Common Diseases of Reptiles Flashcards
Why are reptiles not recommended for immunocompromised individuals?
carriers of Leptospirosis and Salmonella, where eradication is impossible
- can prevent shedding by minimizing stress and improving husbandry
- do not clean cage by food prep area
Why are quarantines especially important in reptiles? How long is it recommended?
they are often wild caught and can harbor disease
60-90 days
What is the host of Adenovirus/Atadenovirus? How is it transmitted?
neonate/young bearded dragons (+/- other lizards and snakes)
fecal-oral, possibly vertical
What co-infection is commonly associated with Adenovirus/Atadenovirus? What effect does it have?
Depedovirus and Coccidia
ruptures host cells and targets hepatocytes, causing hepatitis (can also infect intestines, kidneys, and nerves)
What are the 4 groups of individuals affected by Adenovirus/Atadenovirus?
- acute death
- poor doer
- intermittent
- subclinical
What clinical signs are associated with Adenovirus/Atadenovirus?
- anorexia, lethargy, weight loss
- limb paresis
- head tilt, opisthotonos
- seizure/tremors
- diarrhea
- sudden death
What 2 methods of diagnostics are used for Adenovirus/Atadenovirus?
- PCR - oral, cloacal swab
- histology - liver, intestines
What are the 3 major histologic findings associated with Adenovirus/Atadenovirus?
- basophilic IN inclusions in liver/GI
- hemorrhagic hepatitis and enteritis
- intestinal and hepatic necrosis
What treatment is recommended for Adenovirus/Atadenovirus infection?
- isolation and supportive care
- treat secondary infections
- treat environment
guarded to poor prognosis
What is the host of Paramyxovirus/Ferlavirus? How is it transmitted?
snakes —> secondary bacterial infections common
direct contact with aerosols and fomites
What clinical signs are associated with Paramyxovirus/Ferlavirus? How long can carrier status last?
- anorexia
- regurgitation
- dyspnea
- star gazing
- head tremors
- flaccid paralysis
- ACUTE = paresis and death within 24-48 hours
10 months
What 2 diagnostics are performed for Paramyxovirus/Ferlavirus? What gross pathology can be appreciated?
- PCR - oral/cloacal swab or pulmonary wash
- hemagglutination inhibition antibody titer
inflammation/necrosis of lungs, CNS, and liver
WHat treatment is recommended for Paramyxovirus/Ferlavirus?
- isolation and supportive care
- treat secondary infections
- improve husbandry
poor prognosis
What is the host of Arenavirus? What does it cause?
boas and pythons
inclusion body disease
What are 4 methods of transmission of Arenavirus?
- direct contact
- fomites
- snake mite (Ophionyssus natricis)
- vertical
What clinical signs are seen in boids and pythons with Arenavirus infection?
BOIDS = regurgitation and progressive weight loss, secondary infections (stomatitis, pneumonia, neurologic disease)
PYTHONS = acute severe neurologic disease
What are 3 ways of diagnosing Arenavirus infection?
- biopsy - liver or esophageal tonsils
- CBC - leukocytosis with lymphocytosis occasionally with IB in the cytoplasm
- PCR - oral/esophageal swab
How is Arenavirus infection treated?
- isolation and supportive care
- treat secondary infections
- improve husbandry
poor prognosis —> euthanasia
What novel virus is associated with fatal respiratory disease in pythons? How is it transmitted? Diagnosed?
Nidovirus
contact with fecal matter and bedding
PCR of respiratory secretions or cloacal swabs
What is the main reptile host of Herpesvirus? How is it transmitted?
chelonians
direct horizontal - respiratory secretions, feces, saliva
What are the 2 major clinical signs associated with Herpesvirus infection? What else is seen?
stomatitis and rhinitis
- conjunctivitis, blepharoedema, serous/mucopurulent nasal discharge
- hypersalvation, glossitis (diphtheric membrane)
- dyspnea
- dehydration
- neurologic signs
- weight loss
What are 2 options for diagnosing Herpesvirus infection?
- PCR - swab or biopsy or oral lesion
- histopath - IN inclusion bodies
What treatment is available for Herpesvirus infection? What happens with survivors?
no effective treatment —> try Acyclovir, supportive care, treatment of secondary infections, and improve husbandry
will be carriers for life - allows for continuous spread to other household chelonians, must minimize stress (no brumation!)
