Secondary Nutritional Hyperparathyroidism
Clinical Signs: Anorexia, depression, ileus and constipation, cloacal prolapse, swollen compressible mandible, lethargy and inability to
support body weight, muscle fasciculations due to hypocalcemia, and rarely seizures.
Diagnostics: History and complete physical exam are extremely important. Total plasma calcium is usually normal until the terminal stages
of the disease. Ionized calcium may be more useful than total calcium. True hypocalcemia is often the cause of muscle tremors,
but hyperphosphatemia can cause neurologic signs. Radiography is useful to assess ileus, retained eggs or follicles, bone
mineralization, renomegaly (secondary renal hyperparathyroidism).
Treatment: Fluid administration to resolve dehydration and hyperphosphataemia. Warm water soaks to encourage defecation and also promote
cloacal fluid uptake. Nutritional support is seldom required as part of emergency assessment and stabilization but long term
nutritional management will be essential, and usually involves correction of dietary calcium and phosphorus imbalances and
improvements in environmental light for cutaneous vitamin D3 production. It is preferable not to administer bolus injections of calcium to a hyperphosphatemic reptile due to the dangers
of inducing mineralization. In cases of severe hypocalcemia and tetany place the reptile on intravenous or intraosseous fluid
therapy and add calcium gluconate (100-200 mg/kg) to fluids. If the animal is able to eat, administer oral calcium (200 mg/kg
q24h) with a dilute enteral feeding formula. Oral calcium glubionate (Neocalglucon® 23 mg/mL), calcium carbonate (100 mg/mL)
or calcium citrate (Tums®). After one week of both calcium and vit D3 supplementation (exposure to UV-B light, preferably unfiltered sunlight), recheck calcium levels. If the reptile is not hypocalcemic,
calcitonin can be administered (50 IU/kg IM q 1 week x 2-3 doses) to increase bone mineralization. Warm water enemas may be
required in cases of severe ileus and obstipation, but beware of infusing into the bladder. An ovariosalpingectomy is generally
recommended in cases of egg or follicle retention once the reptile is stable. If hyperphosphatemic, administer phosphate binder
(e.g., Amphogel® 1ml/kg PO q 12 h, inbetween meals).
Prevention: Correct husbandry e.g. UV lighting, nutrition, heat, cage design, etc. UV-B light exposure 12-14 hours daily, unfiltered sunlight
best, Active UV heat (mercury halide) lamps and ZooMed Reptisun 5.0 fluorescent tubes are secondary options. Environmental
(vivarium) temperature at species-specific preferred optimum temperature zone.
Clinical Signs: Common in herbivorous chelonians with accompanying clinical signs of chemosis, aural abscesses (manifesting as swelling on
the sides of the head), nasal and/or ocular discharge.
Diagnostics: Lesions should be biopsied for confirmation of characteristic metaplastic lesions. Treatment: Improve diet and husbandry. Use injectable vitamin A very cautiously (500-1000 iu/kg) as iatrogenic hypervitaminosis A causes
skin sloughing and moist erythematous dermatitis.