Prevalence and molecular characterization of Giardia duodenalis in companion dogs, domestic livestock and wildlife in the Jordan Basin, Israel.

Giardiasis is a small intestinal disease caused by the zoonotic parasite, Giardia duodenalis. This study presents the molecular findings of G. duodenalis infection in companion dogs, domestic livestock and wildlife in the Northern Jordan Basin, Israel. Identification of G. duodenalis was accomplished by nested PCR (nPCR) targeting the 18S rRNA gene. Samples were collected from water (five samples from four sources of which one was recycled water), as well as feces from wolves (Canis lupus) (n = 34), jackals (Canis aureus) (n = 24), wild boars (Sus scrofa) (n = 40), cattle (Bos taurus) (n = 40), dogs (Canis lupus familiaris) (n = 37) and nutria (Mayocastor coypus) (n = 100). All positive samples were sequenced and a phylogenetic tree was drawn using the Bayesian Inference (BI) algorithm. Differences in G. duodenalis prevalence between the different hosts were analyzed by Pearson's chi-square (p < 0.05). Of the total 275 fecal samples, 36 were positive for G. duodenalis (13%). Frequency rates among different animal species was highest in wolves (32.3%), whilst rates in wild boars (22.5%), dogs (16.2%), cattle (12.5%) and jackals (4.2%), were observed to be significantly lower (p < 0.001). Three out of 5 recycled water (RW) samples were G. duodenalis positive. Three clusters with high posterior probabilities (PP) were found in the BI: Cluster 1: samples from wolves, wild boars, water and cattle together with database sequences of assemblages A, B and F, Cluster 2: samples from dogs, nutria and a jackal with sequences from assemblage D and Cluster 3: samples from cattle, wild boars, wolves and dogs with sequences from assemblage C and D. We suggest that wolves serve as reservoirs of G. duodenalis in this region. The finding of Giardia in RW suggests that this vehicle may further contaminate crops intended for human consumption as this water source is used for agricultural irrigation.

Comparison of multiplex copro PCR with coproscopy followed by PCR on recovered eggs for the detection of Echinococcus granulosus and Taenia spp. infection in dogs.

Echinococcosis and taeniasis are important helminth diseases that carry considerable impact on human and animal health. Domestic dogs and other canids are definitive hosts for several parasites of this group, including Echinococcus granulosus, Taenia multiceps, T. ovis, T. hydatigena and E. multilocularis. Detection of infection in dog populations is imperative for estimating the risk to susceptible humans and animals, and for its mitigation through prevention measures in dogs, other animals and humans. To date, identification of taeniid eggs, antigens or DNA in fecal samples are the most practical diagnostic modalities available for canine definitive hosts. Although widely used for this purpose, there is limited information comparing copro PCR and combined coproscopy-PCR protocols for the detection of taeniids. In the current study, a widely used multiplex PCR was performed on a large number of dog fecal samples using DNA extracted directly from feces. The samples were also tested by fecal flotation and coproscopy, eggs were isolated from microscopically-positive samples and extracted DNA was tested using the same multiplex PCR. The total number of taeniid positive samples detected using both methods was 46/317 (14.5%), including 10/317 (3.2%) E. granulosus positive samples. Both copro PCR and coproscopy have identified an equal number of samples as taeniid positive (n = 32). However, for the purpose of identification to species level, the copro PCR was significantly more sensitive than coproscopy followed by PCR on isolated eggs (sensitivity 0.7 vs. 0.41, p = 0.012), with 32/317 (10.1%) and 19/317 (6%) positive samples identified, respectively. The difference in identification of E. granulosus was highly apparent, as the majority of the E. granulosus positive samples (8/10) were detected by the copro PCR only. Coproscopy and egg PCR have identified 5/317 (1.6%) positive samples not detected by the copro PCR, including only a single sample (0.3%) positive for E. granulosus. Adding these positive samples to those identified by the copro PCR did not significantly improve the overall sensitivity (p = 0.074). Therefore, using both copro PCR and coproscopy in parallel may not be advantageous for taeniid detection and identification, at least until the egg PCR is further optimized and performs better. These results should be weighed against the different advantages that coproscopy based approach may offer.

Ultrasonography is insensitive but specific for detecting aortic wall abnormalities in dogs infected with Spirocerca lupi.