What Poxvirus commonly affects crocodilians? What signs are associated? Treatment?
Caiman pox —> white circular lesions
isolation + supportive therapy
What is West Nile virus associated with? What are the 3 most common clinical signs?
acute death in American Alligators
- depression
- lethargy
- neurological signs
What is the host of infectious stomatitis? What is the most common cause?
(mouth rot/ulcerative stomatitis) - all reptiles, most common in snakes
poor husbandry, trauma, or systemic illness allows Aeromonas or Pseudomonas infection likely
What are the most common clinical signs associated with infectious stomatitis?
- anorexia
- hypersalivation
- oral petechiae
- caseous exudate
- tooth loss
- osteomyelitis
- eye infections
- pneumonia
How is infectious stomatitis diagnosed? What are the 3 most common treatments necessary?
bacterial culture
- MILD CASES - improve husbandry, topical iodine
- SEVERE CASES - improve husbandry, topical iodine, systemic antibiotics
- periodic trimming for resulting beak and jaw deformation
(iodine safer near eyes)
What is the most common host of vascular dermatitis? What is a major predisposing factor?
(blister disease/scale rot) - captive snakes and occasionally lizards
increased humidity = poor ventilation, wet substrate
How does vascular dermatitis progress? How is it treated?
SQ fluid-filled, sterile lesions —> secondary bacterial infection —> bacteremia
improve husbandry + topical iodine +/- systemic antibiotics
What is the most common host of Mycoplasma? What is the most common clinical sign?
chelonians +/- squamates, crocodilians
chronic nasal sinusitis
- ACUTE = hyporexia, lethargy, clear nasal d/c
- CHRONIC = weight loss, mucoid-mucopurulent nasal/ocular d/c, conjunctivitis, palpebral edema
How is Mycoplasma transmitted? When are flareups common?
direct - nasal exudates (very contagious)
cold weather
How is Mycoplasma infection diagnosed? What are 3 treatment options?
difficult - culture, ELISA, PCR
- tetracyclines +/- fluoroquinolones
- supportive treatment
- isolate survivors due to asymptomatic carriers
(Enrofloxacin nasal wash + Dexamethasone + NaCl fluids —> recurrence common)
What are the main 2 causes of abscesses in reptiles? How does it compare to mammals?
G- or anaerobic bactertia
caseous exudate does no drain well - heterophils lack lytic enzymes responsible for the production of abscesses in mammals
How are abscesses treated?
- lance and leave open
- flush with iodine q 1-2 weeks
- topical/systemic antibiotics
What antibiotics are more commonly used in reptiles?
injectable Enrofloxacin or Cefrazidime
What causes onygenalean dermatomycosis? What are the most common hosts?
Nannizziopsis spp. (yellow fungus disease, CANV)
lizards and snakes —> bearded dragons, chameleons, green iguanas
What is the most common clinical sign associated with onygenalean dermatomycosis? What else can be seen?
yellow-brown skin lesions with hyperkeratosis and ulceraition
- skin necrosis
- slough exposes muscle and bone
- anorexia
What is the preferred diagnostic for onygenalean dermatomycosis? What else can be done?
histopath - hyphae
- broad range, next generation PCR (bacteria + fungi, sensitivity)
- cytology
- culture
What are 5 aspects to the treatment plan in cases of onygenalean dermatomycosis?
- isolate
- prolonged antifungal therapy for 30-50 days
- aggressively debride and topical treatment
- supportive treatment
- clean the environment
What causes ophidimyces? What is the most common host? Clincial sign?
Ophidiomyces ophiodiicola —> Snake Fungal disease
wild North American species (eastern MA)
crusting lesions that can lead to deep granulomatous infection
What causes emydomyces? What does it cause?
Emydomyces testavorans
only fungal species that causes disease in aquatic chelonians —> bleaching of carapace
What 2 species of Cryptosporidium affect reptiles? What clinical signs are associated?
- C. serpentis —> stomach, hypertrophic gastritis causes regurgitation and midbody swelling
- C. saurophila —> intestines, chronic weight loss, abdominal swelling
ZOONOTIC - all quarantine reptiles should be assessed for crypto
What are 2 options for diagnosing Cryptosporidium infection in reptiles? How is it treated?
