DR MUHAMMAD IJAZ According to the Agriculture Census Organisation, the total population of equines in Pakistan was 4.8 million during the year 2006, while the population has risen to 5.1 million (Horses 0.4, Asses 4.5 and Mules 0.2) as per census report for the year 2008-2009. The population of equines in the country is increasing day by day in view of their utility and service to mankind. Thus these valuable animals need special attention and care with regard to management, well being and diseases prevention and control, to ensure their soundness and utility. Strangles is an infectious malady of equidae (horses, donkeys and mules) characterized by upper respiratory tract infection, dysponea, anorexia, regional suppurative lymphadenitis and causes high morbidity and low mortality. Young equines of all ages are susceptible, though strangles is most common in animals less than five years of age and especially in groups of yearling. Foals younger than four months are usually protected by passive immunity through the colostrums in their mothers milk. Considering the significance and utilization of equines in our country and the substantial losses rendered by Strangles, the present project was designed to study epidemiology, diagnosis and chemotherapy of strangles in Pakistan. Although, strangles is a potentially fatal disease, even then it can be contained and treated by paying due attention. The highest prevalence of strangles was recorded in equines less than 2 year of age as compared to those having age more than 2 years. Round the year prevalence of strangles were also calculated and it was found to be the highest during the months of February, March, April and May while few cases were seen during the months of January, June and July and no cases were observed during others months. Similarly when compared the prevalence of strangles in different seasons of Pakistan i.e. summer, winter, spring and autumn. The highest prevalence rate was recorded during the spring season. The culture along with PCR is the best diagnostic technique for causative agent of strangles, as PCR test does not differentiate between dead and live bacteria, hence a positive test may not correlate with active infection; therefore, a positive culture may be necessary to confirm the diagnosis. Sequences of genes of 25 S. equi alleles isolated from different countries of the world over a period of 40 years were compared. Twenty different SeM alleles were identified including 6 (one from Pakistan) not included in the data base (http:// pubmlst.org/szooepidemicus). This is the reason that imported strangles vaccines not worked in Pakistan because the protein that is used in making strangles vaccine is totally different from the rest of the world. My future goal is to make strangles vaccine by isolating local protein from strangles causative organism. In horses the mortality rate was recorded as 1.64pcwhereas the mortality rate in mules having less than 5 years of age was found to be 0.88%. Moreover, recovered animals should be kept in quarantine period at least upto 9th week because the recovered horses and mules remain carrier for prolonged period of time and can act as source of infection for susceptible animals through periodic shedding of S equi. The effect of strangles on total serum proteins, serum albumin, serum globulin and fibrinogen were also studied. Total serum protein, serum globulin, and fibrinogen were found to be significantly increased, whereas a significant decrease was observed in the value of serum albumin in strangles affected horses and mules. In-vitro antibiotic sensitivity revealed that in horses and mules, S equi was most sensitive to Procaine penicillin followed by ceftiofur Na, cephradine, erythromycin, ampicillin, tetracycline, chloramphenicol, sulfamethoxazole, trimethoprim + sulfdiazine and gentamycin whereas the result of in-vivo antibiotic trials revealed that horses and mules suffered from strangles without abscess formation were most sensitive to Procaine penicillin followed by ceftiofur Na, cephradine and erythromycin whereas animals which developed abscess showed no response. It is concluded from the result of present study that Procaine penicillin is most effective in-vitro and in-vivo antibiotic followed by ceftiofur Na and cephradine. These antibiotics might be used for the treatment of strangles infection. Efficacy of disinfectants, like povidone iodine, 0.6pcH2SO4, dettol and bleach was also assessed. Among four disinfectants, povidone iodine was found to be the best one with a phenol coefficient of 1.25 that is greater than phenol i.e. 1.00 while 0.6pcH2SO4 showed similar phenol coefficient as that of phenol. The phenol coefficient of dettol and bleach were observed as 0.5 and 0.75 respectively. Therefore it is recommended that causative agent of strangles is highly sensitive to povidone iodine and 0.6pcH2SO4.