[Diagnostics in epilepsy - potential of magnetic resonance imaging]

Epilepsy is a common neurologic disease frequently encountered by small animal practitioners. The disease comprises a multiplicity of clinical presentations and etiologies and often necessitates a comprehensive as well as cost-intensive diagnostic workup. This is mandatory in order to be able to diagnose or exclude a metabolic cause of the seizures and to distinguish between idiopathic and structural epilepsy. The examination by means of magnetic resonance imaging (MRI) represents a central component of the diagnostic workup, which in turn has essential effects on treatment and prognosis. In order to achieve standardized examination and comparable results, it is of utmost importance to use defined MRI protocols. Accordingly, communication and interaction between clinical institutions may be facilitated and as of yet undetected structural changes might be recorded in future MRI techniques. This review article sets particularly emphasis on the definition and classification of epilepsy as well as its diagnostic imaging procedures and refers to statistics and specialists' recommendations for the diagnostic workup in dogs.

'We should classify pet obesity as a disease'

Alexander German, Ian Ramsey and Philip Lhermette address some of the concerns raised over calling pet obesity a disease and argue that this classification can bring many management opportunities.

‘Wound cat’

‘Wound man’ refers to a stylised diagram used in early medical textbooks to illustrate the various injuries that the human body can sustain in battle. We have adapted this concept to create ‘Wound cat’, as a way to emphasise the type and location of injuries cats may inflict on one another during combat. We have further extended this concept to include wounds that may result from interactions with rodents and snakes. It is hoped that our ‘Wound cat’ concept will assist less experienced clinicians locate sites of cat bites and scratches, and to recognise why certain infections arise in particular stereotyped locations. In addition, this approach should assist veterinarians in determining which pathogens are most likely to be involved in wounds located in a given anatomical region.

What's in a Name? Classification of Diabetes Mellitus in Veterinary Medicine and Why It Matters

Diabetes Mellitus (DM) is a syndrome caused by various etiologies. The clinical manifestations of DM are not indicative of the cause of the disease, but might be indicative of the stage and severity of the disease process. Accurately diagnosing and classifying diabetic dogs and cats by the underlying disease process is essential for current and future studies on early detection, prevention, and treatment of underlying disease. Here, we review the current etiology-based classification of DM and definitions of DM types in human medicine and discuss key points on the pathogenesis of each DM type and prediabetes. We then review current evidence for application of this etiology-based classification scheme in dogs and cats. In dogs, we emphasize the lack of consistent evidence for autoimmune DM (Type 1) and the possible importance of other DM types such as DM associated with exocrine pancreatic disease. While most dogs are first examined because of DM in an insulin-dependent state, early and accurate diagnosis of the underlying disease process could change the long-term outcome and allow some degree of insulin independence. In cats, we review the appropriateness of using the umbrella term of Type 2 DM and differentiating it from DM secondary to other endocrine disease like hypersomatotropism. This differentiation could have crucial implications on treatment and prognosis. We also discuss the challenges in defining and diagnosing prediabetes in cats.

Animal models of disease: classification and etiology of diabetes in dogs and cats

Diabetes mellitus is a common disease in dogs and cats. The most common form of diabetes in dogs resembles type 1 diabetes in humans. Studies suggest that genetics, an immune-mediated component, and environmental factors are involved in the development of diabetes in dogs. A variant of gestational diabetes also occurs in dogs. The most common form of diabetes in cats resembles type 2 diabetes in humans. A major risk factor in cats is obesity. Obese cats have altered expression of several insulin signaling genes and glucose transporters and are leptin resistant. Cats also form amyloid deposits within the islets of the pancreas and develop glucotoxicity when exposed to prolonged hyperglycemia. This review will briefly summarize our current knowledge about the etiology of diabetes in dogs and cats and illustrate the similarities among dogs, cats, and humans.

