Experimental Salmonella-associated conjunctivitis in cats.

Cats were infected experimentally with Salmonella typhimurium via the conjunctiva. Clinical signs consisted of lacrimation, conjunctivitis, blepharospasm, prominent nictitating membrane and scleral injection. These signs were accompanied by an absolute neutrophilia and conjunctival smears indicative of moderate to severe suppurative inflammation. Ocular signs disappeared by day 6 postinfection. Salmonella typhimurium was cultured intermittently from the inoculated conjunctivae and rectal swabs through day 7. At necropsy, mesenteric and cervical lymph nodes were enlarged. Histopathological findings included chronic conjunctivitis and lymphoid hyperplasia in cervical and mesenteric lymph nodes. This study confirms that S. typhimurium can cause a primary conjunctivitis and that the ocular route of infection can lead to fecal excretion of Salmonella, in the absence of other clinical manifestations.     

A lysosomal storage disorder in the BALB/c mouse: bone marrow transplantation

The morphological and biochemical consequences of transplanting affected bone marrow from donor BALB/c mice with a lysosomal storage disorder (BALB/c LSD) into normal recipient mice were studied. Bone marrow was removed from normal BALB/c and BALB/c LSD mice and transfused into normal BALB/c recipient mice four hours after the mice received 850 rads of irradiation. Tissues of the recipient mice were examined 240 days later. This study revealed that the defective cells that constituted the visceral lesions of BALB/c LSD could be transplanted to normal BALB/c mice by the use of bone marrow from affected BALB/c LSD homozygote; that the defective cells of BALB/c LSD proliferated and disseminated throughout the mononuclear phagocytic system of the recipient; that there were increases in cholesterol, sphingolipids, and cystine with decreases in sphingomyelinase and glucocerebrosidase activity in tissues of the recipients; and that the recipients survived substantially longer than BALB/c LSD homozygotes and their lifespan was compromised mainly by the secondary effects of irradiation. These lesions, although not as extensive as in homozygous BALB/c LSD, paralleled the lesions which develop in BALB/c LSD. Since the recipient mice were not compromised by the short life span (70 days) of the BALB/c LSD mice, they may be used to study the long-term chronic effects of these metabolic lesions.     

Distribution of immunoglobulin-bearing cells in the gut-associated lymphoid tissues of the turkey: effect of antibiotics

Distribution of immunoglobulin (Ig)-bearing cells in the gut-associated lymphoid tissues of antibiotic treated and untreated control turkeys (Meleagris gallopavo) was compared. Antibiotic treatment was similar to a regimen used in commercial turkey production, which included preincubation dipping of fertile eggs in gentamicin solution, injection of turkeys with gentamicin at hatching, and inclusion of chlortetracycline in the diet. Tissues were examined from turkeys at 3, 7, 14, and 21 days of age with a direct immunofluorescence procedure. Cell distribution in control turkeys was as follows: In the bursa of Fabricius, IgA-carrying cells predominated at 3 days of age, but at later intervals, the 3 classes of Ig-bearing cells were in equal numbers. In the cecal tonsils, IgM- and IgA-bearing cells were in larger numbers at 3 days of age, whereas, the IgG-bearing cells were sparsely distributed. By 7 days of age, IgM cells became more numerous in the cecal tonsils and remained numerous until 21 days of age. At 3 days of age, IgA cells predominated in the small intestines and IgM cells predominated in the large intestine. At 7 and 14 days of age, IgM cells were more numerous in the small and large intestines, but by 21 days of age, IgA cell population equaled that of IgM. The IgG cells were generally sparse in the intestines. Antibiotic treatment often resulted in lower numbers of Ig-positive cells, especially those bearing IgM and IgA. Normal development of the bursa of Fabricius was also retarded in this group.     

