Enteric campylobacter infection in gnotobiotic calves and lambs

Gnotobiotic calves and lambs were infected orally with Campylobacter jejuni, C coli or C hyointestinalis to assess pathogenicity. All animals were successfully colonised and excreted mucoid faeces but showed no other clinical signs. Campylobacters colonised the large intestine better than the small intestine, in which bacterial numbers decreased with time after infection. Campylobacters were found occasionally in the lumen of crypts in close proximity to epithelial cells and included in a mucus-like material. Lesions were mostly in the large intestine in calves whereas in lambs they were present in the ileum. In animals inoculated with C jejuni or C coli scattered crypt abscesses, focal inflammatory infiltrates in the lamina propria and goblet cell discharge were found. In lambs inoculated with C hyointestinalis only minor changes were found in the small intestine. Serum antibody response was either absent or present at a low level only from the 19th day after infection.     

The safety and efficacy of immunizing foxes (Vulpes vulpes) using bait containing attenuated rabies virus vaccine.

Foxes given ERA rabies vaccine baits were challenged at one, six, 12 and 24 months later and showed a resistance to challenge in 80%, 78%, 60% and 44% of individuals respectively. All animals showing seroconversion following vaccination, resisted challenge at 24 months, suggesting that successful vaccination by the oral route could confer a relatively long term duration of immunity. The trials showed that fox pups did not immunize as easily as adult foxes using ERA rabies vaccine baits. Back-passage studies and the consumption of ERA injected mice by foxes failed to show any reversion of the vaccine virus to a virulent state. The fox and mouse are shown to be highly susceptible to rabies street virus, while the domestic species tested are consisderably more resistant. Monkeys were found to be intermediate in susceptibility to the virus. Safety tests carried out on various species of wildlife showed only the mouse to be susceptible to infection from ingesting the vaccine in the form of a bait. ERA rabies vaccine was shown to be safe in monkeys even when high titred virus was administered by the oral route.     

The ERA Strain of Rabies Vaccine

An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine.

Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland “street” rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats.

Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent “street” rabies virus two years later.

     

Luxation of the crystalline lens in the dog

Luxation of the crystalline lens is a heritable defect in the dog and is virtually confined to a small group of terrier breeds. The condition is usually bilateral, although both eyes are not necessarily affected simultaneously. The lens may subluxate or dislocate, usually into the anterior chamber. Secondary glaucoma follows and leads to hydrophthalmos and gross damage to the eye. Lens extraction is effective in preventing hydrophthalmos if carried out sufficiently early, but is of little value, even if combined with a pressure relieving operation once hydrophthalmos is established.     

Development of components of the extracellular matrix, basal lamina and sarcomere in chick quadriceps and pectoralis muscles

1. The purpose of this study was to investigate differences in the development of components of the cell/matrix linkage in two functionally different muscle types: the pectoralis muscle, a major locomotory muscle in birds but not particularly functional in chickens, and the quadriceps muscle, a smaller and more functionally active muscle in the chicken. 2. The development of the extracellular matrix, basal lamina and sarcomere in the pectoralis and quadriceps muscles in chick embryos was examined biochemically to determine differences in the rate of development between these two muscles. Samples of these muscle types were dissected out from chick embryos from embryonic day 10 until 8 weeks post hatch. 3. Using SDS-PAGE electrophoresis and western blotting with antibodies against sarcomeric actin, laminin and collagens I, III and IV, it was apparent that muscle development begins earlier in the quadriceps muscle than in the pectoralis, and that late in the developmental process (d 18) both muscle types were well differentiated. The final concentration of collagens in the mature muscle remained higher in the quadriceps than in the pectoralis muscle. 4. The onset of development of the extracellular matrix, basal lamina and sarcomere was earlier in the quadriceps than the pectoralis, which could have functional implications for these muscles as a whole.     

Equine duodenal motility,assessed by ultrasonography,as a predictor of reflux and survival following colic surgery

Intestinal dysmotility following equine colic surgery contributes negatively to financial and prognostic outcomes. This study assessed duodenal contractility as a predictor of post-operative reflux and survival to discharge in horses following colic surgery. Duodenal contractility was assessed using daily transabdominal ultrasound examinations in 49 horses for up to 7 days (Day 1 scan performed between 6 and 36 h post-surgery and sequential daily scans performed between 08.00 and 20.00 h) following colic surgery (September 2014–April 2017). The duodenum was visualised ventral to the right kidney, and duodenal contractions were measured over 2 min. The signalment of each horse and surgical findings were noted. Outcomes were defined as horses that refluxed (>5 L/24 h beyond 24 h) or did not reflux post-operatively and those that were survivors or were nonsurvivors. A significant difference in duodenal contractions at Day 1 post-operatively was identified between horses that refluxed (n = 8) and those who did not reflux (n = 32; P = 0.013) but not between those who were nonsurvivors (n = 7) and survivors (n = 32; P = 0.113). Horses in the reflux group had reduced duodenal contractility comparatively. There were no significant differences in duodenal contractions in the sequential days after the Day 1 scan or between duodenal contractions and surgical findings. A significant association was identified between duodenal contractions and survivors (P = 0.039; odds ratio 1.88). The main study limitations were the single centre design with consequent small numbers of horses included. The study did not account for other factors that may contribute to alterations in motility such as drug administration or stages of re-feeding. This preliminary study indicates that Day 1 (6–36 h post-operatively) duodenal contractions may predict reflux (>5 L/24 h beyond 24 h) and that increased duodenal contractions are associated with survival. However, there was no clear distinction or cut-off between groups. Future studies with greater numbers of horses yielding better statistical power are required.