Laparoscopic ovariectomy in guinea pigs: A pilot study.

OBJECTIVE: To assess the feasibility and safety of laparoscopic ovariectomy in guinea pigs utilizing 3-mm minilaparoscopic instruments. STUDY DESIGN: Experimental pilot study. ANIMALS: Guinea pigs (n = 3). METHODS: The guinea pigs were sedated, placed under general anesthesia, and intubated under endoscopic visualization. A 3-port technique was used with a 3.9-mm cannula for the endoscope and two 3.5-mm cannulas accommodating 3-mm endoscopic instruments including a 3-mm vessel sealing device, grasping forceps, and endoscopic scissors. The abdomen was insufflated with CO2 to a pressure of 6-8 mm Hg. The guinea pigs were manually tilted 90° laterally to visualize the dorsally positioned ovaries. RESULTS: The procedure was successfully performed in all 3 animals. The surgery times were 120, 45, 45 minutes for the 3 guinea pigs, and anesthesia times were 186, 90, and 76 minutes, respectively. Placing the animals in complete lateral recumbency was found to be critical to visualize and manipulate the ovaries. The guinea pigs recovered smoothly from anesthesia. CONCLUSION: Laparoscopic ovariectomy with 3-mm minilaparoscopic instrumentation using a 3-port technique was feasible in guinea pigs. CLINICAL SIGNIFICANCE: Laparoscopic ovariectomy can be considered as an alternative to open ovariectomy as an elective surgical technique to prevent reproductive disorders in guinea pigs.

Unilateral flank ovariohysterectomy in guinea pigs (Cavia porcellus).

AIMS: To describe a simple, minimally invasive method of ovariohysterectomy via a unilateral flank approach in guinea pigs, for use in routine desexing of healthy female guinea pigs or treatment of ovarian cysts. METHODS: The subjects of this retrospective study were 41 client-owned guinea pigs submitted for routine desexing or treatment of ovarian cysts. They included 16 healthy female guinea pigs aged 8-12 months (Group 1), and 15 females aged from 9 months to 3 years (Group 2), and 10 females aged from 3 to 7 years (Group 3) with different-sized ovarian cysts. Prior to surgery, the animals received clinical examination, blood testing (complete blood count and serum biochemistry profile) and examination of the abdomen using ultrasonography, to assess the condition of the reproductive tract and ensure the guinea pigs were fit for surgery. Ovariohysterectomy was performed via a unilateral flank incision made close to the erector spinae muscle starting approximately 1 cm caudal to the last rib. Both ovaries, uterine horns, and the uterine cervix were localised, ligated, and dissected through this unilateral retroperitoneal incision. RESULTS: Ovariohysterectomy was successfully completed via a single flank incision in 38/41 (93%) guinea pigs. Three guinea pigs with ovarian cysts from Group 3, which were >6 years old died during surgery due to circulatory and respiratory failure under anaesthesia. In the remaining 38 cases, surgery proceeded without complications. A further two guinea pigs from Group 3 were reluctant to move or eat for the first 3 days after surgery but recovered after provision of supportive care. All 38 animals fully recovered and wound healing was normal. CONCLUSIONS: This is the first report of ovariohysterectomy via a unilateral flank incision in guinea pigs. This approach is a simple, minimally invasive and safe alternative to the midline or bilateral flank approaches currently used for surgery of the reproductive tract in guinea pigs.

Transurethral Cystoscopy and Endoscopic Urolith Removal in Female Guinea Pigs (Cavia porcellus).

Urinary diseases are commonly found in guinea pigs. Diagnostic workup includes clinical examination, blood testing, imaging studies, urine culture, and urinalysis. This article describes the use of transurethral cystoscopy in female guinea pigs as an ancillary tool to diagnose abnormalities within the bladder and urethra. In addition, the transurethral cystoscopic removal of uroliths measuring up to 5 mm and situated within the urinary bladder is described.

Femoral fracture repair and sciatic and femoral nerve blocks in a guinea pig.

A four-month-old, entire male guinea pig was presented for surgical repair of a closed oblique femoral fracture. Analgesia was provided with 30 µg/kg buprenorphine intramuscularly (im) four times a day and 0 · 3 mg/kg meloxicam subcutaneously once a day. The following day, anaesthesia was induced and maintained with 100 µg/kg medetomidine im, 20 mg/kg ketamine im, 30 µg/kg buprenorphine im and isoflurane in oxygen. Femoral and sciatic nerve blocks were performed with bupivacaine. The fracture was reduced and aligned using an intramedullary 1 · 4 mm K-wire and a 3 metric polydioxanone cerclage. Three weeks postoperatively remodelling and callus formation was documented, with no evidence of complications. Complete union was present 14 weeks postoperatively.

