Pathogenesis of two strains of lion (Panthera leo) morbillivirus in ferrets (Mustela putorius furo).

Canine distemper virus (CDV) was previously considered to have a host range restricted to the canid family. In 1994, the virus was associated with sporadic outbreaks of distemper in captive felids. However, after severe mortality occurred in the Serengeti lions (Panthera leo), attention became focused on the pathogenesis of the virus and a concerted effort was made to identify the virus as CDV or a closely related feline morbillivirus. The present study was designed to explore the susceptibility of ferrets to challenge with two morbilliviruses isolated from lions and the protective effects of a modified-live mink distemper vaccine. Because mortality in ferrets infected with pathogenic CDV approaches 100%, the ferret was selected as a test animal. Two strains of lion morbillivirus were used as a challenge, A92-27/20 (California lion isolate) and A94-11/13 (Serengeti lion isolate). The two strains of lion morbillivirus were antigenically related to CDV (Rockborn strain), and ferrets were susceptible to both of the viruses when inoculated intraperitoneally. The inoculated ferrets were anorectic at 5-6 days postinoculation (PI), exhibited oculonasal discharge at 9-12 days PI, and became moribund at 12-22 days PI. Severe bilateral conjunctivitis was the typical clinical sign. Inclusion bodies characteristic of morbillivirus (eosinophilic, intranuclear, and intracytoplasmic) were distributed in many epithelial cells, including those of the skin, conjunctiva, gallbladder, liver, pancreas, stomach, trachea, lung, urinary bladder, and kidney. Virus was reisolated from selected lung tissues collected at necropsy and identified by CDV-specific immunofluorescence. Ferrets vaccinated with the mink distemper vaccine (Onderstepoort strain) were protected from challenge with the two lion strains, adding further support to the premise that the viruses are closely related to CDV.

Efficacy of parathyroid gland autotransplantation in maintaining serum calcium concentrations after bilateral thyroparathyroidectomy in cats.

Bilateral thyroidectomy is a commonly indicated treatment for feline hyperthyroidism. The most common postoperative complication is hypocalcemia due to disruption of the parathyroid glands. When parathyroid gland disruption is obvious, many authors suggest autotransplantation (AT) of the glands. This technique never has been supported by a scientific study which monitored postoperative calcium or parathyroid hormone (PTH) concentrations. Cats in this study each underwent bilateral thyroidectomy and parathyroid AT to mimic a clinical situation. Serum calcium concentrations normalized much quicker than concentrations in previously reported cats undergoing bilateral thyroidectomy and parathyroidectomy. Parathyroid AT greatly reduces morbidity in the parathyroidectomized cat.

Retrospective review of 50 canine intracranial tumors evaluated by magnetic resonance imaging.

Magnetic resonance imaging (MRI) was performed on 50 dogs with intracranial neoplasia. The following tumor features were assessed: axial origin, location, shape, growth pattern, MRI signal intensity, evidence for edema, and paramagnetic contrast enhancement. Histologic diagnosis included 5 intracranially invading nasal tumors, 7 pituitary tumors, 22 meningiomas, 6 choroid plexus tumors, 7 astrocytomas, 1 ependymoma, and 2 oligodendrogliomas. Axial origin, site, shape, and growth pattern were important diagnostic characteristics for tumor type. Signal intensity and contrast enhancement pattern allowed further differentiation. Characteristic MRI features that facilitate diagnosis and prognosis were identified. Accurate diagnosis of tumor type based on these features was not always possible because of similarities in MRI appearance for some tumors. Tissue biopsy remains necessary for definitive diagnosis of intracranial tumors.

Bot fly larvae (Cephenemyia jellisoni) as a cause of neurologic signs in an elk.

In June 1993, a yearling female elk (Cervus elaphus) near John Day, Oregon (USA) was observed twice over a four week period with signs of neurologic disease including weakness, walking in circles with an uncoordinated gait and disorientation. The elk was shot, and the head and neck were examined grossly for parasites and lesions. Thirty-five second and third instar larvae of Cephenemyia jellisoni were recovered from an encapsulated space in the nasopharyngeal area dorsal to the soft palate. Larvae protruded into the caudodorsal end of the ventral nasal meatus, obliterating the opening of the left eustachian tube. Larvae were not recovered from their normal location in the retropharyngeal recesses. Thus the effects of several Cephenemyia jellisoni larvae in an aberrant location mimicked signs observed in meningeal worm infections.

