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.     

Serum thyroxine concentrations in clinically healthy pet guinea pigs (Cavia porcellus)

Background: Guinea pigs (Cavia porcellus) are often presented as patients in veterinary practice. Nevertheless, only limited information is available about endocrine diseases or thyroxine reference values for the species. Objective: The aim of this study was to determine serum thyroxine concentrations in a well‐defined population of clinically healthy pet guinea pigs. Methods: Between October 2007 and July 2008, serum samples were collected from 40 clinically healthy guinea pigs of different sexes, ages, and breeds that were presented to our clinic for a general health check or for castration. Pregnant females were excluded from the study. Thyroxine concentration was measured using a chemiluminescence test (Immulite 2000 Canine Total T4). Results: Thyroxine concentrations ranged from 14.2 to 66.9 nmol/L (1.1–5.2 μg/dL) with a median value of 27.0 nmol/L (2.1 μg/dL). Females (n=16) had significantly (P=.039; Mann–Whitney U‐test) lower thyroxine values than castrated males (n=8), whereas no differences were found between females and intact males (n=16) or between intact and castrated males. No significant correlation was found between thyroxine concentration and age. Conclusion: This is the first report of serum thyroxine reference values for a well‐defined population of healthy pet guinea pigs as measured by a chemiluminescence assay. The results were higher than those previously reported for this species and emphasize the importance of using appropriate reference intervals for the diagnosis of hyperthyroidism.     

Estimation of the selenium requirement of growing guinea pigs (Cavia porcellus)

The aim of the study was to determine the selenium (Se) requirement of guinea pigs as a species unable to synthesize ascorbic acid. Forty-nine male guinea pigs (average weight 208 ± 3.5 g) were divided into an initial status group and six experimental groups. The animals received a Se deficient Torula yeast based basal diet (<0.02 mg Se and 26 mg α-tocopherol/kg) or a Se addition of 0.05, 0.10, 0.15, 0.20 and 0.25 mg/kg diet as sodium selenate for 10 weeks. There was no significant difference in weight gain (final weight 643 ± 21 g) between the groups and no clinical symptoms of Se deficiency occurred. With the exception of the testes, there was an increasing Se concentration in liver, plasma and haemolysate dependent on supplementation level. Glutathione peroxidase was determined in the plasma and Se dependent glutathione peroxidase (GPx1) in haemolysate, liver, kidney, heart and lung. Thioredoxin reductase (TR) activity was measured in liver, kidney and heart and deiodinase activity in the liver. A phospholipid hydroperoxide reducing activity with Se influence was determined in liver, kidney, heart, testes and brain. With the exception of GPx1 activity in heart and haemolysate and TR activity in the kidney, all enzymes already reached their maximal activity at 0.05 mg Se/kg diet. The activities of GPx1 and TR were used as parameters for broken line analysis and a Se requirement of 0.080 mg Se/kg diet was derived as sufficient for growing guinea pigs adequately supplied with vitamin E.     

Cutaneous vascular malformation in a guinea pig (Cavia porcellus)

Abstract   A skin lesion classified as a vascular malformation is reported in a young-adult, female guinea pig. The physical examination revealed a 3 × 2-cm irregularly shaped violaceous plaque located on the left caudal flank. The surface of the plaque was ulcerated and bled intermittently, resulting in fatal blood loss. On histology the mass consisted of variably sized vascular spaces filled with red blood cells and variable amounts of extramedullary haematopoietic cells, lined by well-differentiated endothelial cells often surrounded by one layer of spindle-shaped cells. Based on immunohistochemistry, the spindle cell population was confirmed to be smooth muscle cells and no proliferation of endothelial cells was found with the Ki67 proliferation marker. Histological and immunohistochemical findings were consistent with a vascular malformation. Classification of vascular malformations and potential treatments are discussed. To the authors' knowledge, this is the first reported case of a cutaneous vascular lesion in a guinea pig.     

