Adipsia and hypernatraemia in a 6-month-old Staffordshire bull terrier

A 6-month-old female Staffordshire bull terrier cross presented to the Onderstepoort Veterinary Academic Hospital with lethargy, weakness, decreased appetite, abnormal vocalisation, twitching of the facial muscles and ears, circling, alopecia, pruritus, seborrhoea sicca and erythema. Serum biochemistry revealed severe hypernatraemia (200.4 mmol/L; Reference Interval 140 mmol/L – 155 mmol/L). Treatment required careful administration of intravenous fluids. The electrolytes were monitored to ensure slow and controlled sodium normalisation (the target reduction of Na concentration was by 0.5 mmol/L/h –1 mmol/L/h or 12 mmol/L/24 h – 24 mmol/L/24 h). Despite the careful fluid calculations and close monitoring, the serum sodium levels dropped more than the recommended 0.5 mmol/L/h – 1 mmol/L/h in the first 4 h and the fluids had to be adjusted. The patient’s habitus improved and the central nervous system signs started to resolve after 1 day of fluid treatment. The puppy started eating food mixed with water, but made no attempt to drink water. The pruritus and erythema resolved once the sodium levels normalised and the seborrhoea sicca began to resolve. At a follow up visit 20 days post discharge the skin was normal. A diagnosis of hypernatraemia as a result of pure water loss due to hypodipsia or adipsia was made, as the puppy made no attempt to drink water when her serum sodium levels increased (a strong thirst stimulus). Hypernatraemia recurred if she was not forced to take in adequate amounts of water mixed with her food. Dermatological changes such as seborrhoea, hyperkeratosis and alopecia have been reported in a few other cases of hypernatraemia in dogs and sodium levels should be investigated in dermatological patients when no other cause can be established. This study, supported by another retrospective study done in 2008, suggests that the Staffordshire bull terrier may be a breed that is predisposed to hypernatraemia

Cardiac histopathology and electrocardiographic changes in canine babesiosis

Electrocardiographic (ECG) changes have never been reported in canine babesiosis. Based on the metabolic, electrolyte, and myocardial alterations described for the disease, such changes are to be expected. The purpose of this study was to describe ECG changes in canine babesiosis, and to correlate those changes to clinical severity, outcome and cardiac histopathological changes. Four groups of dogs with babesiosis were studied: mild to moderate anaemia (n=40), severe anaemia (n=35), concurrent immune-mediated haemolytic anaemia (n=18) and complicated (n=28). Lead II ECG was recorded at admission for 1 minute in all dogs, and repeated after 24 hours in admitted dogs (groups II – IV). Six lead ECG was recorded in 88 dogs. Full necropsy was performed between 30-60 minutes after death on 16 dogs (5 died on arrival, 11 had ECG recording). Gross cardiac pathology was recorded and histopathology of myocardial sections from ventricles, atria, apex and interventricular septa was evaluated, using a scoring system for haemorrhages, necrosis, inflammatory infiltrate and fibrin microthrombi. The following ECG changes were recorded: sinoatrial (7%) and atrioventricular blocks (4%), ventricular premature complexes (7%), low R-amplitude (23%), prominent Q (33%), axis deviations (40%), prolonged QRS (32%), ST depression and coving (28%), large T (42%), and notched R (28%). Differences between groups were minor and inconsistent. Gross pathological changes were pericardial effusion (25%) and subepicardial (56%) and subendocardial haemorrhages (63%). Histological changes were haemorrhages (69%), necrosis (50%), inflammation (63%) and fibrin microthrombi (75%). The only correlation between pathology and ECG was low R-amplitude and pericardial effusion. There was a significantly higher prevalence of sinus bradycardia and irregular sinus rhythm in the non-survivors. Both ECG and pathological changes were non-specific, but there were similarities to the pattern of changes that have been described for myocarditis and myocardial ischaemia. Antiarrhythmic treatment was only required in 1 dog. Thus, the clinical application of the ECG changes found in this study was limited. It was concluded that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. Cardiovascular management, if necessary, should be based on functional monitoring rather than ECG.Dissertation (MMedVet (Med))--University of Pretoria, 2001.Companion Animal Clinical Studiesunrestricte

