Intravenous Regional Limb Perfusion in Standing and Recumbent Horses: A Comparative Radiographic Study

Although pharmacokinetic studies of drugs administered by intravenous regional limb perfusion (IRLP) to treat equine orthopedic infections suggest efficient drug distribution in the limbs, it remains unclear whether drug perfusion is affected by the position of the horse during the procedure. This study compared the perfusion of a radiopaque contrast into tissues of the extremities of horses maintained in standing and recumbent positions during an IRLP. Radiopaque contrast was administered through IRLP into the cephalic vein of 10 healthy adult horses under general anesthesia and right lateral recumbency (RG) or under sedation and standing (SG). The same animals were used in both groups, respecting a two-week washout period. Sequential radiographic images were performed immediately at the beginning of contrast administration (T0) and after 10, 20, 30, 40, and 50 minutes. Tourniquets were removed after 30 minutes. The time required for the contrast to reach the hooves was compared between groups. Contrast reached the hooves faster in SG (114 ± 15 seconds) compared with RG (236 ± 29 seconds) (P < 0.5). SG showed more uniform perfusion of the limb vessels, whereas RG showed more deposition of the contrast in the lateral digital vein, with smaller amounts reaching the hooves. From T10 onward, soft tissue radiopacity increased, albeit more markedly in standing than in recumbent animals, remaining until T50. Contrast radiography evidenced that IRLP performed in standing position leads to a quicker and more uniform perfusion of the vasculature and a more noticeable diffusion to the tissues than in recumbent horses.

Correlation Between Peritonitis and Incisional Infections in Horses

Surgical site infection of abdominal incisions is an important complication after laparotomy with increased risk of incisional hernia formation in horses. This study aims to evaluate the healing process of abdominal incisions and correlate peritonitis with the occurrence of surgical site infection and incisional hernias. Nine horses underwent standardized laparotomy, intestinal exploration, and induced septic peritonitis. Standardized relaparotomy was performed two (n = 3), four (n = 3), and six (n = 3) months later to evaluate the abdominal cavity for adhesions and to collect the sutured ventral abdominal wall to evaluate and prepare it for histopathological and tensile strength study. All horses presented with endotoxemia, controllable peritonitis, heat and touch-sensitive ventral abdominal edema and surgical wound infection with presence of purulent discharge. Adhesion of the cecum or colon to the internal portion of the surgical wound was observed. Healing of the infected surgical wounds occurred by second intention and a space between the rectus abdominis muscles developed because of the presence of a scar, which was related to incisional hernia. In the histopathological evaluation, the collagen content increased, and the inflammation decreased over time. The tensile strength increased over time and was highest after 6 months. After the second surgical intervention, there was no infection of the surgical wound in any of the animals and healing by first intention occurred. Surgical site infection may be a symptom of peritonitis in horses recovering from abdominal surgery. Infected surgical wounds heal by second intention, which favors the spacing of rectus abdominis muscle and the formation of incisional hernia.

Evaluation of potential changes in liver and lung tissue of rats in an ischemia-reperfusion injury model (modified pringle maneuver)

In surgical procedures involving the liver, such as transplantation, resection, and trauma, a temporary occlusion of hepatic vessels may be required. This study was designed to analyze the lesions promoted by ischemia and reperfusion injury of the hepatic pedicle, in the liver and lung, using histopathological and immunohistochemical techniques. In total, 39 Wistar rats were divided into four groups: control group (C n = 3) and ischemia groups subjected to 10, 20, and 30 minutes of hepatic pedicle clamping (I10, n = 12; I20, n = 12; I30, n = 12). Each ischemia group was subdivided into four subgroups of reperfusion (R15, n = 3; R30, n = 3; R60, n = 3; R120, n = 3), after 15, 30, 60, and 120 minutes of reperfusion, respectively. Significant differences were observed in the liver parenchyma (P < 0.05) between the values of microvesicles and hydropic degeneration at different times of ischemia and reperfusion. However, the values of vascular congestion, necrosis, and pyknotic nuclei showed no significant differences (P > 0.05). In the lung parenchyma, a significant difference was observed (P < 0.05) between the values of alveolar septal wall thickening and inflammatory infiltration at different times of ischemia and reperfusion. However, there was no significant difference (P < 0.05) between the values of vascular congestion, bronchial epithelial degeneration, interstitial edema, and hemorrhage. The positive immunoreactivity of caspase-3 protein in the liver parenchyma (indication of ongoing apoptosis), showed no significant differences (P > 0.05) at different times of ischemia and reperfusion. In the pulmonary parenchyma, the immunoreactivity was not specific, and was not quantified. This study demonstrated that the longer the duration of ischemia and reperfusion, the greater are the morphological lesions found in the hepatic and pulmonary parenchyma.

