Applying molecular genetic tools to tiger conservation

The utility of molecular genetic approaches in conservation of endangered taxa is now commonly recognized. Over the past decade, conservation genetic analyses based on mitochondrial DNA sequencing and microsatellite genotyping have provided powerful tools to resolve taxonomy uncertainty of tiger subspecies, to define conservation units, to reconstruct phylogeography and demographic history, to examine the genetic ancestry of extinct subspecies, to assess population genetic status non-invasively, and to verify genetic background of captive tigers worldwide. The genetic status of tiger subspecies and populations and implications for developing strategies for the survival of this charismatic species both in situ and ex situ are discussed.     

IgE ELISA using antisera derived from epsilon chain antigenic peptides detects allergen-specific IgE in allergic horses

Equine disease with an allergic etiology is common. Environmental antigens most often implicated as allergens in horses include molds, dusty hay, grass pollen, hay dust mites, and insect saliva. Although intradermal testing with allergen is a useful diagnostic tool for some species, skin testing frequently produces false positive results in horses. Allergen deprivation as a diagnostic tool is often impossible and at best it is ineffective at diagnosing the specific allergic reactivity. Synthesis of IgE after exposure to allergen is the instigator of the allergic process. While IgE exerts its effect after binding strongly to mast cell Fc receptors, the presence of free IgE in the serum can be used to quantify and determine the allergen specificity of the allergic disease. A lack of widely available reagents for detection of equine IgE has limited this approach in horses. We have used the nucleotide sequence of equine IgE to prepare a peptide-based immunogen to elicit equine epsilon chain-specific antisera. Selection of peptides was based on antigenic attributes of the deduced amino acid sequence of the equine epsilon chain. Six peptides were selected for conjugation to carrier molecules and rabbit immunization. Of these, one peptide elicited antisera that was successfully used in enzyme linked immunosorbant assay (ELISA) to screen horse serum from 64 allergic horses for allergen-specific IgE. Twenty-four of the 64 horses showed positive reactivity to one or more of the following allergens: grass, grain mill dust, mosquito, and horsefly. This study demonstrates the usefulness of peptide-based immunogens for development of antisera to rare or difficult to purify antigens such as IgE. Resultant antisera has great usefulness in diagnostic assays for equine allergy and as a research tool.     

Cryptococcosis in Gilbert's and long-nosed potoroo

Two cases of fatal cryptococcosis are described, one of Cryptococcus neoformans infection in a Gilbert's potoroo (Potorous gilbertii) and one of Cryptococcus gattii infection in a long-nosed potoroo (Potorous tridactylus). The diagnoses were confirmed by culture and specific immunohistochemistry, respectively. The long-nosed potoroo tested positive using the latex cryptococcal antigen test (LCAT), whereas the Gilbert's potoroo had a negative LCAT result despite having advanced disease of some duration. In both cases, the clinical presentation was a progressive neurologic disease associated with a central nervous system infection. Pulmonary infection was also observed in the long-nosed potoroo. Specific treatment with antifungal agents was unsuccessful in the long-nosed potoroo.     

Evaluation of a breast support conveyor to improve poultry welfare on the shackle line

A breast support conveyor has the potential to improve bird welfare by avoiding the need to invert and suspend broilers by their legs as they move from the point of shackling to entry into the electric waterbath. To evaluate its effect on welfare under commercial conditions, a breast support conveyor was installed under the conventional shackle line of a small poultry processing plant. A structured assessment of the behaviour of the birds indicated a significant decrease in struggling and wing flapping at the point of shackling, on the straight conveyor and at entry into the waterbath. This resulted in a lower prevalence of red wing tips and bruising in the first wing joint. The shackle line and conveyor in this installation, however, passed around a 90° corner, which appeared to cause more disturbance to the birds on the conveyor than to comparable birds suspended from shackles in the traditional manner. The results indicate that a breast support conveyor has the potential to improve bird welfare on straight shackle lines and that, because struggling activity and duration following shackling are reduced, the time between shackling and stunning could also be reduced using this method, further improving bird welfare. Breast support conveyors should not be used when the shackle lines have sharp bends.     

