Experimental Neurology By Prof Paul Glees Pp xii + 532 (Oxford: Clarendon Press; London: Oxford University Press, 1961) 75s net

The Nervous System

Tumors of the Hemolymphatic System

Histiocytic proliferative disorders are commonly observed in dogs and less often cats. Histiocytic disorders occur in most of the dendritic cell (DC) lineages. Canine cutaneous histiocytoma originates from Langerhans cells (LCs) indicated by expression of CD1a, CD11c/CD18, and E-cadherin. When histiocytomas occur as multiple lesions in skin with optional metastasis to lymph nodes and internal organs, the disease resembles cutaneous Langerhans cell histiocytosis of humans. Langerhans cell disorders do not occur in feline skin. Feline pulmonary LCH has been recognized as a cause of respiratory failure due to diffuse pulmonary infiltration by histiocytes, which express CD18 and E-cadherin and contain Birbeck's granules. In dogs and cats, histiocytic sarcomas (HS) arise from interstitial DCs that occur in most tissues of the body. Histiocytic sarcomas begin as localized lesions, which rapidly disseminate to many organs. Primary sites include spleen, lung, skin, brain (meninges), lymph node, bone marrow, and synovial tissues of limbs. An indolent form of localized HS, progressive histiocytosis, originates in the skin of cats. Hemophagocytic HS originates in splenic red pulp and bone marrow macrophages in dogs and cats. In dogs, histiocytes in hemophagocytic HS express CD11d/CD18, which is a leuko-integrin highly expressed by macrophages in splenic red pulp and bone marrow. Canine reactive histiocytic diseases, systemic histiocytosis (SH) and cutaneous histiocytosis, are complex inflammatory diseases with underlying immune dysregulation. The lesions are dominated by activated interstitial DCs and lymphocytes, which invade vessel walls and extend as vasocentric infiltrates in skin, lymph nodes, and internal organs (SH).

https://journals.sagepub.com/doi/pdf/10.1177/0300985813510413

A Review of Histiocytic Diseases of Dogs and Cats

This study reports cytomorphological, histomorphological, and immunological characterization of 608 biopsy cases of canine malignant lymphoma, with epidemiological and clinical data, collected from 7 French veterinary pathology laboratories. It compares morphological characteristics of malignant lymphoma in canines, per the updated Kiel classification system, with those reported in humans, per the World Health Organization (WHO) classification system. Of tumors described, 24.5% and 75.5% were classified as low- and high-grade malignant lymphomas, respectively. Presenting clinical signs included generalized or localized lymphadenopathy (82.4%) and extranodal diseases (17.6%) involving the skin (12.34%) and other sites (5.26%). Immunohistochemistry confirmed 63.8% B-cell (CD3-, CD79a+), 35.4% T-cell (CD3+, CD79a-), and 0.8% null-cell (CD3-, CD79a-) lymphomas. Most B-cell cases (38.49%) were of high-grade centroblastic polymorphic subtype; most T-cell cases (8.55%), high-grade pleomorphic mixed and large T-cell lymphoma subtypes. Some B-cell tumors showed morphologic characteristics consistent with follicular lymphomas and marginal zone lymphomas per the Revised European American Classification of Lymphoid Neoplasms and WHO canine classification systems and the WHO human classification system. Unusual high-grade B-cell subtypes included an atypical high-grade small B-cell lymphoma (0.66%), Burkitt-type B-cell lymphoma (1.64%), plasmacytoid lymphoma (0.99%), and mediastinal anaplastic large B-cell lymphoma (0.16%). Unusual T-cell subtypes included a previously undescribed high-grade canine immunoblastic T-cell type (1.15%), a rare low-grade prolymphocytic T-cell lymphoma (0.16%), and a recently described high-grade canine T-cell entity--aggressive granulocytic large-cell lymphoma (0.16%). Marginal zone lymphomas were common (10.86%); follicular lymphomas were rare (0.49%). Canine primary cutaneous malignant lymphoma subtypes were present (11.84%). There was no significant difference between B- and T-cell malignant lymphoma in regard to canine age and sex. A significant overrepresentation of Boxers (24.19%) was found for T-cell lymphomas.

https://journals.sagepub.com/doi/pdf/10.1177/0300985810363902

A morphological study of 608 cases of canine malignant lymphoma in France with a focus on comparative similarities between canine and human lymphoma morphology.