Prevalence and classification of chronic kidney disease in cats randomly selected from four age groups and in cats recruited for degenerative joint disease studies

Chronic kidney disease (CKD) and degenerative joint disease are both considered common in older cats. Information on the co-prevalence of these two diseases is lacking. This retrospective study was designed to determine the prevalence of CKD in two cohorts of cats: cats randomly selected from four evenly distributed age groups (RS group) and cats recruited for degenerative joint disease studies (DJD group), and to evaluate the concurrence of CKD and DJD in these cohorts. The RS group was randomly selected from four age groups from 6 months to 20 years, and the DJD group comprised cats recruited to four previous DJD studies, with the DJD group excluding cats with a blood urea nitrogen and/or serum creatinine concentration >20% (the upper end of normal) for two studies and cats with CKD stages 3 and 4 for the other two studies. The prevalence of CKD in the RS and DJD groups was higher than expected at 50% and 68.8%, respectively. CKD was common in cats between 1 and 15 years of age, with a similar prevalence of CKD stages 1 and 2 across age groups in both the RS and DJD cats, respectively. We found significant concurrence between CKD and DJD in cats of all ages, indicating the need for increased screening for CKD when selecting DJD treatments. Additionally, this study offers the idea of a relationship and causal commonality between CKD and DJD owing to the striking concurrence across age groups and life stages.

[Odontogenic tumours in the dog and cat]

OBJECTIVE

Odontogenic tumours in the dog and cat, as well as in other domestic animals and in man occur rarely and can be difficult to diagnose. In the present study a great number of canine and feline odontogenic tumours were investigated histopathologically and classified to provide an appropriate basis for the evaluation of these tumours.

MATERIAL AND METHODS

In a retrospective study of a total of 1390 canine and 317 feline oral tumours from the years 1977 to 2007, the tumours of odontogenic origin were selected, characterized histopathologically and classified according to the current human WHO-classification of odontogenic tumours (2005) and the current veterinary WHO-classification of odontogenic tumours (2003).

RESULTS

18% (n=250) of the canine and 3.2% (n=10) of the feline oral tumours proved to be of odontogenic origin. They could be divided into benign (epithelial, epithelial and ectomesenchymal, ectomesenchymal) and malignant (carcinomas and sarcomas) odontogenic tumours with a total of 12 different entities. The odontogenic fibroma was the most common canine (n=167) and feline (n=4) odontogenic tumour. The second most common odontogenic tumour for canines was ameloblastoma (n=74) and that for felines was ameloblastic fibroma (n=2). Four of the 12 entities could be classified according to both WHO-classifications of odontogenic tumours. Seven and two of the 12 entities could only be classified according to the current human WHO-classification and veterinary WHO-classification, respectively.

CONCLUSION AND CLINICAL RELEVANCE

The prognostic evaluation of tumours is of the greatest clinical relevance and calls for an absolutely certain diagnosis. Particularly in the case of the rare and histomorphologically complex odontogenic tumours the current veterinary WHO-classification does not meet this requirement and needs to be revised and extended. The human WHO-classification proved to be more efficient when compared to the veterinary one.

Summary of the World Small Animal Veterinary Association standardization committee guide to classification of liver disease in dogs and cats

Liver disease is a frequently encountered problem in small animal practice. The World Small Animal Veterinary Association has formed a group of experienced clinicians and pathologists to develop a standardized format for diagnostic terminology. This is hoped to lead to greater uniformity in diagnoses and better communication between clinicians and pathologists alike. The aim is to find a sound scientific basis of diagnostic and treatment protocols for hepatobiliary diseases. This article provides an overview of that monograph.

Classification of feline intraocular neoplasms based on morphology, histochemical staining, and immunohistochemical labeling

