Re: Porcine dermatitis and nephropathy syndrome in New Zealand

Extract

We wish to record the source of Figures 1a and 2 from the report “Porcine dermatitis and nephropathy syndrome in New Zealand” published in the New Zealand Veterinary Journal 56, 94–99, 2008. These images were kindly provided by AF Julian from Gribbles Veterinary, Hamilton, New Zealand, and illustrate the gross cutaneous and renal lesions that were typical of those seen in pigs in the reported disease outbreak. The images were obtained from a pig with porcine dermatitis and nephropathy syndrome submitted by one of the authors (DEBL) from a similar outbreak of the disease that was examined by Gribbles Veterinary, Hamilton. The failure to properly acknowledge this contribution is regretted.     

Methods of collection,extender type,and freezability of semen collected from creole bulls raised in the tropical highlands of Ecuador

This study was conducted to determine the best combination between two collection method and two extenders in the cryopreservation of semen from creole bulls adapted to highlands of the Ecuadorian Andes. Sixty ejaculates from three adult Creole bulls were evaluated after collection by artificial vagina (AV) and electroejaculation (EE). Semen samples were split into two aliquots and diluted with a soy lecithin extender (Andromed®; A) or an egg yolk-containing extender (Triladyl®; T) and packed in straws of 0.25 ml with 20 × 10⁶ sperms. Optical microscopy and computer-assisted semen analysis system (CASA) were used to evaluate semen quality characteristics. The effects of collection methods and extender type as well as its interaction were evaluated by a factorial ANOVA and Bonferroni’s test. Semen samples collected with EE and frozen with T (EE-T) and A (EE-A) had greater proportion of spermatozoa with optical assessed individual progressive motility (IPM), plasmatic membrane intact (HosT), and lower tail abnormalities than those obtained with AV and frozen with the same extenders (AV-T and AV-A); however, differences were significant only between EE-A and AV-T. CASA assessment indicated that the total mobility (TM) was greater (P < 0.05) in semen samples diluted with T, although these samples had a greater proportion (P < 0.05) of sperms with local motility (LM) and fewer immobile sperms (IS), than those extended with A. Generally, semen samples obtained with EE or AV and diluted with T seems to be the best option to ciopreserve gametes of Creole bulls raised in highlands of Ecuadorian Andes.

     

Morphometric study of the layers of the canine small intestine at five sampling sites

The histology of the canine intestine has not been accurately defined. To establish the precise thickness of its different layers, whole wall samples of the small intestine were removed from 41 cadavers at five standardised sampling sites (duodenum, proximal jejunum, distal jejunum, proximal ileum and distal ileum). The total thickness was estimated by morphometry, as was the thickness of the mucosa, muscularis mucosae, submucosa and muscularis externa. In addition, the size of the lymphoid aggregates in the submucosa and the thickness of the circular and longitudinal layers within both the muscularis mucosae and the muscularis externa were estimated. The total intestinal thickness depended very much upon the thickness of the mucosa and submucosa. The mucosa decreased progressively from proximal to distal parts of the small intestine (47% reduction). The thickness of the submucosa, however, changed little from the duodenum to the distal jejunum, but increased significantly in the ileum; this change was positively correlated with the amount of lymphoid tissue. Sex influenced the thickness of the intestinal wall, with males displaying higher thickness values along the small intestine. Conversely, no correlation between bodyweight and intestinal thickness was found for any of the five sampling sites. This study gives absolute and relative values for the thickness of the layers of the dog intestine which might help in the diagnosis of small intestinal pathology from postmortem samples and/or endoscopic biopsies.     

Screening for the Mucopolysaccharidosis-IIIA gene in Huntaway dogs

Abstract

Extract

A single case of the inherited lysosomal storage disease known as mucopolysaccharidosis-IIIA (MPS-IIIA), due to a deficiency of the enzyme heparan sulphatase, was reported in an 18-month-old male Huntaway dog (Jolly et al 2000 Jolly, RD, Allan, FJ, Collett, MG, Rozaklis, T, Muller, VJ and Hopwood, JJ. 2000. Mucopolysaccharidosis IIIA (Sanfilippo syndrome) in a New Zealand Huntaway dog with ataxia. New Zealand Veterinary Journal, 48: 144–148. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). He had developed normally but when presented with a history of progressive ataxia over the preceding month, had a high stepping, prancing gait and difficulty in jumping into a utility vehicle. In addition, he had started to defaecate in his kennel. Following diagnosis of the enzyme deficiency, the mutant heparan sulphatase gene was sequenced and a PCR/restriction enzyme diagnostic test developed, based on the mutation. This is capable of detecting both homozygous and heterozygous individuals (Yogalingam et al 2000 Yogalingam, G, Pollard, T, Gliddon, B, Jolly, RD and Hopwood, JJ. 2001. Identification of a mutation causing mucopolysaccharidosis type IIIA in New Zealand Huntaway dogs. Genomics, 79: 150–153.  [Google Scholar]).     