Background
Superficial bacterial folliculitis (SBF) is usually caused by Staphylococcus pseudintermedius and routinely treated with systemic antimicrobial agents. Infection is a consequence of reduced immunity associated with alterations of the skin barrier and underlying diseases that may be difficult to diagnose and resolve; thus, SBF is frequently recurrent and repeated treatment is necessary. The emergence of multiresistant bacteria, particularly meticillin-resistant S. pseudintermedius (MRSP), has focused attention on the need for optimal management of SBF.

Objectives
Provision of an internationally available resource guiding practitioners in the diagnosis, treatment and prevention of SBF.

Development of the guidelines
The guidelines were developed by the Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases, with consultation and advice from diplomates of the American and European Colleges of Veterinary Dermatology. They describe optimal methods for the diagnosis and management of SBF, including isolation of the causative organism, antimicrobial susceptibility testing, selection of antimicrobial drugs, therapeutic protocols and advice on infection control. Guidance is given for topical and systemic modalities, including approaches suitable for MRSP. Systemic drugs are classified in three tiers. Tier one drugs are used when diagnosis is clear cut and risk factors for antimicrobial drug resistance are not present. Otherwise, tier two drugs are used and antimicrobial susceptibility tests are mandatory. Tier three includes drugs reserved for highly resistant infections; their use is strongly discouraged and, when necessary, they should be used in consultation with specialists.

Conclusions and clinical importance
Optimal management of SBF will improve antimicrobial use and reduce selection of MRSP and other multidrug-resistant bacteria affecting animal and human health.

/pdf/guidelines-for-the-diagnosis-and-antimicrobial-therapy-of-2fxsa2bd8r.pdf

Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases).

This study aims to describe the incidence and risk factors for positive urinary tract culture, the prevalence of urinary tract pathogens in single organism and mixed cultures and changes in their antimicrobial resistance over 10 years. A retrospective review of computer records detailing canine urine samples submitted between August 1999 and September 2009 for culture and sensitivity in a UK tertiary referral hospital is described. 17.5 per cent of 5923 samples (670 of 4530 dogs) were positive cultures. 85.3 per cent of cultures yielded a single isolate. The prevalence of bacterial species differed between mixed and single isolate cultures. Entire and neutered female dogs were more likely to return positive cultures than male dogs (OR=2.5 and 1.5, respectively). Escherichia coli was most commonly isolated (53.9 per cent) and affected female dogs, older dogs and neutered dogs more. There was an increase in the antimicrobial resistance of Enterococcus faecalis and Pseudomonas Aeruginosa , and a decrease in the effectiveness of enrofloxacin, cephalexin and oxytetracycline. The prevalence of urinary bacterial isolates is described for a large group of dogs. Monitoring changes in antimicrobial efficacy and microbial resistance guides the empirical use of antimicrobials for the treatment of urinary tract infection and helps formulate strategic plans to limit drug resistance.

Prevalence and antimicrobial resistance of canine urinary tract pathogens

Objective— To investigate the indications for and long-term outcome of prepubic urethrostomy (PPU) in the cat.



Study Design— Retrospective survey.



Animals— Sixteen cats that had undergone PPU.



Methods— Data were recovered from the medical records of the cats. Follow-up information was obtained from the owners and referring veterinarians.



Results— Indications for PPU were: failed perineal urethrostomy for the management of idiopathic lower urinary tract disease (ILUTD) (8 cats) or urethral trauma (1 cat); unresolved pelvic urethral obstruction after recurrent ILUTD (5 cats); and stenosis of the pelvic urethra as a result of trauma (2 cats). A patent urethral stoma was created in all cases. Signs of lower urinary tract disease were present in 8 cats postoperatively. With appropriate dietary management, these signs resolved in 2 cats and improved in another 4 cats. Eleven cats experienced postoperative complications that consisted of peristomal skin irritation or necrosis (7 cats) and urinary incontinence (6 cats). Complications developed in the immediate postoperative period in 6 cats, and resolved in 2 of these. Six cats developed late complications, at 6 to 84 months postoperatively. Six cats were euthanatized between 1 and 26 months' postoperatively. The mean survival time in these cats was 13 months. Reasons for euthanasia included urinary incontinence (3 cats), skin necrosis (2 cats), and unresolvable ILUTD (1 cat).



Conclusions— PPU is a salvage procedure that is successful in relieving the signs of urinary tract obstruction and preventing further obstruction. However, potential complications should limit its use to cases in which standard techniques for perineal urethrostomy cannot be performed.