The objectives of this study were to evaluate morphologic, histochemical, and immunohistochemical characteristics of well-differentiated and anaplastic intraocular neoplasms of cats, and to develop a diagnostic algorithm for, and investigate the association of ruptured lenses with these neoplasms. Seventy-five feline globes with intraocular neoplasms were stained with hematoxylin and eosin and examined by light microscopy. Morphologic diagnoses included 33 intraocular sarcomas, 17 diffuse iris melanomas, 15 lymphosarcomas, three ciliary adenomas, one metastatic carcinoma, and six undifferentiated intraocular neoplasms. Sections of these globes were then stained with periodic acid Schiff (PAS), and immunohistochemical (IHC) labels for various cellular markers. Histochemical staining and IHC labeling confirmed cellular differentiation in 73/75 neoplasms but was discordant with morphologic diagnoses in 8/75. These included four neoplasms morphologically diagnosed as lymphosarcomas but which expressed differentiation antigens consistent with melanoma (n = 3) or ciliary adenocarcinoma (n = 1), and four tumors morphologically diagnosed as intraocular sarcomas that expressed differentiation antigens for melanoma (n = 2), metastatic carcinoma (n = 1), or remained undifferentiated (n = 1). Immunohistochemical labeling suggested a diagnosis in 5/6 morphologically undifferentiated neoplasms including one intraocular sarcoma, two diffuse iridal melanomas, and two ciliary adenocarcinomas. Based upon morphologic, histochemical, and IHC characterization, ruptured lens capsules were detected in 28/30 intraocular sarcomas, 3/24 diffuse iris melanomas and 1/11 lymphosarcomas, but not in ciliary epithelial neoplasms, metastatic carcinomas, or undifferentiated intraocular neoplasms. An algorithm is provided that facilitates stain and IHC label selection for differentiating anaplastic intraocular feline neoplasms.

Immunohistochemical Diagnosis of Alimentary Lymphomas and Severe Intestinal Inflammation in Cats

Intestinal tissue samples were examined from 32 cats in which a histopathological diagnosis of alimentary lymphoma or multicentric lymphoma affecting the gastrointestinal tract had been made. These samples were re-evaluated histopathologically and serial sections were examined immunohistochemically with antisera specific for the lymphoid markers CD3, CD79a and BLA-36 and for class II molecules of the major histocompatability complex. The cats ranged in age from 4-16 years (median 10.5 years). The main presenting clinical signs were vomiting, diarrhoea and weight loss. The majority of alimentary lymphomas were of the B-cell type (n=15), whereas cases of T-cell lymphoma were fewer in number (n=8). Four cats had lymphoma of a mixed T-and B-cell phenotype. In five of the cats, immunohistochemistry suggested an inflammatory process, in contradiction to the original histopathological diagnosis of lymphoma. Immunolabelling would appear to be a useful adjunct to histopathology in classifying cases of feline alimentary lymphoma, and may help in distinguishing lymphoma from severe intestinal inflammation.

Diseases of the ear pinna

In conclusion, there are a wide variety of dermatologic diseases that can affect the ear pinnae. Most of these disorders are manifestations of a generalized dermatosis. Therefore, when pinnal lesions are present, a thorough diagnostic workup is indicated.

[Intracranial astrocytomas in eight cats: clinical and pathological findings]

Intracranial astrocytomas are rarely diagnosed in cats. Clinical and pathological aspects of these tumors are more often described in humans and dogs. The classification scheme used in human medicine is of important prognostic value. We have analyzed clinical neurological and pathological findings from 8 cats with intracranial astrocytomas. The animals were 10.1 years old in average and presented with a history of tetraparesis (n = 3), epilepsy (n = 2), loss of balance (n = 3) and dyspnoe (n = 1). The latter cat died immediately after the first presentation while the other animals were euthanized because of a progressive course of the symptoms despite therapy. Even though feline astrocytomas, that we could classify into 4 different types in this study, are clinically and pathologically well correlated with those of other species, a prognostically useful classification has never been established before.

Histopathological study of feline eosinophilic dermatoses

A retrospective study was conducted on skin specimens from 24 cats with eosinophilic granuloma complex. The specimens were stained with haematoxylin and eosin and Gallego's trichrome stain. In all specimens, flame figures and/or large foci of so-called "collagen degeneration" were detected and histopathological features were not predictive of the clinical picture. Use of the term eosinophilic dermatosis was advocated in diagnostic dermatopathology. On trichrome-stained sections, normally stained collagen fibres were identified in the middle of both flame figures and large foci of "collagen degeneration" and the debris surrounding collagen bundles showed the same tinctorial properties as eosinophil granules. Eosinophil degranulation around collagen bundles seemed to represent the major pathogenetic event in these lesions, analogous with human flame figures. The term flame figures might therefore be more accurately used to designate those foci of eosinophilic to partly basophilic debris commonly referred to as "collagen degeneration".

