Differences in Reproductive Performance, Embryo Development, Interferon-tau Secretion by the Conceptus and Luteal Function in Ewe Lambs Synchronized in Oestrus before or after the Spontaneous Onset of Luteal Activity Preceding Puberty

In mid-September, 1 month before the insertion of intravaginal pessaries to induce sexual activity, blood samples were collected every 4 days from 16 ewe lambs aged 7 months, in order to determine the incidence of ovulations by measurement of plasma progesterone concentrations. It has been studied whether the response to a progestagen treatment of ewe lambs apparently close to puberty could be modified by the onset of the ovarian events preceding puberty. The effect of the presence or absence of ovulations prior to progestagen treatment on the potential reproductive performance (fertility, litter size and fecundity), embryo development [embryo quality and interferon-tau (IFNτ) secretion], luteal function (progesterone secretion in vitro ) and endometrial progesterone content was studied in seven ovulating (Ov+) and nine nonovulating ewe lambs (Ov−) on day 14 after mating. The best potential reproductive results were obtained with Ov+ animals, although these differences could not be initially attributed to either different progesterone secretion in vitro or concentration of endometrial progesterone. Irrespective of the experimental groups, secretion of progesterone by luteal tissue from ewe lambs with normal embryos was significantly greater (p<0.05) than that of animals with abnormal embryos or with no embryos. Normal embryos secreted a higher amount of IFN-τ than those embryos classified as abnormal (p<0.07). In conclusion, ewe lambs which exhibit luteal activity before puberty have the highest levels of reproductive performances after a progestagen treatment. Corpora lutea from ewe lambs with normal embryos had higher rates of progesterone secretion in vitro and their embryos had a higher IFN-τ production by the embryos, indicating greater capacity for subsequent development.     

Ocular manifestations of Rocky Mountain spotted fever in dogs

Dogs were examined ophthalmoscopically to determine the prevalence and type of ocular lesions associated with naturally acquired Rocky Mountain spotted fever (RMSF). In a consecutive series of 11 dogs with serologically confirmed RMSF, 9 had ocular involvement reflecting various degrees of vascular damage, including subconjunctival hemorrhage, hyphema, anterior uveitis, iris stromal hemorrhage, retinal petechiae, and focal areas of retinal edema and perivascular inflammatory cell infiltrate. The ophthalmic lesions generally were mild, and most resolved without complication after systemic administration of appropriate antibiotics. The high prevalence of ocular lesions in these dogs suggested that critical ophthalmologic evaluation is a useful diagnostic tool for the early detection and management of RMSF in dogs.     

Penicillin-induced immune-mediated hemolytic anemia in a horse.

A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.     

Effect of nephropathogenic infectious bronchitis viruses on renal function in young male broiler chickens

1. The acute effects of challenge with Australian T‐strain infectious bronchitis virus (IBV) on renal function were evaluated, following primary vaccination in 1‐d‐old male broilers.

2. Challenge with T‐strain IBV decreased body weight and induced kidney hypertrophy and kidney asymmetry.

3. Haematocrit was reduced in birds challenged with the Australian T‐strain IBV and plasma uric acid was elevated in unvaccinated birds exposed to the IBV challenge.

4. Challenge with T‐strain IBV caused significant increases in urinary water losses, accompanied by decreased urine osmolality and increased fractional excretion of sodium, calcium and potassium.

5. Vaccination at 1‐d‐old with Vic S‐strain IBV provided a limited degree of protection against an heterologous challenge with T‐strain IBV at 15 d of age.     

Scintigraphic evaluation of tissue viability after gunshot injury in a dog.

Triple-phase bone scintigraphy was used to evaluate tissue viability in the forelimb of a dog after gunshot injury. This technique was reliable, noninvasive, and easily performed. It was used to complement radiography by providing functional, rather than structural, assessment of tissues on the basis of regional vascular patterns. In this dog, vascular impairment caused by trauma appeared as photopenic or "cold" spots during immediate (vascular), soft tissue and bone phases of the scintigraphic study. On the basis of gross morphologic and scintigraphic findings, forelimb amputation was performed.