Marek's disease (MD) is a lymphoproliferative disease of chickens that is a significant cost to the poultry industry, mainly because of the cost of vaccination. Live vaccines are used worldwide, but a unique feature of this disease is that the Marek's disease virus (MDV) evolves to become more virulent following blanket vaccination. In the US this means that most vaccines have an effective life of approximately 10 years, and more effective vaccines are needed. The aim of this study (Aust Vet J 2007;85:348–355) was to assess the effects of varying vaccine doses, and amount and timing of challenge on protection of chickens against MDV. The first experiment was a dose response study using 10 doses of turkey herpes virus (HVT) vaccine in 462 chickens, including a sham vaccinated group. Spleens were taken for detection and quantitation of MDV and HVT. The second, using 600 chickens, compared two HVT vaccines, two levels of MDV challenge and five doses of HVT vaccine plus a sham vaccinated group. Peripheral blood leucocytes were isolated and viruses quantified using quantitative real time polymerase chain reaction. Chickens were examined at necropsy for gross MD lesions. Results showed that the dose of vaccine influenced the incidence of disease but the vaccine to challenge interval was the most important determinant. A small increase in challenge dose significantly increased the disease mortality and incidence. Finally, better protection was given after challenge at 5 rather than 2 days after vaccination. A paper from Queensland (Aust Vet J 2007;85:356–361) reports a visual, morphological scoring guide for oesophagogastric ulceration in pigs. This condition is a persistent problem in pig production systems. The gross appearance of the ulcerated stomachs has been shown to be directly related to the histological appearance to assess the value of any treatment or preventative measure the pars oesophagea is scored at necropsy examination. In this study 280 stomachs from finisher pigs were collected and the pars oesophagea everted, then ranked, graded and photographed. They were graded according to the Pig Health Monitoring Service scoring system, which ranks them from 0, with shiny white squamous epithelium, to 3, with developed ulcers, haemorrhage and stenosis. This system is descriptive and relies on the experience of the scorer, so this photographic guide gives a means of making more objective decisions on the ulcer assessment. A second paper from the same author (Aust Vet J 2007;85:362–367) uses the scoring system to show that the addition of a feed supplement (s-methylmethionine sulphonium chloride, SMMSC, or Vitamin U) to pig diets does not improve the ulcerations in pig stomachs. The incidence of oesophagogastric ulcers in Australian pig herds has been reported to be between 5 and 30%, and up to 90% if all lesions types are included. These ulcers may cause significant mortality, and they appears to be closely related to feeding finely ground diets. This study used 48 pigs with or without ulcers and fed the same diet with or without the addition of SMMSC. Ulcers were identified initially using endoscopic examination under anaesthetic. Results showed no significant difference between groups in growth rate, feed intake, feed conversion rate or in back fat levels. The authors note that highly digestible finely ground and pelleted feeds are most likely to be associated with ulcers, but also have high digestibility, so may mask the performance effect of the ulcers. They also suggest that the SMMSC may be inactivated by the heat pelleting process. They concluded that the use of SMMSC cannot be justified at this time. The successful surgical management of a valgus deformity of the metacarpophalangeal joint in a 1-month-old alpaca cria is described in this case report (Aust Vet J 2007;85:368–370). A transphyseal bridging technique was used. Seven weeks after surgery the implants were removed under general anaesthesia. The joints had straightened, although a mild valgus of the lateral joint remained. Transphyseal bridging was chosen in preference to hemicircumferential periosteal elevation in this case because it is less likely to be affected by sporadic growth that may occur in a very young animal, and was felt by the authors to be more reliable. Uterus unicornis (Aust Vet J 2007;85:375–378) is a congenital absence of one uterine horn. It leads to infertility when ovulation occurs ipsilateral to the aplastic horn. Although a rare condition, uterus unicornis has been reported in a number of domestic species including the horse. This report presents two mares in which a diagnosis of uterus unicornis was made by rectal palpation, in one when it was investigated for infertility, and in the other during a routine pre-breeding examination. The diagnosis was confirmed ultrasonographically, and on further palpation and sonography after fluid distension of the uterus with lactated Ringer's solution. Hysteroscopy also provided direct evidence of the absence of one uterine horn. One of the mares had successfully carried a fetus to term, although subsequent breeding attempts were unsuccessful. Given the established effect of uterine size on foal birthweight, uterus unicornis could also affect fetal growth. Once diagnosed, reproductive efficiency of these mares could be improved by removing the ovary ipsilateral to the aplastic uterine horn. Although many commonly used veterinary drugs are potentially photosensitising, drug-induced photosensitivity is rarely diagnosed in animals. In this case report (Aust Vet J 2007;85:379–384) a pale ginger cat treated for feline leprosy with the human anti-leprosy drug clofazimine developed erythematous, moderately pruritic lesions on the pinnae, pre-auricular region and nasal planum. Histological examination of biopsies of the lesions showed that they were confined to areas in which the epidermis contained little or no melanin. The lesions resolved with sunlight avoidance, and recurred with exposure to sunlight. The cat's mycobacterial disease was ultimately successfully managed with clofazimine and the resulting photosensitisation was controlled by regulating that cat's exposure to sunlight while on the drug. Photosensitisation from any cause has not previously been reported in cats. Colonic duplication is a rarely seen congenital defect, thought to arise from faulty division of the hindgut during fetal development. A 9-month-old Shar Pei with a 7-month history of recurrent rectal prolapse that had not been prevented by repeated reduction and anal purse string sutures, nor by laparotomy and incisional coloplexy, was found on barium enema to have a duplicate colonic segment (Aust Vet J 2007;85:385–389). A septal division coursed along the ventral descending colon and rectum. The dog made an uneventful recovery after surgical excision of the duplicated colonic segment at a second laparotomy, with no subsequent recurrence of rectal prolapse. This case report highlights the need to investigate an underlying cause for recurrent rectal prolapse in young dogs, using diagnostic aids such as a barium enema and sonography.