A 6-year old female spayed English Pointer presents for lethargy and weight gain. The owner notes that the dog is eating and drinking a normal amount, but the dog is still gaining weight. A physical exam reveals weak pelvic limbs, facial nerve paralysis, a symmetrically patchy haircoat, and seborrhea. Lab work reveals a normocytic, normochromic anemia with a PCV of 29% (35-57%), lipemic serum, and cholesterol of 1090 mg/dl (135-278 mg/dl). What is the most likely diagnosis?
一只6岁雌性已绝育英国波音达犬由于嗜睡和体重增加前来就诊。主人发现该犬吃喝数量正常但依旧在长胖。体格检查提示后肢虚弱，面神经瘫痪，对称性斑秃以及皮脂溢。血液检查提示正细胞性，正色素性贫血，PCV29%（35-57%），脂血症以及胆固醇1090mg/dl（135-278mg/dl）。最可能的诊断是什么？
A Hypothyroidism 甲状腺机能减退
B Pituitary dependent hyperadrenocorticism 垂体依赖性肾上腺机能亢进
C Adrenal dependent hyperadrenocorticism 腺体性肾上腺机能亢进
D Hyperthyroidism 甲状腺机能亢进