BACKGROUND: Spirocercosis is caused by the nematode Spirocerca lupi (S lupi). The disease mainly affects dogs and is typically diagnosed by oesophagoscopy or faecal examination; however, these diagnostic tests may deliver false negative results during the migration phase of the nematode. The aim of the present prospective study was to evaluate whether ultrasonography could detect abnormalities in the abdominal aorta, celiac artery, and gastric wall structure as a diagnostic aid to detect S lupi infection in dogs. METHODS: Oesophagoscopy and a focused abdominal ultrasound scan were performed in 40 dogs that presented to the Koret School of Veterinary Medicine Teaching Hospital, Hebrew University of Jerusalem, with gastrointestinal complaints. Ultrasonography scan findings of 20 dogs with oesophageal nodules, indicating S lupi infection (study group), were compared with those of 20 control dogs. RESULTS: Vascular wall irregularity was significantly more common in the study group than in the control group (9/20 v 1/20, respectively; P=0.008). CONCLUSION: Ultrasonographic evaluation of the abdominal aorta, celiac artery, and gastric wall structure is not a sensitive diagnostic marker for spirocercosis in dogs. However, the presence of vascular wall irregularity of the abdominal aorta or celiac artery might indicate S lupi migration.

Insights on Spirocerca lupi, the Carcinogenic Dog Nematode.

Spirocerca lupi is a nematode transmitted by dung beetles that infects domestic and wild canids in tropical and subtropical regions and is associated with neoplasia. It produces a distinctive pathology with the formation of esophageal nodules classified as inflammatory, preneoplastic, or neoplastic with metastasis to distant organs. Aberrant central nervous system migration of this nematode is also responsible for severe neurological manifestations. Reports of spirocercosis have increased over the last two decades showing spread of this canine helminth in five continents. S. lupi from different geographical locations is genetically distinct with two genotypes, genotype I from Africa, Asia, and Australia, and genotype II from Europe, and recently separated from Spirocerca vulpis, a new species described in red foxes from Europe.

Vitamin D status in dogs with babesiosis.

Canine babesiosis is a virulent infection of dogs in South Africa caused principally by Babesia rossi. Hypovitaminosis D has been reported in a wide range of infectious diseases in humans and dogs, and low vitamin D status has been associated with poor clinical outcomes. However, the relationship between vitamin D status and canine babesiosis has not been investigated. The objective of this study was to examine the relationship between the presence and severity of B. rossi infection and vitamin D status of infected dogs. Owners with dogs with a confirmed diagnosis of B. rossi infection and of healthy control dogs were invited to enrol onto the study. Vitamin D status was assessed by measurement of serum concentrations of the major circulating vitamin D metabolite, 25-hydroxyvitamin D (25[OH]D). Dogs with babesiosis (n = 34) had significantly lower mean serum 25(OH)D concentrations than healthy dogs (n = 24) (37.76 ± 21.25 vs. 74.2 ± 20.28 nmol/L). The effect of babesiosis on serum 25(OH)D concentrations was still significant after adjusting for any effect of age, body weight and sex. There was a negative relationship between serum 25(OH)D concentrations and disease severity in dogs with babesiosis. Serum concentrations of creatinine and alanine aminotransferase and time to last meal were not associated with serum 25(OH)D concentrations in dogs with babesiosis. In conclusion, dogs with Babesia rossi infections had lower serum 25(OH)D concentrations than healthy dogs. The inverse correlation between 25(OH)D concentrations and the clinical severity score indicate that hypovitaminosis D might be a helpful additional indicator of disease severity.

Phylogenetic analysis of Spirocerca lupi and Spirocerca vulpis reveal high genetic diversity and intra-individual variation.

