Computed tomography as an aid in the diagnosis of chronic nasal disease in dogs

OBJECTIVES: To assess the use of computed tomography (CT) in the diagnosis of chronic nasal disease in dogs. METHODS: A retrospective study of 85 dogs with chronic nasal discharge due to primary nasal disease, which had undergone nasal CT and biopsy, was carried out. Medical records were reviewed for signalment, clinical signs, CT findings, endoscopic findings and histopathology. The results obtained via CT were correlated with nasal histopathology and gross anatomical observations were recorded at the time of rhinoscopy. RESULTS: Neoplasia was diagnosed in 37 dogs for which CT typically revealed a soft tissue density associated with extensive turbinate destruction. Inflammatory rhinitis was diagnosed in 40 dogs. CT disclosed either normal turbinate structures or mild to moderate turbinate destruction, with or without the presence of soft tissue densities (mucopus) within the nasal passages. Fungal rhinitis was diagnosed in seven dogs for which CT disclosed extensive turbinate destruction with hyperlucency of the nasal passages. One dog had normal CT and histopathology findings. CLINICAL SIGNIFICANCE: CT greatly enhanced the ability to diagnose chronic nasal disease in dogs, providing detailed Information regarding the extent of the disease, accurate discrimination of neoplastic versus non-neoplastic diseases, and identification of areas of the nose to examine rhinoscopically and suspicious regions to target for biopsy.     

Computed axial tomography of the porcine nasal cavity and a morphometric comparison of the nasal turbinates with other visualization techniques.

A non-invasive imaging modality, computed tomography (CT), was used to visualize changes in nasal turbinates of anesthetized pigs over a 12-week observation period (pigs were 14 wk of age at study week 0). Normal, non-infected pigs were compared to pigs with mild challenge-induced atrophic rhinitis (AR) in order to detect subtle differences in morphology. To determine feasibility for time course studies in future experiments, morphometric quantitation at the level of the 2nd premolar (turbinate area ratio or TAR) in cross-section CT images at multiple timepoints was done. Additionally, at study termination, the TAR determined from CT images, magnetic resonance imaging (MRI), and wet tissue (WT), were compared to each other and to the standard subjective measure, visual scoring. There were no statistically significant differences between the control and AR groups at CT imaging dates of 0, 3, 6, 9, or 12 wk (P = 0.182). However, a statistically significant decrease in TAR measurements over time (P = 0.015) was observed in both groups, with lower mean values observed on Weeks 3 and 6 before rebounding to baseline values at study termination. At Week 12 (termination of the study), the TAR measurements derived from CT, MRI, and WT were not statistically different from one another (P = 0.220) and the treatment group-by-method interaction was not significant (P = 0.800). This provided evidence of equivalency of the techniques. Mean values for normal and infected groups were not significantly different based on either TAR imaging methods (P = 0.552) or visual scores (P = 0.088). Thus, the current study demonstrated that CT was an acceptable alternative imaging modality which could be used for quantitation of turbinate changes in snouts of live pigs to provide data comparable to tissue taken at necropsy. Computed tomographic imaging would allow non-invasive tracking of disease or treatment responses within individual animals over time. Morphometric analysis of the TAR was equivalent between the CT, MRI, and WT specimens.     

Evaluation of topical nalbuphine or oral tramadol as analgesics for corneal pain in dogs: a pilot study

Objective To evaluate the effectiveness of topical nalbuphine or oral tramadol in the treatment of corneal pain in dogs. Animals studied Fourteen male Beagle dogs. Procedures Dogs were divided into three treatment groups and sedated with dexmedetomidine (5 μ/kg IV). A 4 mm corneal epithelial wound was created in the right eye (OD) of all dogs. Sedation was reversed with atipamazole IM. All dogs received pre/post ophthalmic examinations. Post operatively, Group NB (n = 5) received topical 1% preservative‐free nalbuphine OD q8 h and an oral placebo PO q8 h. Group TR (n = 5) received tramadol (4 mg/kg) PO q8 h and topical sterile saline OD q8 h. Group CNTRL (n = 4) received topical sterile saline OD q8 h and an oral placebo q8 h. All dogs received topical 0.3% gentamicin OD TID until healed. Dogs were pain scored using a pain scoring system modified from the University of Melbourne pain scale at 0, 1, 2, 4, and 6 h, then every 6 h by observers masked to treatment, until corneal wounds were healed. Treatment failure was recorded if cumulative pain scores were above a minimum threshold of acceptable pain and rescue analgesia of morphine (1.0 mg/kg IM) was administered subsequently. Result Four dogs in Group NB, one dog in Group TR, and two dogs in Group CNTRL required rescue analgesia. There was no significant difference in the incidence of treatment failure between groups (P = 0.184). Mean time to rescue was 9.16 h. All corneal wounds were healed by 84 h. Conclusions The results of this study suggest tramadol rather than nalbuphine should be further investigated for the treatment of corneal pain.     