- acid-fast stain - direct fecal smears in lizards, stomach wash in snakes
- PCR
NO EFFECTIVE TREATMENT - prevent!
What causes Amebiasis? What reptiles act as hosts? Carriers?
Entamoeba invadens
snakes, lizards, carnivorous chelonians
herbivorous chelonians
What is the most common sign associated with amebiasis? What other clinical signs are seen?
hemorrhagic gastroenteritis and hepatic necrosis
- depression, anorexia
- CNS signs
- hematochezia
- sudden death
How is amebiasis diagnosed? What treatment is recommended?
- fecal cytology - drop of iodine isolates amoeba
- decal preserved in sodium acetic acid formalin fixative
isolate + clean environmens + Metronidazole, Paromomycin
What are Pentastomids? What clinical signs are associated with infection?
arthropod parasites that infect the lungs and SQ space of snakes
often subclinical, but may see focal tissue damage and hemoptysis
How is Pentasotmid infection diagnosed? Treated?
fecal or tracheal wash
ivermectin and supportive therapy +/- surical removal of SQ larvae
What is the most common sign of snake mite infection? What other infection is infection associated with? How do mites of other species compare?
small, black dots noticed in the bedding or on the spectacle, gular fold, or vent
Arenavirus (inclusion body disease)
green iguana mites are red or gray
How are mite and tick infestations treated?
MITES = ivermectin or pyrethrin flea products + treat the environment
TICKS = permethrin or pyrethrin flea sprays applied to tick + removal
What treatment for ectoparasites is toxic to chelonians?
ivermectin
What species does Coccidia commonly affect? How is it diagnosed? Treated?
necrotizing enteritis in crocodilians
fecal
sulfa antibiotics
What is secondary hyperparathyroidism?
demineralization of bone due to decreased Ca in diet, increase P in diet, or lack of vitamin D (UVB + heat)
- aka metabolic bone disease
What are 5 common signs of secondary hyperparathyroidism?
- lameness, anorexia
- lethargy, depression
- rubber-like mandible - very pliable and swollen
- large/swollen limbs
- seizures/tremors
Is it common for biochemistry values to be altered by secondary hyperparathyroidism?
no - body prioritizes serum Ca over skeletal Ca, so when serum Ca is low due to improper husbandry, vitamin D and PTH will increase Ca absorption from intestines, resorption from bones, and reabsorption from the kidneys
- vitamin D panels are more useful to further cateforize MBD, including PTH and iCa
What is the most common cause of a primary calcium deficiency causing metabolic bone disease? How does it affect the serum assay? What are 3 parts of the treatment plan?
improper diet and/or lack of Ca supplementation
- normal/low tCa and iCa
- normal vit D, PTH, and P
add UVB light, correct diet, injectable/oral Ca supplementation
What is the most common cause of a vitamin D deficiency causing metabolic bone disease? How does it affect the serum assay? What are 3 parts of the treatment plan?
lack of UVB light + improper diet/lack of supplementation
- low tCa/iCa
- low vit D
- normal PTH, P
add UVB light, correct diet, injectable/oral Ca supplementation
What is the most common cause of phosphorus excess causing metabolic bone disease? How does it affect the serum assay? What are 3 parts of the treatment plan?
improper diet
- low tCa/iCa
- low vit D
- high PTH (to increase Ca) and P
- P excretion in urine
add UVB light, correct diet, injectable/oral Ca supplementation
What is the most common cause of renal disease causing metabolic bone disease? How does it affect the serum assay? What treatment plan is recommended?
chronic dehydration, excessive vit D supplementation
- normal tCa, low iCa
- normal vit D and PTH
- high P
rehydrate +/- phosphorus binders, discontinuation of vit D supplementation, colchicine/allopurinol, calcium supplementation
What are the 2 major forms of secondary hyperparathyroidism?
- NUTRITIONAL - lack of calcium in diet, excess phosphorus in diet, lack of vitamin D
- RENAL - chronic dehydration, excess vitamin D
What is the most useful diagnostic for secondary hyperparathryoidism?
radiographs, CBC typically unremarkable
- thin bone cortices, low bone quality
- callus formation
- pathologic fractures
What are the 3 major parts of the treatment plan in treating secondary hyperparathyroidism?