Clinical Relevance— PPU is a comparatively simple procedure that should be considered as a salvage technique for obstructive disease of the pelvic urethra.

Prepubic Urethrostomy: A Long-Term Study in 16 Cats

Objectives: To retrospectively report the complications seen after full-thickness multiple small intestinal biopsies were performed in 66 dogs.

Methods: Animals that died as a result of enteric wound breakdown were compared with the surviving population to identify fatal risk factors.

Results: Seventeen dogs had hypoalbuminaemia and eight had albumin levels below 20 g/l at surgery. Twelve dogs had concurrent disease, of which seven had skin disease. Seven dogs suffered minor complications which resolved with treatment. Eight dogs (12 per cent) died or were euthanased between three and nine days postoperatively (mean [sd] 4·5 [2·1]) due to enteric wound breakdown. Seven of these dogs developed septic peritonitis and one died of haemorrhage. No statistically significant differences were identified in any of the parameters examined for the development of fatal enteric wound dehiscence.

Clinical Significance: Full-thickness intestinal biopsy is not a benign procedure. However, this study concludes that there are no consistent predictors for patients at increased risk of enteric wound breakdown.

Complications following full-thickness small intestinal biopsy in 66 dogs : a retrospective study

Background Flow cytometry may be used to determine immunophenotype or lineage of leukemic cells, but few antibodies are available that are specific for cells of monocytic and granulocytic lineage. Objective The purpose of this study was to evaluate the flow cytometric staining patterns of 3 commercial monoclonal antibodies for monocytes and granulocytes in clinically healthy dogs and in dogs with acute myeloid leukemia (AML). Methods Mouse antihuman macrophage antibody (MAC387), mouse anti-human myeloperoxidase (MPO), and a canine neutrophil-specific antibody (NSA) were evaluated using flow cytometry on blood from 6 clinically healthy control dogs, and on blood (n = 7) and/or bone marrow (n = 2) from 8 dogs with AML. A diagnosis of acute leukemia was confirmed by >30% blasts in bone marrow or >30% blasts in peripheral blood, together with bi- or pancytopenia, circulating CD34-positive blast cells, and clinical signs of disease. Leukemic samples also were evaluated using a wide panel of monoclonal antibodies. Results MAC387 stained neutrophils and monocytes from control dogs, although the staining profiles for the 2 cell types differed. MPO and NSA resulted in strong positive staining of neutrophils; MPO also stained monocytes weakly. Lymphocytes did not stain with any of the antibodies. One case was classified as AML of granulocytic lineage (AML-M1), 6 cases were classified as acute monocytic leukemia (AML-M5), and 1 case was classified as acute myelomonocytic leukemia (AML-M4). Neoplastic myeloblasts in the dog with granulocytic AML were positive for MPO, NSA, MAC387, and CD4. All monoblasts from the dogs with AML-M5 were positive for CD14, 5 of 6 were positive for MAC387, and 2 were positive for MPO. NSA staining was negative in the 2 dogs with AML-M5 in which it was evaluated. In the dog with AML-M4 variable percentages of blast cells were positive for CD14, MPO, MAC387, CD4, and NSA. Conclusions Antigens identified by antibodies to MAC387, MPO, and NSA were expressed not just by normal mature neutrophils and monocytes, but also by neoplastic myeloblasts and monoblasts. These 3 antibodies may be useful as part of a wider panel for immunophenotyping AML in dogs.

Identification of acute myeloid leukemia in dogs using flow cytometry with myeloperoxidase, MAC387, and a canine neutrophil-specific antibody

Methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Staphylococcus pseudintermedius (MRSP) have emerged as important pathogens in animal infections. Associated therapeutic problems and the zoonotic potential of staphylococci have renewed interest in topical antibiotics for treatment and carrier decolonization. Fusidic acid and mupirocin are used topically in humans and animals but resistant strains isolated from people are increasing. This study investigates the in vitro activity of fusidic acid and mupirocin against coagulase-positive staphylococci from pets.

Stephen J. Baines

Papers

Prevalence and antimicrobial resistance of canine urinary tract pathogens

Prepubic Urethrostomy: A Long-Term Study in 16 Cats

Complications following full-thickness small intestinal biopsy in 66 dogs : a retrospective study

Identification of acute myeloid leukemia in dogs using flow cytometry with myeloperoxidase, MAC387, and a canine neutrophil-specific antibody

In vitro activity of fusidic acid and mupirocin against coagulase-positive staphylococci from pets.