Pacemaker implantation should be strongly considered in all dogs with high-grade second- or third-degree AVB regardless of whether clinical signs are evident. If medical treatment is warranted, vagolytic medications may be the best choice. A new classification system for AVB may merit further investigation.

Abstract. Twenty-two lactating Holstein cattle in Tennessee had clinical signs of intoxication with preformed Clostridium botulinum toxin. These signs included weakness, paralysis of the tongue and chest muscles, abdominal breathing, and, in 11 of the 22 cows, death. Differential diagnoses included hypocalcemia, hypomagnesemia, carbohydrate overload, and several toxicoses including mycotoxin, lead, nitrate, organophosphate, atropine or atropine-like alkaloid, and botulism. A diagnosis of botulism by the ingestion of preformed C. botulinum type B toxin was made by eliminating these other diseases, by finding C. botulinum type B spores in 3 bales of round bale barley haylage fed to these cattle, and by isolating preformed type B toxin from 1 of the 3 bales. Confirmation of the toxin type was made by demonstrating mouse lethality by intraperitoneal injection of specimen extracts with neutralization by C. botulinum type B antitoxin. The haylage, harvested green and encased in black plastic bags to facilitate fermentation, was presumably contaminated by the botulinum toxin when fermentation failed to produce enough acid to lower the pH to 4.5, the pH below which C. botulinum growth is inhibited. Farmers and ranchers who use round hay balers to produce haylage should be alert to this potential problem.Botulism is caused by a neurotoxin produced by Clostridium botulinum that can affect all mammals, fish, and birds. 22 The organism is a spore-forming, gram-positive anaerobic rod that elaborates a potent toxin. 4,23 Eight types of this exotoxin including A, B, C1, C2, D, E, F, and G have been identified. 26 Each type is unique in its geographic distribution and species susceptibility. Only types B, C, and D have been shown to produce disease in cattle. 6 The toxin acts at cholinergic nerve endings, 20 preventing the release of the neurotransmitter acetylcholine, which is necessary for muscle contraction, often causing death by respiratory paralysis. 23 Clinical signs are variable, but often include weakness, paralysis of the tongue resulting in an inability to swallow, paralysis of the chest muscles, abdominal-type respiration, and death. 4 Intoxication occurs by 3 routes: ingestion of the preformed toxin, wound botulism, and intestinal toxicoinfectious botulism. 5 Ingestion of preformed toxin in decaying foods (animal or plant) is the most common form of exposure in humans and adult animals. 15,23 Type B organisms are common in the soil in the midAtlantic states. 22 Two forms of type B toxin occur, a proteolytic toxin, which has maximal toxicity, and a nonproteolytic toxin, which must be activated by trypsin to be fully activated. The proteolytic type B toxin occurs most commonly in the soil of the mid-Atlantic states and Kentucky. 22

A total of 2,445 gram-negative bacteria belonging to fecal coliform, Pseudomonas, Moraxella, Acinetobacter, and Flavobacterium-Cytophaga groups were isolated from the rivers and bay of Tillamook, Oregon, and their resistances to chloramphenicol (25 ug/ml), streptomycin (10 ,ug/ml), ampicillin (10 Ag/ml), tetracycline (25 ,ug/ml), chlortetracycline (25 ,tg/ml), oxytetracycline (25 ,tg/ml), neomycin (50 ,ug/ml), nitrofurazone (12.5 ,ug/ml), nalidixic acid (25 ,ug/ml), kanamycin (25 ,ug/ml), and penicillin G (10 IU/ml) were determined. Among fecal coliforms the bay isolates showed greater resistance to antibiotics than those from tributaries or surface runoff. No such well-defined difference was found among other bacterial groups. The antibiotic resistance patterns of gram-negative bacteria from different sources correlated well, perhaps indicating their common origin. The antibiotic resistance patterns of gram-negative bacteria of different genera also correlated well, perhaps indicating that bacteria which share a common environment also share a common mode for developing antibiotic resistance.

No abstract

The National Council on Pet Population Study and Policy Regional Shelter Survey identified moving as the most often cited of 71 reasons for relinquishing dogs and the 3rd most common reason for relinquishing cats. Most relinquished companion animals were less than 3 years old and female. Dogs were most often intact, whereas cats were most often altered. Friends had given the majority of these companion animals to the relinquishers, who had obtained them at no cost. Most had lived with the relinquishers for less than 2 years. The majority of relinquishers were White and female, and had at least a high school education. Based on the U.S. population age distribution, young adults seem to be using shelters at a significantly higher rate than would be expected. These age groups are also more mobile, according to U.S. Census data. Therefore, educational efforts that target young, potentially mobile adults could decrease the number of animals relinquished.

Studies report variable factors associated with dog and cat surpluses in the United States. Estimates of cat and dog birth and death rates help understand the problem. This study collected data through a commercial survey company, distributing questionnaires to 7,399 cat- and dog-owning households (HHs) in 1996. The study used an unequal probability sampling plan and reported estimates of means and variances as weighted averages. The study used estimates of HHs and companion animals for national projections. More than 9 million owned cats and dogs died during 1996-yielding crude death rates of 8.3 cat deaths/100 cats in HHs and 7.9 dog deaths/100 dogs in HHs. The study reported twice as many kitten as puppy litters, with an average litter size of 5.73 and 7.57, respectively. The study reported data on planned versus unplanned litters, reasons caregivers did not spay females, disposition of litters, and sources of animals added to HHs. These first national estimates indicate the magnitude of, and reasons for, animals leaving HHs. The crude birth rate was estimated to be 11.2 kittens/100 cats in HHs and 11.4 puppies/100 dogs in HHs.

There was no significant difference in visual outcomes between a group of BT and a group of NBT undergoing bilateral phacoemulsification at the University of Tennessee between 2002 and 2015. Glaucoma was the leading cause of vision loss in both groups.

Because 36.1% of U.S. households have dogs, the time of death (TOD) of dogs at crime scenes can be useful to forensic investigators. However, there are few published studies based on postmortem changes in dogs. This study, conducted indoors in still air at approximately room temperature, monitored the postmortem reduction in rectal, liver, brain, and aural temperatures in 16 dogs for 32 h after death. Graphs of temperature reduction were prepared to estimate the TOD of dogs within the first 32 h postmortem. Sex, body mass, and hair coat density did not affect the rate of body temperature reduction, but increased body weight and volume slowed it. Rectal temperature was the most convenient, reasonable site for measuring body temperature. Vitreous humor potassium ion concentration [K(+)] was measured in both eyes at c. 1.5 and 7 h after death. Both eyes had the same [K(+)] when measured simultaneously, and [K(+)] increased after death.