A retrospective study of canine and feline cutaneous vasculitis

Twenty-one cases of cutaneous vasculitis in small animals (dogs and cats) were reviewed, and cases were divided by clinical signs into five groups. An attempt was made to correlate clinical types of vasculitis with histological inflammatory patterns, response to therapeutic drugs and prognosis. Greater than 50% of the cases were idiopathic, whereas five were induced by rabies vaccine, two were associated with hypersensitivity to beef, one was associated with lymphosarcoma and two were associated with the administration of oral drugs (ivermectin and itraconazole). Only the cases of rabies vaccine-induced vasculitis in dogs had a consistent histological inflammatory pattern (mononuclear/nonleukocytoclastic) and were responsive to combination therapy with prednisone and pentoxifylline, or to prednisone alone. Most cases with neutrophilic or neutrophilic/eosinophilic inflammatory patterns histologically did not respond to pentoxifylline, but responded to sulfone/sulfonamide drugs, prednisone, or a combination of the two.

Review of feline pancreatitis part one: the normal feline pancreas, the pathophysiology, classification, prevalence and aetiologies of pancreatitis

The cellular mechanisms involved once pancreatitis has been initiated are reasonably well understood. The events leading up to this process are less well established. Much of our current understanding of pancreatitis in cats has been determined from experiments in cats or extrapolated from other species. The normal anatomy and function of the pancreas and a review of the current state of knowledge about the pathophysiology of pancreatitis is discussed. The current prevalence of feline pancreatitis is unknown, but the disease is being reported with increasing frequency. The aetiology of pancreatitis and the types of pancreatic inflammation present in cats is different from other species, such as the dog, a species where the disease is considered more common. Concurrent diseases are often present that may be more serious than the pancreatic inflammation and the treatment of these diseases is often complicated by pancreatitis.

[Health status and causes of mortality in feral cats in a delimited area of the inner city of Berlin]

Results of the veterinary examination of feral cats living in a delimited area of Berlin city are presented. Between 1996 and 1999 thirty nine cats were investigated, among them eleven individuals twice. All animals were positive for one or several pathologies, but only seven cats were in bad condition. Most common were periodontal and gingival diseases, followed by conjunctivitis. Five cats were positive for FIV, seven for FeLV, one tomcat for both. Twenty six cats vanished during the study period of 42 months, only one third of cats survived and remained in the study area throughout. Four cats were given to pet lovers, nine cats disappeared without trace, seven animals died in traffic accidents and six cats died of illnesses. Cats less than three years of age vanished more often than expected from their representation in the population. Dirty or large feeding places for cats constitute a source of infections. Feeding sites should be accessible to only few individuals and left-overs that may attract stray cats, rats or birds should not remain at feeding places.

The histologic classification of 602 cases of feline lymphoproliferative disease using the National Cancer Institute working formulation

Case information and histologic slides for 688 admissions of feline tissues from 12 veterinary institutions were assembled and reviewed to determine tissues obtained by biopsy or necropsy, age and sex of cat, tumor topography, feline leukemia viral antigen status, histologic frequency of mitoses, diagnosis, presence of necrosis, and presence and degree of sclerosis. Histologic sections were examined to place the lesions in one of the diagnostic categories of the National Cancer Institute working formulation (NCI WF) for lymphomas or lymphoid leukemia. Correlations between the various factors determined were tested using contingency tables and chi-square analysis to provide a statistical comparison between the levels of observations determined by case examination with the numbers expected from chance alone. Significant correlations (P < or = 0.05) were found between diagnosis and tumor topography, the frequency of mitoses, necrosis, sclerosis, and age, between mitoses and necrosis, topography, age, and feline leukemia viral infection status, between topography and necrosis and age, and between leukemia viral status and age. Significant correlations between diagnosis and tumor topography included a greater than expected number of cases of acute and chronic lymphoid leukemia and multicentric distribution of tumor. Small cell lymphomas were more frequent than expected in enteric and cutaneous areas and less frequent than expected in mediastinal, renal, and multicentric areas. In contrast, the high-grade small noncleaved type of lymphomas was found significantly more frequently than expected in the mediastinum and less frequently than expected in enteric tissues. In comparing diagnosis and frequency of mitoses, the lymphomas classified as low grade by the NCI WF were significantly more frequent than expected in the lower categories (0-2/100x) of mitoses, and those classified as high-grade lymphomas were more frequent than expected in the higher categories (4-8/1OOx) of mitoses. In comparing diagnosis and sclerosis, diffuse sclerosis was more frequent than expected for the intermediate grade lymphomas of mixed cell type and for the high-grade lymphomas of the immunoblastic polymorphous type. In comparing diagnosis and locally extensive necrosis, this feature was more frequently observed than expected for cases of intermediate grade lymphoma of the small-cleaved cell category and for the high-grade lymphoma of the immunoblastic cell type. In comparing mitoses and necrosis, the lower grade lymphomas were, in general, characterized by a lower frequency of mitoses and a lower incidence of necrosis then would be expected from chance alone. In contrast, the higher grade lymphomas were characterized by more frequent mitoses and a higher incidence of necrosis. In tests comparing mitoses and tumor topography, lymphomas of the alimentary tract were more frequently observed than expected in the category with the lowest level of mitoses (0-1/100x), whereas lymphomas of the mediastinum and kidney were more frequently observed than expected in the categories with a higher level (4-20/ 100x) of mitoses.

