Validation of the periodicity of growth zone formation in the otoliths of four fish species from the Upper Zambezi ecoregion,southern Africa

In the Upper Zambezi and Okavango ecoregions, Brycinus lateralis, Hepsetus cuvieri, Schilbe intermedius and Serranochromis macrocephalus are important in subsistence fisheries, while S. intermedius and S. macrocephalus are often caught in commercial catches. Despite their importance, there is little information on their age and growth and age validation. Growth zone deposition rate in otoliths of B. lateralis, H. cuvieri, S. intermedius and S. macrocephalus was validated as annual using edge analysis in this study. Annual deposition of growth zones was corroborated by a fluorochrome marking experiment. Both methods demonstrated that one growth zone was deposited annually. Edge analysis demonstrated that the highest proportion of opaque zones was detected between August and December, most likely as a result of slow growth during lower temperature water during the preceding winter. With growth zone deposition validated as annual, future research should focus on determining the growth, maturity and mortality rates of these species, parameters which are important for their management.     

Retrospective study of bacterial infective arthritis in 31 dogs

OBJECTIVES: To characterise the presenting signs and pathological changes of canine bacterial infective arthritis in 31 dogs, and to document the response to different treatment regimens. Risk factors that may predispose joints to bacterial infective arthritis and influence the success of treatment were also investigated. METHODS: A retrospective review of cases of bacterial infective arthritis that were presented to three university veterinary referral hospitals over a five-year period (January 1997 to January 2002) was performed. RESULTS: The elbow joint (38 per cent) and stifle joint (44 per cent) were most commonly affected. Radiographic changes consistent with pre-existing osteoarthritis were identified in 14 joints, which had no history of previous surgery (articular or periarticular) or penetrating wound. No significant difference (P = 0.78) was identified between the outcome of combined surgical and medical management, and medical management alone. There were trends for poorer outcomes with increased bodyweight of the dog, longer duration of lameness and a higher nucleated cell count of the affected joint fluid at presentation. The overall infection rate for articular surgical procedures at one institution was 1-3 per cent. CLINICAL SIGNIFICANCE: Medical and/or surgical management were usually successful in resolving infection (94 per cent). However, they were frequently unsuccessful in restoring full joint function; this may in part have been due to the nature of the underlying joint     

Uveodermatologic syndrome in a rat terrier

A 4 yr old intact male rat terrier presented with severe bilateral nonresponsive panuveitis. Bilateral uveitis, blepharospasm, conjunctival hyperemia, diffuse corneal edema, peripheral bullous retinal detachment, and secondary ocular hypertension were noted. Ocular lesions progressed despite aggressive medical treatment and were followed by cutaneous depigmentation and crusting along the nasal planum. Intensive oral and topical anti-inflammatory and topical antiglaucoma medications were administered, but the ocular disease progressed. A bilateral enucleation was performed. Uveodermatologic syndrome was diagnosed from histopathologic examination of a skin biopsy as well as histopathology of both globes after bilateral enucleation. To maintain control of the dermatologic lesions, oral azathioprine was initiated, but it was not well tolerated by this patient. Immunosuppressive doses of oral cyclosporine and anti-inflammatory doses of oral prednisone were used to control the depigmentation and crusting skin lesions.     

Laboratory findings, histopathology, and immunophenotype of lymphoma in domestic ferrets

Lymphoma is a common tumor in ferrets, but anatomic distribution, histomorphology, immunophenotype, laboratory abnormalities, and response to chemotherapy are incompletely defined. In this study, lymphoma was diagnosed by histopathology of tumor tissue in 29 ferrets ranging in age from 0.8 to 8.5 years, including 12 males and 17 females. Tumors involved the viscera of the abdominal cavity (n = 11), thoracic cavity (n = 1), or abdominal and thoracic cavities (n = 7); the skin (n = 2); or the viscera of both body cavities plus other sites (n = 8). Microscopically, all tumors had diffuse architecture. Assessment by histomorphology and immunophenotype classified tumors as peripheral T-cell lymphoma (n = 17), anaplastic large T-cell lymphoma (n = 5), anaplastic large B-cell lymphoma (n = 4), diffuse large B-cell lymphoma (n = 1), and Hodgkin-like lymphoma (n = 2). Cytologic evaluation of tumor tissue was diagnostic in 11 of 13 cases. Twenty-two of 27 ferrets had anemia, 2 had leukemia, and 5 were neutropenic. Common comorbid disorders were adrenal disease (n = 27) and insulinoma (n = 6). Tumors most frequently involved mesenteric lymph nodes, while enlargement of peripheral lymph nodes was uncommon (n = 3). Ferrets with Hodgkin-like lymphoma had massive enlargement of single lymph nodes. Mean survival of ferrets not immediately euthanized was 5.0 months (T-cell lymphoma) and 8.4 months (B-cell lymphoma). Ferrets treated with chemotherapy survived an average of 4.3 months (T-cell lymphoma, n = 9) or 8.8 months (B-cell lymphoma, n = 4). Results indicate that lymphomas in ferrets most commonly affect abdominal viscera, may be amenable to cytologic diagnosis, are frequently associated with anemia and, in some cases, may be chemosensitive, resulting in relatively long survival times.     

