Diagnostic Challenge in Veterinary Pathology: Alopecic Crusting Dermatitis in a Goat

Abstract

In April 2020, a 1-year-old castrated Nigerian dwarf goat presented with a 4-month history of skin lesions unresponsive to topical iodine and extra-label topical miconazole. The wether was bright, alert, and with normal appetite. The goat was the only affected animal in a mixed herd of 7 sheep and 4 goats aged from 6 months to 7 years. The animals were kept on a dry lot and fed strictly timothy and alfalfa hay with access to goat minerals (Purina ® ).The goat had multifocal alopecia with fissures, erosions, crusting, and scaling that predominated on the ventrum (Fig. 1). The cutaneous lesions were nonpruritic, firm, raised, moderately demarcated, and nonpigmented.

Granulomatous mural folliculitis in 16 domestic goats: Infection with malignant catarrhal fever viruses and colocalization with ovine herpesvirus-2 using in situ hybridization

“…These infected mononuclear cells were found surrounding lesions of arteritis, transmigrating and surrounding follicles, and within eroded epidermis, possibly suggesting an immune-mediated pathogenesis. 45 Many previous studies involving various even-toed ungulate species with classic vasculocentric acute MCF have emphasized the importance of immune-mediated mechanisms of injury in the pathogenesis of MCF, rather than lytic viral infection. Precisely which leukocytes are involved, the proportion of intralesional leukocytes that are infected with virus, and to what degree other local cell types are infected within vascular lesions varies between studies.…”

“…In previous case reports of caprine GMF, 1 goat in the United Kingdom was euthanized after 4-weeks, having become depressed and hyporexic, whereas the goat in the United States was still alive more than a year after diagnosis, with no change in skin condition; no treatments had been administered since diagnosis. 10,45 All but one of the previously reported cases of GMF in other ruminants infected with MCFVs have resulted in euthanasia, with the exception of a cow in New Zealand that had complete resolution of skin lesions after 14-weeks. 4,11,24,28,44 Therefore, MCFV-associated GMF appears to have a spectrum of possible outcomes: euthanasia after weeks or months is most common, with partial recovery and a stable condition being less frequent, and full recovery rare.…”

“…Of the 16 goats included in this case series, only 2 underwent full necropsies and neither had systemic MCF-like lesions. Although neither of the previously published case reports of caprine GMF involved necropsy, 10,45 other ruminant species with GMF have undergone full postmortem evaluations. A bighorn sheep infected with the provisionally named OvHV-3 had no evidence of systemic MCF-like disease.…”

“…4 Subsequent to this study, histiocytic mural infiltrates have been reported in an additional Sika deer, as well as a white-tailed deer, two goats, a bighorn sheep, and a cow (Supplemental Table S1). 4,10,11,24,28,44,45 These histiocytic mural infiltrates were variably mixed with multinucleated histiocytic giant cells (MNGCs), eosinophils, lymphocytes, and/or plasma cells, and were associated with either CpHV-2 or OVHV-2 infection. 4,10,11,24,28,44,45 GMF has otherwise been observed with dermatophytosis and presumed idiosyncratic drug reactions associated with L-thyroxine, cefadroxil, and amitraz in dogs, and methimazole in a cat.…”

“…4,10,11,21,30 OvHV-2 caprine infection is most often subclinical, although there have been occasional reports of infection, determined using polymerase chain reaction (PCR) or in situ hybridization (ISH), with vasculocentric and/or cutaneous lesions consistent with MCF. 10,14,30,45,47 CpHV-3 has been detected in clinically normal domestic goats in Europe and North America, and it is suspected that goats may be the reservoir host. 18,26,30…”