Robert L. Toal

Patterns of prenatal survival in the common marmoset (Callithrix jacchus)

Abstract: Fifty common marmoset pregnancies were monitored using ultrasound. The objective was to ascertain if fetal mortality was related to litter size. Prior to analysis we determined abortion rate and litter size were not influenced by repeated ultrasound. Mortality was unrelated to litter size and occurred fairly late in gestation. All singletons born in this study began gestation as twins. It is hypothesized that marmosets may be able to adjust litter size late in pregnancy in response to proximate environmental factors.

ESTIMATION OF GESTATIONAL AGES IN THE COMMON MARMOSET (CALLITHRIX JACCHUS)FROM PUBLISHED PRENATAL GROWTH CURVES

This report compares estimated gestational ages from published cubic spline curves to gestational ages estimated retrospectively from delivery dates in 28 pregnancies from ten common marmosets (Callithrix jacchus). Both CRL‐ and BPD‐based estimates of gestational age were closely correlated with delivery‐based gestational age estimates. Of the three ultrasound machines used, the one with 16 shades of gray and a sequential linear array overestimated gestational age during early pregnancy, based on CRL measures. Measures from the other two machines (64 or 264 shades of gray; linear sector and annular array or electronic phase array) were similar and resulted in a correlation of the two estimates of gestational age of 0.94 and a mean difference between the two estimates of 0.16 days with 80% of CRL‐based gestational age estimates being within ± 5 days of the delivery‐based estimate. The reliability of BPD‐based estimates of gestational age was strongly related to pregnancy outcome. BPD‐based estimates underestimated gestational age in poor outcome pregnancies (i.e., those in which infants died within 7 days of birth) but not in good outcome pregnancies. The combined CRL‐ and BPD‐based estimates on poor outcome pregnancies suggest that there was less growth in BPD in late gestation for those pregnancies that resulted in nonviable offspring. For good outcome pregnancies, the correlation between BPD‐based and delivery‐based estimates of gestational age was 0.871 and the mean difference between the two estimates was −0.06 days with 83.3% of BPD‐based estimates falling within ± 5 days of delivery‐based estimates.

Hiatal hernia and diaphragmatic eventration in a leopard ( Panthera pardus).

Abstract A 1-yr-old male leopard (Panthera pardus) presented for intermittent anorexia, emaciation, and generalized muscle wasting. Plain radiographs, ultrasonography, and esophageal endoscopy led to a diagnosis of diaphragmatic eventration with probable concurrent hiatal hernia. An exploratory laparotomy confirmed both diagnoses, and surgical repair and stabilization were performed. After surgery, the leopard was maintained on small liquid meals for 4 days, with a gradual return to normal diet over 2 wk. By 4 wk after surgery, the leopard was eating well and gaining weight, and it showed no recurrence of clinical signs for 2 yr subsequently, becoming mildly obese.

Unusual presentation of an Amazon parrot (Amazona species) with hepatocellular carcinoma.

Non-haematopoietic hepatic malignancies are uncommon in birds. The clinical presentation (i.e. chronic buphthalmos)and non-specific radiographic findings observed in this adult Amazon parrot (Amazona spp.) were not consistent with previous reports describing the natural behaviour of metastatic hepatocellular carcinoma in birds.