Efecto de amoxapina en preparaciones de órgano aislado de cobaya y de rata "in vitro" / Effect of amoxapine on severa preparations of isolated guinea-pig and rat organ "in vitro"

OBJETIVO. Estudiar las modificaciones inducidas por amoxapina en las respuestas del íleon aislado de cobaya a acetilcolina e histamina, conducto deferente de rata a noradrenalina y dopamina y útero aislado de rata a histamina. MATERIAL Y MÉTODOS. Se utilizó ileon aislado de cobaya incubado en solución de Tyrode, conducto deferente de rata incubado en solución de Krebs-Henseleit y útero aislado de rata incubado en solución de Jalón. Se realizaron curvas dosis-efecto a acetilcolina, histamina, noradrenalina y dopamina en ausencia y en presencia de amoxapina y se calcularon los valores de pA2 y pD'2. RESULTADOS. La amoxapina se comporta como antagonista de los neurotransmisores estudiados. CONCLUSIONES. La amoxapina se comporta como estabilizador inespecífico de membrana (AU)

OBJETIVE. Study the modifications produced by amoxapine in the responses of isolated guinea-pig to acetylcholine and histamine, rat vas deferens to noradrenaline and dopamine and rat uterus to histamine. MATERIAL AND METHODS. Guinea-pig incubated in Tyrode solution were used. Dose-effect curves to acetylcholine and histamine were made in absence and in the presence of amoxapine. Rat vas deferens incubated in Krebs-Henseleit solution were used. Dose-effect to noradrenaline and dopamine were made in the absence and in the presence of amoxapine. Uterus of rat incubated in Jalon solution were used. Dose-effect curves to histamine were made in the absence and in the presence of amoxapine. pA2 and pD'2 were calculated. RESULTS. Amoxapine behave as antagonist of acetylcholine, histamine and dopamine. CONCLUSIONS. Amoxapine acts as unspecific membrane stabilizer (AU)

Use of a hybrid external skeletal fixator for repair of a periarticular tibial fracture in a Patagonian cavy.

An 8-week-old female Patagonian cavy was examined because of acute right hind limb lameness; radiography revealed a moderately displaced, comminuted fracture of the proximal third of the tibia. The fracture was stabilized with a hybrid external skeletal fixator. Two Kirschner wires were placed in the main proximal fragment, parallel to the tibial plateau and at right angles to each other. These wires were connected to a partial circular external fixator ring. Three half pins were placed in the distal fragment, and a straight connecting rod positioned on the medial side of the limb was connected to these pins and the fixator ring. A second connecting rod was positioned on the craniomedial side of the limb and was connected to the fixator ring and a fourth half pin in the distal fragment. The fracture healed without complications, and the fixator was removed 3 weeks after surgery. Hybrid external skeletal fixators combine the benefits of circular and linear external skeletal fixation methods, enabling rigid fixation of periarticular long bone fractures without adversely affecting mobility of the adjacent joint.

Effects of sympathetic denervation on follicular distribution, oestradiol and progesterone serum levels in prepubertal hemi-ovariectomized female guinea pig.

Hemi-gonadectomy performed in prepubertal female guinea pigs is followed by a compensatory ovarian hypertrophy (COH) and compensatory ovulation (CO). Sympathetic denervation diminished the COH (left ovary: 28 +/- 1.6% versus 46 +/- 4% (control), P < 0.05; and right ovary: 21.3 +/- 3.2% versus 34.2 +/- 3.7% (control), P < 0.01) and does not modify the CO. The mean follicular diameter increased only in the right ovary of hemi-gonadectomized animals. This increase is greater in the hemi-gonadectomized-denervated groups. The mean follicular diameter measured in the right and left ovaries showed an opposite response in hemi-ovariectomized and hemi-ovariectomized-denervated animals: the diameter increased in the right ovary without modifications in the left. Present results add further support to the participation of ovarian innervation on the mechanisms, which regulate follicular development.

Anesthesia protocol for hyperpnea-induced airway obstruction in the guinea pig.