Thromboxane as a measure of cutaneous vascular damage following irradiation.

The present study was designed to evaluate the role of thromboxane in radiation-induced cutaneous injury and to use the quantitation of cutaneous thromboxane B2 as an indicator of vascular alteration and tissue viability in canine skin. Ten adult intact male dogs underwent epithermal neutron irradiation with or without boron neutron capture. Skin biopsies were obtained from (1) within, (2) the edge of, and (3) outside the radiation field at 5, 8, 11, 14, 21, and 90 days after irradiation. Clinical changes at each sampling time were assigned a numerical score. One-half of each biopsy was assigned a numerical score based on histologic changes. Thromboxane B2 was measured from the second half by enzyme immunoabsorbent assay. Thromboxane B2 concentration paralleled the response of clinical and histologic score over time, indicating the value of thromboxane measurement for evaluation of skin changes secondary to irradiation.

SCID mouse spleen does not support scrapie agent replication.

BALB/c and severe combined immunodeficiency (SCID) mice were inoculated intracerebrally or intraperitoneally with scrapie agent strain ME7 to examine the role of functional lymphocytes and follicular dendritic cells in splenic infectivity and PrPSc accumulation. Intracerebrally inoculated BALB/c and SCID mice developed the clinical signs and microscopic lesions characteristic of scrapie. Spleens from terminally affected BALB/c mice contained PrPSc which was detectable by immunoblot analysis; SCID mouse spleens did not contain detectable PrPSc. SCID mouse spleens collected during the first 90 days after intraperitoneal infection contained neither infectivity nor PrPSc.

Biodistribution of boron in dogs with spontaneous intracranial tumors following borocaptate sodium administration.

Borocaptate sodium (Na2B12H11SH) is a potentially useful compound for boron neutron capture therapy of intracranial tumors. Tumor and normal tissue boron concentrations were evaluated in 30 dogs with naturally occurring intracranial tumors after i.v. borocaptate sodium infusion (55 mg boron/kg). Postmortem tissue boron concentrations were measured for three postinfusion time periods (2, 6, and 12 h) by inductively coupled plasma atomic emission spectroscopy. Mean boron concentrations for extracerebral tumors were 40.6 +/- 16.9 (2 h; n = 8), 25.9 +/- 11.7 (6 h; n = 5), and 8.6 +/- 4.5 micrograms boron/g (12 h; n = 6). Mean boron concentrations for intracerebral tumors were 30.6 +/- 17.5 (2 h; n = 7) and 2.9 +/- 1.8 micrograms boron/g (6 h; n = 4). Mean tumor boron concentrations were lower at longer postinfusion times. The tumor:normal brain boron concentration ranged from 0.8 to 19.8. Tumor:blood boron concentrations were less than one for all but three dogs and ranged from 0.04 to 1.4. Mean peritumor boron concentrations were highly variable but exceeded that of normal brain in 10 of 20 dogs. In some dogs, the mean peritumor boron concentration was similar to or exceeded the tumor boron concentration. Distant or contralateral normal brain had consistently low boron concentrations. Some cranial and systemic tissues had high boron concentrations, indicating substantial extravascular boron. The spontaneous animal tumors provided a realistic spectrum of data and enabled extensive sampling of diseased and normal tissues. The biodistribution of boron from borocaptate sodium administration was partially favorable because of high tumor boron concentrations. Empirical radiation dose tolerance studies should be used to determine the impact of the unfavorably high boron concentration of blood and some cranial tissues.

Borocaptate sodium: a potential boron delivery compound for boron neutron capture therapy evaluated in dogs with spontaneous intracranial tumors.

