Function of the ramus communicans of the medial and lateral palmar nerves of the horse

Reasons for performing study: The role of the communicating branch between the medial and lateral palmar nerves of horses (i.e. the ramus communicans) in conveying sensory impulses proximally should be determined to avoid errors in interpreting diagnostic anaesthesia of the palmar nerves. Hypothesis: Sensory nerve fibres in the ramus communicans of horses pass proximally from the lateral palmar nerve to merge with the medial palmar nerve, but not vice versa. Objective: To determine the direction of sensory impulses through the ramus communicans between lateral and medial palmar nerves. Methods: Pain in a thoracic foot was created with set‐screw pressure applied to either the medial or lateral aspect of the sole of each forelimb of 6 horses. The palmar nerve on the side of the sole in which pain was created was anaesthetised proximal to the ramus communicans with local anaesthetic. Lameness was evaluated objectively by using a wireless, inertial, sensor‐based, motion analysis system (Lameness Locator). Lameness was also evaluated subjectively by using a graded scoring system. Local anaesthetic was then administered adjacent to the ramus communicans to determine the effect of anaesthesia of the ramus communicans on residual lameness. Results: When pain originated from the medial or the lateral aspect of the sole, anaesthesia of the ipsilateral palmar nerve proximal to the ramus communicans did not entirely resolve lameness. Anaesthesia of the ramus communicans further attenuated or resolved lameness. Conclusions: Sensory fibres pass in both directions in the ramus communicans to connect the medial and lateral palmar nerves. Potential relevance: When administering a low palmar nerve block, both palmar nerves should be anaesthetised distal to the ramus communicans to avoid leaving nondesensitised sensory nerve fibres passing through this neural connection. Alternatively, local anaesthetic could also be deposited adjacent to the ramus communicans when anaesthetising the palmar nerves.     

Coronary arterial anatomy of the one-humped camel (Camelus dromedarius)

The detailed coronary arterial anatomy of seven camels was studied and compared with that of horses and cattle. In camels, there is a bilateral coronary supply, the right coronary artery being the larger. The left coronary artery follows the same pattern as that in horses. The ramus collateralis proximalis in camels separates off some distance away from the origin of the ramus interventricularis paraconalis, as in horses, whereas it separates off very quickly in cattle. The ramus collateralis distalis has two branches in camels, whereas the left distal ventriculi ramus does not branch. The ramus angularis is also absent but the left distal atrii ramus is present.Abbreviations LCR left ramus circumflexus - RCR right circumflexus ramus - RIS ramus interventricularis subsinosus - RIVP ramus interventricularis paraconalis     

False ankylosis of the temporomandibular joint in a cat

Progressive inability to open the mouth developed in a cat after trauma to the head. Evaluation revealed a healed depression fracture of the left zygomatic arch and normal temporomandibular joints. Surgical exploration of the fracture confirmed a false ankylosis that developed between the depression fracture and the ramus of the mandible. Treatment included excision of the central portion of the zygomatic arch and a portion of the ramus. The cat regained normal function of its mouth.     

Arterial vascularization of the uropygial glands (Gl. uropygialis) in geese (Anser anser) and ducks (Anas platyrhynches)

In the present study, arterial vascularization of the uropygial glands (Gl. uropygialis) of 10 adult geese (Anser anser) and 10 adult ducks (Anas platyrhynches) were studied. Takilon was injected into the median coccygeal arteries of six specimens from each species, and Latex (a natural rubber with ammonia) into those of four specimens. Takilon-injected specimens were corrosion casted, and arteries nourishing the gland were revealed via dissection. Vascularization of the uropygial glands of both the goose and the duck was observed to be the right (a. gl. uropygii dextra), left (a. gl. uropygi sinistra) and ventral (a. gl. uropygi ventralis) glandular uropygial arteries, arising from the median coccygeal (a. coccygea media) artery. Both the right and left glandular uropygial arteries were observed, divided into four branches as follows; muscular ramus (ramus muscularis), medial ramus (ramus medialis), ventral ramus (ramus ventralis) and lateral ramus (ramus lateralis). Of these, as the lateral, medial and ventral branches feed the gland, the muscular branch provides blood for the lateral coccygeal (m. coccygealis lateralis) and levator coccygeal (m. levator coccygealis) muscles, and the skin. Among the arteries mentioned above, anastomosis between the first and the second branches of the right ventral uropygial arteries in the five geese and five ducks was found.     

