Occurrence of purulent mandibular and maxillary osteomyelitis associated with Pseudomonas aeruginosa in a sheep flock in south-west of Iran

Document Type : Scientific report


1 Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 Department of Animal Health Management, School of Veterinary Medicine, Shiraz University, Shiraz, Iran

3 Department of Pathobiology, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

4 Resident of Large Animal Internal Medicine, Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran


This report describes an outbreak of purulent mandibular and/or maxillary osteomyelitis caused by Pseudomonas aeruginosa in a sheep flock located in the Khuzestan province, Iran. Jaw bones of almost 100 out of 500 mature sheep in a flock became severely deformed with a variably sized firm swelling, without any signs of inflammation in the surrounding soft tissues. The affected animals showed anorexia, depression, swelling of the mandibular and/or maxillary area, loss of cheek teeth and poor body condition. ‏These animals were gradually culled in a period of 3 months. Postmortem examination showed a hard swelling of jaw bones with dirty greenish pus that filled alveolar molar teeth cavities. Histopathologic findings revealed necrotic areas surrounded by mixed population of inflammatory cells with exuberant fibrosis around some area of the lesions and irregular trabeculae of woven bone. In bacteriology, pure culture of P. aeruginosa was isolated from all of 7 sampled sheep. Based on clinical examination, radiography, histopathological features and bacteriology, the lesions were diagnosed as chronic suppurative osteomyelitis caused by P. aeruginosa. According to bacteriological results, the likely source of bacterial infection in this study was drinking water.


Amorim, RM; Toma, HS; Vulcano, LC; Ribeiro, MG; Fernandes, S; Borges, AS; Chiacchio, SB and Gonçalves, RC (2011). Outbreak of mandibular abscess by Pseudomonas aeruginosa in sheep. Pesqui. Vet. Bras., 31: 747-750.
Antunes, JMAP; Almeida, ACS; Ribeiro, MG; Amorim, RL; Hussni, CA; Listoni, FJP and Megid, J (2012). Jaw actinomycosis in a sheep: case report. Arq. Inst. Biol., 79: 405-409.
Benito-Pena, A; Peris, B; Aduriz, G; Martinez, J and Corpa, JM (2010). Purulent nasomaxillary and mandibular osteomyelitis in sheep caused by Pseudomonas aeruginosa. Vet. Rec., 166: 115-116.
Blood, DC; Studdert, VP and Gay, CC (2007). Saunders comprehensive veterinary dictionary. 3rd Edn., London, UK, Elsevier. P: 1290.
Brookins, MD; Rajeev, S; Thornhill, TD; Kreinheder, K and Miller, DL (2008). Mandibular and maxillary osteomyelitis and myositis in a captive herd of red kangaroos (Macropus rufus). J. Vet. Diagn. Investig., 20: 846-849.
Carter, GR and Blackwell, DJ (2004). Essential of veterinary bacteriology and mycology. 6th Edn., Iowa, USA, Blackwell. P: 125.
Constable, PD; Hinchcliff, KW; Done, SH and Grunberg, W (2017). Veterinary medicine. 11th Edn., Missouri, USA, Elsevier. PP: 1391-1394.
EL-Sukhon, SN (2002). Isolation and characterization of Pseudomonas aeruginosa from sheep with fleece rot in northern and middle Jordan. Vet. Dermatol., 13: 247-251.
Erskine, RJ; Unflat, JG; Eberhart, RJ; Hutchinson, LJ; Hicks, CR and Spencer, SB (1987). Pseudomonas mastitis: difficulties in detection and elimination from contaminated wash water systems. J. Am. Vet. Med. Assoc., 7: 811-815.
Glaze, RL; Hofes, M and Bunch, TD (1982). Aberrations of the tooth arcade and mandible in dall’s sheep from
southwestern Yukon. J. Wildl. Dis., 18: 305-309.
Gyles, CL; Prescott, JF; Songer, G and Thoen, CO (2010). Pathogenesis of bacterial infections in animals. 4th Edn., Iowa, USA, Wiley-Blackwell. PP: 443-461.
Hofes, M and Bunch, TD (2001). Lumpy jaw in wild sheep and its evolutionary implications. J. Wildl. Dis., 37: 39-48.
Las Heras, A; Dominguez, L; Lopez, I and Fernandez-Garayzabal, JF (1999). Outbreak of acute ovine mastitis associated with Pseudomonas aeruginosa infection. Vet. Rec., 145: 111-112.
Leitner, G and Krifucks, O (2007). Pseudomonas aeruginosa mastitis outbreaks in sheep and goat flocks: antibody production and vaccination in a mouse model. Vet. Immunol. Immunopathol., 119: 198-203.
Markey, B; Leonard, F; Archambault, M; Cullinane, A and Maguire, D (2013). Clinical veterinary microbiology. Vol. 1, 2nd Edn., London, Mosby Elsevier. PP: 275-288.
Ogilvie, TH (1998). Large animal internal medicine. 1st Edn., Pennsylvania, USA, Williams and Wilkins. PP: 306-307.
Seifi, HA; Saifzadeh, S; Farshid, AA; Rad, M and Farrokhi, F (2003). Mandibular pyogranulomatous osteomyelitis in a sannen goat. J. Vet. Med. A, 50: 219-221.
Watson, PJ; Jiru, X; Watabe, M and Moore, JE (2003). Purulent rhinitis and otitis caused by Pseudomonas aeruginosa in sheep showered with contaminated “shower wash”. Vet. Rec., 153: 704-707.