Observations on spiral deviation of the penis in beef bulls

Premature spiral deviation of the penis was investigated in 1083 British breed beef bulls in 42 herds in Victoria (35) and Western Australia (7) by means of the serving capacity test. The herd prevalence was 60%. The prevalence of the defect at the initial test for all bulls was 10%. The prevalence in 635 polled bulls was 16% compared to a prevalence of 1 % in 448 horned bulls. The breed prevalence and the number of bulls tested per breed was Red Poll 27% (15), Murray Grey 25% (4), Poll Shorthorn 21 % (34), Angus 17% (415), Poll Hereford 10% (167) and Hereford 1 % (448). The difference between the last 2 breed types was highly significant (P<0.001). The prevalence of the defect increased from 0 to 30% over 9 years in one Victorian herd. The age of affected bulls varied from 2 to 11 years with most affected bulls aged from 3 to 6 years. Common ancestry was found between affected bulls in Western Australia, providing circumstantial evidence that it may be an inherited defect. None of the 103 affected bulls examined in this study had suffered obvious injury to the penis or prepuce. Eighty per cent of 56 affected bulls from Victoria had low serving capacity. Four bulls (2 from each state) with moderate to severe spiral deviation of the penis attained pregnancy rates of 43%, 33%, 3% and 3% respectively, in single sire mating trials. Recommendations for culling defective bulls are presented, based on the herd prevalence and severity of the defect in individual bulls.
It is concluded that bulls with moderate to severe spiral deviation of the penis have reduced fertility and remain permanently affected. The serving capacity test is a valuable diagnostic test for this serving defect in unhandled beef bulls. It is a common, although frequently undiagnosed disorder of polled beef breed bulls in Australia.     

Characterization and mode of inheritance of a paroxysmal dyskinesia in Chinook dogs

Background: Paroxysmal dyskinesias are episodes of abnormal, involuntary movement or muscle tone, distinguished from seizures by the character of the episode and lack of seizure activity on ictal EEG. Hypothesis: Paroxysmal dyskinesia is an inherited, autosomal recessive disorder in Chinook dogs. Animals: Families of Chinook dogs with paroxysmal dyskinesia. Methods: Pedigrees and medical histories were reviewed for 299 Chinook dogs. A family of 51 dogs was used for analysis. Episodes were classified as seizures, paroxysmal dyskinesia, or unknown, and segregation analysis was performed. Results: Paroxysmal dyskinesia was identified in 16 of 51 dogs and characterized by an inability to stand or ambulate, head tremors, and involuntary flexion of 1 or multiple limbs, without autonomic signs or loss of consciousness. Episode duration varied from minutes to an hour. Inter‐ictal EEGs recorded on 2 dogs with dyskinesia were normal. Three dogs with dyskinesia also had generalized tonic‐clonic seizures. One of 51 dogs had episodes of undetermined type. Phenotype was unknown for 6 of 51 dogs, and 28 dogs were unaffected. Segregation was consistent with an autosomal recessive trait. Conclusions and Clinical Importance: This movement disorder is prevalent in the Chinook breed, and consistent with a partially penetrant autosomal recessive or polygenic trait. Insufficient evidence exists for definitive localization; episodes may be of basal nuclear origin, but atypical seizures and muscle membrane disorders remain possible etiologies. The generalized seizures may be a variant phenotype of the same mutation that results in dyskinesia, or the 2 syndromes may be independent.