Surface Of Dogs Research Articles

Micromorphology and topography of tarsal joint capsule's vascular elements in cats and dogs.

Both cats and dogs belong to animals with the same type of limb support but have different nature of movement. Despite belonging to digitigrade animals, cats and dogs have a different nature of motion. While moving, the medial joint surface in cats and lateral surface in dogs carry the larger pressure. The aim of the study was to compare the similar surfaces of the cat's and dog's tarsal joint capsule and to detect differences in its histostructure and vascularisation. For the study, we used the capsule of the tarsal joint of five cats and five dogs dissected with accordance to anatomical surfaces. Sections of the capsule joint were stained with haematoxylin-eosin. The sections were examined with a microscope at magnification ×250 and ×400. The statistical analysis of the results was done using Student's t test. During the research, a difference in histostructure and vascularisation of tarsal joint capsule in cats and dogs on respective surfaces were found. The medial surface of the tarsal joint capsule was the most saturated with hemomicrocirculatory bed structures in cats, whereas this was the lateral surface in dogs. The most active metabolic processes also take place in these areas of the joint capsule, which is important to know when prescribing therapeutic procedures and determining an optimal surgical access.

Effect of preameloblast-conditioned medium and CPNE7 on root surfaces in dogs: a histologic and histomorphometric evaluation.

Preameloblast-conditioned medium (PACM) has been reported as a potent dentin regenerative material, but its effects as a mixture on periodontal regeneration and the role of CPNE7 in PACM are not known. The purpose of this study is to evaluate the histologic and histomorphometric effects of preameloblast-conditioned medium (PACM) and CPNE7 on periodontal tissue healing in dogs. Seventy-two mandibular premolar roots from ten dogs were extracted and randomly divided into six groups (n = 12 each): (1) positive control group; (2) negative control group; (3) cementum-removed and PACM-treated group; (4) cementum-preserved and PACM-treated group; (5) CPNE7-inactivated PACM-treated group; and (6) recombinant CPNE7-treated group. The extracted roots were replanted into extraction sockets for 4 and 8 weeks and analyzed histologically. Most of the root surfaces in the negative control group showed ankylosis; and those in the experimental groups showed newly formed PDL-like and cementum-like tissues. Histomorphometric analysis of horizontal sections showed that the mean length of the PDL on the roots of the positive controls was similar to those in cementum-removed or -preserved and PACM-treated group at 8 weeks (p = 1.08). Sagittal sections showed that the mean length of the new cementum on the roots in cementum-removed and PACM-treated group was significantly greater than that in CPNE7-inactivated PACM-treated group (p = 0.037). The mean length of the newly formed PDL on the roots in CPNE7- inactivated PACM-treated and rCPNE7-treated groups was significantly greater than that in the negative controls at 8weeks (p = 0.037, p = 0.036). The use of PACM and CPNE7 in tooth replantation resulted in increased PDL and cementum formation, suggesting the beneficial role of PACM and CPNE7 in periodontal tissue healing.

Effects of platelet-rich plasma on tooth replantation in dogs: a histologic and histomorphometric analysis.

PurposeThe purpose of this study was to evaluate the effects of platelet-rich plasma (PRP) on periodontal healing of replanted root surfaces in dogs histologically and histomorphometrically.MethodsA total of 36 roots of mandibular incisors and premolars from 6 mongrel dogs were used. The roots were randomly divided into 3 groups: 1) a positive control group (n=12), in which the periodontal ligament (PDL) and cementum were retained and the roots were soaked in saline; 2) a negative control group (n=12), in which the PDL and cementum were removed and the roots were soaked in saline; and 3) an experimental group (n=12), in which the PDL and cementum were removed and the roots were soaked in PRP. After soaking the root surfaces, the extracted roots were replanted into the extraction sockets. The roots were covered using a coronally repositioned flapResultsHistologically, irregular-thickness PDL-like and cementum-like tissues were observed in the 4-week experimental group and the positive control group. PDL-like tissue and cementum-like tissue with a more uniform thickness were observed at 8 weeks. In the negative control group, PDL-like tissue and cementum-like tissue were rarely found, and root resorption and ankylosis were observed. In the cross-sectional histomorphometric analysis, the experimental group demonstrated a higher rate of formation of cementum-like tissue and a lower tooth ankylosis rate than the positive and negative control groups at 4 and 8 weeks. Although there was a significant difference in the tooth ankylosis rate and the formation of cementum-like tissue across the 3 groups (P<0.05), no statistical significance was observed between any pair of groups (P>0.017).ConclusionsApplying PRP to root surfaces during tooth replantation in dogs can reduce tooth ankylosis and increase PDL-like and cementum-like tissue formation.

