Prevalence and characterization of small tympanic bone spicules and drumstick-like hyperostotic tympanic bone spicules in the middle ear cavity of dogs.

Rounded, sessile, hyperattenuating structures detected in computed tomography (CT) studies of canine tympanic bullae have been termed "otoliths." These have been proposed to represent dystrophic mineralizations or heterotopic bone formations in the middle ear that are potentially related to chronic otitis media. Aims of the current study were to describe the prevalence, macroscopic, and histological features of structures consistent with "otoliths" in the canine tympanic cavity. Tympanic bullae from 50 routinely necropsied dogs and 139 retrospectively retrieved CT scans of canine clinical cases were examined. Small tympanic bone spicules with pointed or clubbed tips essentially arising from the free margin of the septum bullae were bilaterally present in the tympanic cavities of all 50 of the necropsied dogs. In 48% of the dogs, "otolith"-like CT-detectable bone spicules carrying drumstick-like hyperostoses that were 1-6 mm in diameter were also present. In the retrospective survey of bulla CT scans of 139 cases, the prevalence of hyperostotic tympanic bone spicules (HTBS) was 20%. Findings from the current study indicated that the presence of small tympanic bone spicules in adult dogs is most likely due to physiological bone growth in the septum bullae and that HTBS represent osseous proliferations of small tympanic bone spicules. However, the factors inducing formation of hyperostotic spicules from small tympanic bone spicules remain unknown. The high prevalence of HTBS displaying a similar appearance in bulla CT scans in dogs suggests that these spicules should be included in a differential diagnosis list for "otoliths."

Topographic and age-dependent distribution of subchondral bone density in the elbow joints of clinically normal dogs.

OBJECTIVE: To investigate topographic and age-dependent adaptation of subchondral bone density in the elbow joints of healthy dogs by means of computed tomographic osteoabsorptiometry (CTOAM). Animals-42 elbow joints of 29 clinically normal dogs of various breeds and ages. PROCEDURES: Subchondral bone densities of the humeral, radial, and ulnar joint surfaces of the elbow relative to a water-hydroxyapatite phantom were assessed by means of CTOAM. Distribution patterns in juvenile, adult, and geriatric dogs (age, < 1 year, 1 to 8 years, and > 8 years, respectively) were determined and compared within and among groups. RESULTS: An area of increased subchondral bone density was detected in the humerus distomedially and cranially on the trochlea and in the olecranon fossa. The ulna had maximum bone densities on the anconeal and medial coronoid processes. Increased bone density was detected in the craniomedial region of the joint surface of the radius. A significant age-dependent increase in subchondral bone density was revealed in elbow joint surfaces of the radius, ulna, and humerus. Mean subchondral bone density of the radius was significantly less than that of the ulna in paired comparisons for all dogs combined and in adult and geriatric, but not juvenile, dog groups. CONCLUSIONS AND CLINICAL RELEVANCE: An age-dependent increase in subchondral bone density at the elbow joint was revealed. Maximal relative subchondral bone densities were detected consistently at the medial coronoid process and central aspect of the humeral trochlea, regions that are commonly affected in dogs with elbow dysplasia.

The topographic and systematic anatomy of the alpaca stomach.

The gastric anatomy of the alpaca (Vicugna pacos) is adapted to the physiological process of ruminating and the degradation of plant cell wall contents to a great extent. Most alpaca husbandries consist of only few animals and with the still increasing number of alpacas worldwide the number of persons who are responsible for these animals is increasing as well. Despite this, little research has been done with regard to the clinical anatomy of the stomach of alpacas. Six animals were used for dissection. The vascular system of two alpacas was injected with latex milk to illustrate the course of the blood supply to the viscera. One stomach was used to prepare formalin-fixed preparations. The stomach consisted of three compartments (C1-C3) and showed two sacculated areas in C1 and another comb-like system in C2. The compartments were lined by a smooth mucosa. Only the deep cells of C2 were lined by a papillated mucosa. The main blood supply was provided by the coeliac artery which was divided into the hepatic artery and the left gastric artery, supplying abdominal organs like liver, spleen, pancreas, and the initial part of the duodenum. Literature research on the llama stomach showed that the alpaca stomachs that were used resembled each other to a very large degree. The specific design of the stomach together with its related functions and physiological processes confirm that the evolution of Tylopoda and Ruminantia took place in parallel and not in homology.