Computed tomography and radiographic lymphography of the thoracic duct by subcutaneous or submucosal injection

A simple method of lymphography of the thoracic duct was investigated. Using three female beagles, contrast media were administered rectally, vaginally and into the perianal tissue. The administration sites were gently massaged, and imaging was carried out at constant intervals using computed tomography and radiograph. Moreover, Indian ink was administered into the rectum mucous membrane in dogs for proof of this method of lymphography, and the lymph drainage routes were observed. The investigation showed that clear computed tomography and radiographic contrast images of the thoracic duct were obtained by subcutaneous and submucosa injection of angiography contrast medium and 3D processing of these images revealed the three-dimensional positions and course of the thoracic duct and cisterna chyli.     

Computed tomography to identify preoperative guidelines for internal fixation of the distal sesamoid bone in horses: an in vitro study

Objective: To assess the reliability of computed tomography (CT) to identify the direction of implant insertion for cortical screws along the longitudinal axis of intact (nonfractured) distal sesamoid bones. Study Design: In vitro study. Sample Population: Cadaveric paired equine forelimbs (n=16). Methods: Insertion of a cortical screw in lag fashion along the longitudinal axis of intact (nonfractured) distal sesamoid bones was evaluated in 2 groups (3.5 and 4.5 mm) of 8 paired limbs. In each group, the direction of the distal sesamoid bone was determined by CT (Equine XTC 3000 pQCT scanner). Screw placement was verified by specimen dissection. Implant direction was considered satisfactory if the entire screw length was within the distal sesamoid bone and not damaging the articular or flexural surfaces. Results: In our sample and according to our criteria, the proportion of satisfactory direction of screws was 0.63 (5/8) for 4.5 mm implants, and 0.87 (7/8) for 3.5 mm implants. Conclusions: CT is a useful imaging modality to identify anatomic landmarks for insertion of a 3.5 mm cortical screw in the distal sesamoid bone.     

Computed tomography as an aid to management of chronic oropharyngeal stick injury in the dog

Objective : To describe the use of computed tomography scanning in the management of dogs with chronic signs after oropharyngeal stick injury. Methods : Dogs with a final diagnosis of chronic oropharyngeal stick injury that underwent a computed tomography scan during their investigation were selected retrospectively from case files at the Royal Veterinary College, London. Results : The six dogs were young (median age 3·1 years) and medium to large breed (19·0 to 42·0 kg). By the time of referral the most common clinical sign was cervical swelling (five dogs). Stick foreign bodies were apparent on the plain computed tomography images in all cases and appeared as well‐demarcated, linear abnormalities. A ventral mid‐line approach was used for foreign body retrieval, and the computed tomography findings corresponded well with the surgical findings, with stick foreign body length ranging from 1 to 7 cm. Closed suction drainage was used in five dogs, for two to four days. Clinical signs fully resolved postoperatively in all cases, although cervical swelling recurred three weeks after surgery in one case. This dog had the smallest foreign body, the greatest number of surgical interventions before referral (three) and the longest disease course before referral (eight months). Clinical Significance : Computed tomography scanning is accurate in identifying the presence and location of chronic stick foreign bodies. Recurrence of disease is possible despite successful retrieval of the wood fragments found by computed tomography scan.     

Computed tomography and scintigraphy for evaluation of dental disease in the horse

Computed tomography (CT) uses x‐ray beams and reconstructive computer technology to create tomographic slices (sections) of the area being imaged. Computed tomography has higher contrast resolution than conventional radiography allowing for more accurate differentiation of soft tissues and fluids. This form of 3D imaging removes problems caused by superimposition of multiple anatomical structures, which is a major impediment when viewing radiographs of the equine head. Once the images are acquired, multi‐planar and 3D reconstructions can be performed to view different teeth or associated structures in an optimal way. Anatomical and pathological changes in the dental tissues, periodontal tissues, alveolar bone and adjacent sinuses can then be assessed. Scintigraphy with 99^m technetium methyl‐diphosphate (methylene‐diphosphonate) can detect changes in bone that precede radiographic changes, and this makes it a very useful imaging modality for diagnosis of early periapical infection of the equine cheek teeth. Additionally, it is invaluable for imaging suspected infections of supernumerary or dysplastic teeth where the results of radiography or even CT may be equivocal. Periapical infections of the cheek teeth typically result in focal and intense increased radionuclide uptake located over the apical region of the affected tooth.     