Canine mange Part 1: surface mites

The infestation of canine skin with parasitic mites of various species (also known as ‘mange’) is a well-known and reasonably common group of dermatological disorders; however, the mites are very small-to-microscopic, hence their detection and positive identification can be challenging. The mites causing canine mange typically reside in different anatomical locations and at different levels of the skin. This article, which forms part 1 of a 2-part article series on the subject, describes the three major types of mange mite affecting the surface of dogs’ skin, whereas part 2 will address the sub-surface mite infestations.

Biological aspects of dental implant; Current knowledge and perspectives in oral implantology

The utilization of dental implants became a scientifically accepted treatment modality for the rehabilitation of fully and partially edentulous patients. The evolution of dental implants has completely changed dentistry. Implants can offer a number of benefits, from improved esthetics, to reducing bone loss, to improving denture retention for edentulous patients. Branemark et al., was the first person to examined submerged titanium implants with a machined surface in dogs and later called this procedure as osseointegration, which is now defined as “A direct structural and functional connection between ordered, living bone and the surface of a load-bearing implant.” Commercially pure titanium is recognized today as a material of choice, since it is characterized by excellent biological and also good mechanical properties. In this comprehensive review, authors have sought to explore various biological aspects of dental implant as pertinent to clinical procedure so as to provide research foundation for the establishment of suitable strategies that can assist in successful implant therapy. Key words: Biocompatible materials, dental implants, surface properties

Grossly apparent cartilage erosion of the patellar articular surface in dogs with congenital medial patellar luxation

One hundred and forty-five stifles of client-owned dogs that underwent corrective surgery for congenital medial patellar luxation were inspected for cartilage erosion on the articular surface of the patella. The lesions were mapped in surface percentage ranges of 20% and by location. Two-thirds of the patellae had cartilage erosion. Cartilage erosion varied between 0 and 100% of the total patellar articular surface and was localised mainly on the medial and distal side of the patella. Dogs with Grade IV patellar luxations and heavier dogs were more affected. The majority of dogs in our study with congenital medial patellar luxation had grossly apparent cartilage erosion on the articular surface of the patella, which may help to explain why certain patients do not function well clinically after technically successful corrective surgery.

Influence of the Interimplant Distance on Crestal Bone Resorption and Bone Density: A Histomorphometric Study in Dogs

The position of gingival soft tissues depends on the position and health of the underlying alveolar bone. The aim of this study was to evaluate the influence of different interimplant distances on crestal bone resorption after prosthetic restoration with a 5-mm distance between the contact point and the bone crest. The mandibular bilateral premolars of six dogs were extracted and, after 12 weeks, each dog received eight implants, totaling 48 implants in the experiment. Two pairs, one in each hemiarch, were separated by 2 mm (group 1) and two by 3 mm (group 2). After 12 weeks, the implants received temporary acrylic prostheses. After 4 more weeks, metallic crowns substituted the temporary prostheses. After 4 more weeks, the animals were sacrificed, and their hemimandibles were removed, dissected, and processed. For groups 1 and 2, respectively, the mean of interimplant bone resorption (IIBR) analyzed histologically was 2.03 and 1.98 mm (P >or=0.05), and the mean of the distal extension bone resorption was 2.04 and 1.92 mm for groups 1 and 2, respectively (P >or=0.05). The crestal bone resorption between the implants was 0.13 mm (P >or=0.05) for both groups. The mean of IIBD for groups 1 and 2 was 79% and 80%, respectively. When the IIBD was compared to the distal extension bone density for group 1 (79% and 64%) and group 2 (80% and 62%), statistically significant differences were obtained for both groups (P <or=0.05). The distances of 2 and 3 mm between implants do not result in statistically significant differences in crestal bone resorption around implant surfaces in dogs. The bone density is enhanced when loading is present at the interimplant area.

