A SURVEY OF HORSES WITH ACUTE DIARRHEA - DIAGNOSIS, ASSESSMENT OF THEPROGNOSIS, AND COMPARISON OF 2 ANTIBIOTIC THERAPIES

Twenty horses, ponies, and foals referred with acute diarrhoea were di vided at random into two treatment groups, One group was treated intra venously with trimethoprim/sulfadiazine and the other group with ampic illin/gentamicin. Both groups were given the same standardized symptom atic therapy, All animals were evaluated clinically and 5 variables (g eneral impression, heart rate, rectal temperature, appetite, and consi stency of the faeces) were estimated on a five point scale (0-4), Jugu lar blood samples were taken at admittance and at regular intervals fo r routine screening, Three blood variables (packed cell volume, white blood cell count, and base excess) were also classified in a 5-point s cale, The 'diarrhoea prognosis index' was the total sum of the eight v ariables scaled. Faecal samples were cultured aerobically and examined for worm eggs and larvae, A definite diagnosis was only reached in 11 horses (55 %). Salmonellosis and parasitic infections were the most c ommon causes of the diarrhoea, Seven horses (35 %), three from the amp icillin/gentamicin group and four from the trimethoprim/sulfadiazine g roup, died or were euthanized because of a poor prognosis, Only the pa cked cell volume differed significantly between horses that died and h orses that survived, No single clinical or haematological/biochemical variable did forecast the prognosis for the individual patient reliabl y, nor did the 'diarrhoea prognosis index), The only reliable indicati on for the outcome of an individual horse appeared to be the clinical response to treatment within 4 days, The clinical outcome of both trea tment groups did not differ significantly, In conclusion, it was diffi cult to reach a specific diagnosis in these horses with diarrhoea, It was not possible to forecast the prognosis of an individual patient by a single variable or by a combination of variables., No significant d ifferences were found between the two antibiotic treatment groups.