Computed tomographic findings in a Bluetick Coonhound with a longitudinal thoracic tracheal tear.

A 9-year-old intact male Bluetick Coonhound presented for progressive subcutaneous emphysema of 5 days' duration due to a suspected tracheal tear. Cervical computed tomography (CT) and thoracic CT were performed after failure to identify the tracheal tear with tracheoscopy. A longitudinal tracheal tear was identified starting 4.3 cm cranial to the tracheal bifurcation and extending caudally over a distance of 3.6 cm. Severe pneumomediastinum, subcutaneous emphysema, and retroperitoneal gas were also present. A follow-up CT 7 days postoperatively confirmed the successful repair of the tear with partial resolution of the presurgical secondary pathology and the patient recovered uneventfully.

Sensitivity and specificity of magnetic resonance imaging and computed tomography for the determination of the developmental state of cranial sutures and synchondroses in the dog.

BACKGROUND: During skull ontogenesis, growth centers in the skull base and calvarial bones allow gradual expansion of the cranial vault. Premature growth termination of cranial base synchondroses and/or calvarial sutures can result in devastating skull dysmorphologies. There is evidence to believe that a premature closure in one or more cranial growth centers contribute to the brachycephalic skull morphology in dogs. To provide a proof of concept for the non-invasive investigation of ontogenetic changes in cranial sutures and synchondroses in living dogs, we compared magnet resonance imaging (MRI) and computed tomography (CT) with histologic findings. Our aim was to determine the in vitro sensitivity and specificity for conventional clinical imaging methods in the assessment of cranial suture closure and synchondroses ossification in dogs. RESULTS: The evaluation of cranial base synchondroses in MRI had a sensitivity of up to 93.1% and a specificity of 72.7% dependent on the observer. The evaluation of cranial base synchondroses in CT had a sensitivity of 92.2% and a specificity of 86.4%. Suture assessment on MRI suture assessment had a sensitivity of 82.1% dependent on the observer and a specificity of 19.3%. CT suture assessment had a sensitivity of 85.1% and a specificity of 40.4% in dependence of the observer. CONCLUSION: Conventional cross-sectional imaging techniques (MRI and CT) allow reliable assessment of the open or closed state of synchondroses within the cranial base. In contrast CT and MRI are not suitable for a reliable assessment of the cranial sutures in dogs.

Radiography is less sensitive relative to CT for detecting thoracic radiographic changes in dogs affected by blunt trauma secondary to a motor vehicle accident.

Thoracic injuries caused by blunt trauma are commonly encountered emergencies in veterinary medicine. However, published studies are lacking that compare radiology to CT in blunt trauma caused by motor vehicle accidents in canine patients. The aim of this prospective diagnostic accuracy, methods comparison study were to estimate the sensitivity (Se) and specificity (Sp) of thoracic radiology relative to CT for detecting lung contusions, pneumothorax, pleural effusion, and rib fractures. The study further aimed to develop a severity scoring system for radiology and CT and to compare the findings between the two modalities. The hypothesis was that radiology would be less sensitive than CT at detecting these injuries and that radiology would underestimate the severity of lung contusions. Fifty-nine patients met the inclusion criteria. Radiology underestimated the presence of lung contusions (Se = 69%, 95% confidence interval) and overestimated the severity of the contusions relative to CT. There was high interobserver variability in evaluating lung contusion severity (coefficient of variation = 91%). Both the three-view thoracic and horizontal beam radiography had poor sensitivities for the detecting pneumothorax (Se = 19% and 63%, respectively) and pleural effusions (Se = 43% and 71%, respectively). Similarly, the sensitivity (56%) of radiographs for the detection of rib fractures was poor relative to CT. Findings from the current study indicated that thoracic radiography had low sensitivity for detecting lesions related to blunt thoracic trauma caused by motor vehicle accidents and supported the use of CT as an additional diagnostic imaging modality in these patients.

INTRAOCULAR PRESSURE, TEAR PRODUCTION, AND OCULAR BIOMETRY IN HEALTHY ADULT CHEETAHS (ACINONYX JUBATUS).