- diet therapy - long-term, 1-3 months
- calcium supplementation - calcium gluconate (injectable), calcium glubionate (oral), calcium carbonate (TUMS), bone meal/crushed eggs
- UVB light therapy
How does diet therapy for insectivores, herbivores, and carnivores with secondary hyperparathyroidism compare?
INSECTIVORES = variety of invertebrate prey + gut loading
HERBIVORES = variety of dark leafy greens with minimal fruit + grassy hay for chelonians
CARNIVORES = whole prey diet
What supportive treatment is recommended for patients with secondary hyperparathyroidism? How long does treatments last?
- analgesics
- stabilize fractures
- fluid therapy
- alter enclosure to avoid further trauma (lower furnishings)
1-3 months —> repeat radiographs at 6-8 weeks
What is the most common cause of hypervitaminosis D in reptiles? In what reptiles is this especially common?
increased vitamin D in diet or supplements
green iguanas fed dog, cat, or monkey food as a majority of the diet
What is the most common sign of hypervitaminosis D? How is it treated?
soft tissue mineralization - blood vessels, kidneys (poor prognosis)
decreased dietary vit D + supportive therapy
In what reptiles is renal disease especially common? What are the 6 most common signs?
older iguanas fed a high protein diet or over-supplemented with vitamin D
- anorexia, depression, inability to support weight
- ileus/retained feces
- cloacal prolapse
- dehydration
- seizures, muscle fasciculations
- swollen joints
What does gout indicate?
renal disease —> dehydration, tubular disease, increased purines (herbivores getting animal protein), aminoglycosides/sulfonamides, hyperuricemia
- articular or visceral forms seen
What are the 2 major diagnostics used for renal disease?
- chemistry - increased P, Ca:P < 1, increased K and uric acid in advances stages
- radiographs - poor bone quality, mineralized gout, renomegaly, constipation
What 6 treatments are recommended for renal disease?
- rehydrate - warm water soaks can encourage defecation
- slow calcium supplementation
- colchicine - blocks UA absorption
- allopurinol - blocks UA production
- phosphate binders
- supportive therapy - decreased P in diet
In what species is hypovitaminosis A common? What does this cause?
juvenile semi-aquatic turtles or herbivorous chelonians fed a diet low in vit A, like raw hamburgers
squamous metaplasia of the eye, oral cavity, respiratory tract, and genitourinary tract
What signs are associated with hypovitaminosis A?
- conjunctivitis
- bilateral blepharoedema
- decreased growth, anorexia, lethargy
- oral lesions, stomatitis
- beak overgrowth
- aural abscess
What treatment is recommended for hypovitaminosis A?
- supplement with vit A
- improve diet and husbandry
hypervitaminosis A due to supplementation can present with necrotizing dermatitis
In what species is thiamine deficiency most common? What signs are associated? How is it treated?
fish-eating species fed diets of solely frozen-thawed feeder fish (goldfish, minnows) or muscle meat
- paralysis, weakness
- pulmonary edema
- dehydration
- blindness
thiamine supplementation + varied diet
In what species are biotin deficiencies most common? What clinical signs are associated? How is it treated?
egg-eating snakes fed raw, unfertile eggs
- paralysis, weakness
- pulmonary edema
- dehydration
- blindness
biotin supplementation + feed fertile eggs or whole animal prey
In what species is vitamin K deficiencies most common? What is the most common sign? How is it treated?
crocodilians fed a marginal diet and on antibiotics
gingival bleeding due to coagulopathy
supplement vitamin K + discontinue antibiotics + improve diet
What is a common ER presentation for reptiles? What is the most common cause?q
cloacal prolapse
excessive tenesmus from an underlying cause
- intracoelomic masses, neoplasia
- cystitis, uroliths
- fecal impaction
- obstructive dystocia
- reproductive infection
- excessive sexual activity
- intussusception, other GI disease
- nematode infection
- enteritis/cloacitis
What are the 5 most common organs involved in cloacal prolapse?
- cloacal tissue - rim of tissue, lumen
- urinary bladder - thin, fluid-filled, no lumen
- distal GIT - no long striations, feces
- oviduct - long, tubular, lumen, longitudinal striations
- hemipenes/phallus
What are 3 aspects to cloacal prolapse treatment?
