Chlamydia pneumoniae infection in a breeding colony of African clawed frogs (Xenopus tropicalis).

More than 90% of a breeding colony of clawed frogs (Xenopus tropicalis) imported to the United States from western Africa died in an epizootic of chlamydiosis. Chlamydial inclusions were observed by light and electron microscopy in the liver of an infected frog. Chlamydia pneumoniae was isolated in cell cultures from four frogs. A cutaneous infection by a chytridiomycete fungus observed in two frogs could have been a cofactor in the die-off.ous Diseases

Cytogenetic survey of Holstein bulls at a commercial artificial insemination company to determine prevalence of bulls with centric fusion and chimeric anomalies.

OBJECTIVE: To determine prevalence of Holstein bulls with chromosomal anomalies, particularly the 1/21 centric fusion (CF), at a commercial artificial insemination (AI) company in the United States. DESIGN: Cross-sectional cytogenetic prevalence study. ANIMALS: All 606 Holstein bulls at a commercial AI company were cytogenetically screened to detect CF, chimerism, and other chromosomal abnormalities. PROCEDURE: Lymphocytes from heparinized blood samples were cultured by standard cytogenetic techniques, and chromosome spreads were prepared for microscopic examination. Chromosomal abnormalities were detected by examining 10 chromosome spreads per bull. Pedigree analysis was performed. RESULTS: None of the bulls had any type of CF. However, 6 bulls were identified as chimeras (i.e., contained lymphocytes with male [XY] and female [XX] chromosomes). One bull was sire or maternal grandsire to 85 of the bulls tested, and 739 of 1,212 (61%) sire and maternal-grandsire possibilities were accounted for by just 18 bulls. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of these results supports previous indications that CF is extremely rare in Holstein bloodlines available commercially via AI in the United States. However, chimeric bulls are more common, and they reportedly have decreased reproductive performance. Therefore, identification of chimeric sires in the AI facility reported here and the possibility of de novo onset of CF at any time indicates that early cytogenetic screening should be encouraged for prospective bulls intended for use in AI programs.

XX/XY chimerism and freemartinism in a female llama co-twin to a male.

A 20-month-old female llama was examined because at the time of mating, the male llama was apparently unable to achieve intromission. The female llama had been born co-twin to a male. On physical examination, the vaginal vestibule appeared to end in a blind pouch, and the uterus, cervix, and ovaries could not be identified during transrectal palpation or ultrasonography. Karyotyping was done, and 43% of blood lymphocytes had 2 X chromosomes, and 57% had 1 X and 1 Y chromosome. All skin fibroblasts had 2 X chromosomes. A diagnosis of freemartinism and XX/XY chimerism was made. Because conception of twins may be more common in llamas than birth of twins, it is possible that freemartinism could develop in singleton females, if, for instance, a male twin was conceived and died after the placentas had anastomosed. More widespread use of karyotyping in llamas with congenital defects of the reproductive tract will help to define the incidence of freemartinism.

Epizootic of paratuberculosis in farmed elk.

After multiple cases of chronic diarrhea and weight loss in a farmed elk herd, 3 yearlings and 1 adult elk with similar clinical signs were euthanatized and necropsied. Gross and histologic evidence of paratuberculosis were found in the yearlings. Evidence of serum antibody to Mycobacterium paratuberculosis was detected in the 2 elk with the most disseminated infection. Acid-fast organisms were isolated from multiple organs in all 4 elk and identified as M paratuberculosis by DNA probe. Thirty-five percent of 1 calf crop (n = 31) died or were euthanatized because of paratuberculosis before they were 2 years old. The organism was believed to have been spread by standing water that was used by calves as a wallow and a source of drinking water. The water was believed to have been contaminated by an infected adult female elk introduced to the herd just before calving season.

A novel stop codon mutation (X417L) of the ferrochelatase gene in bovine protoporphyria, a natural animal model of the human disease.