Computed tomographic diagnosis of a fracture of the floor of the pelvis in a Thoroughbred foal

This case report describes the clinical and diagnostic imaging findings, treatment and outcomes of a 15-day-old Thoroughbred foal referred for the evaluation of severe left hindlimb lameness of 8 days' duration. Radiographic examination of the left hindlimb and transcutaneous ultrasonographic examination of the pelvis were unremarkable. A computed tomographic (CT) examination was performed to investigate the proximal aspect of the limb and the pelvis; CT scans of the thorax were also acquired. In this case, CT images allowed detection of a closed, slightly displaced, oblique wedge-like fracture of the left caudal ramus of the pubis and medial ramus of the ischium, allowing an accurate diagnosis to guide appropriate treatment and prognostication. The foal was treated with anti-inflammatory drugs and box-rest. A follow-up by telephone interview with the trainer 3 years later revealed that the horse is in full athletic activity without any residual gait alteration related to the pelvic fracture.     

Diagnosis and treatment of dynamic closed-mouth jaw locking in a dog

CASE DESCRIPTION: A 5-year-old neutered male English Bulldog was evaluated for intermittent closed-mouth jaw locking of approximately 1 week's duration. CLINICAL FINDINGS: Initial physical examination revealed a nonpainful inability to open the jaw with and without manual assistance; however, manipulation of the jaw after the dog was sedated for diagnostic imaging restored jaw function. Anesthesia was subsequently induced, and computed tomography was performed with the jaw open and closed; contrast agent-enhanced images of the closed jaw were also obtained. No abnormalities of the temporomandibular joints or retrobulbar space were detected. Fluoroscopic examination of movement of the temporomandibular joints revealed a dynamic interference of the rostrodorsal aspect of the coronoid process of the left mandibular ramus with the medial surface of the frontal process of the left zygomatic bone or the left orbital ligament. TREATMENT AND OUTCOME: Partial excision of the coronoid process of the left mandibular ramus was performed. The dog recovered without complication and was able to open and close its jaw and eat within 6 hours after surgery. No additional episodes of jaw locking were detected during the 6 months after surgery. CLINICAL RELEVANCE: To the authors' knowledge, closed-mouth jaw locking in animals attributable to dynamic interference of the rostrodorsal aspect of the coronoid process of a mandibular ramus with the medial surface of the frontal process of a zygomatic bone or an orbital ligament has not been described. Surgical excision of the coronoid process of the mandibular ramus appeared to provide a successful outcome in the dog of this report.     

猪的胸,腰和荐段交感神经交通支的观察

本研究解剖了5头3月龄猪尸体交感神经的交通支。在胸1～14,腰1～3节段每一脊神经都有二条交通支;腰4～6,荐1～4节段各只有一条交通支;仅在腰2～3节段,有斜交通支;荐段有横交通支。在胸、腰段二交通支,多数取前后位置,仅少数只分深浅。前支或深支细,与脊神经的连接点距椎弓孔或椎间孔较近;后支或浅支较粗,与脊神经的连接点距椎弓孔或椎间孔较远。胸、腰段交通支的分支类型与马和驴的交通支相似。     

The macroanatomy of coronary arteries in donkeys (Equus asinus L.)