In Vivo Biofilm Formation of Pathogenic Leptospira spp. in the Vitreous Humor of Horses with Recurrent Uveitis.

Equine recurrent uveitis (ERU) causes painful inflammatory attacks and oftentimes blindness in the affected eyes. The disease is considered a late sequela of systemic leptospirosis. The most effective therapy is the surgical removal of the vitreous (vitrectomy), which is not only therapeutic, but provides vitreous material that can be assessed diagnostically. For example, the lipL32 gene, culturable Leptospira spp., and anti-Leptospira antibodies have all been detected in vitreous samples obtained from eyes with chronic ERU. Despite this clear evidence of leptospiral involvement, the systemic administration of antibiotics in infected horses is ineffective at resolving ERU. This syndrome of chronic recurrent inflammation, which is unresponsive to antibiotic therapy, combined with apparent bacteria evading the immune response, is consistent with a biofilm-associated infection. The purpose of this study, therefore, was to detect the in vivo biofilm formation of Leptospira spp. in vitreous samples collected during vitrectomy and examined using a Warthin-Starry silver stain and immunohistochemistry. All known steps of biofilm formation were visualized in these samples, including individual Leptospira spp., leptospiral microcolonies and dense roundish accumulations of Leptospira spp. In many instances spirochetes were surrounded by an extracellular substance. Taken together, data from the present study show that ERU is a biofilm-associated intraocular leptospiral infection, which best explains the typical clinical course.

Mapping subchondral bone density of selected donor and recipient sites for autologous osteochondral transplantation in the canine stifle joint using computed tomographic osteoabsorptiometry.

OBJECTIVE: To characterize donor and recipient sites for autologous osteochondral transplantation (AOT) in the canine stifle joint with respect to maximal subchondral bone density (mSBD). STUDY DESIGN: Descriptive laboratory study. SAMPLE POPULATION: Femora (n=15) of dogs (>20 kg). METHODS: mSBD at selected donor sites within and outside the femoropatellar joint and at potential recipient sites for both femoral condyles was assessed using nonvolumetric computed tomographic osteoabsorptiometry and normalized to values obtained at the central weight-bearing aspect of the lateral femoral condyle. RESULTS: Only transplants harvested at the axial aspects of the lateral and medial trochlear ridge had a normalized mSBD comparable with the lateral and medial femoral condyle. Grafts from outside the femoropatellar joint, at the most proximal aspect of the medial femoral condyle and at the most distal aspect of the trochlea (the notch area) had mSBD values 13.8-24.4% less than at the femoral condyles. CONCLUSIONS: Choosing between donor sites within or outside the femoropatellar joint may significantly affect subchondral bone quality of harvested transplants. CLINICAL RELEVANCE: Donor sites abaxial to the femoropatellar joint and at the most proximal aspect of the medial femoral condyle may provide transplants of suboptimal bone morphology, challenging their use as primary donor sites for AOT in dogs. However, this statement is based on nonvolumetric assessment of bone density, necessitating verification using volumetric density analysis to finally infer the biomechanical value of different grafts.

Accuracy of conventional radiography and computed tomography in predicting implant position in relation to the vertebral canal in dogs.

OBJECTIVE: To compare the accuracy of radiography and computed tomography (CT) in predicting implant position in relation to the vertebral canal in the cervical and thoracolumbar vertebral column. STUDY DESIGN: In vitro imaging and anatomic study. ANIMALS: Medium-sized canine cadaver vertebral columns (n=12). METHODS: Steinmann pins were inserted into cervical and thoracolumbar vertebrae based on established landmarks but without predetermination of vertebral canal violation. Radiographs and CT images were obtained and evaluated by 6 individuals. A random subset of pins was evaluated for ability to distinguish left from right pins on radiographs. The ability to correctly identify vertebral canal penetration for all pins was assessed both on radiographs and CT. Spines were then anatomically prepared and visual examination of pin penetration into the canal served as the gold standard. RESULTS: Left/right accuracy was 93.1%. Overall sensitivity of radiographs and CT to detect vertebral canal penetration by an implant were significantly different and estimated as 50.7% and 93.4%, respectively (P<.0001). Sensitivity was significantly higher for complete versus partial penetration and for radiologists compared with nonradiologists for both imaging modalities. Overall specificity of radiographs and CT to detect vertebral canal penetration was 82.9% and 86.4%, respectively (P=.049). CONCLUSIONS: CT was superior to radiographic assessment and is the recommended imaging modality to assess penetration into the vertebral canal. CLINICAL RELEVANCE: CT is significantly more accurate in identifying vertebral canal violation by Steinmann pins and should be performed postoperatively to assess implant position.

