Clinicopathological relevance of tumour grading in canine osteosarcoma.

Tumour grading assesses biological aggressiveness and is of prognostic significance in many malignancies. The clinicopathological features of 140 primary canine osteosarcomas and their metastases were analysed, and the interrelations between them and an established grading system and its constituent parameters (mitotic index, necrosis, pleomorphism) were examined. Of these tumours, 35% were grade III (high-grade), 37% grade II and 28% grade I. Primary tumours that had metastasized were of significantly higher grade than non-metastatic osteosarcomas. Osteosarcomas belonging to the osteoblastic minimally productive subtype, but not chondroblastic or telangiectatic subtypes, differed from fibroblastic osteosarcomas in being associated with a significantly higher number of high-grade cases. Dogs younger than 4 years of age had osteosarcomas with higher grade, score and mitotic index than did older animals. Appendicular differed from axial tumours in having a higher mitotic index; distal differed from proximal tumours in being of higher grade; cranial tumours differed from tumours in most other sites in being of lower grade and lower mitotic index. Rib osteosarcomas showed a particularly high degree of necrosis. The mitotic index varied widely between tumour locations. Pleomorphism did not have prognostic merit when examined separately, as most osteosarcomas were highly pleomorphic.

Cardiomyopathy in generalised glycogenosis type II in cattle.

The clinical, electrocardiographic and postmortem findings in five cattle affected by generalised glycogenosis type II are described. Three of the affected animals showed generalised muscle weakness for some months before being killed at 11, 15 and 16 months of age. Of the remaining two, one developed severe respiratory distress when 3 months old and died within 6 h of first being noticed to be ill. The other animal showed respiratory distress on exertion at 5 months of age, became recumbent and died when 7 months old. The sum of the QRS complex amplitudes in ECG leads I, II, a VR, aVL and aVF of the affected animals was significantly increased from the control or carrier animals, but only the two affected animals which showed clinical and pathological signs of congestive heart failure had increased heart weight to body weight, left and right ventricular weight to body weight ratios. In view of the lack of correlation between the increased QRS amplitudes and the presence of cardiac enlargement, it is suggested that the increased QRS amplitudes are a reflection of a conduction disorder. It is further suggested that QRS complex abnormalities in generalised glycogenosis in man, particularly in the late onset form may be due to a similar phenomenon.

Leukemia inhibitory factor induces leukocyte infiltration and cartilage proteoglycan degradation in goat joints.

Recent studies have implicated leukemia inhibitory factor (LIF) in human joint disease. LIF is produced by cultured synovial cells and articular chondrocytes, stimulates cartilage and bone resorption, and has been detected in inflammatory exudates from arthritic joints. The aim of this study was to evaluate the effect of intraarticular injections of human recombinant LIF in the goat. Endotoxin-free, sterile normal saline containing 1 micrograms recombinant human LIF (rhLIF) was injected into the right radiocarpal joints (RCJs) of eight angora goats. The left RCJs were injected with an equivalent volume of vehicle alone (n = 6) or vehicle containing 1 micrograms human albumin (n = 2). Goat joints were examined for clinical features of inflammation, and synovial fluid (SF) was aspirated on days 0, 2, and 6 postinjection. Leukocyte counts and concentrations of keratan sulfate, IL-1 beta, and TNF-alpha were determined in the SF. Proteoglycan synthesis was determined ex vivo in cartilage explants obtained on day 6 postinjection. A statistically significant increase in joint swelling and effusion volume was observed in LIF-injected joints but not in control joints. In the LIF-injected RCJs, the leukocyte count increased from 82 +/- 9 cells/microliters before injection to 10,300 +/- 3357 cells/microliters at day 2 postinjection (p < 0.005) and declined to 678 +/- 113 cells/microliters at day 6 postinjection. Polymorphonuclear leukocytes and monocyte/macrophages predominated in the infiltrate. No appreciable change in leukocyte counts was observed in control joints.(ABSTRACT TRUNCATED AT 250 WORDS)

A cytotoxic haemolysin from Treponema hyodysenteriae--a probable virulence determinant in swine dysentery.