- ID prolapsed structures and determine its vitality for replacement (debridement or amputation required before replacement for necrotic tissue)
- treat underlying cause
- repeat offenders = purse-string and/or cloacapexy (ensure animal is still able to pass feces/urinate)
What is the most common cause of dystocia in reptiles? What are the 4 most common clincial signs?
poor nutrition and/or improper husbandry
- nesting behavior, straining to lay
- anorexia
- depression
- distended coelom
What are 3 options for treating dystocia?
- medically stable = correct husbandry and monitor CBC for toxic heterophils
- SQ Oxytocin or topical prostaglandins
- medically unstable or unresponsive to medial therapy = ovariosalpingectomy, salpingotomy (may need aspirate egg to make it easier to pass)
In what species are thermal burns and prey wounds most common?
THERMAL BURNS = snakes and lizards with heat rocks or unscreened heat source in enclosure
PREY WOUNDS = snakes fed live prey or lethargic lizards fed crickets
How are burns and trauma treated?
- wound debridement
- antiseptic soaks
- antibiotics - topical + systemic
- supportive care
(wounds heal very slowly in reptiles, more healing with every shed)
When are tail amputations contraindicated? Why?
species that demostrate caudal autotomy
- dropping works better and is safer —> surgery causes chronic issues with healing and bleeding since the dropping mechanism is not activated
- normal mechanism obstructs vessels to keep from bleeding out
What is dysecdysis? What are the most common causes? How is it treated?
retained shed
secondary to improper husbandry or secondary to underlying parasitics, bacterial, fungal, or metabolic disease
- improve husbandry
- soak animals (damp pillowcase, tupperwear with moss/soaked paper towels)
- treat underlying disease
What is a common sequelae of dysecdysis in blue-tongued skinks?
limb/digit strangulation —> gangrene
(these species require especially humid environments)
What is a common sequelae of dysecdysis in snakes?
- retained spectacle - cloudy eyes, rest of snake is shed
- subspectacular abscess - multiple sheds retained over the eye, requires surgical drainage or spectectomy
In what turtles is shell rot especially common? What is the most common clinical sign?
aquatic turtules that spend all its time in water or in water of poor quality
superficial/deep ulcerations of the keratinous shell
What is septic cutaneous ulcerative disease (SCUD)?
ulcerative lesions on the skin/shell caused by G- rods, Citrobacter fruendii or Pseudomonas spp.
(type of shell rot)
How is shell rot diagnosed? Treated?
shell scraping cytology, bacterial/fungal culture, next-generation DNA sequencing
- topical iodine and antibiotics +/- systemic antibiotics
- surgical debridement of severe cases
- dry docking aquatic species
What are 4 causes of pyramiding in chelonians? How does it affect them?
- diet
- lack of UVB
- focal head (basking lamps)
- decreased humidity
typically cosmetic, but advanced cases can compress the spinal cord
How can pyramiding be prevented?
- supply wide areas of heat (rather than focal)
- soak/spray carapace
What is the most common prognosis of shell trauma? When is surgical correction recommended? What are some options?
often striking on initial exam, but still carries a good prognosis depending on the area of damage and patient’s overall condition
fixation should be delayed until patient is stabilized
- surgical wire +/- screws
- metal bridge
- builder ties
- fiberglass and epoxy
In what reptiles are uroliths most common? What are the most common clinical signs?
animals fed high-protein diets with limited access to water
- anorexia
- depression
- discolored/foul urine and urates
- stranguria
What diagnostics are recommended for urolithiasis? Treatment?
palpations + radiographs
- cystotomy
- supportive care
What are the 2 major hepatic diseases seen in reptiles? What are the most common clinical signs?
- hepatic lipidosis - obese patients (bearded dragons not transitioned to an herbivorous diet)
- infectious - wild caught/new additions to collection
- anorexia, depression
- icterus
- biliverdinuria
What diagnostics are recommended for hepatic disease? Treatment?
- increased liver enzymes
- diagnostic imaging
- endoscopic biopsy
supportive treatment + treat underlying disease
What are the 2 major GI issues seen in reptiles?
- REGURGITATION - can look like feces, but is acidic (NOT basic like feces); predisposition with low body temperatures and excessive handling
- CONSTIPATION/OBSTRUCTION - low body temperature, FB ingestion, abrupt dietary change
What are the most common neoplasias in reptiles? How does treatment differ?
sarcomas and lymphoproliferative neoplasias associated with Retroviruses
reptiles do not tolerate chemotherapy/radiation schedules used in mammals