Mapping of split-line pattern and cartilage thickness of selected donor and recipient sites for autologous osteochondral transplantation in the canine stifle joint.

OBJECTIVE: To characterize donor and recipient sites for autologous osteochondral transplantation in the canine stifle joint with respect to split-line pattern and cartilage thickness. STUDY DESIGN: In vitro study. Sample Population- Stifle joints (n=30) of dogs >20 kg. METHODS: Collagen network orientation of the hyaline cartilage coverage of the distal femur was assessed using split-line technique (n=10). Cartilage thickness was measured radiographically on osteochondral plugs harvested at the abaxial and axial surfaces of the femoropatellar joint (n=15), the most proximal abaxial aspect of the medial condyle (CO; n=5) and at both femoral condyles (n=15). RESULTS: Cartilage within the femoropatellar joint and both femoral condyles had mostly transversely orientated pattern of split-lines. Abaxial to the femoropatellar joint split-lines were absent. All donor sites had significantly thinner cartilage than the medial condyle (CM). Only the distal trochlea had cartilage thickness comparable to the lateral condyle (CL). The thinnest cartilage was found abaxial to the femoropatellar joint followed by CO, which was approximately 2-3 times thinner than the cartilage at both condyles. CONCLUSIONS: None of the investigated donor sites provided transplants of comparable cartilage thickness to CM. Transplants from within the femoropatellar joint should be harvested in priority as they reach cartilage morphology comparable to CL. CLINICAL RELEVANCE: Adjusting for cartilage thickness and split-line pattern may improve long-term outcome after autologous osteochondral transplantation. But surface curvature and donor-site morbidity have to be considered as well when choosing the most suitable donor site.

Adaptive Anatomical Specialization of the Intestines of Alpacas Taking into Account their Original Habitat and Feeding Behaviour.

The gastrointestinal tract of the alpaca (Vicugna pacos) is most efficiently adapted to its habitat at high altitudes. Alpacas, just like ruminants, feed on hardly digestible forage. However, it has been demonstrated that the anatomy of the camelid digestive tract has developed independently of ruminants and not in homology to them. Despite a long history of domestication and an increasing number of animals worldwide, little research has been done on the intestinal anatomy of alpacas. The purpose of this study was to describe the anatomical features of the alpaca's intestines and to explain anatomical peculiarities in the context of evolutionary function and morphology. Another goal of this study was the demonstration of weaknesses of the intestinal anatomy predisposing alpacas to certain clinical presentations. Six animals were used for dissection. The basic structure of the intestines was comparable to that in ruminants. However, a number of characteristic peculiarities were found in alpacas, like the duodenal ampulla and the proximal and distal loop of the ascending colon. The jejunum and ileum, unlike those of ruminants, had their own mesentery largely separated from the ascending mesocolon. The main blood supply was provided by the cranial and caudal mesenteric artery. The particular lymph nodes were located along the branches of these two arteries. The spiral colon seemed to play a major role in intestinal digestion and water resorption. The size of the distal fermentation chamber allows the presumption that alpacas belong to the group of animals practicing a fractionated fermentation in the proximal and distal fermentation chambers. Anat Rec, 301:1840-1851, 2018. © 2018 Wiley Periodicals, Inc.

[Morphological investigations of deep sole ulcers in cattle. Part 2: Toe ulcers, white line disease in the heel and changes due to inappropriate weight bearing and deficient claw care]. / Morphologische Untersuchungen tiefreichender Klauenerkrankungen beim Rind. Teil 2: Sohlenspitzengeschwür, Sohlenwandgeschwür sowie Veränderungen durch Fehlbelastung und fehlerhafte Klauenpflege.

