Mandibular condylectomy in a horse

Mandibular condylectomy was effective in improving mastication and stopping weight loss in a horse. The horse had a history of intermittent purulent drainage from a facial wound and unilateral ankylosis of the temporomandibular joint.     

Amplification of Bovine Viral Diarrhoea Virus Introduced into an In Vitro Embryo Production System Via Oocytes from Persistently Infected Cattle

The purpose of this study was to determine whether or not embryos derived from in vitro fertilization of oocytes from persistently infected (PI) cattle would contain infectious virus. Three in vitro embryo production treatment groups were assessed: 1) oocytes and uterine tubal cells (UTC) free of bovine viral diarrhoea virus (BVDV) (negative control), 2) oocytes free of BVDV fertilized and cultured in media containing UTC obtained from PI heifers, and 3) oocytes from PI heifers fertilized and cultured in media containing UTC free of BVDV. The developmental media, UTC and embryos (individual or groups of five) were assayed for virus. Virus was not isolated from any samples in treatment group 1. As shown in previous studies, a proportion of embryo samples were positive for BVDV in treatment group 2. In treatment group 3, the virus associated with the oocytes contaminated the developmental media and infected susceptible co-culture cells used during fertilization and culture. In addition, 65% (11/17) of the degenerated ova from treatment group 3 had infectious virus associated with them. While none of the ova developed into transferable embryos, the study did confirm that use of oocytes from PI cows could lead to amplification of BVDV and cross contamination during in vitro embryo production.     

Presence and impact of the exercise-induced collapse associated DNM1 mutation in Labrador retrievers and other breeds

The impact of the mutation causing dynamin 1 (DNM1)-associated exercise-induced collapse (d-EIC) was determined in a retrospective genetic survey. The frequency of DNM1 mutant allele carriers in Labrador retrievers from conformation show, field trial/hunt test, pet or service lines ranged from 17.9% to 38.0% and the frequency of homozygous mutant (EE genotype) individuals ranged from 1.8% to 13.6%; 83.6% of these EE Labradors were reported to have collapsed by 4 years of age. DNM1 mutation carriers and EE dogs with a collapse phenotype were also detected in Chesapeake Bay retrievers, Curly-coated retrievers, Boykin spaniels, Pembroke Welsh corgis and mixed breed dogs thought to be Labrador retriever crosses. The DNM1 mutation was not identified in Golden, Flat-coated, or Nova Scotia duck tolling retrievers, or 15 other non-retrieving breeds. Veterinarians and breeders should be aware that the DNM1 EE genotype is not completely penetrant and that d-EIC is a widespread health concern in several very popular breeds, as well as breeds whose genetic similarity to retrievers is not obvious.     

Mucopolysaccharidosis in a domestic short-haired cat--a disease distinct from that seen in the Siamese cat.

A 10-month-old male domestic short-haired cat was examined because of progressive lameness, a broad face with depressed nasal bridge, small ears, corneal clouding, and multiple bone dysplasia. The cat excreted excessive amounts of glycosaminoglycan (a component of connective tissue) in its urine and had evidence of lysosomal storage of glycosaminoglycans in fibroblasts and neurons. Activity of alpha-L-iduronidase, a lysosomal enzyme involved in glycosaminoglycan degradation, was deficient in cultured fibroblasts and leukocytes. The mucopolysaccharidosis was distinct from that seen in Siamese cats in terms of the pathologic changes and the specific enzyme deficiency.     

Reproductive response of yearling beef heifers to a melengestrol acetate-prostaglandin F2 alpha estrus synchronization system.

A study was designed to evaluate estrus response and fertility after treatment with melengestrol acetate (MGA) and prostaglandin F2 alpha (PGF2 alpha) in yearling beef heifers. Three hundred four heifers at three locations were allotted to one of two treatments: Treatment 1 served as a nonsynchronized control (CON); and heifers in Treatment 2 received .5 mg of MGA.animal-1.d-1 for 14 d and 25 mg of prostaglandin F2 alpha (PGF2 alpha) 17 d after MGA (MGA-PGF). Heifers in CON and MGA-PGF groups were artificially inseminated 12 h after observed estrus for 21 and 6 d after PGF2 alpha, respectively. Blood samples were collected from each heifer 10 d before and on the day MGA feeding began and 10 d before and on the day PGF2 alpha was administered. Heifers with concentrations of serum progesterone greater than 1 ng/mL on either date before administration of MGA or PGF2 alpha were considered pubertal. More (P = .02) prepubertal heifers that received MGA attained puberty by initiation of breeding than did CON heifers (72 vs 45%, respectively). The proportion of heifers that displayed estrus within 6 d after PGF2 alpha was greater (P less than .001) for MGA-PGF than for CON heifers (77 vs 25%, respectively) but was also influenced by location (P = .03). Conception rate at first service for MGA-PGF heifers that attained puberty during MGA feeding and before PGF2 alpha was not different (P = .50) from that of CON that attained puberty during the same period.(ABSTRACT TRUNCATED AT 250 WORDS)     