Evaluation of intravenous regional perfusion with amphotericin B and dimethylsulfoxide to treat horses for pythiosis of a limb

BACKGROUND

Treatment for horses with pythiosis of a limb is challenging. This study aims to evaluate the effects of administering amphotericin B in a 10 % solution of dimethylsulfoxide by intravenous regional limb perfusion (IRLP) to treat horses for cutaneous pythiosis of a limb.

RESULTS

All 15 of the horses treated had complete resolutions of their lesion between 6 to 9 weeks after a single IRLP treatment. No complications were observed at the site of venipuncture for IRLP. Before initiation of treatment, there was anemia and marked leucocytosis which resolved following treatment. Serum biochemistry showed no significant changes.

CONCLUSIONS

IRLP administration of amphotericin B in a 10 % DMSO solution was easily performed, relatively inexpensive and an effective treatment for treating horses for pythiosis of a limb and resolved the infection with no complications.

Physiological and analgesic effects of continuous-rate infusion of morphine, butorphanol, tramadol or methadone in horses with lipopolysaccharide (LPS)-induced carpal synovitis

BACKGROUND

Continuous-rate infusion (CRI) of drugs results in more stable plasma drug concentrations than administration of intermittent boluses, thus providing greater stability of physiological parameters. The aim of this study was to evaluate the physiologic and analgesic effects of the administration of morphine, butorphanol, tramadol or methadone by CRI in horses with induced synovitis of the radiocarpal joint.

RESULTS

Increased values of cardiorespiratory parameters and body temperature were observed in all groups after initiation of opioid administration, and these increases were sustained throughout the CRI period. Morphine, butorphanol and methadone each caused a reduction in gut sounds, and this effect was greatest in animals that received morphine. Administration of morphine or methadone reduced the degree of lameness after the end of intravenous infusion. Administration of tramadol did not alter the degree of lameness in the animals.

CONCLUSIONS

CRI of morphine or methadone, but not butorphanol or tramadol, provided analgesia in horses with carpal synovitis. All of these opioids increased cardiovascular and respiratory parameters and reduced gut sounds during CRI.

Alpha-mannosidosis in goats caused by the swainsonine-containing plant Ipomoea verbascoidea

A disease of the nervous system is reported in goats in the semiarid region of northeastern Brazil. Histological examination showed diffuse vacuolation of neurons and epithelial cells of the pancreas, thyroid, renal tubules, and liver. The swainsonine-containing plant Ipomoea verbascoidea was found on both farms where the goats originated. This plant was experimentally administered to 3 goats, inducing clinical signs and histologic lesions similar to those observed in spontaneous cases. On the lectin histochemical analysis, cerebellar cells and pancreatic acinar cells gave positive reactions to Triticum vulgaris agglutinin (WGA), succinylated Triticum vulgaris agglutinin (sWGA), Lens culinaris agglutinin (LCA), Canavalia ensiformis agglutinin (ConA), Pisum sativum agglutinin (PSA), Ricinus communis agglutinin (RCA120), Arachis hypogaea agglutinin (PNA), and Phaseolus vulgaris erythroagglutinin (PHA-E) suggesting storage of α-fucose, α-D-mannose, α-D-glucose, β-D-N-acetyl-glucosamine, N-acetyl-galactosamine, and acetyl-neuraminic acid. This pattern of lectin staining partially agrees with results previously reported for poisoning by swainsonine-containing plants. The chemical analysis of dried leaves of I. verbascoidea detected swainsonine (0.017%), calystegine B1 (0.16%), calystegine B2 (0.05%), and calystegine C1 (0.34%). It is concluded that I. verbascoidea causes α-mannosidosis in goats.