OBJECTIVE: To demonstrate the morphology of pathological changes to the inner structures of the claw in cases of toe ulcers, white line disease in the heel and changes due to inappropriate weight bearing and deficient claw care. MATERIAL AND METHODS: Hind limbs of 55 cows displaying external signs of complicated sole ulcers were examined externally and internally. To examine the samples internally, a sagittal section was performed. Furthermore, the material was examined after bone maceration and histologically. A total of 43 claws of 112 digits with 120 deep sole ulcers displayed a toe ulcer and in 18 claws white line disease was diagnosed. RESULTS: In animals with toe ulcers, necrosis of the pedal bone was found in severely altered claws. In cows with white line disease, osteolysis in the abaxial region of the margo solearis and arthritis in the distal interphalangeal joint were the most common pathological findings. Claws with deficient claw care displayed severe pathological changes to the pedal bone. CONCLUSION AND CLINICAL RELEVANCE: Sole ulcers may rapidly cause serious and irreversible changes to the structures encased within the hoof capsule and consequently have an impact on animal welfare. Therefore, prophylaxis and functional claw care are essential measures to avoid pathological conditions in claws and to improve animal welfare.

[Morphological investigations of deep sole ulcers in cattle. Part 1: The complicated Rusterholz ulcer]. / Morphologische Untersuchungen tiefreichender Klauenerkrankungen beim Rind. Teil 1: Das komplizierte Rusterholz'sche Sohlengeschwür.

OBJECTIVE: In the context of a larger study on morphological changes of deep sole ulcers, claws with Rusterholz ulcer (RU) were investigated to describe the varied pathological changes of the RU. MATERIAL AND METHODS: Hind limbs of 55 cows displaying external signs of complicated sole ulcers were examined externally and internally. To examine the samples internally, a sagittal section was performed. Furthermore, the material was examined histologically and after bone maceration. A total of 59 claws of 112 digits with 120 deep sole ulcers displayed a complicated RU. RESULTS: The most frequent findings were: fibrosis of the heel cushion, partly in conjunction with cartilaginous/osseous areas; osteomyelitis of the tuberculum flexorium, resulting in osteolysis of the macerated bones, often together with peripheral periosteal exostoses; avulsion fracture of the tuberculum flexorium in severely deformed claws; arthritis in the distal joint, frequently in conjunction with subchondral osteomyelitis, with the macerated bone showing osteolyses near the fossae synoviales and in the periphery of the joint surface as well as periosteal exostoses on the insertion point of the joint capsule. Changes in the bursa podotrochlearis, the common digital flexor tendon sheath and the pastern joint occurred less frequently. CONCLUSIONS AND CLINICAL RELEVANCE: Fibrosis and ossification of the heel cushion were classified as metaplasia, because these processes were considered an adaption to non-physiological strain of the heel. As the infection of the RU spreads, the tuberculum flexorium may play a central role. In advanced cases, an inflammation-related weakening of the bone tissue can lead to a pathological fracture with avulsion of the deep digital flexor tendon. Secondary infection of the distal joint may occur subsequent to any avulsion of the tendon in combination with opening of the joint cavity. More frequently, the infection is likely to have expanded from the insertion point of the joint capsule to the subchondral bone to ultimately infest the joint cavity. Changes in the bursa podotrochlearis, the common digital flexor tendon sheath and the pastern joint are assumed to develop as a consequence of arthritis in the distal joint.

Automatic image registration of three-dimensional images of the head of cats and dogs by use of maximization of mutual information.

OBJECTIVE: To validate mutual information criterion as a ready-to-use technique for automated alignment (ie, registration) of 3-dimensional (3-D) multimodal image data of the head of cats and dogs. SAMPLE POPULATION: Corresponding 3-D magnetic resonance imaging (MRI) and computed tomography (CT) brain scans of a 6-month-old Doberman Pinscher with a brain cyst; CT images of the head of a European shorthair cat with a meningioma before and immediately, 3, and 6 months after surgical resection; and CT and corresponding stacked anatomic cryosection images of the entire head of a 2-year-old sexually intact female Beagle. PROCEDURE: All images were matched retrospectively by use of an in-house computer program developed on the basis of a mutual information image registration algorithm. Accuracy of the resulting registrations was evaluated by visual inspection. RESULTS: All registrations were judged to be highly accurate. Additional manual corrections were not necessary. CONCLUSIONS AND CLINICAL RELEVANCE: Mutual information registration criterion can by applied to 3-D multimodal head images of cats and dogs for full automatic rigid-body image registration. The combination of such aligned images would considerably facilitate efforts of veterinary clinicians as indicated by its widespread use in brain surgery and radiation therapy of humans.