Hematology and plasma chemistry reference intervals for cultured shortnose sturgeon (Acipenser brevirostrum)

BACKGROUND: The shortnose sturgeon, Acipenser brevirostrum, is an imperiled species distributed along the Atlantic coast of North America. Interest in replenishing wild stocks with hatchery-reared fish has created a need for accurate hematologic and biochemical reference intervals to evaluate the health of both fish raised in aquaculture systems and fish in the wild. OBJECTIVES: The objective of this study was to generate hematologic and biochemistry reference intervals for healthy shortnose sturgeon. METHODS: Blood samples were collected in heparinized tubes from 77 shortnose sturgeon raised in flow-through aquaculture systems. Whole blood and plasma samples were analyzed for hematologic and biochemical variables using standard techniques. Reference intervals were calculated as the central 95% (percentile) of data. RESULTS: Hematologic reference intervals (n = 46) were as follows: PCV 26-46%, hemoglobin 5.7-8.7 g/dL, MCV 307-520 fL, MCH 65.9-107.1 pg, MCHC 15-30 g/dL, plasma proteins (refractometry) 2.8-6.0 g/dL, RBC count 0.65-1.09 x 10(6)/microL, total WBC count 28,376-90,789/microL, small lymphocytes 9063-56,656/microL, large lymphocytes 2122-10,435/microL, neutrophils 3758-33,592/microL, monocytes 0-7137/microL, eosinophils 0-1544/microL, thrombocyte-like cells 6863-23,046/microL, thrombocytes 32,205-122,179/microL, and neutrophil:lymphocyte ratio 0.068-1.026. Plasma chemistry reference intervals (n = 77) were as follows: total protein 2.7-5.3 g/dL, albumin 0.8-1.7 g/dL, globulins 1.8-3.7 mg/dL, creatinine 0-1.4 mg/dL, total bilirubin 0-0.1 mg/dL, alkaline phosphatase 47-497 U/L, aspartate aminotransferase 90-311 U/L, sodium 124-141 mmol/L, potassium 2.9-3.7 mmol/L, chloride 106-121 mmol/L, calcium 6.6-12.1 mg/dL, magnesium 1.6-2.3 mg/dL, phosphorus 5.1-8.1 mg/dL, glucose 37-74 mg/dL, cholesterol 42-133 mg/dL, and osmolality 232-289 mOsm/kg. CONCLUSION: Reference values reported here will be useful for the early detection, identification, and monitoring of disease and sublethal conditions in cultured shortnose sturgeon.     

Effects of subcutaneous alfaxalone alone and in combination with dexmedetomidine and buprenorphine in guinea pigs (Cavia porcellus)

Objective

To characterize alfaxalone administered subcutaneously (SC) in guinea pigs, both alone and in combination with dexmedetomidine and buprenorphine.

Hematology and serum chemistry values of the European brown hare

Background: Hematology and serum biochemistry values can be useful for evaluating the health of populations of captive and free-living European brown hares ( Lepus europaeus ). However, current information is fragmented and incomplete.
Objective: The objective of this study was to determine normal hematology and serum chemistry values for a population of captive European brown hares and to investigate differences related to sex and age.
Methods: Routine hematology and serum chemistry values were determined for 48 captive European brown hares in Catalonia (northeastern Spain): 21 young (6 males and 15 females) and 27 adult (14 males and 13 females) hares. Blood was obtained by auricular venipuncture while animals were physically restrained. Results were expressed as the mean ± SD, and reference intervals were calculated as the mean ± 2SD.
Results: RBC count, PCV, concentrations of hemoglobin, total protein, albumin, gamma globulin, urea nitrogen, and creatinine, and alanine aminotransferase activity were significantly higher in adults than in young hares, and alkaline phosphatase activity and total bilirubin concentration were lower. Sex differences were not observed.
Conclusions: Hematology and serum chemistry results obtained in this study are considered representative for healthy captive European brown hares. A single reference interval can be used for values from male and female hares, however, age-specific intervals are needed for some analytes.     

Sedative effects of intramuscular alfaxalone in pet guinea pigs (Cavia porcellus)

Objective

To evaluate the efficacy and side effects of alfaxalone administered intramuscularly (IM) as a sedative agent in guinea pigs undergoing survey radiographs.