Cryptosporidium antibodies in manitoba cattle: a pilot study using an indirect fluorescent antibody procedure

An indirect fluorescent antibody test, using feces-derived oocysts as antigen, was used to detect antibodies to Cryptosporidium spp. in bovine sera in Manitoba. Antibodies were detected in 29 of 50 (58%) sera collected from animals of various ages on farms where calves had laboratory-confirmed cryptosporidiosis and in 76 of 186 (40.9%) sera collected at random from culled breeding stock. Serum antibody, presumably colostral in origin, did not appear to protect young calves from the infection. No geographic preference for the infection was demonstrated.     

Puppy behavior at the veterinary clinic: A pilot study

New owners usually have many questions regarding their puppy’s behavior during the first physical examination. The aim of this pilot study was to investigate the behaviors expressed by puppies when exposed to a veterinary clinic environment. The puppies’ response to physical examination was also studied. A total of 102 puppies, between 8 and 16 weeks of age and of various breeds, were filmed during a standardized physical examination at the veterinary clinic. The study included an observation of the puppy free on the floor (FF) followed by a physical examination on a table (PET) and various manipulations on the floor (MF). During FF, the behavioral categories recorded were: activity, exploration, facial expression, puppy solicitation of interaction with the veterinarian, vocalization, and others. During PET and MF, the type of interaction with the veterinarian, facial expression, and ear position were examined. The study revealed some significant differences between behaviors exhibited by puppies according to their sex, age, and estimated adult weight. Behaviors generally varied widely among puppies, but some individuals showed “extreme behaviors” (outliers) compared to the median puppy. These behaviors included more active avoidance, more locomotion, more panting, or more vocalization, which were often correlated across contexts. These findings suggest that even at a young age, some puppies can be differentiated from others by specific behaviors. Whether or not these individuals are at higher risk of developing behavioral disorders as adults remains to be investigated.     

An anatomical study of the dorsal and ventral nasal conchal bullae and middle nasal conchae in normal Shetland ponies: Computed tomographic anatomical and morphometric findings

Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports considering the morphology of nasal conchal bullae in small horse breeds such as Shetland ponies. The aim of the present study was to evaluate the size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examination and surgical treatment of equine sinus disease in those breeds.     

Systemic lidocaine infusion as an analgesic for intraocular surgery in dogs: a pilot study

Objective To determine if systemic administration of lidocaine during intraocular surgery reduces post-operative ocular pain. Study design Randomized, masked, controlled experimental trial. Animals Twelve dogs weighing 15.5 ± 1.7 kg (mean ± SD) and aged 2.5 ± 0.6 years. Methods All dogs underwent a baseline ophthalmic examination and subjective pain score. Anesthesia consisted of acepromazine (0.1 mg kg⁻¹, IM), propofol (4–6 mg kg⁻¹, IV), and isoflurane in oxygen. There were three groups each receiving a bolus followed by an infusion (n = 4): saline (0.3 mL kg⁻¹ IV + 0.2 mL kg⁻¹hour⁻¹ IV); morphine (0.15 mg kg⁻¹ IV + 0.1 mg kg⁻¹hour⁻¹ IV); and lidocaine (1.0 mg kg⁻¹ IV + 0.025 mg kg⁻¹minute⁻¹ IV). All treatments began 15 minutes prior to starting of phacoemulsification and lens removal from the right eye. Pain scores were recorded at 0.5, 1, 2, 3, 4, 6, 8, 16, and 24 hours after t = 0 (extubation). Rescue morphine was administered (1.0 mg kg⁻¹ IM) if the subjective pain score ≥9 (maximum = 24), and the dog was excluded from further data analysis. Differences in pain scores and time-to-treatment failure (TTF) were analyzed using the Wilcoxon's rank sum test. Differences in incidence of treatment failure were analyzed using Fisher's exact test. Physiologic data were analyzed using repeated measures anova . Significance was defined as P < 0.05. Results Incidence of treatment failure was 100% in saline-treated dogs and 50% in morphine- or lidocaine-treated dogs. There was no difference in intraocular pressure, aqueous flare, cell count (or protein) between groups in the operated eye at any time following extubation. Conclusion and clinical relevance This pilot study suggests that intraoperative lidocaine may provide analgesic benefits similar to morphine for intraocular surgery in dogs, but more definitive research is needed. This model appears to be appropriate for pain assessment studies as the negative control group demonstrated 100% failure rate.     

