Communication of the ulnaris lateralis bursa with the equine elbow joint and evaluation of caudal arthrocentesis.

Elbows from cadaver limbs were evaluated to determine the presence of a communication between the ulnaris lateralis bursa (ULB) and the joint and the extent of the bursa. Thirty-two pairs of joints were studied: 12 pairs were frozen, then transversely sectioned and 20 pairs were injected with methyl methacrylate. The 12 frozen-section pairs revealed a communication between the ULB and the elbow joint in 9/24 joints (37.5%) and a true bursa (absence of communication) in 15/24 joints (62.5%). The mean bursal length in adult horses was 3.8 cm. There was no significant difference in the length of the bursa or presence of bursa-joint communication between the right and left limbs. In the acrylic specimens a communication between the ULB and the joint was found in 19/40 specimens (47.5%). There was no significant correlation between age or sex and frequency of communication. There was a significantly greater prevalence of communications present in Quarter Horse than in non-Quarter Horse (P < 0.05) joints. A communication between the ULB and the joint is not always present, and therefore injection of the elbow joint via the ULB may be unreliable.

Identification of anatomic features of the equine clitoris as potential growth sites for Taylorella equigenitalis.

A median clitoral sinus, as a space canalized from epithelial cells, was distinguishable developmentally in equine fetuses from 33-mm crown-rump length (CRL) to 500-mm CRL (including a mule of 21-mm CRL). In saggital sections of the clitoris of a 480-mm CRL fetus, indentations under the transverse frenular fold were identified as lateral sinuses of the clitoris. Unlike the median sinus, they were shallow; it therefore could not be anatomically substantiated that the lateral sinuses were of sufficient depth to support the growth of the partial anaerobe Taylorella equigenitalis, the organism of contagious equine metritis. This study indicated excision of the lateral clitoral sinuses was unnecessary for treatment of contagious equine metritis.

Light and electron microscopy of keratinization in the laminar epidermis of the equine hoof with reference to laminitis.

The laminar epidermis (epidermis parietis) of hooves from 14 clinically normal horses, 6 months to 15 years old, was examined by light and electron microscopy and immunofluorescence to measure the contributions of this region to the formation of the hoof wall. By their progressive keratinization to form primary epidermal laminae, the secondary epidermal laminae ultimately contributed about 20% of the thickness of the hoof wall (as revealed in the white line [zona alba]). The keratinized, primary epidermal laminae were developed to a height of 4 mm during their proximodistal-course, much of this obscured because of their basal portion being embedded in the cap horn epidermis. From evaluation of structural changes accompanying keratinogenesis in the cell and determination of the contribution of the laminar epidermis to the formation of laminar horn, cap horn, connecting horn, terminal horn, and the white line, we concluded that the sterile bed concept of a nongerminative role for the secondary epidermal laminae is no longer tenable.

Puncture of shoulder, elbow, and carpal joints in goats and sheep.

The forelimbs joints and bones of 16 normal goats and sheep were studied to determine optimal injection techniques for the shoulder, elbow, and carpal joints. Based on the findings, trial injections of marker substances were made in 8 anesthetized animals. The joints were then dissected and rates of success were determined, and they were 88% of shoulder, 87% of elbow, 94% of radiocarpal, and 81% of midcarpal and carpometacarpal joints.

Removal of the cecum, including the ileocecocolic junction, and its effects on digestibility in cattle.

The cecum and ileocecocolic junction in each of five 7-month-old Holstein steers were removed. Two steers of the same breed and age were sham-operated. All steers survived and were subjected to a digestibility experiment for 16 weeks. Digestibility of dry matter, neutral-detergent fiber, acid-detergent fiber, and cellulose decreased (P less than 0.05) during postsurgical weeks (PSW) 1 to 4, but not during PSW 16. However, digestibility of protein and hemicellulose was not significantly (P less than 0.07) influenced by the operation. Digestibility of the previously described components was not significantly different from that in 2 sham-operated steers. The mean daily weight gain of the cecectomized steers decreased during PSW 1 to 4; however, it started to increase at PSW 8 so that at PSW 16 it approached preoperative values. The mean daily weight gain of the sham-operated steers also decreased during PSW 1 to 4, but was higher than the preoperative values at PSW 14. The difference in mean daily weight gains between the cecectomized and sham-operated steers was insignificant. The consistency of the feces of the cecectomized steers was loose to watery for a period of about 4 weeks after surgery. At PSW 16, the feces were firm, but not of normal consistency. Feces of the sham-operated steers were loose after surgery, but returned to normal consistency after approximately 7 days. Adhesions developed at the surgical site and involved the ileum, the proximal loop of the ascending colon, and the adjacent mesentery and greater omentum.(ABSTRACT TRUNCATED AT 250 WORDS)

Occurrence of an accessory pancreatic duct in the sheep.