Schirmer tear test (STT), intraocular pressure (IOP), and ocular biometry were measured in 58 healthy cheetahs (Acinonyx jubatus) between the ages of 2 and 14 yr in two captive groups. During routine health examination under immobilization, each animal underwent ophthalmic examination including STT, IOP, slit-lamp biomicroscopy, indirect ophthalmoscopy, and ocular ultrasonography. Mean ± SD values for STT and IOP were 13.58 ± 5.29 mm/min and 31.40 ± 5.01 mm Hg, respectively. The time between immobilization and examination significantly influenced both STT and IOP measurements. For IOP measurements, a significant group effect was also demonstrated, possibly due to the different anesthetic drug combinations used. Mean ± SD values for biometry were as follows: globe length (32.73 ± 1.74 mm), lens thickness (7.25 ± 1.09 mm), anterior chamber (8.54 ± 1.21 mm), and posterior segment (16.31 ± 2.06 mm). Surprisingly, all of the biometry measurements differed significantly between the two groups. Establishing STT, IOP, and biometric reference values is important for evaluating the ocular health status of the species. These reference values will assist veterinarians working with cheetahs to perform a full and informed ophthalmic examination.

Comparative efficacy of three antiseptics as surgical skin preparations in dogs.

OBJECTIVE: To compare the antimicrobial efficacy of a 2% chlorhexidine gluconate and 70% ethanol solution (CG+A) with that of F10 Skin Prep Solution (F10) and electrochemically activated water (EAW) when used as a surgical preparation in canine patients. STUDY DESIGN: Prospective randomized clinical study. SAMPLE POPULATION: One hundred sixteen dogs presented for ovariohysterectomy. METHODS: Dogs were randomly divided into 1 of the 3 antiseptic groups (CG+A, F10, EAW). Skin samples with replicating organism detection and counting plates were taken at 4 different perioperative sites and time intervals (postskin preparation, postskin antisepsis, 2 hours after the second sample, and at the end of surgery) during ovariohysterectomies performed by students. The colony forming unit (CFU) counts from each sample were quantified according to the level of bacterial contamination. Zero CFU was defined as no contamination, 1-12 CFU was defined as low contamination, and greater than 12 CFU was defined as high contamination. The 3 antiseptics were compared with respect to the level of contamination. RESULTS: There was no difference in the level of colonization between the antiseptics at the first sampling time (P = .454). However, the level of contamination for CG+A was lower compared with F10 and EAW at the second, third, and fourth sampling times (P = .001, P = .01, P = .02, respectively). CONCLUSION: CG+A was more effective at achieving a zero CFU count and low levels of contamination compared with F10 and EAW for surgical preparation in dogs undergoing ovariohysterectomy. CLINICAL SIGNIFICANCE: This study does not provide evidence to support the use of F10 and EAW instead of CG+A for the surgical skin preparation of dogs undergoing ovariohysterectomy.

Ultrasonographically determined renal values and comparisons to serum biochemistry renal variables in aged semi-captive cheetahs (Acinonyx jubatus).

BACKGROUND: Cheetahs in captivity have a high prevalence of chronic renal diseases. We ultrasonographically evaluated the renal volumes, a variety of renal dimensions, interarcuate artery resistive indices (RI) as well as aortic diameters and the length of the ventral aspect of the 6th lumbar vertebrae in 27 aged semi-captive anesthetized cheetahs. Renal size, dimensions and ratios were compared to urine specific gravity, serum creatinine and urea values. RESULTS: There were minimal differences for all values between left and right kidneys. Mean kidney length was 65.1 mm (range 55.2-76.9) with left kidney length ratios to L6 length being 1.60 (range 1.27-2.06) and to the aortic diameter 7.69 (range 4.54-10.72). Significant correlations between left renal length as well as length:L6 ratio to creatinine values were found ((r - 0.66) and (r - 0.60) respectively). The mean RI values of the different sedation/anesthetic protocols ranged from 0.46-0.55. CONCLUSIONS: Left renal length and L6 ventral vertebral body length as well as left kidney RI values should be routinely measured in all cheetah abdominal ultrasound examinations. These measurements, together with serum creatinine, urea and urine specific gravity values may be relatively sensitive indicators of early renal pathology in the absence of gross ultrasonographic changes.

Ultrasonographic adrenal gland findings in healthy semi-captive cheetahs (Acinonyx jubatus).

