Escherichia coli associated cellulitis in broilers: correlation with systemic infection and microscopic visceral lesions, and evaluation for skin trimming.

In Alberta, cellulitis condemnations average 0.5% and are among the highest in Canada. Presently, all cellulitis-affected birds are condemned for fear of systemic infections and public health implications. In a slaughterhouse sample of 102 birds condemned with cellulitis, Escherichia coli was isolated from 83.3% of the lesions. All hearts were cultured and from 11.2% E. coli was recovered. Gross lesions of perihepatitis, infected oviducts, and arthritis were found in 11.2%, 6.7%, and 2.9% of the birds, respectively. Serotyping suggested that visceral infection occurs independent of cellulitis in at least half of the cases. There was no correlation between microscopic visceral lesions and positive bacterial cultures. Two E. coli isolates of serogroup 0157 produced no toxin and neither isolate produced CS31A, F107, or F1845 fimbriae. Cellulitis lesions ranged from 0.55 to 218.9 cm2. All lesions under 16 cm2 and 64% of lesions up to 48 cm2 were considered suitable for trimming.

Injuries and behavior of raccoons (Procyon lotor) captured in the Soft Catch and the EGG traps in simulated natural environments.

The behavior and injuries of raccoons held for 12 and 24 hr in the Soft Catch and the EGG traps were studied in simulated natural environments. Nine raccoons held for 12 hr in the Soft Catch received minor injuries. However, one of nine raccoons held for 24 hr in this trap mutilated itself. The EGG trap caused only minor injuries to nine raccoons held for 12 hr, and nine others held for 24 hr. Thus the EGG trap can be expected, at a 95% level of confidence, to hold > or = 70% of the raccoons on traplines for 24 hr without serious injury. Raccoons captured in the Soft Catch fought their surroundings more than the trap. Those captured in the EGG trap fought the trap more than their surroundings. During the 24-hr capture study, escape behavior was more intense during the first 12 hr of capture, during both day and night.

Induction of follicular development in silver foxes (Vulpes vulpes) with equine chorionic gonadotrophin (eCG) and antibodies against eCG.

Experiments were conducted that demonstrated that 1000 iu equine chorionic gonadotrophin (eCG) was effective in induction of follicular development and ovulation in silver foxes during anoestrus. This treatment resulted in large, unovulated follicles; thus, trials in which the effects of eCG were reduced or abrogated by antibodies against eCG were carried out. Passive immunization against eCG on days 3 and 4 after eCG treatment interfered with subsequent follicular development and prevented ovulation. Treatment with eCG antibodies on days 5 or 7 after eCG treatment did not prevent ovulation and neutralization beginning on day 5 appeared to provide for the best ovulatory yield. The results suggest that combinations of eCG and anti-eCG antibody may provide a useful means of inducing ovarian activity in anoestrous foxes.

Fatal herpesvirus infection in commercial rabbits.

Acute mortality occurred in two unrelated rabbitries. In the rabbits examined, an unidentified herpesvirus caused lesions that have not been reported previously in this species. The primary lesions were multifocal hemorrhagic dermatitis on the face and back, localized pneumonia, and severe splenic necrosis. Large eosinophilic, intranuclear inclusion bodies that were observed in tissue sections of skin, spleen, and lung were identified as herpes-like viral particles by electron microscopy, and herpesvirus was cultured on rabbit kidney cells. Intramuscular injection of tissue culture fluid containing virus resulted in mortality and severe illness in two seven-week-old domestic rabbits four and six days postinfection, respectively. The gross and microscopic lesions were reproduced and herpeslike viral inclusions were observed in skin lesions. Herpesvirus was recovered from lung, trachea, spleen, liver, and from the thigh muscle at the site of inoculation. The experimental infection also activated severe pasteurella septicemia. The herpesvirus isolate needs further characterization.

Efficacy of triclabendazole against natural infections of Fascioloides magna in wapiti.

Fourteen free-ranging adult wapiti (Cervus elaphus nelsoni) were captured in Banff National Park, Alberta (Canada) and held in captivity near Edmonton. A 24% suspension of triclabendazole at doses of 30 to 100 mg/kg body weight was drenched into the rumen of eight females and four males. Two male wapiti were used as untreated controls. Animals were killed and examined at 4 (n = 3), 6 (n = 4), or 8 (n = 4) wk after treatment. Efficacy was 90% against immature Fascioloides magna collected 4 wk after treatment and 98% against adult flukes collected 4, 6 or 8 wk after treatment. All 32 flukes recovered from control wapiti were active and apparently healthy. Treatment at 50 to 60 mg/kg is recommended against F. magna in wapiti. A protocol for treating infected wapiti is outlined.