The haemolysin from a virulent strain of Treponema hyodysenteriae was extracted and injected into ligated loops of the ileum and colon of germ-free pigs. It caused severe epithelial damage, especially to the differentiated cells at the tips of the villi in the ileum and the cells in the intercrypt zones of the colon; goblet cells were less affected. The changes in the colon were similar to those seen in natural cases of swine dysentery. The ligated loop offers a means of investigating pathogenic mechanisms and the mode of action of the toxin. This study demonstrated that the haemolysin was a potent cytotoxin for pig enterocytes, and a probable virulence determinant in swine dysentery.

Feline immunodeficiency virus replicates in salivary gland ductular epithelium during the initial phase of infection.

Feline immunodeficiency virus (FIV) antigen was detected by immunochemistry in salivary glands of cats experimentally inoculated with West Australian isolate T91. Six cats were inoculated subcutaneously with 1.0 ml of tissue culture supernatant fluid from a feline T-lymphoblastoid cell line (MYA-1) infected with T91. FIV antigens were detected in the interlobular ducts of the salivary gland of cats infected with FIV 2, 4 and 6 weeks previously. FIV antigen was not detected in the salivary glands of three FIV negative cats and one naturally infected cat. Further, FIV antigen was located only in interlobular duct epithelial cells. The distribution of FIV in the interlobular ducts confirms the important role of salivary glands as a major reservoir of FIV in the early phase of infection and strengthens suggestions that the salivary route is an important mode of transmission of FIV.

Antibody reactivity to the transmembrane protein of the caprine arthritis encephalitis virus correlates with severity of arthritis: no evidence for the involvement of epitope mimicry.

Serum and synovial antibody reactivities of caprine arthritis encephalitis virus (CAEV) infected goats were assessed by Western blotting against purified CAEV antigen and the greatest intensity of reactivity in the serum of arthritic goats was to the gp45 transmembrane protein (TM). The extracytoplasmic domain of the TM gene was cloned into a pGEX vector and expressed in Escherichia coli as a glutathione S transferase fusion protein (GST-TM). This clone was found to be 90.5 and 89.2% homologous to published sequences of CAEV TM gene. Serum of 16 goats naturally infected with CAEV were examined by Western blotting for reactivity to the fusion protein. Antibody reactivity to the GST-TM correlated with clinically detectable arthritis (R = 0.642, P < or = 0.007). The hypothesis that the immune response to the envelope proteins of the CAEV contributes to the severity of arthritis in goats naturally infected with CAEV via epitope mimicry was tested. Antibodies from 5 CAEV infected goats were affinity purified against the GST-TM fusion protein and tested for cross-reactivity with a series of goat synovial extracts and proteogylcans. No serum antibody response or cross-reactivity of affinity purified antibodies could be detected. Peptides of the CAEV SU that were predicted to be linear epitopes and a similar heat shock protein 83 (HSP) peptide identified by database searching, were synthesized and tested for reactivity in CAEV goats using ELISA, in vitro lymphocyte proliferation and delayed type hypersensitivity (DTH) assays. Peripheral blood lymphocytes from 10 of 17 goats with long term natural CAEV infections proliferated in vitro in response to CAEV and in vivo 3 of 7 CAEV infected goats had a DTH reaction to CAEV antigen. However, none of the peptides elicited significant cell mediated immune responses from CAEV infected goats. No antibody reactivity to the SU peptides or HSP peptide was found. We observed that the antibody reactivity to the CAEV TM protein associated with severity of arthritis however epitope mimicry by the envelope proteins of CAEV is unlikely to be involved.

Quantification of lymphadenopathy in experimentally induced feline immunodeficiency virus infection in domestic cats.

