Use of phenytoin to treat digitalis-induced cardiac arrhythmias in a miniature Shetland pony

Two miniature Shetland ponies showing clinical signs of Digitalis purpurea (foxglove) poisoning were examined. One animal died shortly afterwards, but the second was treated successfully with the anti-arrhythmic agent, phenytoin, and was discharged after 16 days.     

Properties of threshold model predictions

Estimation of genetic parameters and accuracy of threshold model genetic predictions were investigated. Data were simulated for different population structures by using Monte Carlo techniques. Variance components were estimated by using threshold models and linear sire models applied to untransformed data, logarithmically transformed data, and transformation to Snell scores. Effects of number of categories (2, 5, and 10), incidence of categories (extreme, moderate, and normal), heritability in the underlying scale (.04, .20, and .50), and data structure (unbalanced and balanced) on accuracy of genetic prediction were investigated. The real importance of using a threshold model was to estimate genetic parameters. An expected heritability of .20 was estimated to be .22 and .10 by a threshold model and a linear model, respectively. Accuracy increased significantly with a larger number of categories, a more normal distribution of incidences, increased heritability, and more balanced data. Even threshold models were shown to be more efficient with more than two categories (e.g., binomial). Transformation of scale did not accomplish the purpose intended.     

Heat processing changes the protein quality of canned cat foods as measured with a rat bioassay

The purpose of this study was to determine the influence of increasing heat treatment on the protein quality of a canned cat food. A standard recipe cat food was canned and heat-treated for different times in a standard laboratory autoclave to obtain experimental diets containing different lethality values. Estimates of the lethality value of the different diets were calculated using the temperature-time relationship recorded with a data logger positioned at the center of the can. The experimental diets were analyzed for crude protein, amino acids, and reactive lysine (fluorodinitrobenzene and O-methylisourea) and were used in a rat bioassay for the determination of the true ileal digestibility of amino acids. The heat treatment of the cat food resulted in experimental diets with lethality values of 5.3, 8.6, 17.2, and 24.3 min. There was no decrease in the amino acid content of diet with increasing heat treatment. The reactive lysine content of the diets also showed no change with heat treatment. There were significant (P < .05) changes in the true ileal digestibility of all amino acids and amino acid nitrogen, and the digestibility of most amino acids decreased with increasing heat treatment.     

Health and growth performance of barrows reared in all-in/all-out or continuous flow facilities with or without a chlortetracycline feed additive.

OBJECTIVE: To compare health and growth performance in barrows reared in all-in/all-out (AIAO) or continuous flow (CF) management systems. ANIMALS: 400 barrows. PROCEDURE: Barrows (approx 2 months old) were allotted to 4 replications (100 barrows each); barrows were housed in AIAO or CF rooms (10 pens/room), and 50 pigs/replicate received chlortetracycline (CTC, 110 mg/kg of feed). Barrows from each pen were slaughtered at 3, 4, 5, and 6 months old. RESULTS: Barrows in the AIAO room had greater total daily gain (TDG) and lean daily gain (LDG) than did barrows in the CF room. Addition of CTC did not improve TDG or LDG in either environment. Barrows in the AIAO room reached body weight of 104.5 kg in 169.7 days, compared with 177.3 days for barrows in the CF room. Feed-to-gain ratio was not affected by management or CTC. Lungs from barrows reared in AIAO facilities had a lower percentage of lesions than did lungs of barrows reared in CF facilities (1.74% vs 9.52%). Addition of CTC did not affect prevalence and extent of lung lesions. Extent of lung lesions was positively correlated with change in serum optical density (OD) to Mycoplasma hyopneumoniae (r = 0.35), but not with change in serum OD to Actinobacillus pleuropneumoniae. Lean growth and serum OD to M. hyopneumoniae and A. pleuropneumoniae were not correlated. CONCLUSIONS: Health and growth performance were better for barrows in an AIAO facility, compared with a CF facility, but addition of CTC to feed failed to enhance health or performance of barrows in either facility.     

Streptococcus uberis: A Permanent Barrier to the Control of Bovine Mastitis?