Fibrosing cholehepatitis in broiler chickens induced by bile duct ligations or inoculation of Clostridium perfringens.

The pathogenesis of fibrosing hepatitis causing condemnations in broiler chickens was investigated. Three to four week old broilers were inoculated via the hepatoenteric bile duct with saline washed suspensions of Clostridium perfringens (10(7) and 10(8) organisms). In another group of broilers, both bile ducts were ligated. The sequential development of liver and gall bladder lesions was studied at intervals ranging from 1-28 days postsurgery. The lesions were similar in both experiments in that the liver became mottled and swollen by five to seven days. Fibrinoid necrosis, heterophil and lymphocyte infiltration, bile duct hyperplasia and fibrosis with reticulin fiber proliferation occurred. By 14-17 days, the liver was enlarged, tan colored and firm with red and white foci. By 28 days, bile duct proliferation and fibrosis were massive with only a few hepatocytes remaining. The liver capsule was not involved. Jaundice was not present but the birds with ligated bile ducts excreted intensely yellow stained droppings after six to seven days. The gall bladder in inoculated birds was edematous and distended with flocculent or inspissated material. Clostridium perfringens was reisolated from gall bladder and/or liver of inoculated birds up to 28 days postsurgery. It is suggested that this organism plays a role in the pathogenesis of fibrosing cholehepatitis by inducing septic intrahepatic cholestasis.

Prevalence and pathology of nematode infections in the lungs of ringed seals (Phoca hispida) of the western arctic of Canada.

Two genera of lung nematodes were found in a sample of 382 wild ringed seals (Phoca hispida). Otostrongylus circumlitus were found mainly in young of the year where they occupied the main stem bronchi causing extensive mucus production, mucosal hyperplasia and peribronchitis. Immature stages of the nematode were found in pulmonary vessels causing end-arteritis. There was only a slight reduction in respiratory parenchyma in infected seals and no correlation between infection and size or body condition. However, the sharp decline of O. circumlitus infection from 32% in young of the year to 0.5% after the first winter suggests that this parasite may play a role in the population dynamics of ringed seals. Filaroides (Parafilaroides) hispidus was found in alveoli of seals throughout all age classes causing no significant lesions. The infection rate increased from 44 to 71% in the 7 to 13-yr-old animals and declined to 38% in older seals. Concurrent infections occurred in 28% of young of the year seals.

Susceptibility of Rocky Mountain bighorn sheep and domestic sheep to pneumonia induced by bighorn and domestic livestock strains of Pasteurella haemolytica.

Bighorn sheep were inoculated intratracheally with suspensions of nonhemolytic Pasteurella haemolytica biotype T (10(12) organisms) unique to wild bighorns, with beta-hemolytic P. haemolytica biotype T (10(12) organisms) isolated from clinically normal domestic sheep or intradermally with half a dose of a cattle vaccine containing P. haemolytica biotype A (10(5) organisms). The bighorn strain caused lobar necrotizing bronchopneumonia whereas both domestic livestock strains precipitated fatal septicemia and fibrinous bronchopneumonia. The serotypes given were T3, T4, T15 and A1 and these were recovered from lung lesions and other organs. In three trials, domestic sheep were inoculated intratracheally with suspensions of bighorn sheep pneumonic lungs, and two concentrations of the P. haemolytica bighorn strain (10(4) and 10(12) organisms). One of these sheep was inoculated intrabronchially. The domestic sheep experienced a transient fever and elevated white blood cell counts. After six days, none of the sheep had lung lesions and inoculated organisms could not be recovered. It is suggested that bighorn sheep are very susceptible to P. haemolytica from domestic livestock and should not be allowed in contact with sheep or cattle.

Experimental contact transmission of Pasteurella haemolytica from clinically normal domestic sheep causing pneumonia in Rocky Mountain bighorn sheep.