Immunophenotypic and histological characterisation of 109 cases of feline lymphosarcoma

OBJECTIVE

To determine and analyse the immunophenotype and histological appearance of naturally occurring cases of lymphosarcoma in Australian cats.

DESIGN

A prospective multi-institutional study of naturally occurring feline lymphosarcoma.

METHODS

One hundred and eighteen cats were referred for diagnosis and/or management of suspected lymphosarcoma. Tissue samples for histopathological analysis and immunophenotyping were collected as biopsies or at necropsy from 109 cases. Histological classification of the neoplasms followed the Working Formulation Classification System. Four multi-species cross-reactive antibodies were used to classify tumours as having a B or T cell phenotype.

RESULTS

Seventy-six (70%) cases were B cell tumours and 28 (26%) were T cell tumours. The remaining 5 (4%) specimens failed to stain with the four antibodies. Histologically, 11 (10%) cases were classified as low-grade, 72 (66%) were medium-grade and 26 (24%) were high-grade tumours. There were no significant associations between age and either histological grade or immunophenotype. Mediastinal and leukaemic cases were significantly more likely to be T cell tumours (P < 0.001 and P < 0.001, respectively).

CONCLUSIONS

In contrast to previously documented studies in the cat, the majority of cases of lymphosarcoma were of B cell phenotype and intermediate histological grade. Based on our data, the histological phenotype of lymphosarcoma is unlikely to predict immunotype, nor are cases of certain immunotypes likely to be of specific histological subtype. Considered in relation to previous reports, the findings suggest that epidemiological factors operating in these cats to produce lymphosarcoma may be different to those operating in North American and UK cat populations.

Seizures: classification, etiologies, and pathophysiology

Epilepsy is a disorder of recurrent seizures that are neural in origin. Partial seizures are usually due to a structural cerebrocortical lesion and may be simple or complex. Brain injuries may alter inherent neuronal properties and neuronal circuits and lead to recurrent excitatory activity. Potentiation of excitatory synapses and depression of inhibitory synapses are probable critical events in epileptogenesis. The pathogenic factors underlying primary or idiopathic generalized seizures are not as well understood. A more diffuse or multifocal state of neuronal excitability may be the result of early congenital events that are magnified over time. The progression of subclinical neuronal excitatory activity to a clinical seizure may relate directly to the phenomenon of cortical plasticity.

Correlations between ultrasonographic findings and specific hepatic diseases in cats: 72 cases (1985-1997)

OBJECTIVE

To identify correlations between ultrasonographic findings and specific hepatic diseases in cats.

DESIGN

Retrospective study.

SAMPLE POPULATION

Medical records of 72 cats with a histopathologic diagnosis of hepatic disease and diagnostic-quality abdominal ultrasonograms between 1985 and 1997.

PROCEDURE

Abdominal ultrasonographic findings in 72 cats with histologically confirmed hepatic disease (hepatic lipidosis excluded) were reviewed. Rather than attempt to combine individual ultrasonographic findings with specific hepatic diseases, 2 classification trees were created as models to correlate certain groups of abnormalities with specific hepatic diseases or with malignant and benign lesions of the liver. Sensitivity and specificity of classification trees were calculated.