Biomarkers of neoplastic transformation in canine spirocercosis

Spirocerca lupi is a nematode that infects the dog’s oesophagus and promotes the formation of an inflammatory fibroblastic nodule that progresses to sarcoma in approximately 25% of cases. Differentiating neoplastic from non-neoplastic cases ante-mortally is challenging and has major therapeutic and prognostic implications. More importantly, spirocercosis-associated oesophageal sarcoma is an excellent and under-utilized spontaneous model of parasite-associated malignancy and the pathogenesis of the neoplastic transformation is poorly understood. The current study objective was to investigate potential clinical, clinicopathological, radiological and tissue biomarkers for the malignant transformation and an attempt to use these biomarkers to gain a deeper understanding of the pathogenesis of the neoplastic transformation. Our central hypothesis was that the parasite produces excretory product(s) which diverts the immune response from a T helper 1 (Th1) to Th2 cell response, typical of many nematode infections, and further to an immunoregulatory (immunosuppressive), FoxP3+ regulatory T cell-predominated response which then facilitates neoplastic transformation. The following parameters were studied and compared between cases with non-neoplastic and neoplastic spirocercosis: clinical presentation, haematology, serum albumin and globulin, thoracic radiology, haematoxylin-eosin (H&E) histology, Immunohistochemistry for expression of vascular endothelial growth factor (VEGF)-A, fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), MAC387 (myeloid cells), CD3 (T cells), Pax5 (B cells) and FoxP3 (T regulatory cells) and plasma cytokine concentrations including IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, GM-CSF and MCP-1. Hypertrophic osteopathy showed 100% specificity for neoplastic transformation but relatively poor sensitivity (40%). Female gender, anaemia, leukocytosis, thrombocytosis, spondylitis and bronchial displacement were significantly more common in neoplastic cases, but appeared in non-neoplastic cases as well. The H&E study revealed 2 stages in the non-neoplastic nodules: early inflammation, characterized by fibrocytes and abundant collagen, and a pre-neoplastic stage, characterized by activated fibroblasts and reduced collagen. The neoplastic cases were all sarcomas, primarily osteosarcoma with very aggressive features comparable to other appendicular osteosarcoma in the dog. The inflammation in spirocercosis is characterized by pockets of pus (MAC387+ cells) surrounded by organized lymphoid foci (CD3+ and to a lesser degree Pax5+ cells). There was no evidence of a local accumulation of FoxP3+ cells, unlike many previous studies which have reported an increase in Foxp3+ T cells in both malignancies and parasite infections. Interleukin-8 plasma concentration was higher in the neoplastic group compared to the non-neoplastic and the control groups. Interleukin-18 concentration was higher in the non-neoplastic group followed by the control group and finally the neoplastic group. As with most similar studies, no ideal biomarker with high sensitivity and specificity was identified. However, if examined together, a panel of the biomarkers that were identified more commonly in the neoplastic cases should substantially increase the index of suspicion for neoplastic transformation in a diagnosed spirocercosis case. The inflammatory response showed features of increased myeloid (innate) response and lymphocytic response with pro-inflammatory cytokines. This was not our initial hypothesis and the question remains whether the response is secondary to the worm infection, or to a symbiotic bacterium that is carried by the worm. The role of such a reaction in neoplastic transformation remains to be elucidated.Thesis (PhD)--University of Pretoria, 2012.Companion Animal Clinical Studiesunrestricte

Oesophagogastric intussusception associated with spirocercosis in a dog

An oesophagogastric intussusception was diagnosed in an intact Bull Terrier female aged 2 years and 7 months with a concurrent Spirocerca lupi infection. The dog was presented collapsed with a history of inappetance and lethargy of one day’s duration. Anaemia and melaena were present on clinical examination. Thoracic radiographs did not reveal any significant findings. Abdominal ultrasound was suspicious for gastric pathology or a possible foreign body. The final diagnosis of an oesophagogastric intussusception with an S. lupi nodule at the cardia was made on post-mortem. Oesophageal intussusceptions are rare in dogs and often fatal. Gastro-oesophageal intussusceptions usually present with obvious radiographic signs in the caudal thorax, unlike an oesophagogastric intussusception, where the pathology lies within the abdomen and may not be readily diagnosed. Although spirocercosis often presents with a caudal oesophageal mass, this may not be seen radiographically. In this case, the two conditions were present together but the thoracic radiographs were normal.http://www.jsava.co.zaam201

