Page 142 - Clinical Small Animal Internal Medicine

110 Section 2 Endocrine Disease

may be treated with glucagon or dexamethasone. hypoadrenocorticism is not commonly found as a cause
VetBooks.ir Feeding small frequent meals may be beneficial in help­ of hypoglycemia in dogs in the absence of other clinical
clues. Nonislet cell tumor hypoglycemia is often associ­
ing to manage hypoglycemia.
Use antiemetics and gastrointestinal protectants as
●
needed. ated with a large, clinically apparent mesenchymal
tumor (e.g., leiomyoma and leiomyosarcoma) as well as
Avoid drugs that are metabolized by the liver. epithelial tumors that are associated with the liver (e.g.,
●
Antibiotics may be indicated in acute liver failure hepatoma or hepatocellular carcinoma).
●
cases to treat concurrent infection (clavamox or As part of the signalment, age of the animal can be
amoxicillin, ampicillin, cephalexin, or cefadroxil with quite useful in narrowing down the long list of rule‐outs
metronidazole). for hypoglycemia. For example, hypoglycemia in a puppy
or kitten is often idiopathic in origin or related to starva­
Duration of Treatment and Prognosis tion, PSVA, or sepsis. In young adult dogs, hypoglycemia is
The length of treatment depends on the severity of clini­ usually caused by hepatic insufficiency, hypoadrenocor­
cal signs. Treatment for cases without liver involvement ticism, or sepsis. And in older dogs, hepatic insufficiency,
may last 1–3 days. Treatment should continue until glu­ insulinoma (see Chapter XX), nonislet cell tumor‐induced
cose levels are normal. Treatment of cases with liver hypoglycemia, hypoadrenocorticism, and sepsis are the
involvement may last weeks. The prognosis for patients most common causes of hypoglycemia.
that only develop hypoglycemia is good. Prognosis for The results of routine and specialized tests can also be
patients who develop liver failure is guarded and depends quite helpful diagnostically. For example, dogs with adre­
on the severity of the disease. Typically, there are no lin­ nal insufficiency without the classic electrolyte changes
gering medical issues once liver problems have been suc­ of hyperkalemia and hyponatremia often have hypoal­
cessfully resolved. buminemia, hypocholesterolemia and a resting cortisol
<2 μg/dL, although an ACTH response test is required
for a definitive diagnosis. Paired fasting and postprandial
Diagnostic Approach to Disorders serum bile acids are diagnostic for virtually all dogs with
Associated with Hypoglycemia a portosystemic shunt, and CBC findings which include
a neutrophilic leukocytosis with a left shift in a hypogly­
After confirming the finding of hypoglycemia, the cemic febrile dog or cat are highly suggestive of sepsis.
history (including exposure to insulin, sulfonylureas, When the cause of the hypoglycemic disorder is not
or xylitol), signalment, physical exam findings, and a evident in a seemingly well adult dog, serum glucose and
careful review of available laboratory data guide the insulin concentrations should be measured during an
evaluation. This information will either provide clues episode of spontaneous hypoglycemia to rule out an
to the cause of hypoglycemia or exclude hypoglycemia insulinoma. The key pathophysiologic feature of endog­
caused by acknowledged drugs or toxins, critical ill­ enous hyperinsulinism (e.g., an insulinoma) is the failure
nesses, hormone deficiencies, or a nonislet cell tumor. of insulin secretion to fall to very low rates as blood
A test of adrenocortical function is reasonable although glucose concentrations fall to hypoglycemic levels.

Further Reading

Allison RW, Yeagley T, Levis K, et al. Babesia canis rossi 129th Annual Meeting, March 1–3, 2013, Florham
infection in a Texas dog. Vet Clin Pathol 2011; 40: Park, NJ.
345–50. Cohen M, Post GS, Wright JC. Gastrointestinal
Baurnstark ME, Sieber‐Ruckstuhl N, Muller C, et al. leiomyosarcoma in 14 dogs. J Vet Intern Med 2003; 17:
Evaluation of aldosterone concentrations in dogs with 107–10.
hypoadrenocorticism. J Vet Intern Med 2014; 28: 154–9. Cryer PE. Hypoglycemia, functional brain failure, and
Breitschwerdt EB, Loar A, Hribernik T, McGrath R. brain death. J Clin Invest 2007; 117: 868–70.
Hypoglycemia in four dogs with sepsis. J Am Vet Med Cryer PE, Polansky KS. Glucose homeostasis and
Assoc 1981; 178: 1072–6. hypoglycemia. In: Wilson JD, Foster DW, Kronenberg
Breitschwerdt EB, Goldkamp C, Castleman W, et al. HM, Larsen PR, eds. Williams Textbook of Endocrinology,
Hyperinsulinemic hypoglycemia syndrome in 2 dogs 9th edn. Philadelphia, PA: WB Saunders, 1998.
with bartonellosis. J Vet Intern Med 2014; 28: 1331–5. Cryer PE, Axelrod L, Grossman A, et al. Evaluation and
Center SA. Differentiating portosystemic shunts from management of adult hypoglycemia. J Clin Endocrinol
microvascular dysplasia. Paper presented at NJVMA Metab 2009; 94(3): 709–28.