Efficacy of furazolidone in grower diets on subsequent performance of swine--a cooperative study

Nine experiments were conducted at three stations to evaluate the efficacy of furazolidone as a growth promoter in diets for young swine and to determine if an early growth response is maintained after the additive is withdrawn from the diet. A total of 528 pigs (24 replications, 132 pigs/treatment) initially averaging 12 kg body weight were fed a nonmedicated basal diet or a diet with 110 ppm furazolidone for 5 wk, 165 ppm furazolidone for 3 wk or 220 ppm furazolidone for 2 wk. After withdrawal of furazolidone, the basal diet was fed to the end of the test, at which time the pigs averaged 93 kg. During the initial 2-wk period, pigs fed furazolidone gained 15.4% faster (P less than .001) and required 8% less (P less than .001) feed per unit of gain than control pigs fed the nonmedicated diet. At 5 wk, pigs previously fed furazolidone gained 8.4% faster (P less than .001) and 4.5% more efficiently (P less than .001) than controls. By 10 wk, pigs previously fed furazolidone maintained a slight advantage in growth rate over controls (2.6%, P less than .10), but feed/gain responses were similar for the two groups. By the end of the experiment, the early growth response from furazolidone was completely lost. Although there were differences in growth responses among stations, the treatment response patterns were similar for each station, with no evidence of a treatment X station interaction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Histomorphologic structure of the carotid rete-cavernous sinus complex and its functional importance in sheep (Ovis aries)

Paraffin sections of the carotid rete-cavernous sinus complex of sheep were studied, using different stains. The carotid rete of sheep was composed of medium-sized arteries with smooth muscle layers that were oriented in different directions. The carotid body cells may have migrated proximally in the adventitia of the intracranial portion of the internal carotid artery as its extracranial portion degenerates early in life. The cavernous sinus shared a common tunica adventitia with surrounding rete branches. At places, the wall of the cavernous sinus had a distinct tunica media interposed between the endothelial cells and the tunica adventitia. Therefore, the name cavernous venous plexus has been proposed for the cavernous sinus in sheep.     

Assessment of smooth muscle function in Sesbania drummondii toxicosis in Gallus domesticus

An in vitro assessment based on tissue responsiveness to 2 agonists-histamine and carbachol-was made on smooth muscle activity in chickens experimentally poisoned with sesbania. Crude extracts of Sesbania drummondii were prepared and 2 dosage levels, 0.25% and 0.5% of body weight, were used. The birds were dosed orally with the extract for 3 consecutive days, and on the 4th day segments of ileum and lung were collected from each bird. The isometric contractions of each tissue, produced by the addition of histamine or carbachol in graded concentrations, were recorded. The cumulative concentration-effect curves for the tissues to the agonists were constructed and compared with respective control curves. The results indicated the responsiveness of the tissues in the treated groups was significantly decreased, compared with that of tissues in the controls. Responses of both intestinal and parenchymal strips in the chickens given the higher dosage (0.5%) were decreased significantly, whereas in those given the smaller dosage (0.25%), only parenchyma had a significant response. This indicates that the activity of smooth muscles in general was depressed by sesbania. The effect was more evident in the lung than in the intestine. Therefore, an active principle in the extract which affects smooth muscle, rather than causing direct irritation, may exist. This assessment of smooth muscle activity is sensitive and was effective in detecting changes in tissues from sesbania-treated birds which had not shown any clinical signs. The results also support the possibility that smooth muscle involvement could be a primary cause of toxicity in sesbania poisoning.     

Chronic chondritis of the arytenoid cartilages in a pony mare

The upper respiratory tract of a pony mare with marked exercise intolerance and respiratory stridor was examined with a flexible fibreoptoscope. Both arytenoids were adducted and distorted. A diagnosis of bilateral chondritis of the arytenoids was made and confirmed at autopsy after surgery to enlarge the rima glottidis was unsuccessful. Other space occupying lesions of the rima glottidis are discussed and theories on the aetiology are postulated.     

Verminous (Strongylus vulgaris) myelitis in a donkey

A fifth stage Strongylus vulgaris migrated through the spinal cord of a 2-year-old, male donkey resulting in progressive paraparesis and then tetraplegia. A profound neutrophilic pleocytosis was detected on analysis of cerebrospinal fluid. The parasite appeared to have entered the mid-lumbar spinal cord, migrated to the cranial thoracic segments, exited, then re-entered the spinal cord a few segments craniad. It then traveled further cranially and was found in the third cervical spinal cord segment. Some parts of the lesion were remarkably free from tissue necrosis, hemorrhage and inflammation. Severe granulomatous myelitis with hemorrhage and necrosis were seen at other sites. The latter were quite similar to lesions seen in equine protozoal myeloencephalitis.