Intro to Snakes Flashcards
1
Q
What coelomic cavities do snakes have
A
- Single pleuroperitoneal cavity
2
Q
What is the dental anatomy of snakes
A
- 6 rows of teeth
- 4 rows on top, 2 on bottom
- Venomous snakes have venom delivering teeth (voluntary control)
- can deliver a dry bite when striking instead of with intent to kill
3
Q
Describe GI system of snakes
A
- Short GI tract
- very distensible stomach
- Venomous glands - in venomous species
- Viperides, elapids: located in temporal region
- Colubrids: Devernoy’s gland
- Forked tonge
- Metabolism when in the process of digesting may increase by 7-10x
4
Q
Describe respiratory system of snakes
A
- Unicameral lungs
- cranial part of lungs - respiratory
- Caudal part - avascular, air-sac like
- Only have a RIGHT lung
- except in pythonidae and biodae
5
Q
Describe cardiovascular system of snakes
A
- 2 atria + 1 ventricle
- ventricle divided into 3 subchambers
- Location: ⅓ - ¼ of the length caudal to the head
- Very mobile
- Hear rate increases after a meal
6
Q
Describe the renal system of snakes
A
- Loopless “reptilian” nephrons
- Do NOT concentrate water
- Post-renal handling of urine
- Male snakes have a “sexual segment” of the kidneys
- enlarges the renal organ during heightened reproductive activity
- Produces a secretion rich in proteins and lipids ⇢ copulatory plug
- Do NOT have a urinary bladder
7
Q
What special senses do snakes have
A
- Fused eyelids - shed during ecdysis
- Jacobson organ (vomeronasal organ)
- Infrared receptors
- No external ears
8
Q
Describe the repro system of snakes
A
- Intracoelomic gonades
- Hemipenes in males
- housed in openings caudal to the cloaca
- used for sexing
- Most lay eggs
- viviparous - boids, viperids
9
Q
How are snakes sexed?
A
- Use well-lubricated, clean metal probe or rubber feeding tube
- insert into lateral portion of cloaca (left or right) directed caudally
- stop once resistance is met
- Male: enters area of inverted hemipenis - reaches 6-8 subcaudal scale lengths
- Females - enters blind ended scent sacs - reaches 2-4 subcaudal scale lengths
10
Q
Where can venipuncture be done on snakes
A
- ventral coccygeal vein
- Cardiac vein
11
Q
What unique cells are on the CBC of a snake
A
- Heterophil
- Azurophil - behaves like a heterophil
12
Q
What imaging can be done on snakes
A
- Radiographs
- dorsoventral
- lateral - horizontal beam
- Ultrasound
- need to get gel and alcohol between scles
- CT-scan
- MRI
13
Q
where are IM injections given in snakes
A
- Epaxial muscles
- insert needle between scales
- draw back and inject as normal
- CRANIAL half of the body
- renal/portal changes
14
Q
How are SQ injections given in snakes
A
- Small subcutaneous space with imited vascularity - absorption of medications and fluids variable
- May need to use multiple locations
- No need to tent skin
- Location - lateral body wall
- insert needle parallel to body wall in between scales
15
Q
What other routes for medication administration exist for snakes
A
- Intracoelomic - not recommended
- Oral
- Intravenous - challenging - jugular
- Intraosseous - not possible
- Cloacal route
16
Q
What non-infectious diseases are common in snakes
A
- Hypovitaminosis D
- Rodent Trauma
- Thermal burns
- Fecal Impaction
- Retained shed
17
Q
What infectious diseses are common in snakes
A
- Respiratory disease
- Bacterial
- Viral
- Fungal
- Parasitic
- Inclusion body disease
- Fungal disease
- Gastric cryptosporidiosis
- Amaebiasis
- Snake mites
- Infectious stomatitis
18
Q
What contributes to respiratory disease in snakes
A
- Problems wiht humidity
- problems with ventilation
- Inappropriate temperature (too low
19
Q
What are the clnical signs of respiratory disease in snakes
A
- Open mouth breathing
- dyspnea, tachypnea
- Extended/elevated head or neck
- Forced exhalation
- swollen or distended neck
- stomatits
- discharge from choana and glottis with bubbles
- increased respiratory sounds
- anorexia
- Lethargy
20
Q
What are the different causes of Respiraotyr disease in snakes
A
- All have similar presentation
- Bacterial:
- Aeromonas, E. coli, Klebsiella, Proteus, Psuedomonas, Slamonella
- Atypical: Chlamydia spp, Mycobacterium spp. Mycoplasma spp
- Anaerobes
- Viral:
- Ferlavirus (paramyxovirus)
- Nidovirus
- Fungal
- Parasitic
- Pentastomes
- lungworms (Rhabdias spp.
21
Q
How is repiratory disease diagnosed in snakes
A
- Clin Path:
- CBC - Leukocytosis (heterophilia + azurophilia)
- Biochemistry
- Imaging
- CT mor sensitive and precise for pulmonary lesions versus radiographs
- Endoscopy - tracheoscopy, pulmonoscopy
- Cytology, culture
- swab
- trach wash
- endocopically
22
Q
Treatment for respiratory disease in snakes
A
- Fluid therapy
- Agressive antimicrobial therapy
- min 4-6wks
- Cefotaxime, ceftazidime, ceftiofur
- Treat underlying conditions
- Nebulization
- Husbanry corrections
23
Q
What is Ferlavirus? transmission? Clin signs? Dx? Tx?