The prevalence of bovine mastitis has been reduced over the past 25 years due to the implementation of a five-point control plan aimed at reducing exposure, duration and transmission of intramammary infections by bacteria. This has markedly reduced the incidence of bovine mastitis caused by bacteria which show a contagious route of transmission, but has had little effect on the incidence of mastitis due to bacteria which infect the gland from an environmental reservoir. Streptococcus uberis is one such bacterium which is responsible for a significant proportion of clinical mastitis worldwide.The inadequacies of the current methods of mastitis control have led to the search for additional measures, particularly vaccines to prevent intramammary infection by this bacterium. Such an approach requires detailed knowledge of the pathogenesis of intramammary infection. Our understanding of this area has grown in recent years but a lack of information still hampers disease control. Both live vaccines and, recently, crude sub-unit vaccines have shown promise against bovine mastitis due to S. uberis. Vaccines against mastitis must, however, be able to control infection without the participation of a marked inflammatory response. This review provides an overview of the recent advances which have been made in our understanding of host-pathogen interactions which promote infection and disease and highlights areas for strategic research aimed at controlling this bacterial infection.     

Bone plate fixation of distal radius and ulna fractures in small- and miniature-breed dogs.

Bone plate fixation was reviewed in 29 distal radial fractures of small- and miniature-breed dogs. Twenty-two fractures in 18 dogs were available for follow-up. Number of complications and return to function were evaluated. Complications occurred in 54% of the fractures. Catastrophic complications occurred in 18% of fracture repairs with follow-up, while minor complications occurred in 36%. Sixteen (89%) of 18 dogs had a successful return to function. Bone plate fixation is a successful repair method for distal radius and ulna fractures in small-breed dogs, compared to previously reported methods.     

Vaginal position and length in the bitch: relationship to spaying and urinary incontinence

A study was undertaken to determine if the vagina might be a suitable site for the measurement of intra-abdominal pressure during cystometry in the bitch. The position of the cranial vagina and vaginal length were measured radiographically and the effects of spaying and urinary incontinence on these variables were evaluated in 30 continent and 30 incontinent bitches. The study used retrograde vaginourethrograms which had been obtained from animals used in a previous study. The cranial vagina was intra-abdominal on 36 of the vaginourethrograms, being least commonly intra-abdominal in incontinent bitches (11/30). Vaginal position was related linearly to vaginal length and continence status (P < 0.01), while its length was related to bodyweight (P < 0.01). Allowing for bodyweight, neutered animals had significantly shorter vaginas than entire bitches (P < 0.01). Measurement of intra-abdominal pressure with concomitant measurement of intravesical pressure is essential if accurate assessment of detrusor pressure is to be determined during cystometry. The vagina is unlikely to be a useful location from which to measure intra-abdominal pressure since any pressure-measuring catheter inserted into it may fall outside the abdominal pressure zone. This is particularly true of neutered and/or incontinent bitches, the groups in which urodynamic investigations of urinary incontinence are most frequently indicated.     

Liver fluke infestation in New World camelids. Parasitology, pathology, clinical findings and therapy]

In Llamas and Alpacas infestation with Fasciola hepatica or Dicrocoelium dendriticum can cause liver damage, sometimes even with lethal outcome. Once infected South American Camelids (SACs) react more sensitively to these parasites than other domestic ruminants. We report here on the pathology, parasitology, clinics and therapy of this disease. Concerning Dicrocoelium dendriticum we describe own clinical results and therapeutic outcome in addition to the pathological investigation. According to anatomic corrosion casts, the bile ducts of SACs show more similarity with the equine bile system than with the bile system of domestic ruminants.     

Evaluation of scratches as an essential element in the development of avian cellulitis in broiler chickens.

Currently, the published cellulitis models do not adequately address the actual pathogenesis as seen in the commercial broiler industry. In this model, small dermal scratches were made on the skin of broiler chickens, which were then placed on litter seeded with avian cellulitis-associated Escherichia coli. The research confirms scratches are required for the induction of avian cellulitis. The research also confirms that "type I" cellulitis lesions or those previously thought to be due to hatchery-borne infections can be induced with scratches. The described methods provide a realistic model for cellulitis development that will improve the reliability of prophylactic and therapeutic-regimen efficacy testing data, thereby providing information more directly useful to the commercial broiler industry.