Evaluation of serum interleukin 2 receptor and beta-2-microglobulin as prognostic factors for canine lymphoma: A pilot study

Interleukin 2 receptor (IL-2R) is released from activated T cell lymphocytes and related to proliferation of B cells and T cells. Beta-2-microglobulin (B2M) is synthesized from all nucleated cells and constitutes a major histocompatibility complex class I antigen. In human medicine, high concentrations of these two factors have been found to be related to prognosis in aggressive non-Hodgkin's lymphoma. In this pilot study, we aimed to assess the correlation between the serum concentration of IL-2R and B2M and the diagnosis and prognosis of canine lymphoma. This study included 8 healthy dogs and 17 dogs with lymphoma. To measure the serum concentration of IL-2R and B2M, a commercial enzyme-linked immunosorbent assay was used. In dogs with lymphoma, IL-2R concentrations were significantly high at the time of diagnosis, but B2M concentrations were not. In relapsed dogs, both IL-2R and B2M concentrations were significantly higher than those in the control and chemotherapy response groups. When the serum concentrations of IL-2R and B2M during chemotherapy were monitored in four relapsed dogs, B2M levels were more closely related with relapse. This study demonstrated that serum IL-2R and B2M concentration can be a diagnostic or prognostic tool for canine lymphoma. Monitoring of serum B2M concentration seems to be useful for predicting relapse.     

Multiple-center study of reduced-concentration triamcinolone topical solution for the treatment of dogs with known or suspected allergic pruritus

OBJECTIVE: To determine the efficacy of triamcinolone acetonide topical solution (TTS) in dogs for use in reduction of clinical signs of pruritic inflammatory skin diseases of a known or suspected allergic basis and to evaluate adverse effects associated with TTS administration. ANIMALS: 103 pruritic adult dogs with known or suspected allergic skin disease. PROCEDURE: Dogs were treated for 4 weeks with TTS or with vehicle solution (control dogs) in a multiple-center study. Clinical signs were scored by owners and by examining veterinarians before and after treatment. Blood samples obtained before and after treatment were subjected to routine hematologic and serum biochemical analyses. RESULTS: Treatment success, as defined by an improvement of at least 2 of 6 grades in overall clinical score, was evident in 35 of 52 (67%) TTS-treated dogs (mean improvement, 1.98) and 12 of 51 (24%) control dogs (mean improvement, 0.29). For several criteria, TTS was significantly more effective than vehicle in reducing clinical signs. Minor alterations in hematologic determinations in TTS-treated dogs were limited to slightly lower total leukocyte, lymphocyte, and eosinophil counts after treatment. Minor adverse effects were reported by owners in 6 of 52 (12%) TTS-treated and 9 of 51 (18%) control dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Triamcinolone used as a spray solution at a concentration approximately one-sixth the concentration of triamcinolone topical preparations currently available for veterinary use is effective for short-term alleviation of allergic pruritus in dogs. Adverse effects are few and mild and, thus, do not preclude prolonged treatment with the solution.     

Atrial septal pacing in small dogs: A pilot study

ObjectiveTo determine the feasibility of atrial septal pacing via a delivery catheter-guided small non-retracting helix pacing lead.AnimalsSix healthy beagles (8.3-12.9 kg).MethodsUsing single plane fluoroscopic guidance, Medtronic^® 3830 SelectSecure leads were connected to the atrial septum via Medtronic® Attain Select® II standard 90 Left Heart delivery catheter. Pacing threshold and lead impedance were measured at implantation. The Wenckebach point was tested via atrial pacing up to 220 paced pulses per minute (ppm). Thoracic radiographs were performed following implantation to identify the lead position, and repeated at 24 h, 1 month, and 3 months post-operatively.ResultsMacro-lead dislodgement occurred in two dogs at 24 h and in three dogs at one-month post-implantation. Lead impedance, measured at the time of implantation, ranged from 583 to 1421 Ω. The Wenckebach point was >220 ppm in four of the six dogs. The remaining two dogs had Wenckebach points of 120 and 190 ppm.ConclusionsThis pilot study suggests the selected implantation technique and lead system were inadequate for secure placement in the atrial septum of these dogs. The possible reasons for inadequate stability include unsuitable lead design for this location, inadequate lead slack at the time of implantation and inadequate seating of the lead as evidenced by low impedance at the time of implantation. Other implantation techniques and/or pacing leads should be investigated to determine the optimal way of pacing the atria in small breed dogs that are prone to sinus node dysfunction.     

Computed tomography for the diagnosis of a lumbosacral nerve sheath tumour and management by hemipelvectomy

Computed tomography was used to define the gross extent of a lumbosacral plexus nerve sheath tumour in a 10-year-old crossbred dog. The tumour was also visualised ultrasonographically, which enabled a percutaneous biopsy to be taken. Hemipelvectomy was performed to achieve a clean margin of surgical excision.