Palatability of nine fodders species used by guinea pigs (Cavia porcellus)

Tropical Animal Health and Production - Nine fodders commonly offered to the guinea pigs by the breeders in Lubumbashi (Democratic Republic of Congo) were compared for chemical composition and for...     

Hematology and clinical chemistry values in pregnant Wistar Hannover rats compared with nonmated controls

BACKGROUND: The Wistar Hannover rat has been considered as an alternative animal model to the Sprague-Dawley rat in the safety evaluation of candidate pharmaceuticals for potential reproductive and developmental toxicity. Hematology and clinical chemistry results may provide useful evidence of maternal toxicity in the absence of fetal effects. OBJECTIVE: The purpose of this study was to evaluate differences in routine laboratory values between nonmated and pregnant (near-term)Wistar Hannover rats during a control developmental study. METHODS: One hundred fifty pregnant female Wistar Hannover rats (Tac:Glx:WlfBR) were dosed orally once per day with distilled water from gestation days (GDs) 6 through 17. An additional 150 nonmated (nonpregnant) females used as age-matched controls were dosed from study days (SDs) 7 through 18. Blood samples were collected on GD 18 or 19 (SD 19 or 20) for routine hematology and plasma clinical chemistry tests. Reference intervals were established for pregnant and nonmated animals. RESULTS: On GD 18/19, pregnant rats had a lower RBC count, hemoglobin concentration, and HCT, and higher MCH, MCHC, reticulocyte percentage, and platelet, WBC, absolute reticulocyte, segmented neutrophil, lymphocyte, and monocyte counts compared with nonmated rats. Pregnant rats had lower albumin, glucose, urea, and chloride concentrations, lower creatine kinase and alkaline phosphatase activities, higher total bilirubin, cholesterol, triglyceride, calcium, phosphorus, and globulin concentrations, and higher ALT activity than nonmated rats. Serum triglyceride concentration was approximately fourfold higher in pregnant rats compared with nonmated controls. CONCLUSION: Differences in hematology and chemistry values in pregnant Wistar Hannover rats are similar to those in Sprague-Dawley rats and support use of the Wistar Hannover rat as an animal model in the assessment of maternal toxicity. Differences in laboratory values of pregnant rats should be considered when interpreting data following exposure to candidate pharmaceuticals.     

Comparative study of 2 surgical techniques for castration of guinea pigs (Cavia porcellus)

The objective of this study was to compare 2 surgical approaches (scrotal or abdominal) for castration of guinea pigs and to investigate post-operative infection rates with either technique. Forty-eight guinea pigs were castrated by scrotal or abdominal technique after being randomly assigned to 1 of 2 groups (n = 24). Individuals were either castrated by an experienced exotic animal surgeon (n = 12) or by an experienced small animal surgeon (n = 12). Surgical wounds were evaluated daily before euthanasia for histological evaluation 2 wks after surgery. Post-operative infection rate was significantly higher in the scrotal group than in the abdominal group, with a higher rate for the experienced small animal surgeon. Castration of guinea pigs with the abdominal technique is significantly faster and has a significantly lower post-operative infection rate than the scrotal technique.     

Ocular disease in the guinea pig (Cavia porcellus): a survey of 1000 animals

Objective Anecdotal evidence has suggested that guinea pigs have a high prevalence of ocular lesions. Here we undertook a survey of 1000 guinea pigs from populations of animals kept as laboratory animals, breeding show cavies, animals kept as pets and those from rescue and rehoming centers. Each animal was examined to assess for ocular abnormalities. Procedures A full ophthalmic examination was performed on each animal with direct and indirect ophthalmoscopy and with slit lamp biomicroscopy. Measurement of tear production using the Schirmer tear test 1 and intraocular pressure using the Tonopen applanation tonometer after topical anesthesia was undertaken in selected animals. Results Forty‐five percent of animals examined had some ocular abnormality. The majority were lens lesions including 17% with cataract and 21% with subclinical lens abnormalities such as nuclear sclerosis. Other abnormalities included conjunctivitis in 4.7% and keratitis in 3.6%. Lipid deposition in conjunctiva was observed in 2.3% of guinea pigs and ciliary body heterotopic bone formation in 0.8% of animals. Conclusions This study shows a high proportion of eyes with some degree of abnormality in animals otherwise considered healthy. Information on diseases of the guinea pig eye is important given the use of the species as a laboratory rodent and also the number kept as pets and show animals.     

