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Neonatal foals are immunocompetent but immunologically naïve at birth. 1,2 Immediately after birth, production of autogenous immunoglobulins commences in response to antigen exposure, but substantial immunoglobulin concentrations are not achieved

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in Journal of the American Veterinary Medical Association

Sepsis has been implicated as the major cause of morbidity and death in equine neonates. 1,2 Sepsis refers to development of a systemic inflammatory response syndrome in response to a confirmed infectious process. The presence of viable bacteria

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in Journal of the American Veterinary Medical Association

-threatening adverse events, such as injectionsite infections, 1 gastrointestinal ulceration and hypoalbuminemia, 2–4 and renal papillary necrosis. 5–7 The use of NSAIDs in neonatal foals may be further complicated by their increased inherent risk of gastric ulcers

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in American Journal of Veterinary Research

Summary

Single doses (2.2 mg/kg of body weight) of phenylbutazone (pbz) were administered iv to 6 neonatal horses (5 to 17 hours old at time of dosing). Plasma concentrations of pbz and its metabolite oxyphenbutazone were monitored serially for 120 hours after drug administration. Pharmacokinetic variables were calculated, using 1- and 2-compartment open models. Descriptive equations from the best model for each foal were then used to derive model-independent variables describing pbz disposition. Median volume of distribution at steady-state was 0.274 L/ kg (range, 0.190 to 0.401 L/kg). Median terminal half-life was 7.4 (6.4 to 22.1) hours, and median total plasma clearance of pbz for foals in this study was 0.018 L/kg/h (range, 0.013 to 0.038 L/kg/h). Volume of distribution was larger, half-life was longer, and total clearance was lower, compared with similar values reported for administration of pbz to adult horses.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the pharmacokinetics of enrofloxacin in neonatal kittens and compare the pharmacokinetics of enrofloxacin in young and adult cats.

Animals—7 adult cats and 111 kittens (2 to 8 weeks old).

Procedure—A single dose of 5 mg of enrofloxacin/kg was administered to adults (IV) and kittens (IV, SC, or PO). Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined.

Results—The half-life of enrofloxacin administered IV in 2-, 6-, and 8-week-old kittens was significantly shorter and its elimination rate significantly greater than that detected in adults. The apparent volumes of distribution were lower at 2 to 4 weeks and greater at 6 to 8 weeks. This resulted in lower peak plasma concentration (Cmax) at 6 to 8 weeks; however, initial plasma concentration was within the therapeutic range after IV administration at all ages. Compared with IV administration, SC injection of enrofloxacin in 2-weekold kittens resulted in similar Cmax, half-life, clearance, and area under the curve values. Enrofloxacin administered via SC injection was well absorbed in 6- and 8- week-old kittens, but greater clearance and apparent volume of distribution resulted in lower plasma concentrations. Oral administration of enrofloxacin resulted in poor bioavailability.

Conclusions and Clinical Relevance—In neonatal kittens, IV and SC administration of enrofloxacin provided an effective route of administration. Oral administration of enrofloxacin in kittens did not result in therapeutic drug concentrations. Doses may need to be increased to achieve therapeutic drug concentrations in 6- to 8-week-old kittens. ( Am J Vet Res 2004;65:350–356)

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in American Journal of Veterinary Research

awareness of the importance of confirming successful passive transfer of immunity in neonatal calves has led to the development of several assays that provide quantitative or semiquantitative evidence for determining whether a calf has an adequate

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in Journal of the American Veterinary Medical Association

Respiratory distress syndrome is a condition of newborn infants and neonatal calves in which insufficient oxygen uptake and increased retention of carbon dioxide result in respiratory acidosis. 1,2 The condition is more common in premature

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in Journal of the American Veterinary Medical Association

diseases. 1–5 The CT characteristics of the lungs are also well described in dogs and cats, 6–8 and CT is considered superior to standard radiography for the detection of pathological changes within the lungs. 9–12 In equine neonates, for which pulmonary

Full access
in American Journal of Veterinary Research

Summary

Sixteen pregnant queens were inoculated orally with tissue cysts of Toxoplasma gondii, and fetal membranes and offspring were examined for Τ gondii infection by bioassay in mice. Queens appeared clinically normal, although all shed Τ gondii oocysts. Toxoplasma gondii was isolated from tissues of 7 of 33 fetuses or kittens from 5 litters (at 13, 23, 26, 27, and 29 postinaculation days) from 8 queens euthanatized between 10 and 31 postinoculation days. Infection with Τ gondii was found In kittens from all 8 litters from the 8 queens that were allowed to undergo parturition and nurse their kittens. A total of 43 kittens were born to these 8 quean.

Toxoplasma gondii was isolated from tissues of 26 of 40 kittens bioassayed; in 3 kittens, tissues were not available for bioassay. Toxoplasmosis was severe in full-term kittens born to 5 queens; all 25 kittens from these litters died or were ill by 24 days of age. Anorexia, lethargy, hypothermia, and sudden death were the most common manifestations. Cytologic examination of peritoneal fluid aspirate samples and determination of hepatic-associated enzyme concentrations in affected kittens, as well as measurement of anti-T gondii antibodies in serum of kittens and queens, were helpful in the diagnosis of neonatal toxoplasmosis. Transplacental transfer of anti-T gondii antibodies was not observed in cats. Toxoplasma gondii oocysts were found in fecal samples of 3 kittens from different litters at 16, 24, and 63 days of age.

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in Journal of the American Veterinary Medical Association

Abstract

Objective

To examine the association between oxidative stress and antioxidants in neonatal calves after birth.

Sample Population

Sera from 6 healthy Holstein-Friesian cows and 7 of their newborn calves were obtained at various intervals after birth.

Procedure

Lipid peroxides in serum of cows and their newborn calves were estimated by measuring concentrations of thiobarbituric acid-reactive substances (TBARS). The antioxidative activities of neonatal sera were evaluated by measuring their superoxide-scavenging activities, ferroxidase activities, and the concentration of bilirubin-associated albumin.

Results

Concentration of TBARS in neonatal sera within 1 day after birth was significantly higher than concentrations ≥ 2 days after birth and concentrations in serum of the dams. In contrast, antioxidative activities of neonatal sera, evaluated on the basis of superoxide-scavenging activities, ferroxidase activities, and concentration of bilirubin-associated albumin 3 hours after birth, were significantly lower than antioxidative activities in sera of the dams.

Conclusions

Susceptibility of calves to oxidative stress during the neonatal period may be explained by the immature defense system against superoxide radicals. (Am J Vet Res 1999;60:452-457)

Free access
in American Journal of Veterinary Research