A single base deletion in the SLC45A2 gene in a Bullmastiff with oculocutaneous albinism

Oculocutaneous albinism type 4 (OCA4) in humans and similar phenotypes in many animal species are caused by variants in the SLC45A2 gene, encoding a putative sugar transporter. In dog, two independent SLC45A2 variants are known that cause oculocutaneous albinism in Doberman Pinschers and several small dog breeds respectively. For the present study, we investigated a Bullmastiff with oculocutaneous albinism. The affected dog was highly inbred and resulted from the mating of a sire to its own grandmother. We obtained whole genome sequence data from the affected dog and searched specifically for variants in candidate genes known to cause albinism. We detected a single base deletion in exon 6 of the SLC45A2 gene (NM_001037947.1:c.1287delC) that has not been reported thus far. This deletion is predicted to result in an early premature stop codon. It was confirmed by Sanger sequencing and perfectly co‐segregated with the phenotype in the available family members. We genotyped 174 unrelated dogs from diverse breeds, all of which were homozygous wildtype. We therefore suggest that SLC45A2:c.1287delC causes the observed oculocutaneous albinism in the affected Bullmastiff.     

Birth and simultaneous rearing of two litters in a pack of captive African wild dogs (Lycaon pictus)

Two female African wild dogs (Lycaon pictus) in a pack of 10 animals at the Bronx Zoo gave birth to litters of nine and seven pups within a 2‐day period. Two pups from the litter of seven died before they were 2 weeks old, but the other 14 survived past weaning. Litter size, sex ratio, and pup developmental stages were all consistent with data obtained from other captive‐ and wild‐born litters. Both dams were very attentive to their litters, and during the pups' first 2 weeks spent >90% of their time in the dens with the pups. By 2 days after birth and during their first 2 weeks of life, the pups spent 86% of their time in a nursing position. Before parturition and during the first week post‐partum, one of the dams (DAL) was clearly dominant to the other (WHI). However, the females' dominance rank reversed 2 weeks post‐partum. On two occasions during the pups' first 2 weeks DAL stole and reared one of WHI's pups, but between Weeks 3 and 4 all of DAL's pups were stolen and WHI raised both litters as one until they were weaned. The pups began spending time out of their den at approximately 1 month of age. The timing of the births, the design of the wild dogs' management facility, and the presence of several dens in different enclosures within the facility all likely contributed to the successful rearing of the litters. The pups in both litters were very similar in size because of the short interval between births, so one litter did not have a competitive advantage over the other with respect to gaining access to the dam for milk. The facility's design helped mitigate aggression within the pack, and the presence of multiple dens enabled to dams to move the pups to different den sites and allowed the two females to stay visually and spatially apart from each other while remaining with the pack. Zoo Biol 0:1–17, 2006. © 2006 Wiley‐Liss, Inc.     

Two G3 Feline Rotavirus Strains Lacking Cross-Neutralization Reactions Represent Distinct Subtypes of Serotype G3

Two feline rotavirus strains, FRV-1 and FRV64, that have been shown to lack cross-neutralization reactions despite the sharing of serotype G3 were examined by plaque-reduction neutralization assays in relation to other G3 strains originating from cats, dogs, humans and monkeys. While FRV-1 and human G3 strains constituted one subtype (G3A), FRV64, canine strains and simian strains constituted another subtype (G3B).     

Pharmacokinetics of ibuprofen enantiomers in dogs

Inversion of inactive (R)-ibuprofen to active (S)-ibuprofen has been suggested to occur presystemically only. In order to investigate the site of inversion in dogs we administered both enantiomers either intravenously or intraduodenally (10 mg/kg) to adult, male beagle dogs (n = 3) in a crossover design. Plasma, urine, and bile were collected for up to 6 h and analyzed stereospecifically by HPLC, according to a previously published method. Pharmacokinetic parameters were calculated using a linear computer program. Absorption after intraduodenal administration occurred rapidly, resulting in maximum plasma concentrations 0.2 h after giving the enantiomer. Approximately 70% of the (R)-enantiomer (according to AUC) was inverted to the S-enantiomer independent of route of administration. No R-ibuprofen could be detected in plasma after (S)-ibuprofen administration. Mean residence time was found to be 2 to 3 times longer for (S)- than for (R)-ibuprofen. Total systemic clearance from plasma was twice as high for (R)- than for (S)-ibuprofen. There were no differences between plasma clearances after intravenous and intraduodenal administration. Between 8 and 17% of dose was recovered in bile [especially as free and conjugated (S)-ibuprofen] and 3-12% in urine [as (S)-ibuprofen, hydroxy- and carboxyibuprofen, free and conjugated forms]. Small amounts of (R)-ibuprofen were detected in bile after intraduodenal administration of (R)-ibuprofen only (1.8% of dose). In short, the unidirectional inversion of R-ibuprofen appears to occur systemically rather than presystemically in dogs.