Epidemiology and toxicology of arsenic poisoning in domestic animals.

Arsenic poisoning is one of the more important causes of heavy metal poisoning in domestic animals. Two species--dogs and cattle--are intoxicated more frequently than other animals; yet sporadic instances of poisoning have been observed in cats, horses, and pigs. Cases observed by veterinary clinicians are either peracute, acute, or chronic intoxications. Frequently the initial and only indication that a severe problem exists with peracute poisoning in a cattle herd is dead animals. Chronic intoxications are also observed in cattle. Acute intoxication is the most common form of arsenic poisoning observed and documented in the dog. Also intoxicated dogs were younger, i.e., 2-6 months of age. Arsenic is a severe alimentary tract irritant in domestic animals, and treatment in most instances consists mainly of symptomatic and supportive treatment. The source of intoxication, when it can be determined, is usually dips, sprays, powders, or vegetation contaminated by pesticides containing arsenic.

Characteristics of the human and pet populations in animal bite incidents recorded at two Air Force bases.

Animal bites reported at Scott Air Force Base, Ill., and Whiteman Air Force Base, Mo., were investigated to determine the incidence of reported bites and possible causes. Data were collected by abstracting information contained in animal bite files maintained by the Base veterinary Office. A total of 696 bite incidents were reported for the 24 months from January 1976 through December 1977. An overall incidence rate of 1,390 bites per 100,000 persons was calculated from these statistics. This rate is far greater than the previous estimates of 800 animal bites per 100,000 for an urban population. Males less than 18 years old were the group most frequently bitten; they had an incidence rate of 2,419 bites per 100,000. These data support the hypothesis that animal bites occur more frequently than previous studies have shown. Most bites resulted in minor injuries to the victim and were inflicted on the extremities. The incident occurred most commonly on the owner's property. The highest incidence of bites occurred during the summer months and in the early afternoon and evening. Animals in the study had a bite rate of 7.36 per 100 animals. The rate was significantly higher for male dogs 1 to 4 years old (12.1 bites per 100 male dogs). Certain breeds of dogs were more frequently involved. Collies and German shepherds ran twice the risk of being biters as mixed breed dogs. Working breeds and sporting breeds also had a higher risk of being biters than toy breeds as well as a higher rate of more severe bites than toy breeds.

A survey of attitudes toward responsible pet ownership.

The concerns of medical and community officials about responsible pet ownership have increased. Before a practical solution can be found for irresponsible ownership and community health problems associated with pet populations, the public's attitudes on issues related to responsible pet ownership must be determined. Such issues include attitudes on dog and cat overpopulation, potential public health problems associated with pet populations, and methods of controlling pet populations and stray animals. Responses to a questionnaire were used to evaluate the attitudes of 910 pet owners and nonowners toward factors comprising responsible pet ownership. The median age of the respondents was 33 years; 414 (45 percent) were men, and 496 (55 percent) were women. At the time of the study, 18 percent owned a cat and a dog, 35 percent owned only a dog, 11 percent showed only a cat, and 36 percent were nonowners. Not only the sex of the respondent but also the category of pet ownership affected opinions on overpopulation of dogs and cats, nuisance and pollution problems associated with these animals, and methods of controlling pet populations in the community. For example, owners agreed strongly on family planning for pets, but a majority of male owners stated that they would not have their dogs neutered.

Effects of Moraxella bovis vaccination schedules on experimentally induced infectious bovine keratoconjunctivitis.

An oil-adjuvant Moraxella bovis bacterin was administered to weanling calves, using different vaccination schedules. Calves were given a booster vaccination after 3 weeks and were challenge exposed 2 weeks later with virulent M bovis recovered from calves with clinical infectious bovine keratoconjunctivitis (IBK). The effects of different routes of vaccination and homologous and heterologous challenge exposure on the incidence, severity, and duration of induced IBK was evaluated. All calves given a placebo developed clinical IBK. Calves vaccinated subcutaneously in the neck had the shortest duration of M bovis infection, the lowest incidence and the shortest duration of acute IBK, and the lowest disease severity score, compared with effects in calves given a placebo or vaccinated subconjunctivally. Calves challenge exposed with the homologous strain of M bovis had more infected eyes, more eyes with acute IBK, longer duration of infection, and a higher severity and duration disease score.

Epizootiologic features of canine hydrocephalus.

In a retrospective study of hydrocephalus (of congenital origin) diagnosed in 564 dogs, 11 breeds (including 8 "toy" breeds) were identified as being a significantly high risk. An inverse relationship between risk and body size was detected. The smaller the dam at maturity, either in height at the shoulder or body weight, the greater the risk of hydrocephalus in the offspring.

Risk factors related to the prevalence of infectious bovine keratoconjunctivitis.

A cross-sectional epizootiologic study was conducted by mailed questionnaire to determine how the prevalence of infectious bovine keratoconjunctivitis (IBK) related to selected predisposing causes. The prevalence of IBK in Missouri during the summer of 1978 was 4.97 cases/100 cattle, with 45% of respondents reporting cases of IBK. A higher prevalence of IBK was associated with calves and yearlings, Hereford and Hereford-cross cattle, backgrounding cattle operations, and herds with a history of IBK. Vaccination of mature cattle against infectious bovine rhinotracheitis was associated with significantly higher prevalence of IBK in calves. A significantly lower prevalence of IBK was associated with dairy cattle operations, older cattle, and the winter months. There was no association between the prevalence of IBK and locale, nutrient supplementation, pasture management, use of vaccines other than infectious bovine rhinotracheitis, parasite prophylactic measures, or fly control measures.

Risk factors associated with canine heartworm infection.