Borocaptate sodium (Na2B12H11SH) is a boron-carrying compound under consideration for use in boron neutron capture therapy. The biodistribution of boron from borocaptate sodium administration will partly determine boron neutron capture therapy efficacy and normal tissue radiation tolerance. The biodistribution of boron was determined in 30 dogs with spontaneous intracranial tumors at 2, 6, or 12 hr after intravenous borocaptate sodium infusion. Blood and tissue boron concentrations were measured using inductively coupled plasma atomic emission spectroscopy. Mean tumor boron concentration (mean +/- standard error) was 35.9 +/- 4.6 (n = 15), 22.5 +/- 6.0 (n = 9), and 7.0 +/- 1.1 micrograms of boron per g (n = 6) at 2, 6, and 12 hr, respectively, after borocaptate sodium infusion. Peritumor boron concentrations were elevated above that of normal brain in half of the dogs. Normal brain boron concentration (mean +/- standard error) was 4.0 +/- 0.5, 2.0 +/- 0.4, and 2.0 +/- 0.3 micrograms of boron per g at 2, 6, and 12 hr after infusion, respectively. Some cranial and systemic tissues, and blood, had high boron concentration relative to tumor tissue. Geometric dose sparing should partly offset these relatively high normal tissue and blood concentrations. Borocaptate sodium biodistribution is favorable because tumor boron concentrations of recommended magnitude for boron neutron capture therapy were obtained and there was a high tumor-to-normal brain boron concentration ratio.

Naturally occurring aortic aneurysms in owl monkeys (Aotus spp.).

Spontaneous aortic aneurysms were diagnosed in 22 owl monkeys (Aotus spp.) at necropsy. There were 6 males and 16 females. Clinical findings varied including weight loss, weakness, and lethargy and were not present in all animals. Aortic lesions ranged in size from 2 mm to 3 cm in diameter. Nineteen of the aneurysms were classified histologically as dissecting and three as saccular. Lesions occurred less often in karyotype I monkeys than in karyotype II or III monkeys. The etiopathogenesis of aortic aneurysm in owl monkeys is unknown.

Psyllium husk. I: Effect on plasma lipoproteins, cholesterol metabolism, and atherosclerosis in African green monkeys.

Psyllium's effects on plasma and lipoprotein cholesterol concentrations, cholesterol metabolism, and diet-induced atherosclerosis were studied in adult male African green monkeys (Cercopithecus aethiops). Animals were fed for 3.5 y one of three experimental diets: low-cholesterol cellulose (LCC), high-cholesterol cellulose (HCC), or high-cholesterol psyllium (HCP). The LCC and HCP groups had significantly (P less than 0.05) lower plasma cholesterol concentrations (39% lower) at 1 mo than did the HCC group. These responses persisted throughout the study. Plasma cholesterol changes were due to a reduction in intermediate-density and low-density lipoproteins; very-low and high-density-lipoprotein concentrations were similar among groups. Aortic atherosclerosis, evaluated as percent sudanophilia at 3.5 y, was lowest in the LCC group, intermediate in the HCP group, and highest in the HCC group. Cholesterol absorption, neutral steroid and fat excretion, HMGCoA reductase activity (in intestine and liver), and body weight were unrelated to psyllium's hypocholesterolemic effects.

Psyllium husk. II: Effect on the metabolism of apolipoprotein B in African green monkeys.

Dietary psyllium's ability to reduce low-density-lipoprotein (LDL) cholesterol is presumably mediated by increased LDL catabolism and/or reduced LDL synthesis. To distinguish between these possibilities, apolipoprotein B (apo B) metabolism was studied in adult male African green monkeys consuming one of three semipurified diets: low-cholesterol cellulose (LCC), high-cholesterol cellulose (HCC), or high-cholesterol psyllium (HCP). 131I-labeled LDL and 125I-labeled VLDL were injected simultaneously into animals; blood samples were drawn at selected times and apo B specific activity determined in VLDL, IDL, and LDL. Based on a multicompartmental model, LDL apo B pool size and de novo apo B transport were elevated significantly in HCC animals compared with HCP and LCC animals. Differences in LDL transport, although not significant, paralleled differences observed in LDL apo B pool size. Fractional catabolic rates were similar among groups (HCC 0.040 +/- 0.010; HCP 0.042 +/- 0.009, and LCC 0.043 +/- 0.004 pools/h). These data suggest that dietary psyllium reduces plasma cholesterol concentrations by decreasing LDL synthesis.

Squamous cell carcinoma in a free-ranging bighorn sheep (Ovis canadensis californiana).

