Fetal losses and pathologic findings of clones derived from serum-starved versus serum-fed bovine ovarian granulosa cells.

The objective was to evaluate development of cloned embryos constructed with serum-starved versus fed ovarian granulosa cells. Fusion of somatic cells with cytoplasts (50.7 and 50.7%; SEM=5.5), development of cloned embryos to 8-16-cell (59.4 and 62.6%; SEM=6.4), and compact morula/blastocyst-stages (24.9 and 26.5%; SEM=8.5) was similar for serum-starved and fed groups. More heifers were confirmed pregnant with clones derived from serum-starved cells (9/13, 67.2% versus 11/25, 44%). However, embryonic loss between 29-50 days was greater for clones constructed with serum-starved (88.9%) versus fed (36.4%) cells. Development of clones derived from serum-fed cells through placentation and differentiation was not predictive of competency to term. Fetal deaths occurred in the majority of late term pregnancies as a result of complications from hydrallantois. Only one fetus derived from serum-fed ovarian granulosa cells developed to term (278 days). At birth and for approximately 9 consecutive months thereafter, routine veterinary examinations confirmed expected growth patterns. In summary, the use of serum fed granulosa cells for nuclear transfer was coincident with a high incidence of third trimester losses associated with hydrallantois and fetal oversize.

Determination of the acute 50% lethal dose T-2 toxin in adult bobwhite quail: additional studies on the effect of T-2 mycotoxin on blood chemistry and the morphology of internal organs.

Three experiments were conducted to assess mortality rate, blood chemistry, and histologic changes associated with acute exposure to T-2 mycotoxin in adult bobwhite quail. In Experiment 1, adult quail were orally dosed with T-2 toxin to determine the lethal dose that resulted in 50% mortality of the affected population (LD50), and that dose was determined to be 14.7 mg of T-2 toxin per kilogram of body weight (BW). A second experiment was performed to study the effects of 12-18 mg/kg BW T-2 toxin on blood chemistry and liver enzyme profiles. Posttreatment uric acid, aspartate aminotransferase, lactic dehydrogenase, and gamma glutamyltransferase increased as compared with pretreatment values. In contrast, posttreatment plasma total protein, cholesterol, and triglyceride levels numerically decreased as compared with pretreatment values. Changes in blood chemistry values were consistent with liver and kidney damage after T-2 toxin exposure. In Experiment 3, histologic analyses of bone marrow, spleen, liver, small intestine, kidney, and heart were conducted on birds dosed in Experiment 2. Marked lymphocyte necrosis and depletion throughout the spleen, thymus, bursa, and gut-associated lymphoid tissue in the small intestine were observed in birds dosed with 15 and 18 mg/kg BW T-2 toxin. Necrosis of liver and lipid accumulation as a result of malfunctioning hepatocytes were also observed. Little or no morphologic change was observed in bone marrow and heart tissue. The LD50 for adult bobwhite quail as found in this study is two to three times higher than that reported for other species of commercial poultry. Results from these data confirm previous reports of immunosuppressive and/or cytotoxic effects of T-2 toxin in other mammalian and avian species. T-2 toxin may have a negative impact on the viability of wild quail populations.

Adult-onset hypothyroidism in a lynx (Lynx canadensis).

A 19-yr-old female lynx (Lynx canadensis) presented for an acute onset of anorexia and reluctance to move. Physical examination, radiography, hematology, and serum biochemistry revealed evidence of renal failure, presumptive uremic gastritis, chronic intervertebral disk disease at T13-L1, and markedly low serum levels of total thyroxine (1.54 nmol/L) and total triixodothyronine (0.55 nmol/L). Twenty-five hours after its original presentation, the lynx exhibited horizontal nystagmus, which has been suggested as a clinical sign associated with hypothyroidism in domestic dogs. The lynx was euthanatized because of poor prognosis, and medical management concerns related to its chronic renal failure. Necropsy examination substantiated that the lynx had true hypothyroidism with 60-90% of the thyroid gland replaced with adipose tissue. Although feline adult-onset hypothyroidism may have low incidence, it should still be considered as a cause of nonspecific signs of disease in cats, as well as signs suggestive of hypothyroidism. Routine monitoring of baseline exotic felid thyroid levels throughout life would help to identify normal values and diagnose a potential disease that has obscure clinical signs.

Interobserver variation among histopathologic evaluations of intestinal tissues from dogs and cats.

OBJECTIVE: To determine whether substantial interobserver variation exists among diagnostic pathologists for descriptions of intestinal mucosal cell populations and whether histopathologic descriptions accurately predict when a patient does not have clinically evident intestinal disease. DESIGN: Comparative survey. Sample Population-14 histologic slides of duodenal, ileal, or colonic tissue from 10 dogs and 3 cats. PROCEDURE: Each histologic slide was evaluated independently by 5 pathologists at 4 institutions. Pathologists, who had no knowledge of the tissues' origin, indicated whether slides were adequate for histologic evaluation and whether the tissue was normal or abnormal. They also identified the main infiltrating cell type in specimens that were considered abnormal, and whether infiltrates were mild, moderate, severe, or neoplastic. RESULTS: Quality of all slides was considered adequate or superior by at least 4 of the 5 pathologists. For intensity of mucosal cellular infiltrates, there was uniformity of opinion for 1 slide, near-uniformity for 6 slides, and nonuniformity for 7 slides. Five dogs did not have clinical evidence of intestinal disease, yet the pathologists' descriptions indicated that their intestinal tissue specimens were abnormal. CONCLUSIONS AND CLINICAL RELEVANCE: Substantial interobserver variation was detected. Standardization of pathologic descriptions of intestinal tissue is necessary for meaningful comparisons with published articles. Clinicians must be cautious about correlating clinical signs and histopathologic descriptions of intestinal biopsy specimens.

Diagnosis and Treatment of Trichospirura leptostoma Infection in Common Marmosets (Callithrix jacchus).

Trichospirura leptostoma is a spirurid nematode that inhabits the pancreatic ducts of the common marmoset, Callithrix jacchus, and other New World primates. This parasite was diagnosed in members of this species at the Marmoset Research Center in Oak Ridge, Tennessee colony after their importation from multiple colonies outside the United States. Animals with few parasites in the pancreas had few tissue changes, whereas those with many parasites had moderate to severe fibrosis replacing exocrine tissue. Trichospirura leptostoma can cause chronic pancreatitis, resulting in subclinical to clinical pancreatic insufficiency and secondary malnutrition. Clinical signs of pancreatic insufficiency in affected marmosets included weight loss (despite good appetite) and increased fecal volume. Because earlier reports did not mention treatments, experimental therapeutic regimens were attempted to eliminate infections from the marmosets. In the clinical studies, different doses and treatment periods with ivermectin and fenbendazole were evaluated for therapeutic efficacy. Fenbendazole given daily at a dosage of 50 mg/kg of body weight by gavage for 14 days was the most effective treatment (PI 0.052). Control of the cockroach vector, as well as treatment of infected animals, is needed to prevent Trichospirura leptostoma-induced disease.