Nine cats experimentally infected with feline immunodeficiency virus (FIV) and six FIV-negative cats were necropsied to assess the effect of FIV infection on lymph nodes. The FIV infected cats were inoculated with 10(5) TCID50 21-22 weeks previously. The combined weights of all lymph nodes and the combined lymph node to organ weight ratios were significantly greater in FIV-infected cats when compared to uninfected cats. Additionally, by examining all nodes in the body, a regionally severe lymphadenopathy in FIV-infected cats was evident involving the lymph nodes of the hindlimb, forelimb, and head, in decreasing order of severity, with little evidence of enlargement in lymph nodes of the alimentary tract. Use of 99% confidence intervals showed that 9/9 FIV infected cats had enlarged lymph nodes of the hindlimb and forelimb region. In contrast, 7/9 and 3/9 FIV-infected cats exhibited enlargement of the nodes of the head region and alimentary tract, respectively. Similarly the combined weights of both left and right popliteal lymph nodes were enlarged in 9/9 FIV-infected cats whereas 0/6 in uninfected cats were not. The enlargement of the popliteal lymph nodes observed at necropsy was reflected microscopically by an increase in the size and number of germinal centres and an increase in the number of plasma cells, especially in the medullary cords. Because of the regional variation in lymph node size and numbers, it is suggested that the popliteal lymph node is a good indicator node for the assessment of lymph node status in FIV infection.

Evaluation of an autologous red cell agglutination test, VetRED FIV, for the presence of FIV antibody in cats.

A commercially available whole blood agglutination test, VetRED FIV, used for the detection of antibodies to feline immunodeficiency virus (FIV), was evaluated. The test is based on the use of a synthetic peptide conjugated to a non-agglutinating anti-feline red blood cell monoclonal antibody. The amino acid sequence of the synthetic peptide was derived from the predicted sequence of the transmembrane protein of FIV. The sensitivity and specificity of VetRED FIV was 100% when 34 known FIV-positive and 15 known FIV-negative cats were tested. These cats were part of studies on experimentally induced FIV infection, with their FIV status confirmed by virus isolation. Further, VetRED FIV was compared with another commercially available test for FIV antibody, PetChek in a field trial on 548 feline blood samples received by a diagnostic laboratory. Of the test results 94.2% (516/548) were in agreement: 112 were positive by VetRED FIV and PetChek; 404 were negative by both tests and 32 were discordant. These 5.8% discordant samples producing VetRED FIV-positive/PetChek-negative or VetRED FIV-negative/PetChek-positive were further assessed by Western blot assay. In the field trial, the sensitivity and specificity of VetRED FIV was 97% and 97%, respectively, comparable to the 98% sensitivity and 99% specificity for PetChek. The results from the trial also confirm the relatively high overall prevalence of FIV in Australian cats predominantly among mature male cats in the 9-12 year age group. Given the simplicity of the VetRED FIV procedure, it is concluded that VetRED FIV is a useful addition to the available commercial tests for FIV infection.

Autologous red cell agglutination test for antibodies to feline immunodeficiency virus.

The T-lymphotropic lentivirus, feline immunodeficiency virus (FIV) is now recognised as a major viral pathogen affecting domestic cat populations worldwide. A rapid, autologous red cell agglutination test for antibodies to FIV has been developed. A synthetic peptide analog corresponding to the immunodominant epitope within the FIV transmembrane glycoprotein gp40 residues (680-715) KVEAMEKFLYTAFAMQELGC (Acm)NQNQFFK(BrAc)KIPLELWTR was conjugated to an anti-feline erythrocyte antibody using a thio-ether linkage. Within 3 min of adding this reagent to 20 microliters of whole blood, circulating antibody to the peptide epitope caused agglutination of the red blood cells. The performance of this simple test is comparable with the two commercially available enzyme immunoassay (EIA) kits and an EIA based on this peptide. A variant of the gp40 (680-715) peptide corresponding to the FIV, PPR strain gp40 (678-716) sequence was also synthesised and no difference in reactivity was observed in an EIA on 211 seropositive samples, indicating that the peptide-based test may be applicable to other known strains of the virus.

