Objective—To assess the effect of interferon (IFN)-α
on viability of feline corneal epithelial cells, replication
of feline herpesvirus (FHV)-1, and virus-induced cytopathic
Sample Population—Healthy eyes from 10 recently
Procedure—4 replicate primary cultures of feline
corneal epithelial cells were grown after the addition
of 102 to 106 IU of IFN-α/mL. Cultures were examined
every 24 hours for evidence of cytotoxic changes.
Viable cell counts and percentage of viable cells were
determined 48 hours after initiation of culture. In a
separate experiment, cultures of corneal cells were
inoculated with FHV-1 and cultured for 72 hours with
or without 105 IU of IFN-α/mL. The FHV-1–infected cultures
were evaluated for viral-induced cytopathic
effects, and viral titers were determined in samples of
Results—Interferon-α did not have cytotoxic effects
on corneal epithelial cells at concentrations ranging
from 102 to 106 IU of IFN-α/mL. Interferon-α at a concentration
of 105 IU/mL significantly reduced the cytopathic
changes and FHV-1 titers.
Conclusions and Clinical Relevance—Lack of in
vitro cytotoxic effects and efficacy against FHV-1
infection in primary cultures of feline corneal cells
suggests that the in vivo therapeutic effect of IFN-α
should be assessed in controlled clinical trials. (Am J Vet Res 2005;66:210–216)
Objective—To isolate and characterize pure cultures
of feline corneal epithelial cells and to assess the
extent and nature of feline herpesvirus (FHV)-1 infection
in these cells.
Sample Population—Healthy eyes from 23 recently
Procedure—Stroma and epithelium of the rostral
portion of the cornea were surgically isolated, and
epithelial cells were detached from the stroma by
enzymatic incubation. Epithelial cells were cultured in
hormone-supplemented media. Cells were passaged,
and cytokeratin expression was assessed. Cells were
then infected with FHV-1, and cytopathic effects were
Results—Cell cultures were readily established from
samples obtained from each eye and could be maintained
through 6 passages. Cultured cells expressed
cytokeratins 3 and 12 but not other cytokeratins.
Infection with FHV-1 was rapid and caused widespread
Conclusions and Clinical Relevance—Feline corneal
cells cultured in vitro during multiple passages maintain
consistent morphologic characteristics and intermediate
filament expression. They are susceptible to
infection with FHV-1 and may provide a useful in vitro
model for investigation of ocular drugs. (Am J Vet Res 2005;66:205–209)
Objective— To assess the effect of cidofovir on viability
of feline corneal epithelial (FCE) cells, replication
of feline herpesvirus (FHV)-1, and virus-induced cytopathic
Sample Population—Healthy eyes from 14 recently
Procedure—Cidofovir at concentrations ranging from
0.05 to 0.000005 mg/mL was added to primary cultures
of FCE cells, and cytopathic changes and effects
on cell proliferation and cell viability were determined
during the subsequent 48 hours. Efficacy of cidofovir
(0.02 and 0.05 mg/mL) to prevent in vitro infection of
FCE cells with FHV-1 was determined during 72 hours
of culture by assessing viral cytopathic effects and
Results—Cidofovir at concentrations of 0.05, 0.005,
and 0.0005 mg/mL significantly reduced mean viable
cell counts, and cidofovir at a concentration of 0.05
mg/mL significantly reduced the percentage viability
of cultured FCE cells. Minimal cytopathic changes
were observed at concentrations of 0.02 and 0.05 mg
of cidofovir/mL. Cidofovir at concentrations of 0.05
and 0.02 mg/mL abrogated the cytopathic effects
attributable to FHV-1 infection and reduced viral titers
from ≥ 1014 TCID50/mL to ≤ 103.5 TCID50/mL.
Conclusions and Clinical Relevance—Cidofovir in
vitro was highly efficacious against FHV-1 infection of a
primary culture of FCE cells but had cytostatic effects
on cultured cells. (Am J Vet Res 2005;66:217–222)
Case Description—A 5-year-old spayed female cat was evaluated because of lethargy of 3 days' duration, acute respiratory distress, and anemia.
