Gotch Ear in a Goat: A Case Report Kristine T. Edwards, 1 Andrea S. Varela-Stokes, 2 Christopher D. Paddock, 3 and Jerome Goddard 1 Abstract A 1-year-old castrated male Saanen goat was observed to have drooping and edema of the left ear consistent with published accounts of gotch ear in cattle associated with a tick bite. The goat’s left ear was edematous from the tip of the pinna to the base of the ear. No signs of trauma or infectious processes were observed. Three engorged Gulf Coast ticks (Amblyomma maculatum) were observed attached inside the ear. Ticks were removed and the ear biopsied at tick attachment sites. The affected ear was treated topically with betadine after removal of the ticks. No other treatment was administered. The goat remained free of clinical signs and the edema of the ear resolved within 3 days after tick removal. No clinical adverse effects of the condition were evident. All three ticks were positive for spotted fever group rickettsia by polymerase chain reaction analysis and showed 100% similarity with the homologous sequence of Rickettsia parkeri. There was no immunohistochemical evidence of spotted fever group rickettsia in the ear samples, supporting the hypothesis that gotch ear is not due to rickettsial infection. This report represents the first apparent case of gotch ear in a goat. Key Words: PCR—Rickettsia—Ticks—Zoonosis. Introduction T he Gulf Coast tick (GCT), Amblyomma maculatum (Acari: Ixodidae), is a large, Nearctic and Neotropical, three-host tick (Hunter and Hooker 1907, Hooker et al. 1912) that parasitizes a wide range of vertebrate animals including goats in its various life stages (Ketchum et al. 2005). In cattle, adult GCTs generally prefer feeding on or in ears. A path- ological condition in cattle ears, often called ‘‘gotch ear,’’ usually involving GCTs, has been previously documented (Gladney 1976, Williams et al. 1978, Edwards et al. 2010). The clinical definition of gotch ear was recently described as a condition of the ear in cattle associated with tick infesta- tion, predominantly A. maculatum, exhibiting variable de- grees of edema, and lesions at the tick-attachment sites on the outer or inner pinna(e) that included crusting, alopecia, erythema, and excoriation (Edwards et al. 2010). Curling of the tip of the pinna(e) and a loss of a portion of the ear(s) is sometimes also seen (Edwards et al. 2010). In that study, it was also determined that gotch ear resulted from the bite of GCTs and was not dependent on infection with R. parkeri (Edwards et al. 2010). Use of the term ‘‘gotch’’ when refer- ring to this ear deformity may have originated from use of the word to refer to a pitcher or earthen jug, which may resemble the cupped shape of the deformed ear. To our knowledge, gotch ear has never been documented in a goat. A yearling, castrated, male Saanen goat weighing 36.4 kg (80 lb) was evaluated on June 7, 2010 by the owner/veterinarian for drooping of the left ear of 1 day duration. Three partially engorged adult GCTs (two female and one male), A. maculatum, were removed from inside the left ear. No other tick species were observed on the animal. An 8-mm punch was used for biopsy of the tick attachment site on the affected ear. The sample was transferred to neutral-buffered 10% formalin and evaluated using hematoxylin and eosin stain and an immunohistochem- ical assay for spotted fever group Rickettsia spp. (Paddock et al. 1999). DNA extracts for each of the three attached ticks were evaluated using a nested polymerase chain reaction (PCR) as- say designed to amplify a segment of the ompA gene based on a published protocol (Sumner et al. 2007). Extracts were also evaluated using a nested PCR assay designed to amplify a segment of the 17-kDa antigen gene as previously described (Paddock et al. 2004). The wether’s ear was treated topically at the tick attach- ment and biopsy sites with betadine solution. No further treatment was administered. At the time of evaluation, the wether was afebrile. This particular animal is housed with a herd of *40 Saanen dairy goats including kids, bucks, 1 Department of Entomology and Plant Pathology and 2 Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, Mississippi. 3 Centers for Disease Control and Prevention, Infectious Diseases, Pathology Branch, Atlanta, Georgia. VECTOR-BORNE AND ZOONOTIC DISEASES Volume 11, Number 8, 2011 ª Mary Ann Liebert, Inc. DOI: 10.1089/vbz.2010.0204 1217