Protoporphyria (PP) is caused by a deficiency of ferrochelatase (FC) activity, which catalyzes the final step in the heme biosynthesis pathway. Bovine are the only species other than man with naturally occurring PP. For expression of the PP phenotype, two copies of the mutated gene are necessary in bovine, whereas one copy is sufficient in humans. We report the first potential disease-causing mutation in the bovine FC gene. The coding region of FC was sequenced from the liver tissue of protoporphyric and normal bovine. A transversion was identified at nucleotide position 1250 which changed the stop codon to leucine (TGA-->TTA) in the protoporphyric FC sequence. As a consequence, the mutant protein is predicted to have an additional 27 amino acids. To screen other bovine for the G-->T transversion, cDNAs from liver tissue of clinically and biochemically normal, and from heterozygous and homozygous affected animals were used for allele-specific polymerase chain reaction. Three normal animals had only the G allele, five affected animals had only the T allele, and three heterozygous animals had both the G and T alleles. These results support our hypothesis that this mutation causes PP in bovine.

X-chromosome monosomy in an infertile female llama.

A 3-year-old female llama was examined because of a history of infertility and apparent anovulation. The llama had indifferent behavior when penned with a male, but eventually would assume sternal recumbency for breeding. On examination, the llama was underweight and small in stature. The uterine horns and ovaries could not be identified during palpation or ultrasonography per rectum, and the cervix was dilated when examined with a speculum. Chromosomal preparations of lymphocytes and skin fibroblasts were performed; all cells examined had a 73, X karyotype (X-chromosome monosomy). To our knowledge, this is the first report of a chromosomal anomaly in a llama. Signs seen in this llama were similar to those seen in mares with X-chromosome monosomy. This condition should be considered in the differential diagnosis of infertility in llamas that fail to ovulate, especially if other abnormalities such as indifferent sexual behavior and short stature are present.

Ferula communis variety brevifolia intoxication of sheep.

Sheep given powdered Ferula communis variety brevifolia at dosage of 2.5 g/kg of body weight/d for 15 days developed classical clinical signs of intoxication: anorexia, somnolence, apparent weakness, and hemorrhage. Marked reduction of vitamin K-dependent coagulation factors and prolongation of prothrombin time and activated partial thromboplastin time were consistent with presence of ferulenol, a toxic coumarinic factor in the plant. Changes induced in the coagulation system developed by the second day of plant administration and were normal within 4 days after dosing was stopped. There was no evidence of primary liver damage or platelet malfunction. Of 6 intoxicated sheep, 2 died with only minimal evidence of hemorrhage.

Plasma ferulenol concentration and activity of clotting factors in sheep with Ferula communis variety brevifolia intoxication.

Dynamics of plasma ferulenol concentration and its effect on the vitamin K-dependent coagulation factors, prothrombin time (PT), and activated partial thromboplastin time (APTT) were determined in 4 sheep intoxicated individually with 600 g of powdered Ferula communis variety brevifolia (FCb) given in 8 doses at intervals of 6 hours. Ferulenol was detected in the plasma of all sheep at initial blood sample collection, 6 hours after the first dose of approximately 75 g of FCb was placed in the rumen. The last observed peak of approximately 20 micrograms/ml was detected at about 12 hours after the last of 8 doses, and the mean concentration then decreased to < 1 microgram/ml during the next 70 hours. Maximal concentration of ferulenol and time for plasma clearance varied with individual sheep. The PT increased steadily to a maximum of 6 times normal about 70 hours after the last peak plasma ferulenol concentration and about 80 hours after FCb administration was stopped. The PT then returned to almost normal (ratio of 1.12) from the maximum (ratio of 6.12) within approximately 5 days. The APTT results generally paralleled the PT results, but the change was not as marked. Maximal PT and APTT ratios were animal-dependent and not always related to plasma ferulenol concentration. The activity of all the vitamin K-dependent coagulation factors was depressed, but the variations were unique to each factor. Factor V, a vitamin K-independent coagulation factor actually had a brief period of increased plasma activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of freemartinism in cattle: the need for clinical and cytogenic evaluation.

