Pelaksanaan Praktek Kerja Lapangan Program Diploma III Kesehatan Hewan Universitas Gadjah Mada tahun 2015 yang dilaksanakan di Balai Besar Veteriner (BBVet) Wates Yogyakarta pada tanggal 9-13 Maret 2015 di Laboratorium Patologi bertujuan untuk menambah wawasan dan ilmu pengetahuan, khususnya pengujian histopatologik terhadap penyakit kolibasilosis. Penyusunan karya tulis ini berdasarkan pengambilan data sampel positif uji kolibasilosis tahun 2012-2015 dan pengamatan histopatologi yang dilakukan di Laboratorium Patologi Balai Besar Veteriner Wates Yogyakarta. Hasil pengujian dilaporkan sebagai berikut: positif kolibasilosis pada tahun 2012 sebanyak 23 ekor ayam, pada tahun 2013 sebanyak 4 ekor ayam, pada tahun 2014 sebanyak 16 ekor ayam dan pada tahun 2015 terdapat 9 ekor ayam. Hasil bedah bangkai ditemukan adanya eksudat kering pada bawah otot paha, demikian juga pada jantung, hati dan kantung udara diselaputi oleh eksudat yang telah mulai mengering. Hasil pengamatan histopatologi dengan menggunakan pewarnaan Hematoxyline-Eosin (HE) terlihat adanya akut difus supuratif airsakulitis berat, akut difus supuratif perihepatitis berat dan akut difus supuratif perikarditis berat.

Implementation job training for Diplome Program of Animal Health Gadjah Mada University in 2015 which was held at the Balai Besar Veteriner (BBVet) Wates Yogyakarta. Job Training was held on 9-13 March 2015 in the Laboratory of Pathology with the aim to add insight and knowledge, especially testing with histopathological observation of the Colibacillosis disease. Preparation of this paper is based on data retrieval samples positive test of the colibacillosis period 2012 until 2015 and histopathological observations conducted at the Laboratory of Pathology, Balai Besar Veteriner Wates, Yogyakarta. From the data retrieval colibacillosis obtained positive test results in 2012 as many as 23 chickens, in 2013 as many as four chickens, in 2014 as many as 16 chickens and in 2015 there were nine chickens. Laboratory Pathology testing by performing histopathological observation using Hematoxylin-Eosin staining (HE), testing is done to identify the organ undergoing changes caused by colibacillosis in chickens. Surgical results carcass was found at the bottom of the dry exudate thigh muscle. Heart and liver wrapped by exudates that have started to dry up, so does the air bag containing exudate has dried and hard histopathological examination results are seen for severe acute diffuse suppurative inflammation airsacculitis, heavy acute diffuse suppurative perihepatitis and severe acute diffuse suppurative pericarditis.

Kata Kunci : Histopathological, Collibacillosis, Chicken