BACKGROUND: Spirocerca lupi is a parasitic nematode of canids that can lead to a severe and potentially fatal disease. Recently, a new species, Spirocerca vulpis, was described from red foxes in Europe, suggesting a high genetic diversity of the Spirocerca spp. infecting canids. The genetic variation and phylogenetic relationships of S. lupi collected from naturally-infected domestic dogs from Australia, Hungary, Israel, Italy, India and South Africa, and S. vulpis from red foxes from Bosnia and Herzegovina, Italy and Spain, was studied using mitochondrial and rDNA markers. RESULTS: A high intra-individual variation was found in the first internal transcribed spacer (ITS1) locus in all Spirocerca spp., ranging between 0.37-2.84%, with up to six haplotypes per specimen. In addition, a combination of phylogenetic and haplotype analyses revealed a large variability between S. lupi specimens collected from different geographical locations using the ITS1 (0.37-9.33%) and the cytochrome c oxidase subunit 1 (cox1) gene (1.42-6.74%). This genetic diversity led to the identification of two S. lupi genotypes circulating among dogs (PTP support > 0.829), including genotype 1 found in S. lupi from Australia, India, Israel and South Africa, and genotype 2 represented by specimens from Hungary and Italy. These genotypes presented pairwise nucleotide distances of 0.14%, 8.06% and 6.48 ± 0.28% in the small rDNA subunit (18S), ITS1 and cox1 loci, respectively. Additionally, Nei's genetic distance in the ITS1 showed a further subdivision of genotype 1 worms into 1A (Israel and South Africa) and 1B (Australia and India). A morphological analysis of the anterior and posterior extremities of genotype 1 and genotype 2 worms using scanning electron microscopy did not show any differences between the specimens, contrary to the morphological differences between S. lupi and S. vulpis. CONCLUSIONS: These findings demonstrate the high genetic variability among Spirocerca spp. from different geographical locations, thereby expanding our understanding of the epidemiology, evolution and phylogenetic variability within the genus.

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 <33 g/dL, P = 0.023) or leucocytosis (>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 <36% and leucocytosis >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.

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.

Theileriosis in six dogs in South Africa and its potential clinical significance.

Theileriosis is a tick-borne disease caused by a piroplasma of the genus Theileria that can causeanaemia and thrombocytopenia. Its clinical importance for dogs' remains poorly understood,as only some develop clinical signs. In this study, physical and laboratory findings, treatment and outcomes of six client-owned diseased dogs presented at the Onderstepoort Veterinary Academic Hospital are described retrospectively. In the dogs, Theileria species (n = 4) and Theileria equi (n = 2) were detected by a polymerase chain reaction (PCR)-reverse blothybridisation assay in blood samples, whilst PCR for Babesia, Anaplasma and Ehrlichia were negative. The most common physical findings were pale mucous membranes (five out of six dogs), bleeding tendencies (five out of six dogs) and lethargy (three out of six dogs). All dogs were thrombocytopenic [median 59.5 x 10(9)/L (range 13-199)] and five out of six dogs were anaemic [median haematocrit 18% (range 5-32)]. Bone marrow core biopsies performed in two dogs showed myelofibrosis. Theileriosis was treated with imidocarb dipropionate and the suspected secondary immune-mediated haematological disorders with prednisolone and azathioprine. Five dogs achieved clinical cure and post-treatment PCR performed in three out of five dogs confirmed absence of circulating parasitaemia. An immune-mediated response to Theileria species is thought to result in anaemia and/or thrombocytopenia in diseased dogs with theileriosis. A bleeding tendency, most likely secondary to thrombocytopenia and/or thrombocytopathy, was the most significant clinical finding in these cases. The link between thrombocytopenia, anaemia and myelofibrosis in theileriosis requires further investigation and theileriosis should be considered a differential diagnosis for dogs presenting with anaemia and/or thrombocytopenia in endemic tick-borne disease areas.

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.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.

Computed tomographic and radiographic characteristics of aortic lesions in 42 dogs with spirocercosis.

Spirocerca lupi is a common cause of vomiting, regurgitation, and sudden death in dogs that live in tropical or subtropical regions. Sudden death due to aortic rupture may occur with no preceding clinical signs. The purpose of this prospective study was to compare radiographic and computed tomographic (CT) characteristics of aortic lesions in a cohort of 42 dogs with endoscopically confirmed spirocercosis. Dorsoventral and right lateral recumbent thoracic radiographic findings were compared with pre- and postcontrast thoracic CT findings. Aortic mineralization was detected using CT in 18/42 dogs (43%). Three dogs had faint diffuse aortic wall mineralization. Using CT as the reference standard, radiographs had a sensitivity and specificity of 6% and 96%, respectively, for detecting aortic mineralization. A total of 20 aortic aneurysms were detected using CT in 15/42 dogs (36%). Using CT as the reference standard, radiographs had a sensitivity and specificity of 86% and 56%, respectively, for detecting aortic aneurysms. Respiratory motion, aortic displacement by esophageal masses and Spirocerca nodules adjacent to the aorta mimicked aneurysm formation on radiographs. Aortic thrombi were seen in two dogs in postcontrast CT images. Findings from this study indicated that aortic mineralization and aneurysm formation are common in dogs with spirocercosis. Findings also supported the use of pre- and postcontrast CT as effective methods for detecting and characterizing these lesions.

Spirocerca lupi-associated vertebral changes: a radiologic-pathologic study.