The pathological features of an interstitial pneumonia of goats.

An interstitial pneumonia in goats which predominantly affects the caudal lung lobes is described. It is characterized microscopically by hypertrophy of type 2 pneumocytes, the presence of an abundant eosinophilic, PAS-positive material within alveolar spaces, and a diffuse and focal lymphoid infiltration of alveolar septa. The material present within alveolar spaces is considered to be composed of surfactant and fibrin. Although the aetiology is not known the gross and microscopic appearance suggests that a retro-virus may be involved.

T-cell-rich B-cell lymphoma in the cat.

The clinical and pathological features of eight cases of feline T-cell-rich B-cell lymphoma are described. The disease occurred in older cats (mean age 11.4 +/- 3.9 years), which on initial examination generally showed enlargement of a single submandibular or cervical lymph node. After excision, there was no recurrence of the lesions at 6 months in three cats. In one further case, however, the lesion had recurred 6 months later; it was again excised but recurred after an additional 6 months. Microscopically, there was effacement of normal lymph node architecture by a nodular (n = 4) or diffuse (n = 4) proliferation of small to blastic lymphocytes, accompanied by a characteristic population of bizarre giant, or multinucleate, cells. The mitotic rate was low and mitoses were restricted to the atypical population. Immunophenotyping revealed the smaller lymphocytes to be a mixture of CD3+ MHC Class II+ T lymphocytes and BLA36+CD79variable MHC Class IIvariable B lymphocytes. The atypical cells were of the B-cell lineage (BLA36+MHC Class IIvariable). Polymerase chain reaction analysis revealed no proviral DNA products of feline leukaemia virus or feline immunodeficiency virus in tissue from any tumour, confirming that these neoplasms were not associated with either virus. The clinical, histological and immunophenotypic findings in these cats were identical with those of "nodular lymphocyte predominance (lymphocytic and histiocytic/L&H) Hodgkin's disease" in man.

Characterisation of three novel canine osteosarcoma cell lines producing high levels of matrix metalloproteinases.

Three canine osteosarcoma cell lines were established from spontaneous pelvic and radial osteosarcomas. The cell populations cultured exhibited characteristics of malignancy and consisted of adherent, pleomorphic, mostly large spindle-shaped or polyhedral cells, characterised by the presence of numerous cytoplasmic granules and vacuoles. The main ultrastructural features included the presence of abundant rough endoplasmic reticulum and numerous cytoplasmic vesicles, deposit vacuoles and small cytoplasmic protrusions. Zymography showed that the cell lines produce high levels of MMP-2 and MMP-9, enzymes directly involved in crucial aspects of the metastatic process. Consistent with their osteoblastic lineage and malignant phenotype, all cell lines were immunoreactive to vimentin, osteopontin, PCNA, p53, MMP-2 and MMP-9, while they were negative for cytokeratin, desmin, SMA, Factor VIII, NSE, GFAP, Rb and p21 protein. No retroviral particles or RNA were detected ultrastructurally or with RT-PCR, although the possibility of viral involvement in osteosarcoma cannot be excluded. The new cell lines provide excellent in vitro models that may allow further studies on the pathobiology of canine osteosarcoma to be undertaken.

Echocardiographic characterization of dilatation cardiomyopathy in the English cocker spaniel.