Budd-chiari-like syndrome associated with a pheochromocytoma invading the right atrium in a dog

An 8 year-old spayed female Jack Russell Terrier dog was presented with severe abdominal distension due to ascites and discomfort of five days duration. Abdominal ultrasound revealed ascites and a mass invading the caudal vena cava pointing to Budd-Chiari-like syndrome (BCLS). The peritoneal fluid was a modified transudate. The BCLS was a result of a left adrenal mass that invaded the caudal vena cava to a length of 14 cm, up to the right atrium. A phaeochromocytoma was highly suspected and due to its aggressiveness and poor prognosis the dog was euthanized. The diagnosis was confirmed by histopathology after post mortem. This is a rare case of a 14 cm-long phaeochromocytoma associated with BCLS illustrating the in vivo diagnostic approach. A phaeochromocytoma should be considered in cases presenting with BCLS.http://www.isrvma.orgmn201

Serum alkaline phosphatase activity is not a marker for neoplastic transformation of esophageal nodules in canine spirocercosis

BACKGROUND: Spirocerca lupi is a nematode of Canidae that matures within the esophageal wall to form fibroblastic nodules with potential for malignant transformation. Diagnosis is based on histopathologic examination, but false-negative results may be obtained from samples collected by endoscopy. Serum alkaline phosphatase (ALP) activity, frequently increased in hepatobiliary disease, is also increased in a variety of neoplastic conditions in dogs, including appendicular osteosarcoma, and has also been reported to be increased in dogs with spirocercosis. OBJECTIVE: The aim of this study was to evaluate serum ALP activity as a marker for malignant transformation of esophageal nodules in S. lupi-infected dogs. METHODS: In this retrospective study, medical records of dogs diagnosed with spirocercosis from 1991 to 2008 were reviewed, and serum ALP activity determined at presentation was compared between dogs with nonneoplastic and neoplastic nodules. Owing to use of multiple analyzers, ratios of ALP activity to the upper reference interval for ALP were calculated and compared. RESULTS: Median ALP activity ratios were 0.65 (0.07–4.00) and 0.86 (0.10–3.40) for dogs with nonneoplastic (n = 88) and neoplastic (n=32) nodules, respectively,with no significant difference (P =.18) and substantial overlap between groups. Tumors included osteosarcoma (15 dogs), fibrosarcoma (15 dogs), and anaplastic sarcoma (2 dogs); there was no difference in ALP activity between the dogs with osteosarcoma and fibrosarcoma. CONCLUSION: ALP is a poor marker of malignant transformation in canine spirocercosis.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1939-165X/issue

Spirocerca lupi induced oesophageal neoplasia : predictors of surgical outcome

Canine spirocercosis is caused by the nematode Spirocerca lupi. Migration results in oesophageal fibro-inflammatory nodules that may undergo neoplastic transformation. No studies have assessed pre- or post-surgical prognostic indicators in dogs that undergo intervention for S. lupi induced oesophageal neoplasia. This observational, multi-center study aimed to assess the outcome of dogs with Spirocerca induced sarcoma undergoing endoscopic-guided ablation (n = 12) or surgery (n = 18), and identify prognostic indicators. Parameters evaluated included: age, weight, gender, presenting complaints, duration of clinical signs, complete blood count, serum biochemistry, neoplasia size, placement of percutaneous endoscopically-placed gastrostomy tube, histopathological mitotic indices, days to discharge and chemotherapy administration. Kaplan-Meier survival curves showed no difference in survival between ablation and surgery {(median: 73.5 days (range: 0–1511) vs. 108 days (range: 0–1550), respectively (p = 0.982)}. Reduced survival was documented in patients presenting with weight loss (P = 0.027), hypochromasia (MCHC 15 × 109/L, P = 0.017) with a hazard ratio of 2.51 (CI95% = 1.071–6.018, P = 0.034), 2.71 (CI95% = 1.10–6.65, P = 0.03) and 4.39 (CI95%: 1.21–15.97, P = 0.025) respectively. In the dogs surviving more than 21 days, Ht 15.0 × 109/L at presentation were associated with reduced survival (p = 0.016, p = 0.021 respectively) and hazard ratio of 3.29 (CI95% = 1.18–9.2, P = 0.023) and 3.81 (CI95% = 1.15–12.55, P = 0.028) respectively. Intra-intervention-group survival analysis identified increased survival time in dogs receiving chemotherapy, but only within the surgical group (P = 0.02).The hospitalisation time of dogs undergoing ablation (median: 0 days, range: 0–4) was significantly shorter than dogs undergoing surgery (9 days, 1–21) (P < 0.001). In this study, no clear benefit was identified for surgery, thus when ablation is technically possible it should be considered advantageous, as hospitalisation time is significantly shorter. Weight loss, hypochromasia and leucocytosis were identified as long-term prognostic indicators at presentation.http://www.elsevier.com/locate/vetpar2019-01-30hj2018Companion Animal Clinical Studie