A total of 727 blood samples from female calves born co-twin to male calves were examined cytogenetically for freemartinism between 1978 and 1992. Six hundred calves (82.5%) were determined to be freemartins, and 127 (17.5%) were determined not to be freemartins. The percentage of calves determined not to be freemartins was substantially higher than the 8% reported for an unselected population of female co-twins. We concluded that some obvious freemartins were eliminated prior to submission of samples for confirmatory cytogenetic diagnosis, and that only a small percentage of the estimated 93,000 female calves born co-twin to male calves annually are so examined. Therefore, probably a large number of female co-twins that are not truly freemartins are sold to slaughter every year. We propose that obvious freemartins be identified by use of the vaginal-length test and that the remaining clinically questionable calves be differentiated cytogenetically. This combination of procedures could prevent unnecessary economic losses and preserve important genetic material. Three animals with chromosomal anomalies were found during examination of samples for freemartinism. Cytogenetic evaluation for freemartinism thus offers the added value of simultaneous surveillance for cytogenetic aberrations in male and female cells of a sample.

A chromosomal reciprocal translocation (1q+; 14q-) in a boar siring reduced litter sizes.

In our initial cytogenetic surveillance of boars one of 15 was found to be hypoprolific. It averaged 7.1 piglets per litter in over 51 monospermic matings with sows which, with other boars averaged 10.8 piglets per litter. Cytogenetic evaluations revealed only the hypoprolific boar to have an abnormal karyotype, namely {38XY, t(1;14) (q2.12, q2.2)}. This represents a new type of 1;14 reciprocal translocation, and also the first report of a reciprocal translocation for swine in the United States.

Toxicosis in horses after ingestion of hoary alyssum.

Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.

Prevalence of the 14/20 centric fusion chromosomal aberration in US Simmental cattle.

Cytogenetic evaluation was made on 353 Simmental cattle (166 male, 187 female) from 113 herds in 26 states. One hundred thirty-eight (39%) were found to be heterozygous-positive for the 14/20 centric fusion chromosomal translocation, including 41 (25%) males and 97 (52%) females. One submitted heparinized blood sample from a Simbrah bull was found to be positive for 14/20 and 1/29 centric fusions. Sampling, which was based on requests, was highly selective. Thus, the 39% prevalence found was not representative of 14/20 centric fusion in the national Simmental breed. On the basis of our findings, cytogenetic evaluation of breeding stock was consistent with modern management practice.

Lesions of perirenal hemorrhage syndrome in growing turkeys.

Turkeys from six market flocks were examined at 8 to 19 weeks of age to assess morphologic lesions of perirenal hemorrhage syndrome (PHS). PHS was diagnosed in 165 of 715 turkeys necropsied, and 82 turkeys served as age- and weight-matched controls. The most consistent gross findings were rounded pectoral muscles of normal color, ingesta-filled crops and gizzards, variable retroperitoneal perirenal hemorrhage, a swollen dark red and light purple spleen, congested intestinal blood vessels, and pulmonary edema and/or hemorrhage. The main histologic lesions of PHS were perivascular edema in lungs and kidneys, vascular congestion of various organs, renal perivenous hemorrhage, and proliferative arterial and arteriolar lesions in the spleen and kidneys that were more severe than those in controls. Heart weights, including mean relative weights of the right and combined left ventricles and interventricular septa, were significantly greater in turkeys that died with PHS than in controls. Scores for tibial dyschondroplasia and "breast blisters" were more severe in turkeys that died with PHS than in controls. The cardiovascular system appeared to be the PHS target system.

The incidence of perirenal hemorrhage syndrome in six flocks of market turkey toms.

Four flocks of the Nicholas strain and two of the British United turkey (BUT) strain of large white market turkey toms were monitored from 8 to 19 weeks of age to identify the presence, incidence, age distribution, and possible cause(s) of perirenal hemorrhage syndrome (PHS), or acute hypertensive angiopathy. Mortality rates varied among the flocks from 0.81% to 1.78% of total poults started. Nicholas flocks has a distinct peak in mortality between 9 and 14 weeks of age. PHS was the main cause of mortality from 8 to 14 weeks of age in all flocks except one, and the incidence diminished after 15 weeks of age. No significant bacterial pathogens were detected in any of the PHS cases. Distinct peaks in overall weekly mortality between 10 and 13 weeks of age similar to those in the four Nicholas flocks were also observed in six of 10 Minnesota flocks surveyed separately.