Two Rocky Mountain bighorn lambs (Ovis canadensis canadensis) were held in captivity for 120 days before being housed with two domestic sheep. The lambs were clinically normal and had no Pasteurella spp. on nasal swab cultures. The domestic sheep were known to carry Pasteurella haemolytica biotype A in the nasal passages. After being in close contact for 19 days. P. haemolytica biotype A was cultured from nasal swabs of one of the bighorn lambs. By 26 days, both bighorn sheep developed coughs, were anorectic and became lethargic and nasal swabs yielded P. haemolytica biotype T, serotype 10. Twenty-nine days after contact, the lambs were necropsied and found to have extensive fibrinous bronchopneumonia. From affected tissues pure cultures of beta-hemolytic P. haemolytica biotype T, serotype 10 were grown. Both domestic sheep remained clinically normal and had no gross or microscopic lesions, but they carried the same P. haemolytica serotype in their tonsils. Behavioural observations gave no indication of stress in the bighorn lambs.

Use of equine chorionic gonadotrophin in female mink.

This study was comprised of three trials to determine the effects of equine chrionic gonadotrophin (eCG) on induction of sexual receptivity in female mink that had failed to mate by late in the breeding season. In the first trial one ovary was removed from unmated mink, which were then injected with 100 IU eCG. This treatment induced ovarian activity, including ovulation in the remaining ovary. In the second experiment, mink that had not been observed to mate were treated with 100 IU eCG or saline, resulting in mating of 10 11 of the eCG-treated animals, compared to 5 11 controls. Litter sizes were larger in mink in the control group, suggesting that eCG interfered with some phase of the reproductive process. In the third trial, 226 mink that had failed to mate until late in the breeding season were treated with 100 IU eCG. Of the 191 that subsequently mated, 99 produced litters, but litter sizes were reduced slightly from those observed in the remainder of the herd that bred without hormone treatment prior to March 20. Neonatal kit loss per female whelping was greater in mink treated with eCG. It is concluded that eCG treatment will induce mating in mink that refuse to mate, but this treatment results in reduced whelping success and greater neonatal kit loss. Its utility may be restricted to salvage situations where large numbers of mink fail to mate.

Renal pathology in chicks following water deprivation.

Total water deprivation of 2-day-old broiler chicks for 24, 48, 72, 96, and 120 hours did not result in visceral urate deposits. Renal tubular changes consisted of increased spaces between membrane infoldings of the distal convoluted tubular epithelium, increased number of cytoplasmic vacuoles in proximal convoluted tubules, and increased mucin production and dilation of collecting ducts.

Salmonellae and salmonellosis in captive reptiles.

In a survey of 150 pet reptiles submitted for necropsy, 51% of snakes, 48% of lizards and 7% of turtles were infected with Salmonella. About one third of the positive animals had died due to various manifestations of salmonellosis. Thirty-one Salmonella serotypes were identified including three isolates new to Canada. The public health implications are discussed in view of the restricted popularity of reptiles and their possible infection from domestic agricultural products.

Ultrastructural changes of sodium chloride-induced cardiomyopathy in turkey poults.

Round heart disease and ascites were induced in 8-day-old turkey poults by administering 0.75% sodium chloride in distilled water. Clinical signs included increased water consumption, loose feces, depression, and increased respiratory rate. Mortality was noticed after 3 days on the saline solution. Light microscopic and electron microscopic studies were made on the right and left free cardiac ventricular walls. Massive glycogen accumulations were demonstrated by periodic acid-Schiff staining and malt diastase digestion. Electron microscopic studies further showed the presence of extensive intrafibrillar glycogen, myofibrillar disarray, lysis of myofilaments, Z-band streaming, and disruption of intercalated discs. These changes are consistent with congestive heart failure and are similar to furazolidone-induced cardiomyopathy. A mechanism is suggested whereby sodium ions may cause hypertension and also act directly to influence the electrical and contractile activity of the heart muscle.

Actinobacillus septicemia in a black swan (Cygnus atratus).

A species of Actinobacillus was isolated in pure culture from the carcass of a captive Australian black swan (Cygnus atratus) dying of acute septicemia. The gross and microscopic findings are described and the significance of the isolate is discussed.

Granulosa cell tumor in a garter snake (Thamnophis sirtalis).

A granulosa cell tumor was identified in a captive six year old Garter Snake (Thamnophis sirtalis). Metastasis to both kidneys was manifested as miliary white foci and structure distortion.