testing of adrenal glands
- Histopathology - large eosinophilic protein inclusions (not viral particles), clinical syndrome, not single pathogen
Agamid adenovirus 1
- Cause of neuro signs, poor growth,
immunosuppression + death - Demonstrated in clinically healthy
bearded dragons - 18.5% PCR +ve for agamid adenovirus 1
- Breeding groups should be screened to maintain clean colonies
- Dx - combined choanal and cloacal swabs for PCR
Autotomy (tail slip)
- Tail autoamputation = natural defence + minimises bleeding
- Rough handling, acute stress or tail trauma
triggers vertebral cleavage - Ongoing contractions focus attention on the
tail - Keep the stump clean but do not apply medication or suture the site
- House the gecko alone, on paper
- Feed daily as energy and fluid storage is compromised
- Within 8 weeks a primitive tail will reform
Osteomyelitis
- Requires initial entry wound
- Skin trauma common
- Bacterial emboli block smallest capillaries
- Toes typically affected
- Other joints may less commonly be involved
- Swelling and pain results
- Dx = aspiration + radio
- Analgesia
- Broad-spectrum AB therapy pending culture
- Cytology of joints assists in diagnosis - Gout, Mycoplasmosis, Mycobacteriosis, Fungal infections
Urolithiasis (bearded dragons)
- Urates = semi-solid waste produced by the kidneys
- Urates stored in the rectum + cloaca until they are voided with faeces
- Infrequent defaecation predisposes to dessication of
urates refluxed into the colon - Colon absorbs fluid to leave a solid urolith
Urolithiasis - Tx (bearded dragon)
- Usually easily flushed by instilling fluid into the cloaca and rectum via a blunt ended tube
Prevention - Adequate fibre
- Appropriate temperatures
- Hydration
- Calcium and UVB provision
Tail autotomy uses
Minimise bleeding for tail amputation procedure
