Intro to Lizards and Lizard Diseases

Why do you need to know how to identify species?

Tells you how to handle them and what husbandry requirements they need

What lizards do you need to approach with caution?

Iguanas, monitor lizards, and tegus

T/F all lizards can bite?

True

What are their signs of aggression and territorialism?

Sideway standing, head nodding, swallowing air, standing high off the ground, lashing at the threat with the tail

What lizards has tail autotomy?

Tokay gecko, iguana, geckos, skinks

Where does it break with a tail autotomy?

Through the vertebrae, some species can drop it and some cant

What lizards rarely drop their tail?

Bearded dragons, monitors, true chameleons

Why is covering their eyes with gentle pressure useful?

Causes a vasovagal response causing them to calm down

T/F lizards do not need to be sedated for radiogrpahs?

True

What is a concern of covering lizard eyes with gentle pressure?

It can worsen heart disease due to vasovagal response

How can you handle small lizards?

Hone hand, two fingers by chest supporting ventrum

Tail should be free

How do you handle larger lizards?

2-hand hold with one hand at thoracic girdle or neck

Second hand holding legs into the body or to base of the tail

How do you do your PE?

Observe carrier, interaction with environment, posture, skin and eyes, signs of aggression

T/F auscultation of heart and lungs is possible?

False

T/F peripheral pulses are not palpabral?

True

How is HR obtained?

Doppler (cannot hear murmurs)

Where is fat in lizards?

Minimal SQ fat, most species have fat bodies

What lizard stores fat in the tail?

Leopard gecko

What two lizards have venom glands?

Beaded lizard and gila monster in their mandible. Need to chew prey for it to get into them

How can you handle aggressive lizards?

Use a towel or leathered gloves

What species of lizard is especially aggressive?

Iguanas, they will use their tail and claws

What are signs of dehydration?

Ropey saliva

Sunken eyes

What is your database for reptiles?

CBC,CHEM, ionized calcium

Rads

Fecal exam

What are the sites for blood collection in lizards?

Jugular vein (hard to locate)

Tail vein (careful for caudal anatomy)

Abdominal vein

What are the risks of an abdominal vein collection?

Cannot be palpated or help to allow clotting

Can lead to uncontrolled coelomic bleeding

What should always be done on new pets?

Fecal exam, once at initial exam and repeat in 3 weeks

When should you repeat fecal exams/

Annually

What is commonly found on fecal exams?

Protozoa, most of them are commensals

Pinworms (oxyurids) also commensals

When are pinworms a problem?

At high numbers AND if diarrhea is present. If seen think to fix husbandry and other disease processes

What does Cryptosporidium varanii infect?

Leopard geckos

What are C/S of Cryptosporidium varanii infection?

Severe progressive weight loss, anorexia, coelomic swelling, diarrhea

What is the prognosis of Cryptosporidium varanii?

High morbidity and mortality (poor)

If you have a severely emaciated leopard gecko come in what should you suspect?

Cryptosporidium varanii

How do you dx Cryptosporidium varanii?

Fecal smears of fresh feces but difficult

Biopsy is done on necropsy

How do you tx Cryptosporidium varanii?

Paromomycin but rarely effective and not successful

What causes fungal dermatitis in many species, but especially Bearded dragons?

Nannizziopsis guarroi

What are the C/S of Nannizziopsis guarroi?

Cutaneous vesicles that rupture and form crusts and hyperpigmentation

Can lead to systemic disease

T/F Nannizziopsis guarroi is highly contagious?

True

How do you diagnose Nannizziopsis guarroi?

Cytology with arthroconidia

PCR is definitive

HIsto is ok

How do you treat Nannizziopsis guarroi?

Terbinafine PO for a long time

Brushing of skin q48h

How do you decontaminate the environment after Nannizziopsis guarroi infection?

10% bleach VERY IMPORTANT to decontaminate

What type of dentition do bearded dragons have?

Acrodont

What species commonly has dental disease?

Bearded dragons

What is a significant risk factor for dental disease in bearded dragons?

Fruit in the diet

What are the grades of dental disease in bearded dragons?

0: normal

1: staining of teeth

2: mild tartar and erythema

3: moderate tartar, erythema, and recession

4: Severe tartar, erythema, osteomyelitis

5: pathological fractures and severe everything else

What are the problems of calcium deficiency?

Nutritional secondary hyperparathyroidism

Hypocalcemia

Renal secondary hyperparathyroidism

Osteomalacia/osteoporosis

Rickets/fibrous osteodystrophy

What is Osteomalacia/osteoporosis seen in?

Adults

What is Rickets/fibrous osteodystrophy seen in?

Young

What are the C/S of metabolic bone disease and hypocalcemia?

Lethargy, hyporexia/anorexia, weight loss, poor weight gain, weakness, IG impaction/ileus, tremors or ataxia

What are the PE findings of metabolic bone disease and hypocalcemia?

Pliable bones, shortened or swollen mandible, pathologic fractures, swollen bones, spinal deformities

What species is very prone to a swollen mandible during metabolic bone disease/

iguanas

How do you diagnose metabolic bone disease and hypocalcemia?

Low ionized calcium

Very firm femoral area

Why does the femoral area get really firm during metabolic bone disease?

They have so many fractures that are all calcifying at once leading to swelling

How do you treat metabolic bone disease and hypocalcemia?

Correction of husbandry with temp, humidity, and UVB

Correction of diet with high quality calcium supplementation

What is gout?

Overproduction or underexcretion of uric acid leading to hyperuricemia and monosodium urate crystals in tissues

What is pseudogout?

Deposition of a precipitate that is not uric acid like calcium

What are the 3 types of gout?

Visceral, articular, and periarticular

What are possible causes of gout?

Excessive protein in diet

Dehydration

Hypovitaminosis A

Nephrotoxic medications

What are the C/S of gout?

Joint swelling, organ dysfunction, anorexia, lameness

How do you diagnose gout?

Cytology or biopsy showing presence of crystals

How do you treat gout?

Ensure hydration and promote diuresis

Allopurinol to lower UA levels

Surgical removal

Pain control

Why is treating gout so difficult?

Hard to remove crystal firm joints. Can try to wash them out but is not always helpful

What is the key with gout?

Prevention

Why are fireflies toxic to bearded dragons?

They have lucibufagin which is a steroid pyrone leading to heart failure

How much of a firefly can kill a bearded dragon?

¼ of an insect

What are C/S of firefly ingestion in bearded dragons?

Head shaking, oral gaping, dyspnea, color changes from tan to blank on dorsal trunk, tail, and nape

What is the prognosis for firefly ingestion?

Usually die in 15 minutes to 2 hours, but digoxin immune Fab has been listed as a possible treatment

What is hypovitaminosis A secondary to?

Deficient diet

What is hypovitaminosis A common in and why?

Insectivorous species because insects cannot produce vitamin A

What does hypovitaminosis A lead to?

squamous metaplasia

What are C/S of hypovitaminosis A?

Hyperkeratosis leading to blockage and swelling of lacrimal and salivary glands, swollen eyelids ocular abnormalities and gout

What animal really struggles to eat if they are blind due to hypovitaminosis A?

Leopard geckos, need to help them eat

How do you diagnose hypovitaminosis A?

History, biopsy, and liver levels

How do you treat hypovitaminosis A?

Oral only supplementation

Treat secondary infections

Correct husbandry

How do lizards normally shed (except leopard gecko)?

In pieces

How do leopard geckos shed?

Shed in full and eat their shed

What can cause dysecdysis?

Metabolic abnormalities or poor husbandry