Effect of Torso Shape and Heart Location in the Chest on Formation of Cardiac Electric Potentials on Body Surface in Dogs

Experimental and theoretical methods were employed to study the effects of torso shape and heart orientation in the thoracic cavity on peculiarities of the formation cardiac electric field on the body surface in dogs. It was found that heart orientation to a greater extent than torso shape affected projections of cardiac electric potentials from the epicardium onto the body surface.

Time correlation between initial activation of ventricular myocardium and cardiac electric potentials on body surface in dogs.

Parameters of cardioelectric field on body surface and propagation of excitation in ventricular myocardium during initial activation were studied using multichannel synchronous electrocardiotopography. It was shown that inversion of areas of negative and positive potentials of cardioelectric field on body surface at the moment of excitation propagation to the epicardium reflected changes in the main direction of excitation wavefront in ventricles.

SYNTHETIC OSTEOCHONDRAL REPLACEMENT OF THE FEMORAL ARTICULAR SURFACE

We have studied damage to the tibial articular surface after replacement of the femoral surface in dogs. We inserted pairs of implants made of alumina, titanium and polyvinyl alcohol (PVA) hydrogel on titanium fibre mesh into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. We discuss the clinical implications of the possible use of this material in articular resurfacing and joint replacement.

Synthetic osteochondral replacement of the femoral articular surface.

We have studied damage to the tibial articular surface after replacement of the femoral surface in dogs. We inserted pairs of implants made of alumina, titanium and polyvinyl alcohol (PVA) hydrogel on titanium fibre mesh into the femoral condyles. The two hard materials caused marked pathological changes in the articular cartilage and menisci, but the hydrogel composite replacement caused minimal damage. The composite osteochondral device became rapidly attached to host bone by ingrowth into the supporting mesh. We discuss the clinical implications of the possible use of this material in articular resurfacing and joint replacement.

Histologie features of normal canine and feline skin

The skin provides an anatomic barrier and at the same time acts as a principal organ of communication between the animal and its environment. The skin displays remarkable species-dependent anatomic variations in its components, but its general functions are basically preserved throughout the different species. 1–6 The majority of the body surface in dogs and cats is covered by a variably dense haircoat, which exhibits species- and breed-dependent characteristics. It is partially or completely absent in a few feline and canine breeds, such as Devon rex cats, Chinese crested dogs, Mexican hairless dogs, and Abyssinian dogs. 6,7 The hairs provide an additional mechanical and physical barrier and are involved in thermoregulation as well. 6,8 The haircoat itself is often involved in cutaneous disorders and acts as an important mirror for internal diseases. On the other hand, it renders the skin itself less easily accessible for clinical observations. The thickness of the skin varies with species, breed, and body location and ranges from 0.5 to 5 mm in the dog 9 and from 0.4 to 2 mm in the cat. 7 The skin is thickest on the back and dorsal neck, becomes thinner toward the abdomen, and is thinnest in the inguinal and axillary regions. 7,9,10 Its thickness decreases from proximal to distal extremities as well. Histologic features of canine and feline skin in comparison with the human integument are presented according to their anatomic location: (1) epidermis, (2) basement membrane zone, (3) hair follicles, (4) sebaceous glands, (5) sweat glands, and (6) dermis.

