Factors affecting urinary pyridinoline and deoxypyridinoline excretion in the growing lamb.

Changes in urinary pyridinium crosslink excretion and plasma osteocalcin and growth hormone levels were measured at 3-5 week intervals in lambs from 2-22 weeks of age, in relation to changes in metatarsal length. There were close correlations between pyridinium crosslink excretion and plasma growth hormone levels and live weight gain, but no direct relationship was seen between the rates of excretion of the pyridinium crosslinks and linear bone growth. Plasma osteocalcin levels were correlated with linear bone growth rate up to about 12 weeks of age but, thereafter, showed no correlation despite a continued decline in bone growth rate. In the young lamb, daily pyridinium crosslink excretion represented 1.3-2.9% of that in the body, declining to 0.06% of pool size in adult sheep.

Experimental copper poisoning in the camel (Camelus dromedarius).

Copper sulphate was administered by the oral or intravenous route to five dromedary camels. Two camels (1 and 2) receiving copper sulphate at 200 mg per kg per day by drench died within 8 days and camel 3, receiving 100 mg per kg per day by the same route, was slaughtered on day 172. Intravenous injection of 2 mg per kg per day caused the death of camel 4 on day 95 and camel 5, treated similarly, was slaughtered on day 138. Anorexia, dullness, diarrhoea, dehydration and recumbency in camels 1 and 2 were probably clinical signs of copper toxicity. Camels 3, 4 and 5 lost weight. Jaundice was not a prominent clinical sign. The main lesions in camels 1 and 2 were fatty change and necrosis of the liver cells, dilatation and necrosis of kidney tubules, catarrhal abomasitis, enteritis and congestion of the blood vessels of the heart. In camels 3, 4 and 5 the hepatic lesions were mild, with leucocytic infiltration and gastrointestinal and heart lesions were either mild (camel 3) or absent (camels 4 and 5). Cytoplasmic copper granules in hepatic cells were generalized in distribution but more concentrated in the centrilobular zone. In the kidney these granules were confined to the cells of the proximal convoluted tubules. Copper accumulated in the liver and kidneys of all the camels and zinc accumulated in the liver and kidneys of those receiving copper sulphate intravenously. Macrocytic hypochromic anaemia developed in camels 3, 4 and 5 and haemoconcentration in camels 1 and 2. The concentration of serum copper, zinc and iron increased in animals 1, 2 and 4, and unbound iron binding capacity decreased in four camels. There was a rise in the activity of gamma GT, GOT, LDH and CPK in the serum of all the animals. Serum ALP activity, however, increased in camels 1 and 2 and decreased in camels 3, 4 and 5.

Effects of dietary acidity on calcium balance and mobilisation, bone morphology and 1,25 dihydroxyvitamin D in prepartal dairy cows.

The effect of an acid or alkali diet was investigated in 14 mature dairy cows during the last 28 days of pregnancy. The acid diet reduced the incidence of parturient hypocalcaemia compared with the alkali diet and was associated with higher blood ionised calcium and plasma chloride concentrations and lower blood pH and acid-base excess before parturition. Plasma 1,25-dihydroxyvitamin D concentrations before parturition were increased by the acid diet but the concentrations of parathyroid hormone and intact 1-86 parathyroid-hormone-related peptide were unaffected. The estimated fractional calcium absorption and calcium mobilisation rate during an ethylenediamine tetraacetic acid infusion were increased by the acid diet 14 days before parturition. Cortical bone remodelling occurred in all the animals during late pregnancy but was particularly evident in the cows given the acid diet. The data suggest that an acid diet ameliorates parturient hypocalcaemia by enhancing calcium mobilisation before parturition by increasing calcium absorption and bone resorption, these increases possibly being mediated by increases in the plasma concentration of 1,25-dihydroxyvitamin D.

Isolation of Brucella abortus from experimentally infected dromedary camels in Sudan: a preliminary report.

Six camels were experimentally infected with two strains of Brucella abortus, four with S19 and two with a field bovine strain. In all cases antibody titres were detected within 6 to 11 days. Serum agglutination titres peaked between days 11 and 32 and complement fixation titres between days 11 and 52; both titres then declined steadily. No clinical signs were observed in the four camels inoculated with S19. Slight non-specific symptoms were seen in the two camels infected with the field bovine strain. On post mortem examination no gross lesions were observed although histopathological sections showed focal granulomata in the liver and a generalized lymphadenitis. The organism was recovered mainly from the lymph nodes of the head and genital tract.