Risk factors associated with canine heartworm infection were determined by screening medical records from the Veterinary Medical Data Program of June 1964--May 1976. Data represented were from 14 colleges and schools of veterinary medicine in the United States and Canada. A total of 3,655 dogs were infected. Intact male dogs 4 to 7 years old and of the larger hound breeds had the highest relative risk, whereas dogs of smaller breeds, those less than 2 years old, spayed females, and castrated males were at least risk.

Effect of age and sex on the prevalence of intestinal parasitism in dogs.

The effects of age, sex, and neutering on the prevalence of canine intestinal parasitism were evaluated by fecal examination of 1,468 pet dogs admitted to the University of Missouri Veterinary Teaching Hospital during 1975. Evidence of hookworm infection was encountered in 35.8% of the dogs examined, whipworms in 18.5%, ascarids in 17.9%, tapeworms in 5.2%, and coccidia in 4.5%. Evidence of intestinal parasitism was not detected in 653 (44.4%) dogs. Whipworm infections were detected less often in young dogs than in older ones, whereas ascarid and coccidial infections were more prevalent in pups that in mature dogs. In dogs more than 6 months old, hookworm infections were the most common parasitism. Tapeworm infections were diagnosed sporadically in all age groups. For most of these parasites, castrated males and spayed females had decreased prevalence of infection, compared with their respective intact counterparts. There were significant (P less than 0.05) differences in the prevalence of both ascarid and hookworm infections between intact and spayed female dogs. Also, there were significant (P less than 0.001) differences between age categories for all parasites observed. Overall, parasitism tended to decrease with age.

Effect of age and sex on the prevalence of intestinal parasitism in cats.

The effects of age, sex, and neutering on the prevalence of feline intestinal parasitism were evaluated by fecal examination of 1,294 cats admitted to the University of Missouri Veterinary Teaching Hospital for the 3-year period, 1974 to 1976. Approximately 37% of the cats examined had 1 or more parasite species. Ascarids were the most commonly encountered parasites (24.4%), with coccidia (6.7%), hookworms (6.4%), tapeworms (5.2%), and trichurids (2.6%) being less frequently observed. Most parasitisms were monospecific. Considering age categories from birth to 5 years, patent ascarid infections were less prevalent in cats greater than 6 months old, whereas hookworm infections were most prevalent in cats 1 to 5 years old; trichurids (whipworms and capillarids) were most often found in cats greater than 6 months old; and coccidia were found with uniform frequency in cats of all age categories. Sex seemed to have no effect on prevalence of parasitism, and the only effect of neutering was on the occurrence of ascarid infection, with spayed females having a prevalance of 14.3%, castrated males, 17.8%, and their intact counterparts, 26%.

Values and limitations of pet ownership.

A questionnaire was used to collect information concerning the values and limitations of pet ownership. The major reasons given for nonownership were housing limitations, emotional dissatisfaction with animals, destructive habits of pets, and a transient household status. Various stages of the family's "life cycle" had a role in determining pet ownership. The pet's agreeable temperament (eg, intelligence, gentleness, and playfulness) was considered to be the major advantages of pet ownership. The major negative characteristics of pet ownership were the destructiveness and overaggressiveness of the pet.

Prevalence of Dirofilaria immitis and Dipetalonema reconditum infections in Missouri dogs.

The prevalence of Dirofilaria immitis and Dipetalonema reconditum infections in Missouri dogs was investigated by means of a statewide veterinary mail survey and a study of shelter dogs from central Missouri and Mississippi River communities. The veterinary survey revealed microfilariae of D immitis in 447 of 11,823 (3.8%) dogs, microfilariae of D reconditum in 14 (0.1%), and microfilariae of both species in 8 (less than 0.1%). Of 493 shelter dogs examined, using the modified Knott test, 23 (4.7%) were positive for D immitis, 23 (4.7%) for D reconditum, and 2 (0.4%) for both helminths. The prevalence of infection with both D immitis (9.4%) and D reconditum (6.3%) was higher in shelter dogs from the Mississippi River communities than in those from central Missouri (1.7% for D immitis, 3.7% for D reconditum). The microfilariae of D immitis in shelter dogs ranged in length from 255 to 343 micrometer (mean, 314 micrometer) and in width from 5.0 to 7.5 micrometer (mean, 6.5 micrometer); those of D reconditum ranged in length from 238 to 295 micrometer (mean, 257 micrometer) and in width from 3.2 to 6.5 micrometer (mean, 4.9 micrometer). Buttonhook tails were seen in 41% of D reconditum. In the final analysis, the shape of the anterior end was considered the most reliable criterion for differentiation.

Antimicrobial resistance among Pasteurella spp recovered from Missouri and Iowa cattle with bovine respiratory disease complex.

A retrospective study was conducted to determine the prevalence of antimicrobial resistance among Pasteurella spp recovered from cattle with bovine respiratory disease complex. The study extended from January 1976 through May 1980, and included a review of the necropsy records of 386 beef cattle. Susceptibility or resistance of the Pasteurella isolants was determined by using the standard disk diffusion susceptibility test. Each isolant was tested for susceptibility with 15 different antimicrobial agents. A high prevalence of resistance (greater than 80%) was found when Pasteurella was tested with triple sulfonamides. For P haemolytica isolants, 57% to 70% were resistant to ampicillin (56/97), penicillin (58/101), and streptomycin (70/100); for unidentified Pasteurella spp isolants, 64% to 91% were resistant to ampicillin (83/129), penicillin (89/129), and streptomycin (118/129). For P haemolytica (21/100) and P multocida (34/146) isolants, 21% to 23% were resistant to tetracycline. Most of the P multocida isolants did not show marked antimicrobial resistance to 9 of the 15 drugs tested. However, 58% of the P multocida isolants (84/145) were resistant to streptomycin and 88% of them were resistant to three combined sulfonamides (126/144).