RESULTS

Use of a classification tree resulted in correct classification of malignant versus benign hepatic lesions in 88.9% of cats that had hepatic disease (sensitivity, 90.7%; specificity, 86.1%). Use of a classification tree to distinguish individual types of hepatic diseases resulted in mostly accurate classification of hepatic lymphosarcoma (sensitivity, 70.5%; specificity, 98.2%), cholangitis-cholangiohepatitis syndrome (sensitivity, 87%; specificity, 90%), and benign lesions of the liver (sensitivity, 84.6%; specificity, 86.4%). Criteria that helped most in differentiating among various hepatic diseases were abnormalities within other organs (spleen, lymph nodes) and appearance of the hepatic portal system. A correlation was not found between focal or multifocal appearance of hepatic lesions and specific hepatic diseases.

CLINICAL IMPLICATIONS

Use of classification trees to distinguish among specific hepatic diseases or between malignant and benign hepatic lesions provides potentially useful algorithms for ultrasonographic evaluation of cats with hepatic disease.

Principles of antimicrobial therapy

It has been 2500 years since the Chinese began applying moldy soybean curd to cure skin infections. Technology today has refined the benefits of antibiotic-forming molds and bacteria and has greatly increased the number of antimicrobial drugs available to combat infection. Understanding the principles fundamental to rational therapy with these drugs will ensure the best of possible outcomes.

Primary lung tumors in cats: 86 cases (1979-1994)

OBJECTIVE

To classify histologic type and morphology of primary lung tumors in cats, to describe clinical findings in these cats, and to determine whether clinical findings were associated with histologic type or morphology.

DESIGN

Retrospective study.

ANIMALS

86 cats with histologically confirmed primary lung tumors.

PROCEDURE

Medical records for cats treated between 1979 and 1994 at any of 14 participating veterinary referral hospitals were reviewed.

RESULTS

Weight loss, lethargy, and dyspnea were the most common clinical signs. Solitary or multiple pulmonary masses were seen on radiographs from 53 of 79 cats; effusion was seen on radiographs from the other 26. In 45 cats, tumors involved a single lung lobe. Caudal lung lobes were more commonly affected than were cranial lung lobes. Sixty-five cats had metastases. Tumors were classified as bronchial (n = 65), bronchiolar-alveolar (9), or other (12) and as poorly differentiated (59), moderately differentiated (20), or well differentiated (7). Breed, age, sex, weight, clinical signs, duration of clinical signs, and radiographic findings were not associated with histologic type or morphology.

CLINICAL IMPLICATIONS

To identify possible occult primary lung tumors, thoracic radiography should be performed on cats with clinical signs of long duration, including weight loss, lethargy, and dyspnea.

A diagnostic classification of problem behavior in dogs and cats

Veterinary clinical ethology is a relatively new field in veterinary practice; with the development of a new discipline, problems often arise regarding diagnosis and the use of terminology. This article proposes a diagnostic system that can be applied by practitioners and researchers. The classification is divided into six main etiologic categories of behavior problems: (1) problems of a genetic origin, (2) problems caused during the animal's developmental stages, (3) ethogram deviations, (4) disturbed social interaction, (5) disease-related behavior, and (6) adaptation inabilities. Conditions may overlap, and all categories involved in a diagnosis should be mentioned for the sake of clarity and completeness.

