RETROPHARYNGEAL LYMPH-NODE INFECTION IN HORSES - 46 CASES (1977-1992)

A retrospective study of 46 horses with retropharyngeal lymph node (RP LN) infection presented to the Rural Veterinary Centre between 1977 an d 1992 was undertaken. Horses aged less than one year were most common ly represented (46%). Thirty-nine percent of cases had been exposed to horses with confirmed or suspected strangles (Streptococcus equi subs p equi infection) within the previous 8 weeks. Most frequent signs wer e unilateral or bilateral swelling of the throat region (65%), respira tory stertor/dyspnoea (35%), purulent nasal discharge (20%), inappeten ce and signs of depression (15%), and dysphagia (9%). All horses had a soft tissue density in the retropharyngeal region on radiographs. Rhi nopharyngoscopy, ultrasonography, haematology as well as cytological a nd microbial analysis of material aspirated from the soft tissue swell ing facilitated diagnosis in some horses. Fifteen horses (33%) were tr eated with procaine penicillin intramuscularly for 4 to 7 days followe d by oral trimethoprim-sulphadimidine for 7 to 14 days. Non-steroidal antiinflammatory drugs were administered to 6 horses. Four required tr acheostomy for severe respiratory distress. The 15 horses treated medi cally responded to treatment and were discharged from hospital. Three horses (6%) with mild signs received no treatment and recovered uneven tfully. Twenty-eight horses (61%) underwent general anaesthesia and su rgical drainage of a RPLN abscess. Nineteen received procaine penicill in G for 4 to 7 days. Four of the nine horses that did not receive ant ibiotic treatment after surgery required further surgical drainage 10 days to 7 weeks after the initial surgery. Limited follow-up informati on was available for 37 horses. Thirty-two horses were considered to h ave made complete recovery, 3 horses had died through misadventure and 2 had been euthanased because of chronic ill-thrift.