Clinical Findings—Physical examination revealed the cat was in good body condition but had pale mucous membranes and elevated heart and respiratory rates. Results of hematologic analysis indicated the cat had severe anemia (Hct, 0.07 L/L; reference range, 0.28 to 0.49 L/L) and marked rubricytosis (19.0 × 109 cells/L; reference value, 0 cells/L). Results of serologic and PCR assays for detection of FeLV and FIV and PCR assays for detection of Mycoplasma spp were negative. Cytologic evaluation of a bone marrow aspirate and histologic evaluation of a biopsy specimen revealed a predominance of rubriblasts and rubricytes with granulocytopenia. Cytologic evaluation of fine-needle aspirates of the spleen and liver also revealed numerous rubriblasts.
Treatment and Outcome—The cat received transfusions of packed RBCs, and supportive treatment was administered. Analysis of test results yielded a diagnosis of acute myeloid leukemia (erythroid subtype). Because of continued hemolysis and anemia in combination with the diagnosis of erythroleukemia (which has a poor prognosis), the cat was euthanized.
Clinical Relevance—To the authors' knowledge, erythroleukemia has only been reported in cats infected with FeLV. However, results of all diagnostic assays for FeLV were negative in the cat reported here, which suggested that erythroleukemia can develop in cats in the absence of FeLV infection.
Case Description—A 10-year-old Golden Retriever evaluated because of recurrent pericardial and pleural effusion underwent thoracoscopy with biopsy of the pleura and mediastinum.
Clinical Findings—Before thoracoscopy, 5 L of serosanguinous fluid was removed from the pleural cavity via thoracocentesis. During thoracoscopic exploration, it was observed that the parietal pleura and mediastinum were covered by miliary white to tan nodules 1 to 3 mm in diameter. Biopsy specimens were obtained, and partial pericardiectomy was performed. Portal sites were closed routinely. Cytologic evaluation of the pleural fluid revealed high protein concentration and cellularity, with cellular changes consistent with an exfoliating carcinoma. Results of bacterial culture were negative.
Treatment and Outcome—Carboplatin was administered via intracavitary instillation, and prednisone was administered orally. Twenty-one days later, 1 firm, irregularly shaped 6.5 × 3-cm mass and 4 smaller masses were detected in the area of the left thoracic wall where the cannula had been inserted during thoracoscopy. Histologic analysis of tissue from the masses collected at necropsy confirmed that they were malignant tumors with similar appearance to the pleural mesothelioma and immunohistochemical staining properties identical to those of the primary tumor.
Clinical Relevance—Although thoracoscopy is associated with less postoperative pain, shorter hospitalization times, and faster patient recovery than sternotomy procedures, complications are also possible with minimally invasive endoscopic surgery. Portal site metastasis can develop from contamination of portal sites with cells on instruments or cannulas or via leakage of effusion fluid. Although rare, this potential complication should be discussed with owners prior to performing the procedure.
Objective—To compare differential cell counts and
cell characteristics of CSF samples analyzed immediately
or after storage for 24 and 48 hours at 4 C with
and without the addition of autologous serum.
Animals—36 dogs and 6 cats.
Procedure—CSF samples were collected from the
cerebellomedullary cistern and divided into 250-μl
aliquots. Slides of CSF samples were prepared by use
of cytocentrifugation immediately and after 24 and 48
hours of storage with addition of autologous serum
(final concentrations, 11 and 29%). Differential cell
counts and number of unrecognizable cells were
compared among preparations.
Results—Significant differences in the differential
cell counts were not detected among samples analyzed
before or after storage. Although the number of
unrecognizable cells increased with storage time,
this did not result in a significant effect on cell distribution
or diagnosis. Cells in CSF samples stored with
11% serum more closely resembled cells in fresh
samples than did cells in samples stored with 29%
Conclusions and Clinical Relevance—CSF samples
collected at veterinary clinics remote from a diagnostic
laboratory or during nonoperational hours may be
preserved through the addition of autologous serum.
Evaluation of such samples is likely to result in an
accurate diagnosis for at least 48 hours after collection.
(J Am Vet Med Assoc 2000;216:1761–1764)
Objective—To determine associations between oral health status and seropositivity for FIV or FeLV in cats.
Procedures—Veterinarians at veterinary clinics and animal shelters completed online training on oral conditions in cats and then scored oral health status of cats with no known history of vaccination against FIV. Age, sex, and results of an ELISA for retroviruses were recorded. Results were analyzed by means of standard logistic regression with binary outcome.
