Ocular manifestations of Rocky Mountain spotted fever in dogs

Dogs were examined ophthalmoscopically to determine the prevalence and type of ocular lesions associated with naturally acquired Rocky Mountain spotted fever (RMSF). In a consecutive series of 11 dogs with serologically confirmed RMSF, 9 had ocular involvement reflecting various degrees of vascular damage, including subconjunctival hemorrhage, hyphema, anterior uveitis, iris stromal hemorrhage, retinal petechiae, and focal areas of retinal edema and perivascular inflammatory cell infiltrate. The ophthalmic lesions generally were mild, and most resolved without complication after systemic administration of appropriate antibiotics. The high prevalence of ocular lesions in these dogs suggested that critical ophthalmologic evaluation is a useful diagnostic tool for the early detection and management of RMSF in dogs.     

Penicillin-induced immune-mediated hemolytic anemia in a horse.

A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.     

Effect of nephropathogenic infectious bronchitis viruses on renal function in young male broiler chickens

1. The acute effects of challenge with Australian T‐strain infectious bronchitis virus (IBV) on renal function were evaluated, following primary vaccination in 1‐d‐old male broilers.

2. Challenge with T‐strain IBV decreased body weight and induced kidney hypertrophy and kidney asymmetry.

3. Haematocrit was reduced in birds challenged with the Australian T‐strain IBV and plasma uric acid was elevated in unvaccinated birds exposed to the IBV challenge.

4. Challenge with T‐strain IBV caused significant increases in urinary water losses, accompanied by decreased urine osmolality and increased fractional excretion of sodium, calcium and potassium.

5. Vaccination at 1‐d‐old with Vic S‐strain IBV provided a limited degree of protection against an heterologous challenge with T‐strain IBV at 15 d of age.     

Scintigraphic evaluation of tissue viability after gunshot injury in a dog.

Triple-phase bone scintigraphy was used to evaluate tissue viability in the forelimb of a dog after gunshot injury. This technique was reliable, noninvasive, and easily performed. It was used to complement radiography by providing functional, rather than structural, assessment of tissues on the basis of regional vascular patterns. In this dog, vascular impairment caused by trauma appeared as photopenic or "cold" spots during immediate (vascular), soft tissue and bone phases of the scintigraphic study. On the basis of gross morphologic and scintigraphic findings, forelimb amputation was performed.     

The effect of level of nutrition on the development of resistance to Haemonchus contortus in sheep

Merino wether weaners, 5-months old at the start of the experiment and fed lucerne-based pellets at 600 g per head per day, developed resistance to Haemonchus contortus given as a continuous or "trickle" infection at the rate of 500 larvae 3 times per week over a period of 17 weeks. By contrast, the development of resistance was impaired in weaners fed pellets at 400 g per head per day. Low food intake and protein-energy deprivation, therefore, have a major effect in impairing the development and expression of host-protective immunity against haemonchosis. The point at which low food intake causes outbreaks of haemonchosis in sheep at pasture is critical in determining procedures for prevention and control of the disease.