Myelopoiesis and myeloproliferative disorders

Myeloid cells arise from a common stem cell whose development is regulated by stimulatory and inhibitory growth factors. Pluripotential hematopoietic stem cells are most influenced by IL-3, GM-CSF, and stem cell factor while committed progenitor cells are regulated by variable concentrations of GM-CSF, G-CSF, M-CSF, IL-5, Epo, and Tpo. As a result of their common origin, a key point to remember about myeloproliferative disorders is the involvement of multiple cell lines in dysplastic and neoplastic conditions. Dysplastic changes may signal early neoplastic changes with cases progressing to acute leukemia. Myelodysplastic syndrome (MDS) is associated with anemia or multiple cytopenias, normal to hypercellular bone marrow, ineffective hematopoiesis, and less than 30% blast cells of all nucleated cells in the bone marrow. Chronic myeloid leukemias also have less than 30% blast cells of all nucleated cells in the bone marrow and are distinguished from MDS by elevated cell counts of one or more cell lines with mature forms predominating. Acute myeloid leukemias, often the end result of all myeloproliferative disorders, are recognized by equal or greater 30% blast cells of all nucleated cells in the bone marrow. Additional diagnostic information from cytochemical stains, immunohistochemical staining, and cytogenetic analysis can influence the final diagnosis when morphology alone is equivocal. In conclusion, prognosis and response to treatment are best determined by application of a uniform set of standards in evaluating hematolymphatic neoplasia. Critical to diagnosis are complete blood and bone marrow evaluations including observation for dysplastic changes and blast cell quantitation. In addition, evidence for tissue infiltration identified through cytologic or histologic evaluations of lymph node, spleen, or liver is recommended.

Histologic classification and immunophenotype of lymphosarcomas in cats with naturally and experimentally acquired feline immunodeficiency virus infections

Lymphosarcoma (malignant lymphoma) is the commonest hematopoietic tumor in the cat. Many cases are associated with feline leukemia virus (FeLV) infection, but epidemiologic and experimental data suggest that feline immunodeficiency virus (FIV) may also have a role in lymphomagenesis. In this paper, we describe the clinical presentation, histologic classification, and immunophenotype of lymphosarcoma in eight domestic cats with natural or experimental FIV infections. The tumors were often of unusual distribution, with the majority of cases conforming to the least common anatomic classification of "miscellaneous." Histopathologic and immunophenotypic analysis using a panel of anti-cat and cross-reactive anti-human monoclonal and polyclonal antibodies identified seven of these tumors as high-grade B cell lymphomas of the centroblastic or immunoblastic subtypes. The remaining case was a T-cell tumor associated with a concurrent FeLV infection. Our findings, together with the results of an analysis of FIV proviral DNA in these tumors, indicate that the B-cell lymphosarcomas were comparable to those observed in human and simian immunodeficiency virus infections and that the role of FIV in lymphomagenesis is indirect and related to the potential for malignant transformation during polyclonal B cell activation.

[Classifications of 202 tibial fractures in dogs and cats]

202 Tibial fractures, in 138 dogs and 64 cats, were classified according to the system of Unger. The animals were presented between 1989 and 1994 to four Dutch veterinary orthopaedic referral clinics. In addition to the type of fracture, demographic information was taken into account including the species, the age of the patient, the size of the breed, the treatment, whether it was a open or closed fracture and the orthopaedic clinic. Possible correlation between the type of fracture and the variables, as well as correlations among the latter, were examined statistically. In this study 73% of the tibial fractures in dogs and cats were in the diaphysis, oblique fracture being the most frequent (24%). Proximal tibial fractures in dogs were usually extra-articular and 87% of these involved avulsion of the tibial tubercle. Malleolar fractures accounted for 57% of the distal fractures. A significant correlation was found between the localization of the fracture (proximal, diaphyseal or distal) and the species (cat or dog), between an avulsion fracture of the tibial tubercle and the age in dogs, between an incomplete tibial fracture and the age, between a malleolar fracture and a complicated (i.e., open) fracture, between a butterfly fracture and a complicated fracture, and between the applied therapy and the orthopaedic clinic. The classification system of Unger is very useful for inventory and documentation, but because of the lack of data about physeal fractures, the degree of injury to the surrounding soft tissues, and the influence of differences between surgeons, it cannot be used to determine therapy.

Feline lower urinary tract disorders. Definition of terms and concepts

Lower urinary tract disorders of male and female cats may be caused by a variety of fundamentally different causes. The term Feline urologic syndrome should be abandoned and substituted with descriptive etiopathogenic terms whenever possible. If the underlying cause cannot be identified, the term Idiopathic lower urinary tract disease is recommended.