The echocardiographic characterization of a dilatation cardiomyopathy in small-breed dogs is reported. Twelve clinically healthy adult English Cocker Spaniel dogs (between 2 and 9 years old and weighing 11.5 to 15.4 kg [mean 12.9 +/- 1.00 kg]) from a kennel population with a history of cardiomyopathy were assessed, using M-mode echocardiography. The dogs were selected on ECG and/or radiographic evidence of ventricular enlargement. Nine dogs had R-wave amplitude in lead 11 of greater than 3.0 mV. Two dogs had an unusual right-axis deviation, the result of deep Q waves in the limb leads and deep S waves in chest leads CV6LL and CV6LU, indicating that there was right ventricular enlargement. All dogs had increased end-systolic dimensions (mean 3.0 +/- 0.6 cm). End-diastolic dimensions were increased in 9 dogs (mean 4.0 +/- 0.5 cm), and there was a decrease of left ventricular (LV) function as measured by fractional shortening in 8 dogs. Mean fractional shortening for the 12 dogs was 25.4 +/- 5.7%. There was significant correlation between LV dimensions and age at echocardiographic assessment, indicating that LV dilatation was progressive. Three of the oldest dogs had severe dilatation of the LV, and in 2 of these, LV function was severely decreased. Left ventricular function in the 3rd dog, however, was within the acceptable range. Fractional shortening and thickness of the LV caudal wall and interventricular septum were significantly correlated (P less than 0.01 for interventricular system and P less than 0.05 for LV caudal wall).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic assessment of left ventricular dimensions in clinically normal English cocker spaniels.

Seventeen clinically normal adult English Cocker Spaniels from a kennel population with a history of cardiomyopathy were assessed, using M-mode echocardiography, to establish reference values for left ventricular (LV) dimensions for this breed of dog. Echocardiographic measurements were compared with postmortem measurements in 10 of 17 dogs. The LV weight calculated from the echocardiographic measurements correlated significantly with LV weight at postmortem (P less than 0.05). Echocardiographic measurements of end diastolic and end systolic diameters for the 17 dogs correlated significantly with body surface area (P less than 0.01). Measurements of the interventricular septum were in close agreement with values in clinically normal dogs and were significantly correlated with postmortem measurements (r = 0.94, P less than 0.01). However, 76% of the measurements for LV caudal wall thickness in this group of dogs were above the normal range. Calculation of fractional shortening values identified a group of 5 dogs with reduced fractional shortening (mean +/- SD, 20.97 +/- 3.66%), which indicates that a depression in contractility may be present in some apparently healthy dogs of this kennel population. The remaining 12 dogs had fractional shortening values of mean +/- SD, 34.26 +/- 4.54%.

Hereditary nephritis in the bull terrier: evidence for inheritance by an autosomal dominant gene.

A high prevalence of renal failure has been reported in bull terriers in Australia. The pattern of inheritance was analysed in a family of 33 bull terriers in which 10 dogs had renal disease manifested by proteinuria, ultrastructural abnormalities in the glomerular basement membrane, renal failure, or 'end stage' kidneys. The presence of at least one affected parent for each affected offspring, the approximately equal male/female ratio and the apparent absence of 'generation-skipping', strongly supported an autosomal dominant mode of inheritance, assuming a fully penetrant single major gene locus. Further evidence was not compatible with either an autosomal recessive or X-linked inheritance pattern. This contrasts with the X-linked inheritance shown in Alport's-type human hereditary nephritis and hereditary glomerulopathy in the samoyeds. Hereditary nephritis in the bull terrier should be a useful model for non-Alport's-type human hereditary nephritis, which is also reported to have an autosomal dominant inheritance pattern.

Chronic interstitial pneumonia in association with a granulomatous encephalitis in a goat.

A 30-month-old British Alpine goat had clinical and pathological findings consistent with the diagnosis of a chronic interstitial pneumonia. The goat also had lesions in the brain similar to those described for granulomatous encephalomyelitis (GE) of goats. Lesions similar to GE were reproduced experimentally in feral goats following intracerebral inoculation of a lung homogenate from the naturally occurring case. The differential diagnosis of chronic interstitial pneumonia in goats, the differentiation of GE from viral leucoencephalomyelitis, and possible aetiological role of retroviruses in these diseases is discussed.

Suspected monensin toxicosis in feedlot cattle.