Results—Of 5,179 cats, 237 (4.6%) and 186 (3.6%) were seropositive for FIV and FeLV, respectively, and of these, 12 (0.2%) were seropositive for FIV and FeLV. Of all 5,179 cats, 1,073 (20.7%) had gingivitis, 576 (11.1%) had periodontitis, 203 (3.9%) had stomatitis, and 252 (4.9%) had other oral conditions (overall oral disease prevalence, 2,104/5,179 [40.6%]). Across all age categories, inflammatory oral disease was associated with a significantly higher risk of a positive test result for FIV, compared with the seropositivity risk associated with other oral diseases or no oral disease. Stomatitis was most highly associated with risk of FIV seropositivity. Cats with any oral inflammatory disease were more likely than orally healthy cats to have a positive test result for FeLV. Increasing age was associated with a higher prevalence of oral disease in retrovirus-seronegative cats.
Conclusions and Clinical Relevance—Inflammatory oral disease was associated with an increased risk of seropositivity for retroviruses in naturally infected cats. Therefore, retroviral status of cats with oral inflammatory disease should be determined and appropriate management initiated.
Objective—To describe the effects of lithium carbonate on thrombopoiesis in clinically normal dogs and in dogs treated with carboplatin.
Animals—18 young adult sexually intact female Beagles.
Procedures—Dogs were assigned to each of 3 treatment groups (6 dogs/group). Group 1 received 150 mg of lithium carbonate (14 to 16 mg/kg), PO, every 12 hours on days 1 through 21. Group 2 received carboplatin (300 mg/m2, IV) on day 0 and cephalexin (30 mg/kg, PO, q 12 h) on days 14 through 21. Group 3 received lithium, carboplatin, and cephalexin at the aforementioned doses and schedules. Plasma lithium and blood platelet concentrations were measured on days 0, 2, 4, 7, 9, 11, 14, 16, 18, and 21. Number of megakaryocytes in bone marrow specimens and the percentage of large unstained cells and CD34+ mononuclear cells in bone marrow aspirates were determined on days 0, 7, 14, and 21 by manual enumeration, automated hematologic analysis, and flow cytometric immunophenotyping, respectively.
Results—Plasma lithium concentrations ranged from 0.12 to 2.41 mmol/L. All dogs given lithium achieved a concentration within the target interval of 0.5 to 1.5 mmol/L by days 4 to 7. Thrombopoiesis was increased in dogs receiving lithium alone. All dogs given carboplatin developed mild thrombocytopenia. There were no differences between group 2 and group 3 throughout the study.
Conclusions and Clinical Relevance—Lithium stimulated thrombopoiesis in clinically normal dogs. Lithium administration at the doses and schedules used, with concurrent administration of cephalexin, did not prevent thrombocytopenia induced by carboplatin.
OBJECTIVE To characterize the distribution and intensity of cyclooxygenase (COX)-2 expression in the eyes of cats with and without uveitis and to determine whether COX-2 expression is correlated with severity of inflammation.
SAMPLES Archived ocular tissue specimens from 51 cats with and 10 cats without ocular disease.
PROCEDURES Specimens from only 1 eye were evaluated for each cat. Specimens were stained with H&E stain or immunohistochemical stain for detection of COX-2 and reviewed. For each eye, the type, severity, and distribution of inflammation and the distribution and intensity of COX-2 expression were determined for the uvea and other ocular tissues. Correlation between COX-2 expression and inflammation severity was also assessed.
RESULTS COX-2 was not expressed in any nondiseased eye. Of the 51 diseased eyes, 20 had histologic evidence of lymphocytic-plasmacytic uveitis, 13 had neutrophilic uveitis, 11 had diffuse iris melanoma with uveitis, and 7 had diffuse iris melanoma without uveitis. Of the 44 eyes with uveitis, COX-2 was detected in the uvea of 16, including 11 eyes with lymphocytic-plasmacytic uveitis, 4 with neutrophilic uveitis, and 1 with diffuse iris melanoma–induced uveitis. Inflammation was severe, moderate, or mild in 10, 5, and 1 of those eyes, respectively. Cyclooxygenase-2 was detected in the cornea of 21 eyes with uveitis and 1 eye with diffuse iris melanoma without uveitis. Uveitis severity was positively correlated with COX-2 expression in both the uvea and cornea.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that COX-2 is an inflammatory mediator in feline uveitis but not diffuse iris melanoma.