The aim of this study was to define the arteries that supply the cardiac muscle in donkeys with regard to their course and possible variations. Six hearts belonging to donkeys of different age and sex constituted the material of the study. Following exposition of the arteries by means of injection of latex coloured with Rotring ink to a. coronaria sinistra and a. coronaria dextra, dissection was performed. The arterial vascularization of the heart in donkeys was determined to be supplied by a. coronaria sinistra and a. coronaria dextra which originate from the aorta. A. coronaria sinistra, measured to be larger than a. coronaria dextra, was determined to have its origin at the aorta, at the level of the free border of valvula semilunaris sinistra, and to extend between truncus pulmonalis and auricula sinistra. The mentioned artery was detected to give off two branches, namely, ramus interventricularis paraconalis and ramus circumflexus sinister which extend in sulcus interventricularis paraconalis and sulcus coronarius, respectively. However, a. coronaria dextra was determined to have its origin at the beginning of the aorta, at the level of valvula semilunaris dextra, and to extend to margo ventricularis dexter between truncus pulmonalis and auricula dexter. This study has revealed ramus interventricularis subsinuosus and ramus circumflexus dexter to intercommunicate by means of anastomosis and to form a. coronaria dexter. Examination of material revealed the absence of anastomosis between r. circumflexus sinister and r. circumflexus dexter. Branches named rami septales, originating from ramus interventricularis paraconalis and ramus interventricularis subsinuosus were determined to supply septum interventriculare. Ramus proximalis atrii sinistri was determined to have its origin at ramus circumflexus sinister whereas ramus proximalis venriculi dextri was determined to stem from the beginning of a. coronaria dextra in the material of this study. However, examination of the cranial and caudal branches of ramus coni arteriosi, revealed the cranial branch to be ramus proximalis ventriculi dextri in a cadaver.     

The arterial vascularization of septum interventriculare in donkeys (Equus asinus L.)

In this study, arteries that supply the septum interventriculare in donkeys, their course and variations, if present, were defined. Six hearts belonging to donkeys of varying age and sex constituted the material of the study. In order to expose the arteries, latex coloured with Rotring ink was injected into a. coronaria sinistra and a. coronaria dextra and dissection was performed. The arterial vascularization of the heart in donkeys is supplied by a. coronaria sinistra and a. coronoria dextra, which have their origin at the aorta. A. coronaria sinistra gives off two branches: one is ramus interventricularis paraconalis, which extends into the sulcus interventricularis paraconalis and the other is ramus circumflexus sinister, which lies within the sulcus coronarius. A. coronaria dextra is formed by the union of ramus interventricularis subsinuosus and ramus circumflexus dexter. Septum interventriculare is supplied by rr. septales, which originate from ramus interventricularis paraconalis, a branch of a. coronaria sinistra, as well as rami septales which have their origin in ramus interventricularis subsinuosus, a branch of a. coronaria dextra.     

Anatomical Studies of the Accessory Nerve in the Indian Buffalo (Bubalus bubalis)*

This is a study of the origin, formation, course, distribution, the fascicular number, their area and arrangement, total fibre count, density and diameterspectra of the accessory nerve in the Indian buffalo. The radices spinales are located from the level of C₁ to midlevel of C₆cord segments. The radices craniales arise in series from the medulla oblongata caudal to those of the vagus nerve. The accessory nerve contains 7931 myelinated fibres arranged in 31 fascicles. Of these 41 % have an external diameter of 10–12 μm. The greatest density of fibres viz. 1781/mm² is obtained in the anastomosing ramus from the second cervical spinal nerve. The least value (377/mm²) is found in its ventral ramus. However, the dorsal ramus appears to have a larger cross-sectional area.     

Dysphagia caused by focal guttural pouch mycosis: mononeuropathy of the pharyngeal ramus of the vagal nerve in a 20-year-old pony mare

A 20-year-old pony mare was presented to the equine hospital with a ten-day history of dysphagia, regurgitation and coughing. An obstruction of the oesophagus was excluded via endoscopy, but the proximal oesophagus appeared to be distended and circular contractions were missing. A guttural pouch endoscopy revealed a single, black-mottled plaque on the pharyngeal ramus of the vagus nerve in the left guttural pouch, causing a local swelling of this nerve. The pharyngeal ramus seemed to be atrophic distal to the lesion. A biopsy was taken from the lesion and histopathological findings proved the reasonable suspicion of a guttural pouch mycosis with a high degree of purulent-necrotic inflammation and invasion of fungal hyphae. There were no signs of neoplasia, such as melanoma. Daily guttural pouch irrigations with a clotrimazole emulsion (20 g Canesten^® Gyn⁴ solved in 500 ml water), led to a good recovery of the mucosa above the nerve. Periodic endoscopic examination of the left guttural pouch showed that local thickening and distal atrophy of this pharyngeal ramus did not improve, neither did the clinical symptoms. Due to progressive weight loss, acute respiratory distress and aspiration pneumonia, the 20-year-old pony mare unfortunately had to be euthanized three weeks after discharge. This case report emphasizes the enormous importance of a single nerve for the realization of the swallowing process. The one-sided loss of function of the pharyngeal branch of the vagal nerve cannot be compensated neither by the remaining ipsilateral nerves nor by the contralateral normal functioning glossopharyngeal and vagal nerves and thus inevitably leads to severe dysphagia.     