Triple phase dynamic computed tomographic perfusion characteristics of spirocercosis induced esophageal nodules in non-neoplastic versus neoplastic canine cases

Neoplastic transformation of Spirocerca lupi induced esophageal nodules carries a poor prognosis. Clinical, clinicopathological, endoscopic, and radiographic characteristics may be indicative of neoplastic transformation but variable sensitivity and specificity of these parameters makes their use questionable. We hypothesized that CT would be a better diagnostic modality to discriminate between non-neoplastic and neoplastic nodules. In this prospective study of 38 dogs, the appearance and perfusion characteristics of confirmed spirocercosis-induced neoplastic and non-neoplastic esophageal nodules were described using survey CT and triple phase dynamic CT angiography (CTA). Pre- and post-contrast early arterial, late arterial, and venous CTA images were evaluated. Non-neoplastic nodules were smooth and nonmineralized with a higher proportion of hypoattenuating necropurulent cavities compared to neoplastic nodules that had a more irregular surface, with 93% having mineralized foci and rarely any hypoattenuating pockets. Non-neoplastic nodules were significantly more perfused than neoplastic nodules with the difference being up to 23 Hounsfield units. The difference was most marked in the early and late arterial phases (P = 0.0005 and 0.00005, respectively). Ratios of the normal esophagus adjacent to the neoplastic and non-neoplastic nodules did not differ significantly from each other. Perfusion findings demonstrated relative hypoperfusion of the esophageal sarcomas. Findings from the current study indicated that CT characteristics of relative postcontrast hypoperfusion, combined with nodule irregularity and mineralization warrant a high level of concern for neoplastic transformation in canine spirocercosis-induced esophageal nodules.South African National Research Foundationhttp://www.elsevier.com/locate/funbiohb2016Companion Animal Clinical Studie

Serum C-reactive protein concentration in benign and malignant canine spirocercosis

BACKGROUND: Spirocerca lupi is a nematode of canids that forms a nodule in the esophagus that can undergo neoplastic transformation. C-reactive protein (CRP) is a major acute phase protein in the dog that has been used for treatment, monitoring, and prognostication in inflammatory and neoplastic disease. HYPOTHESIS/OBJECTIVES: The objectives of this study were to determine if serum CRP concentration (1) is increased in canine spirocercosis, (2) can be used to determine neoplastic transformation, and (3) can be used to monitor response to treatment in benign spirocercosis. ANIMALS: Forty-two dogs naturally infected with S. lupi and 21 control dogs. METHODS: A retrospective study was performed. The infected cases were divided into benign (n = 28) or malignant (n = 14) spirocercosis. CRP was performed on all of the spirocercosis and control cases at presentation. Statistical analysis was done by the one-way analysis of variance and Student’s t-test. RESULTS: The mean CRP concentration in the benign cases was 60.4 ± 48.0 mg/L and that of the malignant cases was 76.5 ± 44.8 mg/L; both values were significantly higher (P < .001) than those of the control group where the mean was 13.4 ± 17.9 mg/L. The mean CRP concentration for the convalescent sera in the benign group was lower than the pretreatment concentrations (P = .01). CONCLUSION AND CLINICAL IMPORTANCE: CRP cannot be used to differentiate between benign and malignant spirocercosis. There is a decrease in CRP concentration in dogs with benign spirocercosis once treatment has commenced. Serial CRP measurement can be used to monitor response to treatment in benign spirocercosis.The Department of Companion Animal Clinical Studies at the Faculty of Veterinary Science, University of Pretoria.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1939-1676mn201