Cheetahs in captivity are believed to suffer from stress predisposing them to poor health. To date fecal glucocorticoids have been used as a non-invasive indicator of chronic stress. This study examines, the feasibility of transabdominal adrenal gland ultrasonography in cheetahs and determined normal adrenal measurements that can potentially be used as a more reliable indicator of chronic stress and/or adrenal function. Thirty-three adult cheetahs, aged between 2 and 13 years, accommodated in large off-display camps were examined over 9 days under general anesthesia. The adrenals were readily identified, with the right adrenal being more difficult to find and measure than the left, and were smaller than those expected in similar sized dogs. The left adrenal was shorter and slightly more oval shaped than the right with a length and cranial pole width at a 95% prediction interval of 16.3-22.4 and 4.1-8.7 mm. The same measurements for the right adrenal were 16.8-26.2 and 3.4-10.8 mm, respectively. Corticomedullary ratios were larger for the left adrenal. When corrected for body size, females had significantly longer and greater left adrenal corticomedullary ratios than males. Adrenal measurements did not correlate with left renal length, body size measurements, or enclosure size. Measurements that increased with age included the cortical and total adrenal widths. Adrenal ultrasonography offers potential benefits in assessment of individual cheetah adrenal pathology or the evaluation of stress induced adrenomegally especially in combination with other evaluations such as non-invasive fecal glucocorticoid analyses. Zoo Biol. 35:260-268, 2016. © 2016 Wiley Periodicals, Inc.

Computed Tomography Determined Changes in Position of the Urogenital System After CO2 Insufflation to Determine Optimal Positioning for Abdominal Laparoscopy.

OBJECTIVE: To evaluate changes, using computed tomography (CT), in position of the urogenital system before and after CO2 abdominal insufflation for the most commonly used body positions to determine the optimal laparoscopic approach. STUDY DESIGN: Experimental study. ANIMALS: Healthy intact female Beagles (n = 6) of similar age, weight, and body condition score. METHODS: Dogs had urinalysis, peripheral blood smear, and abdominal ultrasonography. Pre-insufflation (PrI) CT scans were performed in ventrodorsal routine (VDR), ventrodorsal Trendelenburg (VDT), left lateral (LL) and right lateral (RL) recumbency, and repeated post insufflation (PoI). Pre-determined measurements were made on PrI and PoI scans and differences compared. RESULTS: The position of the uterus and ovaries was mainly determined by gravitational effects and the attachment of the suspensory ligament. VDT provided best exposure of the uterine body. The kidneys remained in the non-dependent part of the abdomen when the dog was positioned in the opposite lateral position. The bladder remained in the ventral part of the abdomen in all positions. CONCLUSIONS: The best approach to the kidney and associated ovary and uterine horn would be the opposite lateral position to the side being approached. For ovariohysterectomy, this would require the dog to be rotated into each lateral position for the left and right uterine horn and ovary. VDT was best to access the bladder and uterine body.

Single-Incision Laparoscopic Sterilization of the Cheetah (Acinonyx jubatus).

OBJECTIVE: To describe laparoscopic ovariectomy and salpingectomy in the cheetah (Acinonyx jubatus) using single-incision laparoscopic surgery (SILS). STUDY DESIGN: Prospective cohort. ANIMALS: Female cheetahs (Acinonyx jubatus) (n = 21). METHODS: Cheetahs were randomly divided to receive either ovariectomy (n = 11) or salpingectomy (n = 10). The use and complications of a SILS port was evaluated in all of cheetahs. Surgery duration and insufflation volumes of carbon dioxide (CO2 ) were recorded and compared across procedures. RESULTS: Laparoscopic ovariectomy and salpingectomy were performed without complications using a SILS port. The poorly-developed mesosalpinx and ovarian bursa facilitated access to the uterine tube for salpingectomy in the cheetah. The median surgery duration for ovariectomy was 24 minutes (interquartile range 3) and for salpingectomy was 19.5 minutes (interquartile range 3) (P = .005). The median volume of CO2 used for ovariectomy was 11.25 L (interquartile range 3.08) and for salpingectomy was 4.90 L (interquartile range 2.52), (P = .001) CONCLUSIONS: Laparoscopic ovariectomy and salpingectomy can be performed in the cheetah using SILS without perioperative complications. Salpingectomy is faster than ovariectomy and requires less total CO2 for insufflation.

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.

LAPAROSCOPIC SALPINGECTOMY IN TWO CAPTIVE LEOPARDS (PANTHERA PARDUS) USING A SINGLE PORTAL ACCESS SYSTEM.

Laparoscopic salpingectomy was performed in two adult leopards (Panthera pardus) using a single portal access system, with a multicannulated single-incision laparoscopic surgery port, without any complications. The poorly developed ovarian bursa provided easy access to the uterine tube for salpingectomy. Laparoscopic salpingectomy can be safely performed in the leopard using a single portal access system.

Laparoscopic sterilization of the African Lioness (Panthera leo).