Spirocerca lupi causes a caudal esophageal mass in dogs which may be accompanied by aortic changes and caudal thoracic spondylitis. Previous literature hypothesized that the spondylitis was caused by either aberrant larval migration or was secondary to the inflammation caused by the aortic migration. The current study aimed to evaluate these hypotheses. Ten dogs of various breeds and ages with radiographic evidence of spondylitis, which were necropsied, had the affected vertebrae removed and prepared for light and transmission electron microscopy examination. Transverse and sagittal sections of the ventral vertebrae were taken from 27 spondylitis and 8 spondylosis deformans lesions as well as from 8 normal vertebrae. Early spondylitis changes were characterized by periosteal woven new bone covered by hyperplastic periosteum with some involvement of the ventral longitudinal ligament. More mature lesions were characterized by nodules of denser trabecular bone and cartilage, also covered by hyperplastic periosteum and involved the ventral longitudinal ligament. It was difficult to distinguish the spondylitis and spondylosis deformans new bone. Inflammation was seen in five spondylitis cases (edema, lymphocytes, plasma cells, eosinophils and fibrin fibers). Spirocerca eggs were seen in one histologic section. This study shows that inflammation is mild and inconsistent in spirocercosis-induced spondylitis and that aberrant migration of the larvae or adults did not appear to be a predominant cause. Inflammatory mediators or osteoproliferative growth factors, which may be related to the primary esophageal lesion or to the worm itself, could be involved. This requires further investigation.

NT-ProBNP and cardiac troponin I in virulent canine babesiosis.

Although cardiac pathology and consequently elevated serum cardiac troponin I (cTnI) have been reported, clinically it remains difficult to diagnose cardiac involvement in canine babesiosis. Thus the use of cardiac biomarkers would be useful in determining if a dog with babesiosis also has concurrent cardiac dysfunction. The objectives of this study were to determine plasma N terminal brain natriuretic peptide (NT-proBNP) in canine babesiosis and if it is correlated with cTnI. Three groups of dogs with babesiosis were used: mild uncomplicated (Group 1), severe uncomplicated (Group 2), and complicated (Group 3), and a control group (Group 4) with 15 dogs per group. Each animal had the following determined: serum urea and creatinine, urea: creatinine ratio, cystatin-C, cTnI, blood lactate, plasma NT-proBNP, fractional shortening (FS), and blood pressure. The median NT-proBNP value in Groups 1-4 was 246, 650, 638, and 106 pmol/l. All 3 babesiosis groups had a statistically elevated NT-proBNP level compared to the control group and Groups 2 and 3 showed significantly higher values compared to Group 1. Median cTnI in Group 1-3 was 0.39, 0.4, and 1.45 ng/ml, respectively with the control group having concentrations below the detection limit (0.2 ng/ml). There was a significant difference in cTnI concentration between the control group and group 3 but no statistical difference between the other babesiosis groups. The study concluded that dogs with babesiosis showed elevated levels NT-proBNP and the more severe the disease process the greater the elevation. This elevation is earlier or independent of the increased cTnI.

Pneumoesophagography and the appearance of masses in the caudal portion of the esophagus in dogs with spirocercosis.

OBJECTIVE: To determine the usefulness of pneumoesophagography, compared with that of survey radiography, for characterization of esophageal pathological changes in dogs with endoscopically confirmed intraluminal Spirocerca lupi nodules in the caudal portion of the esophagus. DESIGN: Diagnostic test evaluation. ANIMALS: 30 dogs with endoscopically confirmed spirocercosis. PROCEDURES: Dorsoventral (DV) and right lateral recumbent (RLR) thoracic survey radiographs were obtained for each dog. Endoscopy was subsequently performed, the esophagus was inflated with air, and left lateral recumbent, RLR, DV, and ventrodorsal thoracic radiographs were obtained. The amount of esophageal and gastric distention was recorded. Visibility, location, and surface characteristics of lesions and total length of esophageal involvement were recorded independently for each radiograph and modality and compared with each other. RESULTS: Survey DV radiographs were more reliable than survey RLR radiographs for detecting caudal esophageal pathological changes. Lateral pneumoesophagograms showed more esophageal air and had more visible nodules than did their orthogonal counterparts. Right lateral recumbent pneumoesophagograms allowed for evaluation of the air-filled stomach, particularly the cardiac portion, for additional pathological changes. Pneumoesophagography allowed the mural position (47% located dorsally) and surface characteristics of Spirocerca nodules to be determined. Six of 9 dogs with confirmed malignant disease had an irregular nodule surface suggestive of neoplastic transformation. CONCLUSIONS AND CLINICAL RELEVANCE: Pneumoesophagography was easily performed in dogs with spirocercosis and showed promise as a cost-effective and safe initial diagnostic procedure for further evaluation and characterization of suspected caudal esophageal lesions.

