Charles W. Bradley

Postmortem Evaluation of 435 Cases of Intracranial Neoplasia in Dogs and Relationship of Neoplasm with Breed, Age, and Body Weight

BACKGROUND Intracranial neoplasia of dogs is frequently encountered in veterinary medicine, but large-scale studies on prevalence are lacking. OBJECTIVES To determine the prevalence of intracranial neoplasia in a large population of dogs examined postmortem and the relationship between breed, age, and weight with the presence of primary intracranial neoplasms. ANIMALS All dogs that underwent postmortem examination from 1986 through 2010 (n = 9,574), including dogs with a histopathologic diagnosis of primary (n = 227) and secondary (n = 208) intracranial neoplasia. METHODS Retrospective evaluation of medical records from 1986 through 2010. RESULTS Overall prevalence of intracranial neoplasia in this studys population of dogs was 4.5%. A statistically significant higher prevalence of primary intracranial neoplasms was found in dogs with increasing age and body weights. Dogs ≥15 kg had an increased risk of meningioma (odds ratio 2.3) when compared to dogs <15 kg. The Boxer, Boston Terrier, Golden Retriever, French Bulldog, and Rat Terrier had a significantly increased risk of primary intracranial neoplasms while the Cocker Spaniel and Doberman Pinscher showed a significantly decreased risk of primary intracranial neoplasms. CONCLUSIONS AND CLINICAL IMPORTANCE Intracranial neoplasia in dogs might be more common than previous estimates. The study suggests that primary intracranial neoplasia should be a strong differential in older and larger breed dogs presenting with signs of nontraumatic intracranial disease. Specific breeds have been identified with an increased risk, and others with a decreased risk of primary intracranial neoplasms. The results warrant future investigations into the role of age, size, genetics, and breed on the development of intracranial neoplasms.

COMPUTED TOMOGRAPHIC CHARACTERISTICS OF ODONTOGENIC NEOPLASMS IN DOGS

Odontogenic neoplasms are locally invasive oral tumors in dogs. The purpose of this retrospective study was to describe CT characteristics for varying histopathologic types of canine odontogenic neoplasms. A board-certified veterinary radiologist who was unaware of histologic findings reviewed and scored imaging studies. A total of 29 dogs were included in the study. Twenty-three of these dogs had concurrent dental radiographs. The most common CT characteristics for all tumor types were a direct association with or in the region of multiple teeth in 96.4% (27/28), contrast enhancement in 96.3% (26/27), alveolar bone lysis in 93.1% (27/29), and mass-associated tooth displacement in 85.2% (23/27). Mass-associated cyst-like structures were identified in 53.6% (15/28) and were only present in tumors containing odontogenic epithelium. Canine acanthomatous ameloblastomas (n = 15) appeared as extra-osseous (10/15) or intra-osseous (5/15) masses. Intra-osseous canine acanthomatous ameloblastomas were more likely to have mass-associated cyst-like structures and were subjectively more aggressive when compared with extra-osseous canine acanthomatous ameloblastomas. Amyloid-producing odontogenic tumors (n = 3) had subjectively uniform CT imaging characteristics and consisted of round soft tissue and mineral attenuating masses with multiple associated cyst-like structures. Fibromatous epulides of periodontal ligament origin (n = 4) were contrast enhancing extra-osseous masses that were rarely referred for CT examinations and 25% (1/4) were not visible with CT. Other odontogenic tumors were less represented or had more variable CT imaging characteristics. Mass-associated tooth destruction was appreciated more often with dental radiographs and extra-oral tumor extension was identified more often with CT.

Encephalitozoon cuniculi in pet rabbits: diagnosis and optimal management

Abstract Encephalitozoonosis is a significant microsporidial disease of captive pet rabbits (Oryctolagus cuniculus). This article overviews the life cycle, pathogenesis, and host immune response to the parasite. Clinical presentation, differential diagnoses, antemortem diagnostics, and postmortem diagnosis will be discussed. International seroprevalence data and histologic prevalence estimates in the US are presented. A review of current treatment and control recommendations are discussed based on extensive review of controlled studies, which have found fenbendazole to be effective for limiting spread of the disease.