Hematology and plasma chemistry reference intervals for cultured tilapia (Oreochromis hybrid)

Abstract: Tilapia are a commonly aquacultured fish yet little is known about their normal physiology and response to disease. In this study we determined the results of complete hematologic (n = 40) and plasma biochemical profiles (n = 63) in production tilapia ( Oreochromis hybrids). The fish were raised in recirculating systems with a high stocking density (120 g/L), and were in the middle of a 15-month production cycle. Blood was analyzed using standard techniques, and reference intervals were determined using nonparametric methods. Non-production tilapia (n = 15) from low-density tanks (4 g/L) also were sampled; the clinical chemistry results were compared to reference intervals from the fish raised in high-density tanks. Differences were noted in plasma protein, calcium and phosphorus concentrations, such that reference intervals for high-density production tilapia were not applicable to fish raised under different environmental and management conditions.     

The association between bloodwork,signalment, and urolithiasis in guinea pigs (Cavia porcellus)

Urolithiasis represents a common, potentially life-threatening condition in pet guinea pigs (Cavia porcellus). The purpose of this study is to determine the potential association between signalment, packed cell volume, total solids, selected biochemical parameters, and imaging evidence of urolithiasis in client-owned guinea pigs presented to two veterinary teaching hospitals. Medical record databases from two veterinary teaching hospitals were searched for cases of client-owned guinea pigs that had both a plasma biochemistry panel and an imaging study performed during one medical event. Other parameters including age, sex, weight, packed cell volume, and total solids were also recorded.Of the 81 guinea pigs that met the inclusion criteria, 32 animals (40%) had evidence of urolithiasis present on at least one of their imaging modalities. The odds for the imaging presence of urolithiasis increased with a decreasing packed cell volume, an increasing plasma creatinine concentration, and with a decreasing plasma phosphorus concentration.While these variables were statistically significant and associated with imaging presence of urolithiasis, they had low predictive value to discriminate between guinea pigs with and without imaging evidence of urolithiasis.Given the relatively high prevalence of urolithiasis in guinea pigs in this study, imaging is strongly recommended for every animal with suspected affliction.     

Hematology and serum clinical chemistry reference intervals for free‐ranging Scandinavian gray wolves (Canis lupus)

Background: Scandinavian free‐ranging wolves (Canis lupus) are endangered, such that laboratory data to assess their health status is increasingly important. Although wolves have been studied for decades, most biological information comes from captive animals. Objectives: The objective of the present study was to establish reference intervals for 30 clinical chemical and 8 hematologic analytes in Scandinavian free‐ranging wolves. Methods: All wolves were tracked and chemically immobilized from a helicopter before examination and blood sampling in the winter of 7 consecutive years (1998–2004). Seventy‐nine blood samples were collected from 57 gray wolves, including 24 juveniles (24 samples), 17 adult females (25 samples), and 16 adult males (30 samples). Whole blood and serum samples were stored at refrigeration temperature for 1–3 days before hematologic analyses and for 1–5 days before serum biochemical analyses. Reference intervals were calculated as 95% confidence intervals except for juveniles where the minimum and maximum values were used. Results: Significant differences were observed between adult and juvenile wolves for RBC parameters, alkaline phosphatase and amylase activities, and total protein, albumin, γ‐globulins, cholesterol, creatinine, calcium, chloride, magnesium, phosphate, and sodium concentrations. Conclusion: Compared with published reference values for captive wolves, reference intervals for free‐ranging wolves reflected exercise activity associated with capture (higher creatine kinase activity, higher glucose concentration), and differences in nutritional status (higher urea concentration).