An accessory pancreatic duct was studied in 10 Dorset male sheep (5 to 12 months old) and in 7 sheep fetuses (crown-rump length, 63 to 200 mm). The duct was present in 9 of the 10 adult sheep examined. It could not be seen grossly, but in serial sections, an accessory duct with some pancreatic tissue was seen to pass distally from the main pancreatic mass ahead of the bile duct, enter the wall of the duodenum at the beginning of its descending portion, pass distally in the submucosa for about 10 mm, and then approach the mucosa. The wall of the duct acquired tubular mucous glands and was supported by muscle bundles during its intramural course. The sections from the sheep fetuses confirmed the presence of a patent accessory duct until it united with the duodenal mucosa. In the adult, the accessory duct and the accompanying pancreatic tissue and glands appeared functional. It could not be determined how much of the pancreas may be drained by the accessory duct.

Distal intertarsal and tarsometatarsal joints in the horse: communication and injection sites.

One hundred three equine hocks, obtained from the postmortem room, were used to study the communication and injection of material into the distal intertarsal and tarsometatarsal joints. Excluding the hocks with fused central and 3rd tarsal bones, in 8.3% of hocks injected with low (clinical) pressure and in 23.8% injected with high pressure, the distal intertarsal and tarsometatarsal joints communicated by dissection of the material through 2 internal spaces: the tarsal canal and the space between the combined tarsal bones 1 and 2 tarsal bone 3. A "pop" sometimes felt when high pressure was used did not necessarily indicate that a communication between the 2 joints had been established. The distal intertarsal joint was best punctured medially through the proximal part of the gap between the combined tarsal bones 1 and 2, tarsal bone 3, and the central tarsal bone. The tarsometatarsal joint was most reliably punctured plantarolaterally between the head of the 4th metatarsal and 4th tarsal bones.

Equine verminous arteritis. An arteriographic evaluation of the larvicidal activity of albendazole.

Albendazole was an effective larvicidal anthelmintic against the fourth stage Strongylus vulgaris larvae as late as one month post-infection. The drug was administered at a dose rate of 25 mg/kg three times daily for 5 days. Diarrhoea occurred in 3 of 4 foals treated and of these one died during belated intravenous therapy for dehydration. Arteriography allowed for an in vivo assessment of the development and regression of lesions in infected-treated foals compared to the continued development of lesions in infected-untreated foals. The arteriographic findings were confirmed at necropsy.

Ductuli efferentes in the epididymis of boar, goat, ram, bull, and stallion.

Dutculi efferentes were studied by microdissection and histologic methods in 2 boar, 6 goat, 5 ram, 25 bull, and 19 stallion epididymides. On the basis of the present findings and the data of others and relating them to the total number of specimens examined in each species, an estimate (narrow range) was made of the minimal-maximal numbers of efferent ductules as follows: dog 13 to 15; cat 14 to 17; boar 14 to 16; goat 18 to 19; ram 17 to 20; bull 13 to 16; and stallion 14 to 17. The histologic appearance of the efferent ductules of the bull, including measurements of their diameter, lumen, and epithelium, was briefly described. Attention was focused on the presence of blind-ending ductules, because it was thought that they might be a factor in the cause of spermiostasis. Blind-ending ductules were found in 1 of 2 porcine, 1 of 6 caprine, 2 of 5 ovine, 8 of 25 bovine, and 13 of 19 equine ductules per affected male were 4 in the boar, 1 in the goat, 2 to 3 in the ram, 1 to 5 in the bull, and 1 to 14 in the stallion. From our work, it appears that in the bull and stallion at least, blind-ending ductules were present in sufficient numbers to be considered a factor in spermiostasis and the infertility resulting from it.

Clinically important structures of the equine hock.

A study method has been devised to review clinically important structures of the equine hock joint on a fresh specimen. The review can be done alone; dissection takes about 2 hours; special tools or materials are not required.

Nerve distribution in the metacarpus and front digit of the horse.

The nerve distribution to the digit of the horse was studied with the compound microscope in serial transverse sections of fetal limbs and plotted on life-size outlines of the horse's foot. It was learned that there is much variation in the topography of the branches of the principal nerves. There is no mirror-image nerve distribution on the 2 sides of the foot. The dorsal branch of the ulnar nerve does not extend below the fetlock. The communication between the palmar metacarpal nerves and branches of the dorsal branch of the digital nerves is only a crossing of nerves without exchange of fibers. The palmar metacarpal nerves usually do not innervate structures distal to the pastern joint. The innervation of the deep structures of the equine foot was tabulated.