Macroanatomy of coronary arteries in Bactrian camel (<Emphasis Type="Italic">Camelus bactrianus</Emphasis>)

The aim of present study was to determine the origin, distribution and course of the coronary arteries in Bactrian camels. Ten hearts of adult healthy Bactrian camels of different sex constituted the material. Following exposition of the arteries by means of injection of 15% ABS coloured with red carmine to a. coronaria sinistra and a. coronaria dextra, dissection was performed. The arterial vascularization of the heart in Bactrian camels was determined to be supplied by a. coronaria sinistra and a. coronaria dextra which originate from the aorta. The results showed that ramus interventricularis subsinuosus is one branch of a. coronaria dextra in Bactrian camels, which is characteristic of a. coronaria dextra pattern. Ramus septi interventricularis that supplied the interventricular septum mainly originates from ramus interventricular paraconalis. Two muscular bridges ware observed crossing ramus interventricular paraconalis in the middle third of sulcus interventricularis paraconalis. Muscular bridge was not found above ramus interventricularis subsinuosus in this study.     

The right coronary artery is absent in the chinchilla (Chinchilla lanigera)

A total of 10 adult, healthy, male chinchillas (Chinchilla lanigera) were used to investigate the origin, course, and termination of the coronary arteries. Coloured latex was injected into the carotid arteries following conventional anatomical applications. In all the chinchillas examined, the left coronary artery was the single coronary artery. The right coronary artery was missing. Additionally, a small vessel originating from the cranial border of the aorta was observed in one chinchilla. The left coronary artery divided into the paraconal, interventricular and left circumflex rami. The left marginis ventricular ramus arose from the paraconal interventricular ramus in eight chinchillas, and from the left circumflex ramus in two. The ventricular and septal branches of the left coronary artery ran subepicardially at the beginning mostly parallel to the muscle fibres, also surrounded by a thin adipose tissue. It was concluded that the only left coroner artery supplied blood to the heart in the chinchilla.     

A Macro‐Anatomical Investigation of the Some Skull Bones of Nehring's Blind Mole Rats (Spalacidae: Nannospalax nehringi)

This study was aimed to demonstrate the specific anatomical features of the skull bones of Nehring's blind mole rats. Eight skulls, belonging to animals of both sexes, were used. The occipital squama contributed to the formation of the caudal portion of the skull roof. The foramen magnum was quite large. The external occipital crest was present only in the males. The parietal bones formed the middle portion of the skull roof together with the well‐developed inter‐parietal bones. The zygomatic process of the temporal bone formed the zygomatic arch by extending to the temporal process of the zygomatic bone. The zygomatic process of the frontal bone and the frontal process of the zygomatic bone laterally bordered the orbit. There was a single septal process of the nasal bone. Each ramus of the mandibula had four processes. The mandibular ramus had an angular process on its caudal rim, which extended dorsolaterally. The dorsal free end of the mandibular ramus possessed a coronoid process. In the back, there were two other processes, situated medially and laterally. The medially situated process was referred to as a condylar process, and the laterally situated process was referred to as an alveolar process. The alveolar process detected on the mandibular ramus has not been reported in any rodent species, other than those of the family Spalacidae. Blind mole rats can be a real eye‐opener for evolutionary science. The burrowing rodents are key to answering a controversial question about how new species arise.     

Bone abscess in the mandible of a quarter horse gelding

A 4-year-old Quarter horse gelding presented with a swelling in the soft tissues over the junction of the body and ramus of the left mandible. Radiography showed a well circumscribed lytic area within the mandible surrounded by sclerosis unassociated with any tooth. Aspiration of the lesion yielded pus. The abscess cavity was opened, curetted and lavaged. A Penrose drain was placed in the abscess cavity for 10 days. Bacteriological culture of the exudate and soft tissues from the abscess produced a few colonies of Staphylococcus intermedius. Histopathology showed chronic pyogenic infection. The horse recovered well and was normal 1 year after treatment.     