Bilateral thyroarytenoid cartilage lateralization and vocal fold excision with mucosoplasty for treatment of idiopathic laryngeal paralysis: 67 dogs (1998-2005)

Objective— To evaluate combined bilateral thyroarytenoid cartilage lateralization, vocal fold excision, and mucosoplasty technique (BTAL) through ventral median laryngotomy for treatment of laryngeal paralysis in dogs.
Design— Retrospective study.
Animals— Dogs (n=67) with laryngeal paralysis.
Methods— Medical records were reviewed for dogs with idiopathic laryngeal paralysis that had BTAL between January 1998 and March 2005. Retrieved data included signalment, history, physical and laryngoscopic examination findings, clinicopathologic tests, and results of recheck examination findings.
Results— BTAL was performed by a single surgeon. Short-term (<6 months) follow-up information was available for 67 dogs and long-term (>12 months) for 40 dogs. Major postoperative complications were surgical failures (13; 7 short term, 6 long term) and aspiration pneumonia (1). Mean recurrence of clinical signs was at 19 weeks (range, 2–30 weeks). Minor complications occurred in 22 (33%) dogs including occasional coughing or gagging, stridorous breathing during exercise, panting, noisy or heavy breathing, and aspiration pneumonia (3 dogs) that did not require hospitalization. All owners reported an improved quality of life and had no regrets with surgical outcome.
Conclusions— BTAL is seemingly an effective procedure for treatment of laryngeal paralysis.
Clinical Relevance— BTAL is associated with a low incidence of aspiration pneumonia; however, there is substantial risk of recurrence of clinical signs associated with narrowing of the glottis. Consequently, unilateral arytenoid lateralization currently represents the accepted approach to the treatment of laryngeal paralysis.     

EFFECT OF DISRUPTION OF THE SEBACEOUS LAYER OF THE SHEEP''S SKIN ON THE INCIDENCE OF FLEECE-ROT

It was postulated that integrity of the sebaceous layer on the skin is important in maintaining resistance to fleece-rot. This hypothesis was tested in an experimenta of a 2 x 2 factorial design in which sebaceous layer disruption and wetting were the 2 treatments. The sebaceous layer was disrupted by applying a light petroleum solvent to the skin of the sheep. Fleece-rot occurred in all sheep (20) that were both wetted and had the sebaceous layer disrupted while 9/19 of those wetted but without the sebaceous layer disrupted developed fleece-rot. The fleece-rot lesions observed were more severe in sheep in the disrupted wetted treatments than in the intact wetted treatment. Interpretation of these differences was complicated by a possible reaction of the skin to the solvent used. The differences were not due to an effect of treatment on fleece wettability. No fleece-rot developed in the sheep not wetted and application of the solvent alone did not induce fleece-rot.     

Effect of homogenized embryos on IUD-induced luteal regression in the ewe

The effect of homogenized embryos on IUD-induced luteal regression in the ewe was studied. Plastic spiral IUDs were inserted in an uterine horn adjacent to an ovary containing a corpus luteum during various times of the estrous cycle. The ewes were sacrificed on Day 6 for examination of the corpus luteum. Estrous Cycle Day 3 was the last day in which the IUD insertion induced luteal regression. Corpus luteum was maintained in ewes when the IUD was inserted on Day 4, 5, or 6. Corpus luteum regression was not prevented when homogenized 14- or 15-day-old embryos were injected into the uterus at the time of IUD insertion. Ewes which received an IUD, a cannula, and an infusion of saline or homogenized embryos on Days 3, 4, and 5 maintained corpora lutea in 4 of 7 embryo-infused ewes and in none of 7 saline-infused ewes (p less than .05). It was determined that the IUD must remain in the uterine horn for longer than 1 day to induce corpus luteum regression and that embryos can sometimes prevent the IUD-induced regression.     

Cytokine activity in bovine mammary gland secretions during the periparturient period.

The presence of cytokine activity in periparturient bovine mammary secretions was evaluated. Mammary secretions were modified for use in biological assays for interleukin-2 (IL-2) like and antiviral activity. The level of IL-2 like activity in mammary gland secretions was lower during the last week of gestation when compared to levels detected approximately two weeks prepartum. Antiviral titers gradually increased as parturition approached. Results from Western blots indicated that the antiviral activity observed in prepartum secretions may be due to tumor necrosis factor (TNF). Interferons (IFN) were not detected in the colostrum samples.