Biphasic Calcium Phosphate Ceramic Combined With Fibrillar Collagen With and Without Citric Acid Conditioning in the Treatment of Periodontal Osseous Defects

The purpose of this study is to determine whether the combination of biphasic calcium phosphate ceramic (BCP) and collagen and citric acid root conditioning would promote accelerated new attachment of periodontal tissue to the root surface in dogs. Intrabony defects were surgically produced for each animal and were made chronic for 16 weeks. These defects were assigned to two study treatment and one control group: ceramic-collagen without citric acid (CO-CE); ceramic-collagen with citric acid (CO-CE-CA); and control (surgical debridement and root planing only). Results showed that all groups gained new attachment level as demonstrated both clinically and histometrically. The treatment groups showed a significant mean gain greater than the control (P less than .005), but no significant difference was found between treatment groups. Small areas of ankylosis was also found in both treatments but there was no evidence of active root resorption. It is concluded that the use of combined BCP and fibrillar collagen is beneficial in promoting new attachment of periodontal tissues to the root surface in dogs. Although citric acid root conditioning did as well or better than ceramic and collagen alone, its benefits are still speculative and need further experimentation.

Rhythm analysis of arterial blood pressure.

Rhythms identified in the power spectra of blood pressure and ECG recordings were used as probes of the intact cardiovascular control systems. A prominent vasomotor rhythm was detected in human subjects and experimental dogs, with a period ranging between 15 and 30 s. This rhythm did not depend on specific rhythms of heart rate but was dependent on the sympathetic nervous system, and was identified as a third-order rhythm of blood pressure. The parasympathetic nervous system appears to mediate a separate rhythm having a slightly shorter period. Another rhythm studied was a subharmonic of heart rate that appeared during episodes of tachycardia. Electrophysiological mapping of the ventricular surface in dogs revealed that tachycardia induced an alternating pattern of electrical conduction in ischemic areas of the ventricle, coincident with the appearance of subharmonics in pressure and ECG. Our results illustrate the potential utility of spectral analysis of cardiovascular signals in assessing cardiovascular regulation.

Effect of Uniformly Prolonged, and Increased Basic Dispersion of Repolarization on Premature Dispersion on Ventricular Surface in Dogs: Role of Action Potential Duration and Activation Time Differences

Strong experimental evidence links ventricular fibrillation to an increased temporal dispersion of the recovery of excitability. The effect of an overall prolongation of repolarization and an increased basic dispersion of repolarization on premature dispersion was studied on ventricular surface in 10 dogs. Our observations reveal the operation of several fundamental electrophysiologic mechanisms controlling the conduction and the refractoriness in the ventricular myocardium in vivo. Action potential (AP) duration was influenced by the heart rate, the duration of the preceding AP and the proximity to the repolarization of the preceding AP. These effects can both slow, or enhance ventricular conduction, during propagation of premature impulses. This model may be applicable to several clinical situations where APs are prolonged (hypothermia, drug effects, changes in electrolytes) or when dispersion of refractoriness is increased (long QT-time syndrome, neural imbalance of the heart with and without heart disease.

The effect of notching and citric acid on healthy root surfaces in dogs.

The purpose of this study was to determine the following on healthy root surfaces: (1) the effect of placement of a notch within dentin on the formation of cementum and/or connective tissue attachment and (2) the effect of citric acid on the notched root surface on the formation of cementum and/or connective tissue attachment. Five young adult dogs were used in the study. Full thickness buccal flaps were reflected on canines, P3, P4, and M1, 4 mm of buccal bone was removed, and the roots carefully planed. One, two, or three parallel notches were placed in the exposed root surface of each tooth. The root surfaces were then treated with either citric acid or saline, and the flaps were replaced and sutured. Animals were sacrificed at intervals of 5 weeks, 9 weeks, 10 weeks, and 12 weeks. Block specimens were examined in step‐serial fashion via light microscopy. The data pool consisted of 19‐matched paired teeth, including 72 roots. Healing responses in a specific notch or on an isthmus varied, including epithelium‐root, connective tissue‐cementum‐root, bone‐connective tissue‐root, ankylosis, or any combination.There was a statistically significant increase in the formation of connective tissue attachment, cementum, and bone toward the apical part of the notches and isthmuses. Epithelium interfaces were significantly higher in notches compared with isthmus surfaces (α= 0.05). The frequency of connective tissue attachment on isthmuses was statistically greater than in notches (α= 0.05). When citric acid was used, in comparison to saline, cementum was observed significantly more often in the coronal portion of the lesions (α= 0.05). This study indicates that citric acid applied to healthy root surfaces in dogs enhances cementum formation in areas farther coronally to the alveolar process than areas treated with saline. Notching per se does not enhance cementum and/or connective tissue attachment. There was no difference in the incidence of ankylosis between saline and citric acid treated specimens.