OBJECTIVE: To describe laparoscopic ovariectomy and salpingectomy in the African lioness (Panthera leo). STUDY DESIGN: Descriptive clinical study. ANIMALS: Female lions (n = 16). METHODS: Lionesses were randomly divided into 2 groups: O = ovariectomy (n = 8) and S = salpingectomy (n = 8) for laparoscopic surgery. Two Veress needle placement techniques were used. RESULTS: Laparoscopic ovariectomy and salpingectomy were performed without complications. The poorly developed mesosalpinx and ovarian bursa rendered the uterine tube more accessible for salpingectomy compared to the dog making the procedure easier in the lioness. Similarly, salpingectomy is a relatively easier procedure compared with ovariectomy especially when the modified Hasson technique for Veress needle placement is used. CONCLUSIONS: Laparoscopic ovariectomy and salpingectomy can be safely performed in the African lioness.

Feasibility for mapping cartilage t1 relaxation times in the distal metacarpus3/metatarsus3 of thoroughbred racehorses using delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC): normal cadaver study.

Osteoarthritis of the metacarpo/metatarsophalangeal joints is one of the major causes of poor performance in horses. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) may be a useful technique for noninvasively quantifying articular cartilage damage in horses. The purpose of this study was to describe dGEMRIC characteristics of the distal metacarpus3/metatarsus3 (Mc3/Mt3) articular cartilage in 20 cadaver specimens collected from normal Thoroughbred horses. For each specimen, T1 relaxation time was measured from scans acquired precontrast and at 30, 60, 120, and 180 min post intraarticular injection of Gd-DTPA(2-) (dGEMRIC series). For each scan, T1 relaxation times were calculated using five regions of interest (sites 1-5) in the cartilage. For all sites, a significant decrease in T1 relaxation times occurred between precontrast scans and 30, 60, 120, and 180 min scans of the dGEMRIC series (P < 0.0001). A significant increase in T1 relaxation times occurred between 60 and 180 min and between 120 and 180 min post Gd injection for all sites. For sites 1-4, a significant increase in T1 relaxation time occurred between 30 and 180 min postinjection (P < 0.05). Sites 1-5 differed significantly among one another for all times (P < 0.0001). Findings from this cadaver study indicated that dGEMRIC using intraarticular Gd-DTPA(2-) is a feasible technique for measuring and mapping changes in T1 relaxation times in equine metacarpo/metatarsophalangeal joint cartilage. Optimal times for postcontrast scans were 60-120 min. Future studies are needed to determine whether these findings are reproducible in live horses.

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.

Unilateral salpingectomy in Sprague Dawley rats and its effect on litter size.

The study described a novel, rapidly performed, successful and safe surgical procedure in rats to achieve a reduction in the number of conceptuses. The objectives were to investigate the total foetal count and foetal health in both uterine horns after unilateral salpingectomy compared to the control group. Sixteen female Sprague-Dawley rats (Rattus norvegicus) were allocated to the study of which 10 rats underwent unilateral salpingectomy with six controls before all 16 were mated at 8-10 weeks of age. Gestational length was taken as 22 days coma? determined from the day of appearance of the copulatory plug. The female rats were terminated on day 19 or 20 of the gestational period. The foetuses in each horn were mapped and counted for comparison between the salpingectomy and control groups. The gravid uteri, individual foetal weights and placental weights were measured and compared between the two groups. This study described a novel, rapidly performed, successful and safe surgical procedure in rats. The mean number of foetuses in the salpingectomy group was significantly smaller than the control group. No significant differences in foetal and placental development were observed between the groups. These observations support future investigation of unilateral salpingectomy in other species as an alternative surgical method for population control.

Radiographic analysis of the thickness of the cranial bones in captive compared to wild-living cheetahs and in cheetahs with hypovitaminosis A.

Captive cheetahs often demonstrate a high incidence of diseases in which vitamin A imbalances are implicated. These can occur even under controlled and optimised feeding regimens, which is why surveillance of vitamin A status is mandatory in the successful health management of cheetahs. Serum levels of the vitamin do not reflect the true vitamin A status and liver tissue analysis is rather impractical for routine application in large felids. A biomarker for evaluating overt and subclinical vitamin A deficiency in cheetahs is needed. This study evaluates whether increased calvarial bone thickness can be detected on routine skull radiographs of vitamin A deficient cheetahs compared to unaffected animals, and secondly, evaluates whether there is increased bone thickness in clinically sound captive cheetahs in general compared to wild-living controls. Bone thickness in the neuro- and splanchnocranium was measured in 138 skull radiographs. Significant thickening of the parietal bones was found in latero-lateral radiographs of immature cheetahs (< 12 months) with vitamin A deficiency. This finding may allow a presumptive diagnosis of hypovitaminosis A in immature cheetahs. A general difference in skull thickness between free-living and captive cheetahs was not found.

