Keloidal fibromas and fibrosarcomas in the dog

Sixteen dogs (2-12 years of age) presented with one (n = 15) or two (n = 1) cutaneous nodules (n = 16) or a dermal plaque (n = 1). Intact males (n = 9) and neutered males (n = 4) were more affected than were females (n = 3). Histologically, these lesions were characterized by focal dermal and subcutaneous deposition of thick hyalinized collagen fibers intermingled with fibroblasts, and in 13 of 17 lesions, a variable number of CD18-positive cells were interpreted as reactive macrophages. Fibroblasts in three dogs formed intersecting fascicles, interpreted as evidence of malignant transformation. The terms keloidal fibroma and keloidal fibrosarcoma can be applied to these lesions. Excision was curative in five dogs with keloidal fibroma for which follow-up was available. However, because malignant transformation may occur, wide excision of canine keloidal lesions is warranted.     

Genomic analysis of antifungal metabolite production by <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> Pf-5

The complete genomic sequences of several Pseudomonas spp. that inhabit the rhizosphere are now available, providing a new opportunity to advance knowledge of plant growth-promoting rhizobacteria (PGPR) through genomics. Among these is the biological control bacterium Pseudomonas fluorescens Pf-5. Nearly 6% of the 7.07 Mb genome of Pf-5 is devoted to the biosynthesis of secondary metabolites, including antibiotics toxic to soilborne fungi and Oomycetes that infect plant roots, and two siderophores involved in iron acquisition. Three orphan gene clusters, for which the encoded natural product was unknown, also were identified in the genome of Pf-5. The product synthesized from one of the orphan gene clusters was identified recently using a new ‘genomisotopic approach’, which employs a combination of genomic sequence analysis and isotope guided fractionation. Application of the genomisotopic approach to one orphan gene cluster in Pf-5 resulted in the discovery of orfamide A, founder of a new group of bioactive cyclic lipopeptides with a putative role in biological control of plant disease.     

Divergent selection of chickens for antibody response to sheep erythrocytes: kinetics of primary and secondary immunizations

Chicks from lines selectively bred for either high or low antibody response post-primary immunization (PPI) to sheep erythrocytes (SRBC) and their reciprocal crosses were immunized intravenously with 0.1 ml of 0.25% SRBC antigen in Trials 1 and 3 and with 0.1 ml of 0.025%, 0.25%, or 25% SRBC antigen in Trial 2. All initial immunizations were made at 35 days of age, and 0.1 ml of 0.25% SRBC booster dose was given 24 days later. Results showed that (a) population differences appeared by day 4 PPI and persisted through day 24 PPI, (b) regardless of population, peak titers occurred at about the same time for primary and secondary immunizations, (c) dosage of antigen influenced differences among populations in antibody response to primary immunization, and (d) both selected lines had similar responses in 2-mercaptoethanol-sensitive and 2-mercaptoethanol-resistant antibodies to primary but not secondary immunization.     

Efficacy of ivermectin against induced gastrointestinal nematode infections in goats

The efficacy of ivermectin (0.08 per cent w/v oral solution) at different dose levels was evaluated against induced infections of adult Haemonchus contortus (21 days old) and Trichostrongylus colubriformis (21 days old) and fourth stage larvae of Oesophagostomum columbianum (17 days old), Ostertagia circumcincta (five days old) and Strongyloides papillosus (five days old). Twenty-five Boergoats (mutton goats) were randomly allocated by bodyweight within each sex to an untreated control group and four ivermectin treatment groups; ivermectin was administered at either 25, 50, 100 or 200 micrograms/kg orally, once. The goats were killed and processed for worm recovery 25 to 27 days after treatment. At 25 micrograms/kg the efficacy of ivermectin varied from 43 per cent for adult T colubriformis to more than 99 per cent for fourth larval stage O columbianum. Ivermectin at 50 micrograms/kg or higher was 99 per cent or more effective against all induced parasite infections with the exception of ivermectin at 50 micrograms/kg against S papillosus (97 per cent). For all parasites there was a statistically significant (P less than 0.05) difference between the control group and the pooled treated groups. No adverse reactions to ivermectin treatment were observed in the goats.     

Introduction to endoscopy

Endoscopy is an area of rapidly growing interest within veterinary medicine. This is understandable, because it is a relatively noninvasive procedure in which a tremendous amount of diagnostic data may be obtained. The purpose of this article is to introduce the novice to the equipment and potential uses of endoscopy.