Guinea pigs (GP; Cavia porcellus) are used extensively as an experimental animal model in a wide range of disciplines including respiratory physiology. Guinea pigs are difficult to anesthetize, and many investigators use paralytic agents to eliminate spontaneous respiratory movements; however, strict federal regulations and institutional policies governing use of paralytic agents are few. We report an anesthesia protocol, using the injectable anesthetic agents sodium pentobarbital (SP) and xylazine (XYL) for the GP that induces consistent anesthesia while eliminating use of paralytic agents. Sixty percent of the calculated SP dose (45 mg/kg of body weight) was given for anesthesia induction, followed by 50% of the calculated XYL dose (7 mg/kg) 15 min later. Depth of anesthesia was monitored by response to toe pinch, ECG, and spontaneous respiratory movements. The animals were given additional boosts of SP (5 to 15% of the original dose, i.p. or i.v.) if a change in anesthesia depth was noted. Thirty-one animals completed the hyperpnea-induced bronchoconstriction (HIB) study with no fatalities. Using this protocol, we collected consistent, repeatable, and reliable data without use of propranolol or skeletal muscle paralytics. We believe that this protocol is not restricted to the GP and could be adapted for use in other terminal experiments.

A ventral approach to stereotaxy of the guinea pig brain.

The guinea pig (Cavia porcellus) is a species frequently used in neuromorphological and neurophysiological studies. Some experimental data suggest that the guinea pig might also be used to develop an animal model of Alzheimer's disease. These studies would require microsurgical manipulations of the nervous system. The present paper describes a method for ventral stereotaxic intrusions in the guinea pig brain through the oval foramen at the skull base. The topographic relationships of the bony landmarks to major parts of the central nervous system and the cranial nerves are analysed, and the results are tested by intrahippocampal injection of horseradish peroxidase.

Nonreproductive surgery in small mammals.

The sophistication of soft-tissue surgery techniques in small mammals is increasing rapidly. Exotic animal practitioners must be familiar with the diseases, conditions, and anatomic variations of each small-mammal species. The small size of these patients should not preclude the use of technologic advances available for other small animals. Despite these challenges, successful resolution of surgical problems in small exotic mammals is not only possible but also should be the expected result of veterinarians' efforts in such cases.

Aplicación de lidocaína en el tejido subcutáneo, para la prevención de infección del área quirúrgica, en un modelo experimental / Application of lidocaine on subcutaneous tissue to prevent infection of the surgical area in an experimental model

Objetivo. Evaluar la eficacia de la lidocaína, aplicada en forma tópica, durante el cierre de la herida, para reducir la frecuencia de infección en la misma. Sede. Hospital general de tercer nivel de atención médica. Diseño. estudio experimental, prospectivo, aleatorio, longitudinal y doble ciego. Material y métodos. Se estudiaron 33 cobayos hembra de la cepa Harley, de 4 meses de edad, con peso de 400 a 500 g. Se asignaron en forma aletoria en tres grupos. Grupo A= control negativo; Grupo B = grupo control y Grupo C = grupo de estudio. En todos los cobayos se hicieron 2 incisiones, de 30 mm de longitud, en la línea media dorsal que incluyó piel y aponeurosis superficial. A los cobayos del grupo A se les irrigó la herida con 10 ml de agua destilada y se suturó; a los del grupo B se les aplicó su propia materia fecal por 5 minutos y se suturó la herida previo lavado de la misma con agua destilada, a los animales del grupo C se les hizo lo mismo que a los del grupo B pero se les instiló lidocaína, 10 mg, sobre la herida y finalmente se les suturó igual que a los dos grupos restantes. Se efectuó estudio clínico, bacteriológico e histopatológico a las 24 hs y al séptimo día. El análisis estadístico de los reusltados se hizo con las pruebas de Ji cuadrada y de Kruskall-Wallis. Se compararon los grupos A con B, A con C y B con C. Resultados. Se realizaron 63 procedimientos quirúrgicos en 33 cobayos, no hubo diferencia estadísticamente significativa en el peso de los cobayos en los 3 grupos. Para determinar la presencia de infección se utilizaron tres criterios: el clínico, el bacteriológico y el histopatológico. La evaluación clínica favoreció significativamente al grupo C con respecto al B, ninguna herida del grupo a se infectó. La evaluación bacteriológica sólo demostró diferencias significativas entre el grupo A y los otros dos, pero no entre el B y C. En cambio, en el análisis cuantitativo con la determianción de las unidades formadoras de colonias por gramo de tejido, se encontró una diferencia significativa entre los grupos B y C (p=0.012). La evaluación histopatológica reveló una menor reacción inflamatoria en el grupo C, que en el B. Conclusiones. La lidocaína mostró ser un agente antimicrobiano tópico efectivo para disminuir la frecuencia de infecciones en heridas quirúrgicas contaminadas en el cobayo