Salivary gland enlargement and sialorrhoea in dogs with spirocercosis: a retrospective and prospective study of 298 cases.

This longitudinal cross-sectional clinical study investigated the incidence of sialorrhoea in dogs with spirocercosis and determined whether breed, body weight and the extent of the oesophageal involvement was associated with this presentation. A retrospective analysis was performed on the medical records of 233 dogs and information pertaining to 65 dogs was collected as part of a prospective study. All the animals were client-owned. Patients from the retrospective study underwent thoracic radiography or oesophageal endoscopy to diagnose and characterise the infection and were placed on therapy with a macrocyclic lactone, whereas the patients in the prospective study had both radiography and endoscopy routinely performed and biopsies of the oesophageal nodules collected where possible. Tru-cut biopsies of affected salivary glands were taken in 10 of 13 patients demonstrating clinical signs of sialorrhoea and salivary gland enlargement. The entire salivary gland was sectioned in an additional three dogs with spirocercosis and no sialorrhoea that were presented for post mortem examination. Sialorrhoea was present in 33/298 cases (11%). Fox terrier breeds were over-represented in the patients with sialorrhoea, comprising 36% of cases, whereas they only comprised 1.5% of the patients without sialorrhoea (p < 0.001, chi squared test) and 5% of the combined group. Dogs weighing 12 kg or less were significantly over-represented in the sialorrhoea group, 69% versus 19.5% (p < 0.001, chi square test). Age was not significantly different between the two groups (p < 0.08, Mann-Whitney test). The number of oesophageal nodules per case was significantly higher in the non-sialorrhoea cases (p = 0.048, Mann-Whitney test). The prevalence of distal oesophageal and lower oesophageal sphincter involvement, and neoplastic transformation of the nodules were not statistically different between the two groups. None of the fox terriers in either group showed neoplastic transformation of the parasitic nodules even though they were over-represented as a breed. Mandibular salivary glands were affected in 86% of cases showing sialorrhoea. Histopathology revealed acinar hyperplasia in all cases with concurrent necrosis detected in only two cases.Sialorrhoea and salivary gland enlargement has an incidence of 11% (33/298 cases) in canine spirocercosis. Small breeds (≤ 12 kg) and particularly fox terrier breeds are over-represented in the group demonstrating sialorrhoea and this appeared to be the only risk factor.The conclusion was that sialorrhoea secondary to canine spirocercosis occurs frequently and its presence should prompt further investigation for oesophageal and gastro-intestinal disease. Severely affected patients can be managed with phenobarbitone to control the dysphagia in addition to the routine macrocyclic lactones treatment.

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.

Evaluation of selected growth factor expression in canine spirocercosis (Spirocerca lupi)-associated non-neoplastic nodules and sarcomas.

The study aims to assess the expression of vascular endothelial growth factor (VEGF)-A, fibroblast growth factor (FGF) and platelet-derived growth factor (PDGF) in the progression of the spirocercosis-induced oesophageal nodule in the dog from early, non-neoplastic, inflammatory nodule to sarcomatous neoplasia. Triplicate 4 µm-thick sections from 62 paraffin blocks containing Spirocerca-induced nodules were treated according to the steptavidin-biotin (LSAB) immunohistochemical method using polyclonal goat-anti-canine VEGF and anti-human FGF and PDGF antibodies. The nodules were classified as early inflammatory (n=15), pre-neoplastic (n=27) and neoplastic (n=20). Additionally, 10 sections of normal distal third of the oesophagus and 21 non-spirocercosis-related sarcomas were evaluated and compared with the Spirocerca-induced nodules. Five non-overlapping high power fields per case were evaluated under the light microscope and the fibroblasts were evaluated for percentage of labelled cells. The intensity of labelling was further classified as weak (score 1) or strong (score 2). The intensity score was multiplied by the percentage of labelled fibroblasts to yield a field score and the final score was obtained by calculating an average of the five fields. Antigen labelling was compared between the different histological grades and the controls using the Kruskal-Wallis test followed by the Mann-Whitney test for comparison between specific groups. The level of significance was set at 0.05. There were significant differences between the groups' score in all the growth factors that were examined. The normal oesophagus showed no labelling for any of the growth factors. FGF scored highest in the non-spirocercosis-related sarcoma group (median 118, 3-194) followed by the spirocercosis-induced sarcoma (34.5, 0-138), pre-neoplastic nodule (8, 0-99) and early nodule (0, 0-30) groups. All the differences among the groups were significant. VEGF scored highest in the non-spirocercosis-related sarcoma group (median 47, 1-110) followed by the spirocercosis-induced sarcoma (26, 0-136), pre-neoplastic nodule (0, 0-62) and early nodule (0, 0-35) groups. PDGF scored highest in the non-spirocercosis-related sarcoma group (median 29.2, 0-70) followed by the pre-neoplastic nodule (23.4, 0-95), early nodule (13.6, 0-132) and spirocercosis-induced sarcoma (0, 0-47) groups. The expression of VEGF and FGF increased as the nodule progressed from early inflammation to sarcoma, but it was not limited to spirocercosis-induced sarcomas. The expression of PDGF in spirocercosis was restricted to the early stages of nodule progression. Further investigation is warranted to establish whether FGF, VEGF or PDGF play a role in the pathogenesis of the malignant transformation in canine spirocercosis or are they simply integral to angiogenesis induction?