Location of immunoglobulins and complement (C 3) at the surface and within the skin of dogs

The serum proteins present at the skin surface in dogs were found to include the immunoglobulins (Ig) G, M and A, complement (C 3) and albumin. Within the skin IgG and IgM were consistently found in the interstitial tissue throughout the dermis and were commonly present in the dermal blood vessels and hair papillae. IgA was undetectable or present in small amounts in the dermis in most of the 16 samples examined. It was found in the sweat glands, both in the lumen and the fundic epithelium, in some skin samples. C 3 was demonstrated in the dermis and in the inter-cellular spaces of the stratum corneum. Elution of fresh skin specimens with phosphate buffered saline removed the majority of interstitial immunoglobulin and C 3 from the dermis and some of the IgA from the sweat glands. IgM could still be demonstrated in the region ofthe epidermal basement membrane and C 3 was not eluted from the stratum corneum. Removal of interstitial IgG and IgM facilitated the identification of immunoglobulin-bearing cells in the dermis. The distribution of IgG and IgM in dog skin is similar to that found in ruminants. Demonstration of IgA in the canine sweat gland fundus lends further support to the concept of IgA as a secretory immunoglobulin in the skin.

Detection of delayed ventricular activation on the body surface in dogs.

This study describes a noninvasive method for detecting delayed ventricular activation, caused by ischemia, on the body surface. Signal averaging and a newly developed high-pass digital filter were used. The filter has the property that it does not create an artifact or ring after the QRS complex ends, thereby allowing the detection of microvolt-level potentials that occur immediately after the QRS complex. Eleven dogs were studied before and during acute ischemia induced by coronary artery ligation and latex embolization. The ischemic region was mapped with bipolar electrodes and, after the chest was rapidly closed, signal-averaged recordings were made from the body surface. Repeated cycles of ventricular mapping and signal averaging were performed. In each dog, delayed and fractionated electrograms were recorded directly from the ischemic epicardium that lasted a maximum of 118 +/- 18 ms after QRS onset. The duration of the ventricular electrograms varied with time. Whenever delayed epicardial electrograms were recorded, filtered signal-averaged leads showed microvolt-level potentials early in the S-T segment that were continuous with the QRS complex. The duration of ventricular activation, as measured from the bipolar electrograms and from the filtered signal-averaged leads, correlated well (r = 0.93, P less than 0.001). Because of the absence of filter ringing, low-level potentials could be detected less than 40 ms after the QRS complex ended. This study demonstrates that microvolt-level potentials arising from delayed ventricular activation can be reliably detected on the body surface, even when they occur just after the QRS complex.

Natural desensitization of exposed tooth roots in dogs.

With scanning electron microscopy, electron microprobe elemental analysis, and an objective method for eliciting responses to electrical stimuli, exposed tooth root surfaces in dogs were found to become naturally desensitized with time, perhaps because of the formation of acquired pellicle.

"Dog pox": some clinical aspects of an eruptive condition of certain mucous surfaces in dogs

An eruptive condition seen on certain mucous membranes of dogs occurs frequently but often asymptomatically. Lesions have been found to be present in over 60 percent of male dogs. The infection is probably due to a canine herpes virus and has been termed conveniently but inaccurately "dog pox". In many cases lesions are present without observable clinical signs but severe irritation, especially related to lesions in the lower bowel, can give rise to marked symptoms which may be confused with abnormality of the para-anal sacs, or to chronic diarrhoea of a type suggestive of colitis. The incidence, sites of infection and possible syndromes which may be ascribed to the condition are briefly discussed on a clinical basis only.