Development of an estrus synchronization protocol for beef cattle with short-term feeding of melengestrol acetate: 7-11 synch

An estrus synchronization protocol (7-11 Synch) was developed to synchronize the first follicular wave and timing of ovulation in postpartum beef cows. In Exp. 1, follicular development and timing of ovulation in response to the following protocol were evaluated. Beef heifers (n = 12) and cows (n = 6), at random stages of the estrous cycle, were fed melengestrol acetate (MGA; .5 mg x animal(-1) x d(-1)) for 7 d and injected with PGF2alpha (PG; 25 mg) on the last day of MGA. A second injection of PG was administered 11 d after cessation of MGA. After the second injection of PG, estrus was synchronized in 6/12 heifers and 3/6 cows. The interval to estrus in heifers and cows was 54 and 64 h, respectively (P > .10). All animals exhibiting estrus ovulated first-wave follicles. Animals that failed to respond to the second injection of PG were in estrus later than 6 d after cessation of MGA and had corpora lutea that were unresponsive to the injection of PG. Based on the variation in interval to estrus following the first PG injection on the last day of MGA feeding in Exp. 1, an injection of GnRH (100 microg) was added to the protocol 4 d after the cessation of MGA to ensure ovulation or luteinization of dominant follicles and synchronization of first-wave follicular development. This revised protocol was termed "7-11 Synch." In Exp. 2, two estrus synchronization protocols were compared. Multiparous beef cows were stratified by breed and postpartum interval and randomly assigned to the 7-11 Synch (n = 44) or Select Synch protocols (GnRH injection followed by PG injection 7 d later; n = 45). Timing of estrus after the last PG injection (0 h) ranged from 42 to 102 h in the 7-11 Synch group and -30 to 114 h in the Select Synch group. Eight cows (18%) in the Select Synch group exhibited estrus 30 h before to 18 h after PG. Synchronized estrus peaked between 42 and 66 h after the last PG injection, and a maximum number of cows were in estrus at 54 h for both treatment groups. Synchrony of estrus from 42 to 66 h was greater (P < .05) in 7-11 Synch (91%: 41/44) than in Select Synch cows (69%: 31/45). Artificial insemination pregnancy rate from 42 to 66 h was greater (P < .05) in the 7-11 Synch group (66%: 29/44) than in the Select Synch group (40%: 18/45). In summary, the 7-11 Synch protocol improved synchrony of estrus without reducing fertility. This protocol has potential future application for fixed-time AI in beef cattle production systems.     

Etiology of patent ductus arteriosus in dogs

Patent ductus arteriosus (PDA) is the most common congenital heart disease in dogs and usually causes heart failure and death unless corrected at a young age. Previous histologic studies in a line of dogs derived from Miniature Poodles with hereditary PDA identified varying degrees of hypoplasia and asymmetry of ductus-specific smooth muscle and the presence of aortalike elastic tissue in the ductus wall sufficient to cause patency. To determine if similar structural abnormalities cause PDA in other dogs, serial-section, 3-dimensional histology of ductal architecture was studied in 8 non-Poodle purebred dogs with PDA with no immediate family history of PDA. Morphologic abnormalities were observed in 7 of 8 dogs with PDA and essentially were the same as those in dogs known to have a hereditary form of PDA. These findings suggest that apparently sporadic PDA in these breeds is caused by a genetic defect in the structure of the ductus arteriosus that is similar or identical to that in the Poodle. The relatives of dogs with PDA, particularly parents, offspring, and siblings, should be screened for evidence of PDA. Dogs with PDA should not be used for breeding, regardless of breed.     

Diagnosis of eastern equine encephalitis by immunohistochemistry in two flocks of Michigan ring-neck pheasants

The diagnosis of eastern equine encephalitis (EEE) virus infection in avian species is relatively difficult when compared with other species. There are no characteristic histologic lesions in the avian brain that would serve to distinguish EEE from infections with, for example, Newcastle disease or highly pathogenic avian influenza virus. Traditionally, virus isolation (VI) and/or hemagglutination inhibition (HI) has been used for a definitive diagnosis of EEE in birds. Recently, we developed an immunohistochemistry (IHC) technique for confirmatory diagnosis of EEE infection in equine brain. This test also detected EEE virus in formalin-fixed avian brain. VI confirmed IHC finding in two cases of EEE in ring-neck pheasants. IHC is a rapid, sensitive test for confirming and differentiating a histopathologic diagnosis of EEE in avian species and should be considered as an alternative test to VI or HI.