An oral squamous cell carcinoma which invaded maxillary bones with metastasis to the right retropharyngeal lymph node was diagnosed in a free-ranging California bighorn sheep (Ovis canadensis californiana) from Washington. Much of the maxillae had been replaced with tumor and reactive tissue, and many teeth were missing or loose. The tumor was predominantly confined to the shape of the maxillary bones and was unusual because it was bilaterally symmetrical.

Diffuse cerebral and leptomeningeal astrocytoma in dogs: MR features.

Magnetic resonance (MR) imaging has increased sensitivity in detection of nonenhancing brain tumors and may show the extent of CNS neoplasia with greater detail than CT. Magnetic resonance images of the canine brain were acquired in two dogs with diffuse leptomeningeal and cerebral low grade astrocytoma. Abnormalities were identified with MR imaging when CT and CSF analysis were noncontributory. Changes seen with MR included decreased signal on T1-weighted images and increased signal on T2-weighted images consistent with vasogenic edema. Neither MR nor CT showed post-contrast enhancement. Magnetic resonance did not show the full extent of cellular infiltration, however. This was attributed to the diffuse submacroscopic distribution and absence of corresponding edema and contrast enhancement in certain regions of brain.

Isolation of a previously undescribed rickettsia from an aborted bovine fetus.

A previously undescribed obligate intracellular bacterium was isolated from an aborted bovine fetus. The organism was resistant to penicillin, replicated within cytoplasmic vacuoles, exhibited structural characteristics compatible with the rickettsias, and shared antigenic determinants with Cowdria ruminantium.

Neospora caninum-like protozoon associated with fatal myelitis in newborn calves.

Neospora caninum-like organisms were found in histologic sections of spinal cord of 4 paralyzed calves as reported by Parish et al. (1987). Tachyzoites divided by endodyogeny. Tissue cysts were up to 62 microns wide and the cyst wall was up to 2.5 microns thick. The organism in calves was structurally distinct from Toxoplasma gondii and Sarcocystis species and reacted positively with anti-N. caninum serum in an immunoperoxidase test.

Phaeohyphomycosis caused by Alternaria alternata in a cat.

Phaeohyphomycosis caused by Alternaria alternata was diagnosed in a 6-year-old cat. A lesion in the nose resulted in enlargement of the dorsum of the nose. Similar appearing lesions had been removed from the dorsum of the nose 1 and 4 years earlier. The lesion recurred 3 months after surgical excision and irregular administration of ketoconazole. A second cytoreductive operation followed by 5 months' treatment with ketoconazole resolved the infection. Nasal trauma occurring at 8 months and at 5 years before initial examination may have predisposed the cat to development of the Alternaria infection.

Myelitis associated with protozoal infection in newborn calves.

Four newborn calves from different herds were examined because of recumbency and inability to rise. Abnormal physical findings were confined to the nervous and/or musculoskeletal systems. Because of poor prognosis, all calves were euthanatized and necropsied. The histopathologic findings were multifocal lymphocytic myelitis, meningitis, and encephalitis associated with protozoal cysts.

Comparisons of feline panleukopenia virus, canine parvovirus, raccoon parvovirus, and mink enteritis virus and their pathogenicity for mink and ferrets.

Parvoviruses from mink (mink enteritis virus [MEV]), cats (feline panleukopenia virus [FPV]), raccoons (raccoon parvovirus [RPV]), and dogs (canine parvovirus [CPV]) were compared. Restriction enzyme analysis of the viral replicative-form DNA revealed no consistent differences between FPV and RPV isolates, but CPV and MEV isolates could be distinguished readily from other virus types. Feline panleukopenia virus, RPV, and MEV, but not CPV, replicated to high titers in mink. However, on the first passage, disease and microscopic lesions were observed only in mink inoculated with MEV. Feline panleukopenia virus and RPV isolates replicated in ferrets, but disease or microscopic lesions were not observed. Feline panleukopenia virus and RPV isolates could be passaged repeatedly in mink and ferrets. Virulence of FPV and RPV isolates was low compared with that of MEV, and only a single mink inoculated with FPV or with RPV developed clinical disease on the sixth passage of virus.