The effect of positioning on the radiographic appearance of caudodorsal mediastinal masses in the dog.

In this prospective study, the effect of thoracic positioning on the visibility and size of caudal esophageal masses caused by spirocercosis was investigated. Dorsoventral (DV), ventrodorsal (VD) as well as left lateral recumbent (LLR) and right lateral recumbent (RLR) thoracic radiographs of 28 dogs, diagnosed endoscopically with spirocercosis, were evaluated. The radiographic findings were compared with those of esophageal endoscopy. Masses were seen equally well in left vs. right recumbency as well as in DV vs. VD positions but in DV/VD views 86% of masses were detected whereas in lateral views only 50% of masses were identified. In spirocercosis-endemic areas DV and RLR views are advised as they also allow for better visualization of descending aorta aneurysms and to avoid interpreting the potentially normally visible esophagus in LLR in large dogs as a mass.

Clinical differentiation between dogs with benign and malignant spirocercosis.

Spirocerca lupi is a nematode infesting the canine oesophagus, where it induces the formation of a nodule that may transform into a malignant sarcoma. The current, retrospective study compared the clinical presentation, haematology, serum albumin and globulin and radiology of benign cases (n=31) and malignant cases (n=31) of spirocercosis. Dogs with spirocercosis-induced sarcoma were significantly older (6.4+/-1.91 years) than benign cases (4.93+/-2.87). In the malignant cases there were significantly (p=0.03) more sterilized females (10/31) and fewer intact males (4/31) compared to 2/31 and 13/31, respectively, in the benign cases. Hypertrophic osteopathy was observed in 38.7% of malignant cases and in none of the benign cases (p=0.0002). Common clinical signs included weight loss, regurgitation, anorexia, pyrexia (T>or=39.5 degrees ), respiratory complications and salivation but did not differ in prevalence between groups. On haematology, the malignant group had significantly (p<0.05) lower haematocrit (0.34+/-0.08 vs. 0.41+/-0.07) and higher white cell count (31.6+/-27.83 vs. 17.71+/-13.18 x 10(3)microl(-1)), mature neutrophil count (26.06+/-26.08 vs. 12.23+/-9.96 x 10(3)microl(-1)) and thrombocyte count (493.15+/-151.61 vs. 313.27+/-128.54 x 10(9)microl(-1)). There were no differences in the mean corpuscular volume and immature neutrophil count. On radiology, the mass length was not significantly different, but the height and the width of the malignant masses were significantly larger (62.59+/-15.15 mm and 73.93+/-20.94 mm) compared to the benign group (46.43+/-23.62 and 49.29+/-25.56, respectively). Spondylitis was more prevalent in the malignant group (67.86% vs. 38.46%, p=0.03). Examining secondary pulmonary changes revealed significantly higher prevalence of bronchial displacement in the malignant group (52% vs. 17%, p=0.008). Hypertrophic osteopathy appeared to be a very specific but relatively rare (poor sensitivity) marker of malignancy. Female gender, anaemia, leukocytosis, thrombocytosis, spondylitis and bronchial displacement are significantly more common in malignant cases, but appear in benign cases as well. However, if found together in a specific case, they should increase the index of suspicion for malignancy in a diagnosed spirocercosis case.