Subgingival odontoclastic resorptive lesions. Classification, treatment, and results in 58 cats

A commonly recognized dental problem in cats is the resorption of tooth structure and subsequent loss of the tooth. These tooth defects are often very painful, because the sensitive dentin layer is exposed. The destruction of the tooth through odontoclastic resorption is considered a consequence of inflammatory resorption, probably secondary to periodontal inflammation. Because these resorptive lesions are progressive in nature, it is best to stage this progression of resorption in order to address treatment planning. The purpose of this study was to evaluate a group of 58 cats with resorptive lesions to determine the outcome of treatment 6 months or longer after restoration. In 81% of the cats, there was loss of the tooth, evidence of further resorption, or loss of the restoration at one or more resorption sites. Of the 154 teeth restored, only 33% showed no further evidence of loss of tooth structure.

Myeloproliferative disease in the dog and cat: definition, aetiology and classification

The term myeloproliferative disease may be applied to all the non-lymphoid dysplastic and neoplastic conditions arising from the haematopoietic stem cell or its progeny. Thus the chronic and acute myeloid leukaemias, thrombocythaemia, megakaryocytic myelosis, myelofibrosis, the myelodysplastic syndromes and some cases of aplastic anaemia may be viewed as variants of a single disease process. This view is useful in explaining the common occurrence of mixed forms of disease or interconversions between the myeloproliferative diseases. This variability is a consequence of the development of all the haematopoietic lineages from a single class of haematopoietic stem cell by progressive differentiation. The aetiology of the myeloproliferative diseases in the domestic animals is uncertain but feline leukaemia virus infection has been implicated in the cat. These conditions may be classified as aplastic anaemia, as preleukaemic dysplastic conditions with variable cytopenias and morphological abnormalities of blood cells, as smouldering leukaemias, or as leukaemias with a frankly leukaemic blood or bone marrow.

[Clinical aspects of infection with feline leukemia virus in cats]

The leukemia-sarcoma complex constitutes the most common group of malignancies in the cat. Epizootiology of FeLV infections and pathogenesis, which can be divided into three stages, are described. Diagnosis can be made by immunofluorescent, ELISA and virus isolation techniques, as well as FOCMA-antibody tests. Symptomatology of FeLV related illnesses is presented. Feline lymphoma can be categorized into four anatomic types: thymic, alimentary and multicentric type and true leukemia. Forms, which do not fit this classification, are classified as miscellaneous. Treatment of these forms and prevention and control of FeLV infections are discussed.

The classification of feline colitis

Clinical and pathological features of a variety of forms of feline colitis or enterocolitis were examined and classified into 9 separate entities: Salmonella enterocolitis, the colitis of feline infectious peritonitis, mycotic enterocolitis, acute angiopathic colitis, acute angiopathic colitis with ischaemic ulcers, feline granulomatous colitis, the colitis of feline panleucopenia, feline histiocytic colitis, and feline ulcerative, lymphocytic mucosal-submucosal colitis.

Classification of lung carcinomas in the dog and cat

A total of 218 lung carcinomas from dogs and cats were examined histologically. The tumors were classified into adenocarcinoma, squamous-cell carcinoma, bronchial gland carcinoma, and alveolar-cell carcinoma. We believe that adenocarcinoma should be subdivided into differentiated and undifferentiated types because the two are distinct histologically and vary in frequency in the cat and dog. It is also important to recognize bronchial gland carcinoma, a distinct histological type, and to subdivide alveolar-cell carcinoma into three separate types: anaplastic small-cell and large-cell types, and adenomatosis type.

Tumours and dysplasias of the mammary gland

As mammary tumours occur frequently in the dog and cat but rarely in other domestic animals, only the tumours of these two species are classified. The epithelial tumours are termed "complex" when they consist of cells resembling both secretory and myoepithelial cells: these tumours are biologically less malignant than tumours of the "simple" type in which only one of these kinds of cell is present. The carcinomas are subdivided into adenocarcinoma, solid carcinoma, spindle cell carcinoma, anaplastic carcinoma, squamous cell carcinoma, and mucinous carcinoma. The term "carcinosarcoma or malignant mixed tumour" was used only when there were cells morphologically resembling not only one or both of the epithelial components but also connective tissue cells with their products of differentiation. The benign tumours are classed as adenoma, papilloma, fibroadenoma, or benign soft tissue tumour. The dysplasias are described under the following headings: cyst, adenosis, regular typical epithelial proliferation in ducts and lobules (epitheliosis), duct ectasia, fibrosclerosis, and lobular hyperplasia.