A
- Ophidian paramyxovirus
- Neurologic and respiratory signs
- Transmission: repiratory secretions
- Very pathogenic in viperdae and elapidae
- Clinical signs:
- nasal discharge
- open mouth breathing, labored breathing
- pus in oral cavity
- tremors
- opithotonos
- Dx:
- histopath
- EM
- virus isolation
- PCR and sequencing
- serology with paired titers (hemagglutination inhibition)
- Tx;
- supportive care
- husbandry corrections
- antibiotics for secondary bacterial infections
24
Q
What is Nidovirus?
A
- Recently discovered (Coronoaviridae)
- Causes pneumonia and stomatits in pythons and boas
- Clin signs:
- increased clear mucus in oral cavity
- open mouth breathin
- wheezing
- anorexia
- lethergy
- Dx:
- PCR on trach swab or tissue samples
25
Q
What is Inclusion body disease
A
- Caused by Arenavirus - Reptarenavirus
- Transmission: breeding, bite wounds, fecal/oral, snake mites
- Neuro Signs
- Head tremors
- Anisocoria
- Muscle spasms with neck arching (stargazing)
- Impaired righting reflex
- decreased muscle tone
- abnormal tongue flicking
- seizures
- Dx:
- PCR on blood or tissue
- Inclusion bodies in the WBC (examin buffy coat smear with HE stain)
- Often develop secondary infections/disease due to immune suppression
- Bacterial (salmonellosis)
- Fungal (aspergillosis)
- Protozoal (amoebiasis)
- Neoplasia of the blood/bone marrow (lymphoma)
- Tx - NONE
26
Q
WHat is Snake fungal disease
A
- Etiologic agent: Ophidiomyces ophiodiicola
- most common in wild/zoo snakes
- Potential to cause population decline of many important snake species
- Can become systemic
- Clinical signs: dermatologic infections
- Localized thickening and crusting of skin
- skin ulceration
- nodules
- abnormal molting
- cloudy eyes
- facial disfiguration (can lead to emaciation and death
- Dx: skin biopsy with culture, PCR and sequencing
- Tx: difficult
- Terbinafine (Nebulization, SC injection)
- Other antifungals
- Toxicities reported with voriconazole
- Challenges with achieving therapeutic plasma concentrations
27
Q
What is Gastric Cryptosproidiosis
A
-
Cryptosporidium serpentis
- Type A - snakes
- Type B - lizards
- C. varanii - primarily in lizards but has been revocered from snakes with proliferative enteritis
- COntributing factors
- Stress
- Concurrent infection
28
Q
Life cycle of Cryptosporidium
A
- Asexual and sexual reproduction
- Oocysts release sporozoites (S) ⇢ Invade brush border of gastric epithelial cells ⇢ trophozoites (T) and type I meronts (M1) containing type I merozoites (Mz1)
- Merozoites ⇢ trophozoites ⇢ reinfect host
- Merozoites ⇢ macrogamonts (Ma) or Microgamonts (Mi)
- Mi ⇢ microgametes (g) ⇢ fertilize macrogamonts
- 2 mitotic divisions ⇢ Zygote (S)
- zygote ⇢ thick-walled oocyst ⇢ environment
- Zygote ⇢ thin-walled oocyst ⇢ autoinfection
29
Q
Clinical signs of Gastric cryptosporidiosis
A
- Some asymptomatic
- clear infection
- carriers
- pre–clinical
- Mid-body swelling
- chronic regurgitation
- weight loss
- anorexia
30
Q
How is Gastric cryptosporidiosis diagnosed
A
- Fecal testing or cloacal swab
- shedding intermittent
- larger sample better
- Serum antibody testing - interpretation difficult, high false negatives
- Gastric lavage
- best if 3 days after feeding
- Gastric swab - PCR or cytology
- Gastric biopsy - Most sensitive
- Sample analysis:
- easiest - cytology
- Direct smear or wet mount in saline or Wright-Giemsa
- false negatives if asymptomatic are common
- Sheather’s sugar solution floatation
- Acid fast staining
- Direct smear or wet mount in saline or Wright-Giemsa
- Once ID, need further testing to determine species
- Cryptosporidium IFA
- PCR - most sensitive
- easiest - cytology
31
Q
Treatment for Gastric cryptosporidiosis
A
- None completely effective
- Paromomycin
- improved C/s and decreased oocyst shedding, but recrudescence common
- Confirm all suspected positives
- isolate, treat, and monitor
- if clinical, euthanasia most humane
32
Q
What is Amaebiasis?
A
- Entamoeba invadens
- Snakes most commonly affected
- Contact with freshwater turtles
- chelonians and crocodilians have commensal relationship
- Contact with freshwater turtles
- Risk Factors:
- Mixed collections (snakes, carnivorous lizards, aquatic reptiles)
- Poor quarantine and hygiene
- Transfer of infectious cysts form food items such as insects
- Environmental temperatures play role
- Dx: fecal wet mount
- Tx: metronidazole
33
Q
Clinical signs/Histologic lesions of Amaebiasis
A
- Clinical Signs:
- anorexia
- dehydration
- regurgitation
- diarrhea
- hematochezia
- weight loss
- sudden death
- seizures
- Histologic lesions:
- necrotic and hemorrhagic enteritits and colitis
- hepatitis with hepatic necrosis and abscessation
- Can cause amoebic encephalitis - seizures, neurologic disease
34
Q
What are snake mites
A
-
Ophionyssys natricis
- Very common
- vector for many viruses and bacteria
- Tx:
- ivermectin spray of snake and enclosure
- Pyrethrins/permethrin spray of snake and enclosure
- Clean enclosure and discard all substrate and encloseure furniture
- decrease humidity and increase temperature
- predatory mites
- bravecto