Ovine sperm DNA oxidation quantification using an 8‐OHdG immunodetection assay

Our aim was to optimize 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) immunodetection in order to detect DNA damage caused by oxidative stress that may not be detected by other DNA integrity analysis techniques, especially due to the high compaction of DNA in ruminants. Semen samples from 6 rams were cryopreserved. After thawing, samples were subjected to the DNA oxidation quantification using an 8‐OHdG immunodetection assay by flow cytometry. We have evaluated two different incubation times (30 min vs. overnight) at 4°C of the primary antibody (monoclonal anti‐8‐OHdG antibody). We have also compared the results of this technique with the sperm chromatin structure assay (SCSA^®). The analysis revealed that there were no significant differences (p > .05) between different incubation times. However, overnight incubation seems to cause more non‐specific binding of the secondary antibody. Significant differences (p < .05) between subjects and oxidation controls (8 M H₂O₂/800 μM FeSO₄?7H₂O) were evident. We can conclude that the 8‐OHdG immunodetection assay for DNA oxidation quantification of ram sperm can be performed subjecting sperm samples to a very high oxidative treatment.     

Minimal External Masculinization in a SRY-negative XX Male Podenco Dog

Normal mammalian sex differentiation takes place in three genetically controlled steps: chromosomal sex determination (XX or XY), gonadal differentiation and development of the phenotypic sex. Animals are considered to be sex reversed if chromosomal sex determination and gonadal development are not in agreement. In this report, sex reversal is described in a 1.5-year-old Podenco dog that was referred because of suspected recurrent growth of a previously removed os clitoridis in the vulva. With that exception the dog was phenotypically female, but had never been in oestrus and exhibited male behaviour. Abdominal ultrasonography showed a small tubular structure dorsal to the bladder, consistent with a uterus. An ovoid structure resembling a gonad was visible between the right kidney and inguinal canal. Plasma testosterone concentrations before and after GnRH administration indicated the presence of functional testicular tissue. Two testes, each with its epididymis and ductus deferens, and a complete bicornuate uterus were removed surgically. Cytogenetic analysis of peripheral blood lymphocytes showed a normal female karyotype (78, XX). These findings are consistent with the diagnosis of an XX male. PCR analysis of genomic DNA revealed that the SRY gene was absent. In summary, this report describes the first SRY-negative XX male Podenco dog with an almost complete female phenotype despite high basal and stimulated plasma testosterone concentrations. It is hypothesized that the clinical observations in this dog may have been caused by reduced and delayed Müllerian-inhibiting substance secretion and the absence of conversion of testosterone to dihydrotestosterone due to 5α-reductase deficiency.     

Determination of the maximum tolerated dose and the safety index of an experimental fasciolicide in cattle

The aim of the present study was to determine the maximum tolerated dose (MTD) and the safety index (SI) of 5-chloro-2-methylthio-6-(1-napthyloxy)1H-benzimidazole, called compound alpha, in cattle. In addition, to search for possible adverse effects after treatment, the measurement of some biochemical, haematological and physiological parameters were also analysed. Eighteen crossbred heifers were divided into six groups of three animals each. Groups 1-5 received a single oral dose of 12, 36, 60, 120 and 180 mg/kg of body weight (bw) of compound alpha. Group 6 served as an untreated control. To determine the biochemical, haematological and enzymatic parameters, sera and blood samples were individually taken at 0, 4, 8, 16, 32, 128, and 720 h after treatment. Physiological parameters such as rectal temperature, heart rate (HR), respiration rate (RR) and ruminal motility were measured at the time intervals mentioned above. Estimation of the MTD and SI was obtained by using the formula reported by the Food and Drug Administration (FDA), the results showing an MTD of 180 mg/kg/bw and an SI of 15 times the recommended clinical dose. Some statistical differences were observed in a few of the biochemical, haematological and enzymatic parameters, the adverse effects being not highly representative. Alterations on HR and RR were statistically different (P<0.05) only in heifers treated with 180 mg.     

Cooled Storage of Canine Semen: in vitro Effects of Different Concentrations of an Antibiotic Combination on Growth of Mollicutes

The aim of this study was to examine effects of an antibiotic combination at different concentrations on growth of mycoplasma and ureaplasma during cooled storage of canine semen (n = 20). Semen aliquots were diluted with Tris–citric acid–fructose–egg yolk extender containing either 1.0 g/l streptomycin and 0.6 g/l benzylpenicillin (control) or a combination of gentamycin, tylosin, lincomycin and spectinomycin (GTLS‐1: 0.25, 0.05, 0.15 and 0.3; GTLS‐2: 0.5, 0.1, 0.3 and 0.6; GTLS‐3: 1.0, 0.2, 0.6 and 1.2 g/l). Samples were assessed for motility and membrane integrity by computer‐assisted sperm analysis immediately after dilution and at 24, 48 and 72 h of cooled storage. Morphologically, normal spermatozoa were determined, and bacterial culture was performed at 24 and 72 h. Mycoplasma spp. were detected in 14 of 20 ejaculates (70%) with severe growth in 12 samples. A reduction but not total elimination of mycoplasma growth occurred in all GTLS extenders with the most pronounced reduction in group GTLS‐3 (control vs GTLS‐1 and GTLS‐2 p < 0.05, control vs GTLS‐3 p < 0.001). Ureaplasmas were detected in four ejaculates, and growth was reduced to the same extent in GTLS and control extender. Progressive motility in all groups, total motility in groups GTLS 1–3 and percentage of membrane‐intact spermatozoa in groups GTLS 2 and 3 decreased slightly (p < 0.05) over time. In conclusion, dilution of canine semen with GTLS extender has no major detrimental effects on spermatozoa during cooled storage. It reduced the growth but did not totally eliminate mycoplasmas and ureaplasmas from cooled‐stored dog semen.