High allergen-specific serum immunoglobulin E levels in nonatopic West Highland white terriers

Human and canine atopic dermatitis (AD) share an association with IgE specific to environmental allergens, but few studies have evaluated serum allergen‐specific IgE in nonatopic dogs. This study compared serum allergen‐specific IgE levels in 30 atopic and 18 nonatopic West Highland white terriers. Atopic dermatitis was confirmed using standard criteria. Nonatopic dogs were over 5 years of age and had no clinical signs or history of AD. Serum allergen‐specific IgE levels were measured with Allercept^® IgE ELISAs using a 48‐allergen Australian panel. Positive reactions were defined as ≥150 ELISA absorbance units. Intradermal tests were performed in 16 atopic dogs, either at the time of or at various times prior to serum collection. In atopic dogs, the most common positive ELISA and intradermal test results were to Dermatophagoides farinae (11 of 30 dogs), but there were no statistically significant correlations between results from the two methods for any allergen. In nonatopic dogs, multiple high‐positive ELISA reactions were reported to 45 of 48 allergens, most commonly D. farinae and Tyrophagus putrescentiae (17 of 18 dogs each). Positive ELISA results in nonatopic dogs were statistically significantly higher than those in atopic dogs for 44 of 48 allergens, including two allergens (D. farinae and Dermatophagoides pteronyssinus) commonly regarded as significant in canine AD. In conclusion, positive allergen‐specific IgE ELISAs were not specific for canine AD, and high allergen‐specific IgE levels were seen in nonatopic dogs. The clinical significance of this and whether it characterizes a protective phenotype is unclear.     

The effect of two different weaning procedures on the growth of pasture-reared Thoroughbred foals in New Zealand

AIM: To identify if there was a significant difference in the average daily liveweight gain (ADG) between Thoroughbred foals weaned using two weaning protocols commonly used in New Zealand.

METHODS: Sixteen Thoroughbred foals were blocked for sex and age, randomly allocated into progressive (187, SD 33 days; three colts, five fillies) or abrupt (182, SD 28 days; four colts, four fillies) weaning groups, and weighed every second day for 2 weeks either side of weaning, then fortnightly from birth to 480 (SD 31) days old. ADG was calculated to examine the short-term (10 days before weaning, 5 and 10 days post weaning) and long-term (0–6 and 6–16 months of age) effect of the two weaning treatments.

RESULTS: ADG was 1.10 (SD 0.091) kg/day before weaning (0–6 months of age) and 0.59 (SD 0.06) kg/day from weaning to 480 (SD 31) days old. At the start of weaning, liveweights of the progressive and abrupt weaning groups were 276.5 (SD 40.3) kg and 257 (SD 15) kg, respectively (p=0.23). For the 5-day period during weaning, irrespective of treatment, there was a significant decrease in ADG of –0.29 (SD 0.49) kg/day and –0.15 (SD 0.30) kg/day for progressive and abrupt weaning, respectively. There was no significant difference in ADG between weaning methods at any measurement period (short or long term) during and after weaning. However, there was large variation between foals in ADG in the 10 days after the weaning process, which may indicate variation in individual foals' responses to being weaned, rather than the weaning treatment.

CONCLUSIONS: Weaning, irrespective of method, was associated with a decrease in ADG in the first week after weaning. The method of weaning had no effect on post-weaning ADG either short term, 10 days after weaning, or long term up to 480 days of age. Practically, it may be more important to consider maturity and liveweight as criteria for weaning foals rather than age alone.     

Investigation of diabetes mellitus in Burmese cats as an inherited trait: a preliminary study

AIM: To investigate, in a pilot study, a possible genetic component to type 2 diabetes mellitus (T2D) in Burmese cats in New Zealand by analysing pedigree data.

METHODS: Pedigrees were obtained for 305 Burmese cats living in New Zealand; diabetes was diagnosed in 19 of these due to presence of polyuria and polydipsia, persistent concentrations of glucose in plasma >16?mmol/L and glucosuria prior to insulin treatment. Pedigrees were also submitted for 16 cats with no clinical signs of T2D. The remaining 270 cats were unobserved relatives of these individuals. Inbreeding coefficients and heritability were calculated, and a single major locus model segregation analysis was conducted using pedigree analysis software.

RESULTS: Nineteen cats were diagnosed with T2D. Males (n = 14) and females (n = 5) were both affected, suggesting that the gene or genes causing diabetes are autosomal rather than sex-linked. Examination of the pedigree revealed few signs of fully penetrant dominant gene action: diabetes was ostensibly rarely seen in sequential generations and nearly always skipped at least one and often more generations; apparently unaffected offspring of apparently unaffected parents sometimes produced affected progeny. The mean relatedness of the affected animals within the core pedigree (16 diabetic cats) was 0.049, and mean inbreeding 0.033. Based on 100,000 permutations of the trait values, the expected relatedness of a random sample of 16 animals taken from the phenotyped animals would be 0.013 (SD 0.007) (permutation p = 0.0009). The observed inbreeding was also significant (permutation p= 0.02).

Heritability was estimated to be 9 (95% CI = 0–57)% assuming all animals with unknown status were unaffected. The best fitting genetic model was a major gene model with dominant expression with the risk allele frequency at 15% with 60% penetrance.

CONCLUSIONS: In this pilot study the increased inbreeding in the cases, lack of likely sampling bias, the increased frequency of T2D in Burmese, and small number of breed founders are consistent with the involvement of a major locus in diabetes in Burmese cats with a significant risk allele prevalence. However, low case numbers meant this could not be unambiguously confirmed. A genome-wide association study may be useful for investigating the genetic cause of T2D.     

Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. Conclusions

This paper summarises and presents in context the main findings of an extensive series of studies of early training lasting 13 weeks in which the tissue responses of 2-year-old Thoroughbred horses were assessed using a combination of methods. Negligible clinical injury was detected and thus the study fulfilled the intention of investigating adaptive change rather than injury. Cancellous and cortical bone, some digital tendons, and articular cartilage responded to early training exercise to a greater or lesser degree. Clinical examination and ancillary diagnostic aids currently in veterinary clinical use are not sufficient to detect early abnormalities in metacarpo-phalangeal joint (MCPJ) cartilage found in both trained and untrained horses. Future work should centre on detection of such changes, on the precise registration of training workload, and on the manipulation of the responses of musculoskeletal tissues by careful investigation of the effects of introducing conditioning exercise at a young age.     

Cryptosporidium and its potential as a food-borne pathogen

Cryptosporidium species are intestinal protozoan parasites and are excreted in animal feces as stable oocysts. Cryptosporidium has now been detected in the feces of a wide range of ruminant and non-ruminant farmed animals, wild animals, domestic pets and birds and the parasite appears to be well adapted to survive and persist in feces for extended periods, ranging from several weeks to many months. Because of this persistence, these materials are important as potential vehicles of transmission within herds, farms, the water chain, the fresh food chain, and the wider environment. Appropriate handling of animal waste is necessary to control spread of this pathogen and to limit the significant risks of human infection. While water is a well-recognized vector of Cryptosporidium, it has only recently emerged that food may play a more significant role than previously realized in the transmission of the Cryptosporidium to humans. In the last 3-5 years, research efforts have been directed both at the development of suitable methods for isolation and detection of the parasite in foods and at the application of these methods to assess the prevalence and persistence of the parasite in a range of foods. Additionally, molecular subtyping methods have been used to establish the transmission routes of the parasite. This paper summarizes the general biology of Cryptosporidium and overviews the current research on C. parvum in the food chain. The risks posed by certain foods, such as salad/vegetable crops and beef, are discussed and control measures which may be useful in the farm-to-fork chain for these products are described.     

Evaluation of dietary Natustat for control of Histomonas meleagridis in male turkeys on infected litter

Histomoniasis (histomonosis, infectious enterohepatitis, or blackhead) is a disease of turkeys on litter or range caused by the protozoan Histomonas meleagridis, a parasite of worms, primarily spread in feces, in Heterakis gallinarum (cecal worm) eggs, or in Eisenia foetida (earthworms). In this trial, Natustat (Alltech, Inc., Nicholasville, KY), a proprietary plant-derived product, was used at 1.925 kg/tonne and compared with nitarsone in male hybrid turkey diets to 42 days of age on histomonad infected litter (day 7) from broiler breeders. Infected nonsupplemented and uninfected nonsupplemented control groups were also included. Natustat and nitarsone significantly improved 28- and 42-day feed conversion ratios and lowered 28- and 35-day cecal and liver lesion scores compared with infected nonsupplemented turkeys. The body weight at 42 days was greater in the Natustat and nitarsone supplemented groups than in the infected nonsupplemented group.     

Prevalence and characterisation of Cryptosporidium species in cattle faeces and on beef carcases at slaughter

Cattle are known reservoirs and asymptomatic excretors of Cryptosporidium, a protozoan parasite that causes severe and protracted diarrhoea in people. The incidence of Cryptosporidium was investigated in 288 matched samples taken from beef carcases of 1 g samples of faeces retrieved immediately after de-legging, 25 cm2 samples of beef excised from the rump of uneviscerated carcases, and 25 cm2 samples of beef excised from the brisket area of eviscerated carcases. Cryptosporidium species were detected in 21 of the faecal samples after salt flotation and immunofluorescent microscopy. The species isolated from the positive samples were identified by restriction fragment length polymorphism and PCR as Cryptosporidium andersoni (54.5 per cent) and Cryptosporidium parvum genotype 2 (45.5 per cent). In the faecal samples, there was a significantly higher prevalence of the parasite in samples taken in summer (May to July) and winter (November to January) than in spring or autumn. No Cryptosporidium species were recovered from any of the beef samples.     

Effects of Natustat supplementation on performance, feed efficiency and intestinal lesion scores in broiler chickens challenged with Eimeria acervulina, Eimeria maxima and Eimeria tenella

The effects of dietary supplementation of Natustat™, a propriety plant derived product (Alltech Inc., KY, USA) and Salinomycin, on performance, feed efficiency and intestinal lesion scores were observed during two Eimeria challenge trials in broiler chickens. In the first trial chickens were challenged with Eimeria sp. via infecting the litter with a known amount of Eimeria oocysts. In the second trial the source of the Eimeria challenge was the litter from the first trial and the same treatment groups were assigned to the same pens as in the initial trial.

Birds were placed 55 per pen with seven pens per treatment. Performance parameters were recorded on days 21 and 42 during both trials. Intestinal lesion scores were assessed on days 14 and 21 during Trial 1 and on day 21 during Trial 2. Average weight gain and feed conversion ratios were significantly improved in the Natustat™ and Salinomycin treatment groups when compared to the non-supplemented infected group. Furthermore, lesion scores were lower on all sampling days in the Natustat™ and Salinomycin groups when compared to the non-supplemented group. However, only lesions associated with Eimeria tenella were significantly lowered by Natustat™ and Salinomycin supplementation.

Natustat™ and Salinomycin were equivalent in alleviating the negative performance effects associated with coccidiosis challenge. In summary, Natustat™ has the potential to be used as a natural alternative to chemotherapeutic drugs for Eimeria control.