Late-onset cerebellar abiotrophy in a Labrador Retriever

CASE REPORT A 5-year-old female spayed Labrador Retriever was examined for a hindlimb gait abnormality. Initial neurological examination was consistent with vestibular dysfunction. Over the course of 1 year, signs progressed to reflect cerebellar ataxia, vertical nystagmus and delayed postural reactions in all limbs. At the initial examination, subjective evaluation of magnetic resonance imaging scan of the brain was considered normal. Repeat imaging at 1 year after initial examination revealed a reduction in the size of the cerebellum. Retrospectively, the size of the cerebellum on the initial MRI was small when assessed using an objective measurement algorithm. Postmortem histopathological evaluation of the brain showed diffuse degeneration of Purkinje cell neurones with secondary granule cell loss in the cerebellum, in addition to pigment inclusions in brainstem neurones. CONCLUSION The clinical history and clinicopathological data are consistent with late-onset cerebellar abiotrophy, which has not previously been described in this breed.

Cholangitis and Cholangiohepatitis in Dogs: A Descriptive Study of 54 Cases Based on Histopathologic Diagnosis (2004–2014)

Background Cholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete. Objective To describe a population of dogs with cholangitis or cholangiohepatitis. Animals Fifty‐four client‐owned dogs with cholangitis or cholangiohepatitis. Methods Medical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer‐based search and retrospectively reviewed. Results Clinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114–1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0–4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9–13.2) compared to younger dogs. Conclusions and Clinical Significance Chronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.

Percutaneous cholecystocentesis in cats with suspected hepatobiliary disease

Objectives The objective was to evaluate the safety and diagnostic utility of percutaneous ultrasound-guided cholecystocentesis (PUC) in cats with suspected hepatobiliary disease. Methods Medical records of 83 cats with suspected hepatobiliary disease that underwent PUC were retrospectively reviewed. Results At the time of PUC, at least one additional procedure was performed in 79/83 cats, including hepatic aspiration and/or biopsy (n = 75) and splenic aspiration (n = 18). Complications were noted in 14/83 cases, including increased abdominal fluid (n = 11), needle-tip occlusion (n = 1), failed first attempt to penetrate the gall bladder wall (n = 1) and pneumoperitoneum (n = 1). There were no reports of gall bladder rupture, bile peritonitis or hypotension necessitating treatment with vasopressor medication. Blood products were administered to 7/83 (8%) cats. Seventy-two cats (87%) survived to discharge. Of the cats that were euthanized (9/83) or died (2/83), none were reported as a definitive consequence of PUC. Bacteria were identified cytologically in 10/71 samples (14%); all 10 had a positive aerobic bacterial culture. Bile culture was positive in 11/80 samples (14%). Of the cases with a positive bile culture, cytological description of bacteria corresponded to the organism cultured in fewer than 50% of cases. The most common cytologic diagnosis was hepatic lipidosis (49/66). The most common histopathologic diagnosis was cholangitis (10/21). Conclusions and relevance PUC was safe in this group of cats with suspected hepatobiliary disease. Complications were likely associated with ancillary procedures performed at the time of PUC. Bile analysis yielded an abnormal result in nearly one-third of cats with suspected hepatobiliary disease. Complete agreement between bile cytology and culture was lacking. Further evaluation of the correlation between bile cytology and bile culture is warranted.

Clinical and histologic features of acute-onset erythroderma in dogs with gastrointestinal disease: 18 cases (2005–2015)

OBJECTIVE To describe the clinical and histologic features of acute erythroderma in dogs with gastrointestinal disease. DESIGN Retrospective case series. ANIMALS 18 dogs with erythroderma and gastrointestinal disease. PROCEDURES Medical records and biopsy specimens were reviewed. Information collected from medical records included signalment, clinical signs, physical examination and diagnostic test results, treatment, and outcome. The Naranjo algorithm was used to estimate the probability of an adverse drug reaction for each dog. RESULTS All dogs had an acute onset of erythematous macules or generalized erythroderma. Histologic features of skin biopsy specimens had 3 patterns representing a progressive spectrum of inflammation. Most dogs had vomiting (n = 17) and hematochezia (10). Signs of gastrointestinal disease became evident before, after, or concurrent with the onset of skin lesions in 10, 3, and 5 dogs, respectively. Inflammatory bowel disease, pancreatitis, and adverse food reaction were diagnosed in 5, 3, and 3 dogs, respectively. The cause of the gastrointestinal signs was not identified for 8 dogs. Eight dogs had a Naranjo score consistent with a possible adverse drug reaction. Treatment of skin lesions included drug withdrawal (n = 15), antihistamines (16), and corticosteroids (14). Signs of gastrointestinal disease and skin lesions resolved at a mean of 4.6 days and 20.8 days, respectively, after onset. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated acute erythroderma may be associated with > 1 gastrointestinal disease or an adverse drug reaction in some dogs. Recognition of the clinical and histologic features of this syndrome is essential for accurate diagnosis.

