Outcome of superficial keratectomy without conjunctival graft as a surgical technique for immune-mediated keratitis in horses: Four cases

This case report describes four horses with unilateral superficial or mid-stromal immune-mediated keratitis (IMMK) treated with a superficial keratectomy (SK) without a conjunctival graft. In two horses, the surgery was performed under general anaesthesia, and in two horses standing with sedation and local blocks. Results of this report show that SK is a viable treatment option in horses with chronic superficial and/or mid-stromal IMMK that can even be performed in the standing, sedated horse. When sufficient corneal tissue is removed, no recurrence is to be expected in the long-term follow-up (up to 31 months). In two horses, healing occurred without complications. Two horses developed a secondary bacterial infection post-operatively (Enterococcus faecalis and Staphylococcus aureus). In one case, this resulted in a pre-perforating melting corneal ulcer necessitating conjunctival pedicle graft surgery 13 days post keratectomy. In three horses, there was no recurrence of the IMMK with a long-term follow-up of 6–31 months. One case showed recurrence of IMMK in the cornea region surrounding the keratectomy 9 months after surgery.     

Ethnoveterinary Medicine in the Northern Provinces of Cameroon

Veterinary Research Communications -     

Prevalence of bovine genital campylobacteriosis and trichomonosis of bulls in northern Nigeria

Background

A survey was conducted to determine the prevalence of campylobacteriosis and trichomonosis, and their concurrence with brucellosis, in cattle in three states of northern Nigeria.

Methods

A total of 602 preputial samples was collected from bulls in 250 herds and tested using culture and identification. Various indigenous and exotic breeds were studied and four major management systems were encountered. Age of the cattle was estimated using dentition, farm records or cornual rings.

Results

The estimated true animal-level prevalence of Campylobacter fetus infection was 16.4% (95% CI: 13.0-20.7), of which 18.5% was C. f. fetus and 81.5% was C. f. venerealis. Of the latter, 92% were C. f. venerealis biovar intermedius strains. Animal-level prevalences in Adamawa, Kano and Kaduna states were 31.8%, 11.6% and 8.3% respectively, and were highest in bulls >7 years old (33.4%) and in the Gudali breed (28.8%). Of the 250 herds, 78 (25.5%, 95% CI: 19.4-32.7) had at least one infected bull, and herd prevalence was highest in the pastoral management system (43.5%). After adjustment for confounding using multivariable analysis, the odds of C. fetus infection were highest in Adamawa state (P < 0.01), in the pastoral management system (P < 0.01), and in bulls >7 years old (P = 0.01), and tended to be higher in Bos taurus breeds (P = 0.06). There was a strong positive association between the presence of campylobacteriosis and brucellosis (P < 0.01), both within bulls (OR = 8.3) and within herds (OR = 16.0). Trichomonosis was not detected in any herds.

Conclusion

Bovine genital campylobacteriosis is prevalent particularly in the pastoral management system in northern Nigeria, with C. f. venerealis biovar intermedius as the major aetiology. There was a strong positive correlation between the occurrence of campylobacteriosis and brucellosis. No evidence of trichomonosis was found in herds in this study.     

Horizontal transmission dynamics of White spot syndrome virus by cohabitation trials in juvenile Penaeus monodon and P. vannamei

White spot syndrome virus (WSSV), a rod-shaped double-stranded DNA virus, is an infectious agent causing fatal disease in shrimp farming around the globe. Within shrimp populations WSSV is transmitted very fast, however, the modes and dynamics of transmission of this virus are not well understood. In the current study the dynamics of disease transmission of WSSV were investigated in small, closed populations of Penaeus monodon and Penaeus vannamei. Pair cohabitation experiments using PCR as a readout for virus infection were used to estimate transmission parameters for WSSV in these two species. The mortality rate of contact-infected shrimp in P. monodon was higher than the rate in P. vannamei. The transmission rate parameters for WSSV were not different between the two species. The relative contribution of direct and indirect transmission rates of WSSV differed between the two species. For P. vannamei the direct contact transmission rate of WSSV was significantly lower than the indirect environmental transmission rate, but for P. monodon, the opposite was found. The reproduction ratio R₀ for WSSV for these two species of shrimp was estimated to be above one: 2.07 (95%CI 1.53, 2.79) for P. monodon and 1.51 (95%CI 1.12, 2.03) for P. vannamei. The difference in R₀ between the two species is due to a lower host mortality and hence a longer infectious period of WSSV in P. monodon.