Long Bone Fractures in Impala (Aepyceros melampus): A Classification System and Review of 55 Cases.

OBJECTIVE: The purpose of this study was to introduce a modified-Unger fracture classification in impala and report the findings of 58 long bone fractures classified according to this system. METHODS: This was a retrospective radiographical study evaluating 122 radiographs of 58 long bone fractures in 55 impala. The Unger fracture classification was modified and fracture illustrations for the metacarpal and metatarsal bones added. Each fracture was classified and assigned a four symbol α-numeric code using our classification. The patient signalment, skeletal maturity, fracture-associated soft tissue changes, presence of fissure lines, periosteal reaction and cause of the fracture were recorded. RESULTS: The overall fracture distribution based on location, found tibial (n = 17) fractures to be the most common fractured long bone. When combined, the majority of fractures involved the metacarpal and metatarsal bones (n = 23). Forty five of 58 fractures occurred in the diaphyseal bone segment. In all long bones, the distribution based on complexity was simple (n = 27), wedge (n = 16) and multi-fragmentary (n = 15) fractures. Thirty one of 58 fractures were open and fissure lines were detected in 20 of 58 fractures. CLINICAL SIGNIFICANCE: Our modified-Unger fracture classification was applicable in classifying 58 impala long bone fractures. This classification should provide the basis for further advances in veterinary and comparative ungulates, and particularly the antelopes, orthopaedics and traumatology.

A contribution to age determination of cheetahs (Acinonyx jubatus) based on radiographic analysis of the skull and postcranial morphology.

The aim of this retrospective cross-sectional study was to present comprehensive information about the age-dependent change of skeletal characteristics in captive cheetahs with known age and to assess the benefit of these variables for age estimation in this species. Radiographs of 162 known-age captive and semi-captive cheetahs were retrospectively examined and age-related changes of skull, axial and appendicular skeletal systems were documented. Metric and non-metric variables were used. These parameters were checked for the best correlation with age using a multiple stepwise regression analysis. An overview about the time frames, in which ossification centers appeared and physeal closure occurred is presented. Multiple stepwise regression analysis revealed the status of closure of the coronal suture, the maximum length of the frontal sinus, the condylobasal-, hard palate, and facial length are most significantly correlated with age. Together with the pulp size of the upper canine, these values can be used for an age approximation in cheetahs.

Association between computed tomographic thoracic injury scores and blood gas and acid-base balance in dogs with blunt thoracic trauma.

OBJECTIVE: To determine the association between thoracic injuries evaluated by computed tomography (CT) and arterial blood gas and acid-base status in dogs with blunt thoracic trauma caused by motor vehicle accidents. DESIGN: Prospective observational clinical study. SETTING: University teaching hospital. ANIMALS: Thirty-one client owned traumatized dogs and 15 healthy dogs. PROCEDURES: All trauma group dogs underwent a CT scan and simultaneous arterial blood gas analysis within 24 hours, but not before 4 hours, after the traumatic incident within a 45-month enrollment period. MEASUREMENTS AND MAIN RESULTS: Thorax injuries were classified as pulmonary, pleural space, or rib cage and each of these components was scored for severity using a CT composite pulmonary, pleural, and rib score. The trauma group arterial blood gas and acid-base status were evaluated for statistical difference from the control group. The pulmonary-arterial oxygen pressure was significantly lower in the trauma group compared to the control group that was supported by significant differences in the calculated variables of arterial blood oxygenation as well. There was also a significant correlation between the composite lung score and pleural score and the variables of arterial oxygen status. The pulmonary-arterial carbon dioxide pressure was not significantly different to any of the thoracic injury variables indicating normal alveolar ventilation. Acid-base imbalances were generally mild, insignificant, and variable. CONCLUSIONS AND CLINICAL RELEVANCE: Blunt thoracic trauma causes significant pulmonary and pleural injury and the blood oxygen economy is significantly affected by this. The functional measures of arterial blood oxygenation were well correlated with thoracic CT pathology. Alveolar ventilation was mostly spared but a clinically significant ventilation perfusion mismatch was present.

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.