Persistence of Salmonella Typhimurium DT120 in abattoir paddocks holding sheep

In the summer of 1999 there was an outbreak of Salmonella Typhimurium DT120 in people in the north of England which was unusual in being sensitive to antimicrobial drugs. The outbreak was linked to mutton and lamb from a local abattoir, and attention focused on four holding paddocks used to retain sheep before slaughter. In November 1999, samples of soil and faeces were taken from these paddocks and samples of faeces were taken from the concrete race leading from them. Salmonella Typhimurium was isolated from 59 of the 100 samples. Between January 2000 and October 2000 seven visits were made to the abattoir at each of which 100 samples were taken from the paddocks and concrete race and examined for the presence of Salmonella. The paddocks remained heavily contaminated with S Typhimurium DT120 until April when there was a marked reduction in the recovery of the organism. By June the contamination was minimal and by August it had disappeared, and the organism was not recovered in September or October.     

Laser treatment of urethral defects in geldings and stallions used as the primary treatment or in combination with a temporary subischial incision: Eight cases (2003–2011)

Two geldings with haematuria and 6 stallions with haemospermia presented for evaluation between 2003 and 2011 to the Iowa State University Lloyd Veterinary Medical Center. Both geldings presented for haemorrhage at the end of urination. All stallions presented for evaluation of infertility following natural service or artificial insemination that was related to haemospermia. Urethroscopy identified a urethral defect in all 8 horses. Both geldings possessed a urethral rent. One stallion possessed a urethral varicosity while the remaining 5 possessed a urethral rent. Two geldings and 2 stallions received only laser treatment. The remaining 4 stallions received concurrent laser treatment with a temporary subischial incision (TSI) into the corpus spongiosum penis. All 6 stallions received 8 weeks of sexual rest after the completion of the surgical/laser treatment. Laser treatment alone was successful in resolving haematuria in one of 2 geldings. In the stallion group, all 4 horses with a urethral rent receiving laser treatment concurrent with a TSI resolved haemospermia. Of the remaining stallions, one with a urethral varicosity resolved clinical signs with only laser treatment and one stallion with a urethral rent received only laser treatment and haemospermia recurred. We conclude that laser treatment of a urethral rent in geldings can result in resolution of haematuria. Laser treatment used in combination with a TSI may result in improved success when compared to surgery alone. Laser treatment alone can result in resolution of a urethral varicosity.     

A trial of 13-cis-retinoic acid for treatment of squamous cell carcinoma and preneoplastic lesions of the head in cats

Ten cats with a total of 15 cancerous or precancerous lesions were examined for clinical response to and histopathologic changes after treatment with 13-cis-retinoic acid. Before treatment was started, the lesions were graded according to clinical severity and biopsied for histopathologic examination. Serum samples were prepared for determining vitamin A concentrations. For comparison, serum vitamin A concentrations in 10 clinically healthy cats were determined. 13-cis-Retinoic acid (approx 3.0 mg/kg) was given to affected cats once a day for an average of 68 days. At the completion of the therapeutic trial, additional biopsy tissues were obtained for histopathologic examination, and serum was assayed for 13-cis-retinoic acid. Of the 15 lesions examined, only 1 showed partial clinical and microscopic improvement during the therapy period. The mean serum vitamin A concentration of the affected cats was not statistically different from that of the 10 healthy cats. The results of this trial indicated that 13-cis-retinoic acid used at this dosage, daily frequency, and duration did not have therapeutic efficacy for squamous cell carcinomas or preneoplastic lesions in the cat and that the mean serum vitamin A concentration did not differ between the affected cats and clinically healthy cats.     

Effect of staining and freezing media on sortability of stallion spermatozoa and their post-thaw viability after sex-sorting and cryopreservation

Sex‐sorted, frozen–thawed stallion spermatozoa remain out of reach of commercial horse breeders because of the low efficiency of the sex‐sorting process and unacceptable fertility rates after insemination. Two experiments were designed to test the effects of alternative staining and freezing media to improve the viability of sex‐sorted frozen–thawed stallion spermatozoa. Experiment 1 compared two freezing media, INRA 82^® and a modified lactose‐ethylenediaminetetraacetic acid (EDTA), for the cryopreservation of sex‐sorted stallion spermatozoa. No significant differences between the two freezing media could be identified, suggesting that both cryodiluents would be suitable for incorporation into a sex‐preselection protocol for stallion spermatozoa. Experiment 2 compared Kenney’s modified Tyrode’s (KMT) and Sperm TALP (Sp‐TALP) as the staining and incubation medium for stallion spermatozoa prior to sex‐sorting. A significant increase in the percentage of acrosome‐reacted spermatozoa occurred after staining and incubation in the clarified Sp‐TALP compared with KMT. As no improvements in sorting rates were achieved using Sp‐TALP, it was concluded that stallion sorting protocols could include KMT as the staining and incubation medium while either INRA 82^® or lactose‐EDTA could be employed as a cryodiluents.     

Agammaglobulinemia in a horse with evidence of functional T lymphocytes.

Agammaglobulinemia was diagnosed in a 1-year-old Thoroughbred horse on the basis of the following observations: (1) absence of serum immunoglobulins M, A, and G(T); (2) small amounts of serum immunoglobulin G (16 mg/100 ml); (3) absence of specific antibody in the serum of the horse following immunization and challenge exposure to 2 antigens; (4) absence of plasma cells, primary follicles, and germinal centers in a lymph node removed after antigenic stimulation; (5) absence of "natural" serum antibodies to rabbit-erythrocytes which were easily detectable in age-matched control horse serums; and (6) increased susceptibility to infections. There was evidence of functional cell-mediated immunity which included a skin response to injected phytolectins, skin response to antigen challenge following sensitization, and in vitro proliferative response of lymph node cells to phytohemagglutinin. An intact cell-mediated immune response was also supported by the observation that the horse lived to 17 months of age without antibody production, whereas horses with an absence of both antibody production and cell-mediated immunity (combined immunodeficiency) die by 4 months of age without immunologic intervention. The known features of agammaglobulinemia in this horse are similar to those in sex-linked agammaglobulinemia in persons and are unique among the immunodeficiences described in other animals.