Clinicopathological findings of canine seborrhoeic keratosis with comparison to pigmented viral plaques

BACKGROUND Seborrhoeic keratoses (SKs) are common benign epidermal neoplasms in humans and are rarely diagnosed in the dog. These circumscribed, raised, variably pigmented plaques arise in middle aged to older humans, with a focal or multicentric distribution; although common, the underlying cause of these lesions is not known. Although less common in the dog, the lesions are similar and have features that overlap with papillomavirus-associated pigmented viral plaques. HYPOTHESIS/OBJECTIVES Seborrhoeic keratoses in the dog are negative for canine papillomavirus. ANIMALS Eleven cases of SK from a 12 year period were reviewed. METHODS This was a retrospective study of the histopathological findings and case histories. Complete clinical records following collection of the skin biopsy were available in five of 11 cases. Immunohistochemistry was performed for all cases; PCR analysis was carried out for papillomavirus in six cases. RESULTS Histologically, SKs had an exophytic to mildly endophytic epidermal proliferation, creating a papillomatous to acanthotic, hyperkeratotic, frequently pigmented plaque. There was an absence of hypergranulosis or viral cytopathic effect; PCRs for canine papillomavirus within the formalin-fixed paraffin-embedded skin biopsies were negative. No breed, sex or site predilection was recognized. The mean age at biopsy of the lesions was 8.8 years (range 5-14 years). CONCLUSIONS AND CLINICAL IMPORTANCE Histopathological features and negative papillomavirus status distinguish SK as an important differential diagnosis for pigmented viral plaques in dogs.

Clinical and histopathological features of Burkholderia cepacia complex dermatitis in dogs: a series of four cases

BACKGROUND The Burkholderia cepacia complex (Bcc) is an emerging cause of opportunistic infections. Deep pyoderma associated with Bcc infection has been reported previously in dogs receiving ciclosporin. OBJECTIVE To report the clinical and histopathological features of four additional cases of Bcc dermatitis in dogs, one of which progressed to septicaemia. ANIMALS Four dogs with a skin culture yielding growth of Bcc and skin biopsies for histopathological investigation. METHODS AND MATERIALS Retrospective review of medical records and skin biopsies and PCR for Burkholderia on DNA extracted from paraffin-embedded skin and liver to confirm Bcc sepsis. RESULTS Three different breeds and one mixed breed dog were represented. Two dogs were receiving ciclosporin and one was receiving oclacitinib. One dog had no evidence of immunosuppression. One dog was bathed two days prior to onset of skin lesions. Three dogs presented with dorsally orientated ulcers, crusts and draining tracts; one dog had infection localized to a surgical site. The main histological feature from skin biopsies was severe neutrophilic folliculitis and furunculosis with marked neutrophilic to pyogranulomatous dermatitis. Intracellular Gram-negative and Warthin-Starry positive rods were present in three of four cases. Three dogs were successfully treated with systemic fluoroquinolones or trimethoprim sulfamethoxazole. The Bcc isolate in one dog was resistant to all tested systemic antimicrobials. This dog developed septicaemia and was euthanized. CONCLUSIONS AND CLINICAL IMPORTANCE Bcc skin infections can occur in immunocompetent and immunocompromised dogs. Bcc isolates may be extensively antimicrobial resistant, presenting a challenge for clinical management. Cutaneous infection may progress to life-threatening sepsis.

Antiseptic Agents Elicit Short-Term, Personalized, and Body Site–Specific Shifts in Resident Skin Bacterial Communities

Despite critical functions in cutaneous health and disease, it is unclear how resident skin microbial communities are altered by topical antimicrobial interventions commonly used in personal and clinical settings. Here we show that acute exposure to antiseptic treatments elicits rapid but short-term depletion of microbial community diversity and membership. Thirteen subjects were enrolled in a longitudinal treatment study to analyze the effects of topical treatments (i.e., ethanol, povidone-iodine, chlorhexidine, and water) on the skin microbiome at two skin sites of disparate microenvironment: forearm and back. Treatment effects were highly dependent on personalized and body site-specific colonization signatures, which concealed community dynamics at the population level when not accounted for in this analysis. The magnitude of disruption was influenced by the identity and abundance of particular bacterial inhabitants. Lowly abundant members of the skin microbiota were more likely to be displaced, and subsequently replaced, by the most abundant taxa prior to treatment. Members of the skin commensal family Propionibactericeae were particularly resilient to treatment, suggesting a distinct competitive advantage in the face of disturbance. These results provide insight into the stability and resilience of the skin microbiome, while establishing the impact of topical antiseptic treatment on skin bacterial dynamics and community ecology.