Pharmacokinetics of tulathromycin in fetal sheep and pregnant ewes.

Macrolides are important antimicrobials frequently used in human and veterinary medicine in the treatment of pregnant women and pregnant livestock. They may be useful for the control of infectious ovine abortion, which has economic, animal health, and human health impacts. In this study, catheters were surgically placed in the fetal vasculature and amnion of pregnant ewes at 115 (±2) days of gestation. Ewes were given a single dose of 2.5 mg/kg tulathromycin subcutaneously, and drug concentrations were determined in fetal plasma, maternal plasma, and amniotic fluid at 4, 8, 12, 24, 36, 48, 72, 144, and 288 hr after drug administration. Pharmacokinetic parameters in maternal plasma were estimated using noncompartmental analysis and were similar to those previously reported in nonpregnant ewes. Tulathromycin was present in fetal plasma and amniotic fluid, indicating therapeutic potential for use against organisms in these compartments, though concentrations were lower than those in maternal plasma. Time-course of drug concentrations in the fetus was quite different than that in the ewe, with plasma concentrations reaching a plateau at 4 hr and remaining at this concentration for the remainder of the sampling period (288 hr), raising questions about how tulathromycin may be transported into or metabolized and eliminated by the fetus.

Multicenter study of uterine tears and other reproductive complications in periparturient goats presented to veterinary teaching hospitals.

BACKGROUND: Goats are increasingly popular as both production animals and pets. The frequency of and factors associated with periparturient reproductive complications in goats are largely unreported. OBJECTIVES: (1) To report the frequency of periparturient reproductive complications in does presented to university veterinary hospitals and (2) to identify factors associated with uterine tears in the study population. ANIMALS: A total of 198 periparturient does presented to 9 university veterinary hospitals from October 2021 to June 2022. METHODS: Multicenter, cross-sectional study, with data collected from questionnaires completed by attending veterinarians. Logistic regression was used to identify factors associated with diagnosis of uterine tears. RESULTS: Ninety-three (47%) does had at least 1 periparturient reproductive complication. Periparturient complications included retained fetal membranes (n = 38, 26%), vaginal or perineal trauma (n = 33, 19%), uterine tears (n = 32, 18%), metritis (n = 22, 13%), uterine or vaginal hemorrhage (n = 8, 5%), Cesarean section complications (n = 8, 8%), and uterine prolapse (n = 1, 0.5%). A positive interaction effect was found between small breeds (Nigerian Dwarf and Pygmy) and manipulation on the farm by a layperson upon diagnosis of uterine tears (odd ratios [OR], 5.48; 95% confidence interval [CI], 1.41, 21.25; P = .01). CONCLUSIONS AND CLINICAL IMPORTANCE: Periparturient reproductive complications were common. Small breed combined with manipulation on the farm by layperson was associated with diagnosis of uterine tears. Clients should be educated that in the event of dystocia, small breed does are at greater risk of uterine tears and prompt veterinary intervention is critical.

Cerebrospinal nematodosis caused by Parelaphostrongylus species in an adult bull.

A 2-y-old Brahman bull was presented with progressive hindlimb ataxia and paraparesis that led to recumbency. Postmortem examination revealed scattered pinpoint, red-brown foci within the brainstem and gray matter of the spinal cord, and a larger lesion within the spinal cord at the level of T13. Histology of the section of T13 contained cross-sections of nematodes consistent with Parelaphostrongylus tenuis. Evidence of inflammation was present in other affected areas of the spinal cord and brain. DNA extraction and nested PCR were performed, which demonstrated 98% identity and 100% coverage to both P. tenuis and P. andersoni. Our case highlights the utility of DNA sequencing in parasite identification.

Comparison of analgesic efficacy and fetal effects between transdermal administration of fentanyl and intramuscular administration of buprenorphine in pregnant sheep.

OBJECTIVE: To compare analgesic efficacy and fetal effects between transdermal administration of fentanyl and IM administration of buprenorphine in pregnant sheep. ANIMALS: 12 healthy pregnant ewes. PROCEDURES: Before study initiation, each ewe was confirmed pregnant with a single fetus between 113 and 117 days of gestation. Ewes were randomly assigned to receive buprenorphine (0.01 mg/kg, IM, q 8 h for 48 hours beginning 1 hour before anesthesia induction; n = 6) or fentanyl (a combination of transdermal fentanyl patches sufficient to deliver a dose of 2 µg of fentanyl/kg/h applied between the dorsal borders of the scapulae 24 hours before anesthesia induction; 6). Ewes were anesthetized and underwent a surgical procedure to instrument the fetus with an arterial catheter and place a catheter in utero for collection of amniotic fluid samples. Physiologic variables and behavioral changes indicative of pain were assessed, and amniotic fluid and blood samples from ewes and fetuses were collected for determination of drug concentrations at predetermined times. RESULTS: Both protocols provided acceptable postoperative analgesia with no adverse effects observed in the ewes or fetuses. Compared with the buprenorphine protocol, the fentanyl protocol induced more profound analgesia, decreased the requirement for isoflurane during surgery, and was associated with a shorter anesthesia recovery time. Fetal indices did not differ significantly between the 2 analgesic protocols. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that both protocols provided acceptable analgesia. However, the fentanyl protocol was superior in regard to the extent of analgesia induced, inhalant-sparing effects, and anesthesia recovery time.