A retrospective clinical study of the fractures and luxations of the mandible in the cat

Twenty-six cases of mandibular fractures and luxations are reviewed. Mandibular trauma was due to car accidents (46%) and falls from great heights (23%). Cardiovascular shocks (40%), thoracic injuries (23%), epistaxis (30%), cleft palates (19%), subconjunctival hemorrhages (15%), broken canines (15%), concussions (15%), maxillary fractures (12%) were the most frequently encountered associated problems. Of the 26 cats, 22 had symphyseal fractures, 6 mandibular body fractures, 4 ramus fractures (3 of which were articular) and 6 had temporo-mandibular luxations. Open reduction and internal fixation was performed in 21 cases, surgery being indicated for unstable symphyseal and body fractures, the rostral body fractures being the most challenging to repair. Conservative therapy and ancillary treatment methods such as external coaptation and pharyngostomy were used for the fractures of the ramus. Six temporo-mandibular luxations associated with mandibular fractures in 5 cases were reduced under anesthesia. Good dental occlusion and mandibular function was obtained in the 24 treated cases.     

Exophthalmos due to a wooden foreign body in a dog

An 8-year-old Golden Retriever dog was presented with a 10-month history of right-sided exophthalmos. Radiographs and CT demonstrated a linear density, suggestive of a foreign body, in the region of the ramus of the right mandible. A 7 cm stick, located medial to the right zygomatic arch, was removed during exploratory surgery. The dog recovered with the aid of antibiotics, however was left with a residual facial nerve paralysis.     

Facial swelling and discharging lesions associated with abnormalities of the mandible in kunekune pigs

Abstract

CASE HISTORIES: Four adult kunekune pigs developed facial swelling at the base of the right ear that ruptured and discharged food material. A further six pigs that had similar clinical signs were reported by members of the New Zealand Kunekune Association who responded to an email survey, one of which was confirmed by post-mortem examination.

CLINICAL FINDINGS: Inside the mouth of each pig there was an opening at the junction of the body and ramus of the mandible just lateral to the most caudal visible molar that was impacted with masticated feed. The food packed into the mandible resulted in infection and progressive erosion of the medullary cavity of the bone until it reached the ramus where it eroded through the lateral cortex. The feed material then tracked through the soft tissues to form a subcutaneous abscess, which eventually ruptured resulting in a draining lesion. In Case 2, which had had the lesion for 2 years, the cavity in the mandible was lined with mucosa that had healed to the skin to produce a fistula. In all four pigs there was also a lesion in the left side of the mandible that was not as developed as that on the right side.

DIAGNOSIS: The facial swellings were produced by feed material that had impacted into the mandible through an opening immediately caudal to the cheek teeth and then emerged through one or more lesions in the lateral aspect of the ramus of the mandible.

CLINICAL RELEVANCE: Although it has not been previously reported, anecdotal reports and our survey suggest that this condition may occur relatively frequently in kunekune pigs. It should be considered as a differential diagnosis for facial swellings and discharging lesions in these animals.     

Arterial vascularization of the uropygial glands (Gl. uropygialis) in the rock partridge (Alectoris graeca) living in Turkey

This study aims to observe the morphological characteristics of the uropygial gland (Glandula uropygialis), specifically the arterial vascularization, in rock partridges (Alectoris graeca) living in Turkey. Coloured-latex-injected animals were dissected and the gland and related arteries were observed. Mostly, the fourth paired caudal segmental arteries (Aa. segmentales caudales) arising from the median caudal artery (A. mediana caudae) were specified as the uropygial gland arteries. These arteries, in turn, gave the following rami: the muscular ramus (Ramus muscularis) to the levator coccygeus and lateral caudal muscles, the lateral ramus (Ramus lateralis) to the lateral coccygeus muscle and a small ventro-lateral division of the caudal component of the gland, and the medial rami (Ramus medialis) to the dorsal surface of the gland.