Suspected monensin toxicosis was seen in feedlot cattle aged 6 to 9 months. Twenty cattle died following inclusion of monensin in the feed at 400g/tonne, which was 13 times the recommended level. The deaths occurred over 2 weeks. Clinical signs were inappetance, respiratory distress and sudden death. Post-mortem features were those of right-sided heart failure and included dependent subcutaneous oedema, ascites, hydrothorax, and periancinar hepatocyte congestion and necrosis. However, in contrast to previous reports no myocardial necrosis was found, but focal skeletal muscle necrosis was observed. Additional findings were marked pulmonary oedema accompanied by fibrin and erythrocyte exudation into alveoli and interlobular lymphatics. From these findings it appears that monensin, as well as affecting both cardiac and skeletal muscle, has a primary effect on lung vasculature.

Maternal antibody, vaccination and reproductive failure in dogs with parvovirus infection.

The maternal antibody (MAb) titre to canine parvovirus (CPV) was determined on consecutive serums from 39 puppies in 7 litters. Vaccination with inactivated CPV was performed at a variety of ages and the response of the puppies determined. Transfer of MAb was demonstrated in 71% (5/7) of the litters and persisted for up to 10 weeks in some litters. MAb titres of greater than 20 precluded a vaccination response by puppies. Sixty- one per cent (8/13) of puppies responded to vaccination when the MAb titre was less than 20. However, no anamestic response occurred and in some cases a decrease in antibody titre was observed following a second vaccination. During an outbreak of canine parvovirus enteritis (CPE) in the kennel, 33 puppies developed clinical signs of enteritis. Of these puppies 85% (28) had MAb titres of less than 80 at the onset of clinical signs. Fifty per cent (4/8) of the puppies which responded to vaccination developed CPE, whereas 100% (5/5) of those that did not respond to vaccination developed CPE. The results indicate that MAb may persist for up to 10 weeks and puppies with MAb in the titre range greater than 20 to less than 80 do not respond to vaccination but are still susceptible to infection. It is also apparent that a significant minority of puppies with MAb less than 20 do not respond to vaccination. An examination of the breeding records of the kennel for the 7 year period 1973-1981 demonstrated a sudden decrease in reproductive efficiency during and subsequent to 1978. This coincided with the recognition of cases of CPV infection in the kennel. It is suggested that further investigation is required into the possible role of CPV in reproductive failure.

Congenital hypothyroidism in Scottish Deerhound puppies.

Two Scottish Deerhound puppies had clinical and pathological features consistent with the diagnosis of congenital non-goitrous hypothyroidism. They were from separate litters, but were the progeny of the same sire and dam. The puppies were smaller, had shorter limbs and shorter, broader heads than their littermates. They also had histories of weakness, difficulty in walking and somnolence. A characteristic radiographic feature was the absence of epiphyseal growth centres. Both had depressed serum thyroxine (T4) levels and one did not respond to exogenous thyroid stimulating hormone. On necropsy, the thyroid glands were small, the follicles varied in size and contained little or no colloid. The adenohypophysis contained many cells with markedly vacuolated cytoplasm. It is suggested that the clinicopathological pattern is the result of a primary thyroid abnormality. Possible mechanisms include either primary thyroid hypoplasia or an unresponsiveness to thyroid stimulating hormone.

The pathology and aetiology of lung lesions in goats infected with caprine arthritis-encephalitis virus.

Fifty dairy goats, of various ages, sexes and breeds were selected for examination on the basis of positive serological reactions to caprine arthritis-encephalitis virus (CAEV). Thirty-one had lung lesions including chronic interstitial pneumonia of caudal or cranioventral lobes, bronchopneumonia, verminous pneumonia, pulmonary cryptococcosis or combinations of these. The only infective agent recovered from all the chronic interstitial pneumonia cases examined was CAEV, which was also recovered from lung tissue of 3 goats with arthritis but no lung lesions. The presence of CAEV in lavaged alveolar macrophages from normal lung tissue and from lungs affected with chronic interstitial pneumonia and verminous pneumonia, and the demonstration of a marked increase in nonspecific esterase staining macrophages in areas of chronic interstitial pneumonia, are discussed in relation to the aetiology of the pneumonia.