Page 1554 - Clinical Small Animal Internal Medicine

1492 Section 12 Skin and Ear Diseases

pallor which could result in an erroneous diagnosis of
VetBooks.ir zinc‐responsive dermatosis. Epidermal pustulation,
cleft formation, necrosis, erosions, and ulcers may also
be seen. In the dermis, there may be a mild superficial
perivascular lymphoplasmacytic infiltrate, edema with
vascular ectasia, and congestion.
Abdominal ultrasound of dogs with hepatic disease
and SND reveals a liver with a slightly irregular surface.
There are variable sized hyperechoic regions (strands)
present diffusely throughout the parenchyma. The strands
encompass round to oval hypoechoic areas. The result is a
“Swiss cheese” or “honeycomb” appearance to the liver.
Biopsies taken from the liver display a vacuolar hepatopa-
thy with parenchymal collapse. Pancreatic tumors may be
Figure 169.1 Shih tzu with superficial necrolytic dermatitis. visualized with ultrasound; however, if not visualized and
Pawpads are inflamed and hyperkeratotic.
the liver ultrasound is normal, glucagon levels should be
assayed to rule out a glucagonoma.

Therapy

Treatment for dogs with SND is usually short‐lived
and largely unrewarding. Most cases are fatal, with life
expectancy ranging from 1.7 to 6.4 months. One
reported case survived for 32 months before being
euthanized.
Treatment should initially be directed at stabilizing
dogs with diabetes. Surgical resection can be beneficial
in cases associated with glucagonomas but it is impor-
tant to keep in mind that glucagonomas typically
Figure 169.2 Crusty lesion covering an inflamed and eroded metastasize rapidly, so the improvement post surgery
lesion localized to the hock of a dog with superficial necrolytic may be temporary. In one reported case, metastasis
dermatitis. Note that the lesion extends to the ventral aspect of precluded surgery, and the dog was treated with sub-
the metatarsus. Source: Courtesy of Sheila Torres. cutaneous octreotide (2 μg/kg twice daily), a somato-
statin analog that inhibits glucagon release. Skin
correlation between the severity of the liver pathology lesions and systemic signs improved within five days.
and the severity of the skin lesions. The dosage was increased to nearly 3 μg/kg twice daily
and all clinical signs improved further within 10 days.
Anorexia was the main side‐effect. The dose (1–3.4 μg/
Diagnosis kg) and frequency of administration (2–3 times daily)
of the octreotide injections were adjusted to maintain
Skin biopsies of early lesions display very characteristic disease control with minimal side‐effects. The dog was
histologic changes. The epidermis has moderate to later euthanized due to progressive metastatic disease.
severe parakeratotic hyperkeratosis and acanthosis. In another case report, adipose tissue-derived mesen-
There is both intercellular and intracellular edema with chymal stem cells were infused in addition to intrave-
keratinocyte vacuolation in the upper half of the epider- nous amino acids, 46 times over a 30 month period.
mis, which results in significant epidermal pallor. There Survival time was increased to 32 months after
is basilar epidermal hyperplasia. Because of the eosino- diagnosis.
philic superficial keratin accumulation coupled with Many dogs with liver disease have been treated with
central pallor and basilar hyperplasia which stains deep amino acids, either intravenously or orally. Amino acid
blue, skin biopsies taken from early lesions display a solutions which have been used include Aminosyn® 10%
striking “red” (eosinophilic), “white” (central pallor), and solution (Abbott Laboratories), Procalamine® (B. Braun
“blue” (basophilic basilar hyperplasia) pattern. Biopsy Medical Inc.) and Travasol® 8.5% amino acid injection
tissues taken from chronic lesions often lose the central (Baxter Healthcare) though no particular product has