Copper status in breeding and racing camels (Camelus dromedarius) and response to cupric oxide needle capsules.

Copper was determined in the blood of breeding camels, camel calves and racing camels to evaluate copper status in these animals in UAE. Low blood copper concentrations were reported in newly born camel calves (100%) and calves 2-4 months old (68%), breeding camels at early (55.6%) and at mid lactation (48%) and at late pregnancy (69%). This is attributed to the low copper and high sulfate in the Rhodes grass which is the only diet offered to the breeding camels. On the other hand only 9.7% of racing camels showed low copper levels. This is because copper is routinely offered to racing camels when their blood copper is low. Cupric oxide needle capsules orally administered at the rate of 8 g per adult camel was effective in elevating blood copper from 7.083 micromol/L at day zero to 10.074 micromol/L at day 28 after dosing.

Clinical and subclinical colloid goitre in adult camels (Camelus dromedarius) at Kordofan region of Sudan.

Colloid goitre was diagnosed in adult camels in the Kordofan region of the Sudan. The disease is characterized by gross enlargement of the thyroid, histopathological follicular changes, reproductive disorders, low concentrations of circulating thyroid hormones (T3, T4) and normocytic normochromic anaemia. The possible cause of the condition is discussed and iodine supplementation is recommended.

The effects of feeding diets containing either NaHCO3 or NH4Cl on indices of bone formation and resorption and on mineral balance in the lamb.

The effects of diet-induced changes in blood acid-base status on mineral retention has been studied in lambs fed diets containing either 1% NH4Cl or 2% NaHCO3. Balance measurements using 45Ca and 32P showed no difference between them in the amounts of dietary Ca and P absorbed from the gut. Retention of both minerals, however, was lower and their excretion in urine higher in those fed the acid diet. Plasma Ca and P levels were unaffected but parathyroid hormone and 1,25-dihydroxyvitamin D3 levels were higher in lambs on this diet while measurements of tartrate-resistant acid phosphatase and alkaline phosphatase levels in rib samples indicated an increase in osteoclast and a reduction in osteoblast activity in these lambs. Cell-mediated changes in bone turnover together with changes in urinary mineral loss would thus appear to be the major factors contributing to the lower rates of mineral retention seen in lambs fed acid diets.

Camel (Camelus dromedarius) contagious ecthyma in the Sudan. A case report.

The clinical and pathological features of the contagious ecthyma in camel calves in the Sudan were investigated. The animals were inappetant, emaciated and slightly anaemic. The disease was characterized by skin lesions around the lips and nostrils with occasional involvement of mucocutaneous junctions. The pathology includes vaculoar changes of the epithelial layers. Affected areas were ulcerated, haemorrhagic and with frequent secondary bacterial surinfection. Negative contrast electron microscopy has proven to be an extremely useful procedure for quick differential diagnosis.

Toxicity of Abrus precatorius in Nubian goats.

Eight Nubian goats were given Abrus precatorius seed at 2, 1 and 0.5 g/kg/day by stomach tube. Six goats receiving the plant seed at 2 and 1 g/kg died between days 2 and 5. One goat receiving Abrus seed at 0.5 g/kg/day died on day 32 and the other animal in the group was killed on day 33. The main signs of Abrus poisoning were inappetence, bloody diarrhea, dyspnea, dehydration, loss of condition and recumbency. The lesions were fatty change and necrosis of hepatocytes and renal convoluted tubules, pulmonary hemorrhage, edema and emphysema, and erosions of the abomasal and intestinal epithelium. These changes were accompanied by increases in GOT and gamma GT activities and urea, creatinine, sodium and potassium and by decreases in total protein and albumin in the serum of Abrus-poisoned goats. The blood cell changes indicated hemoconcentration.

Effects of acute acid loading on parathyroid hormone secretion and on urinary calcium and cAMP excretion in the growing lamb.

Growing lambs fed a diet containing NaHCO3 were made acidotic by intravenously infusing HCl at the rate of 1 mmol/min over a 4 h period. Acid infusion led to a fall in blood and urine pH and a prompt increase in urinary Ca excretion. This in turn led to a fall in plasma Ca concentration and a rise in parathyroid hormone (PTH) levels. Urinary cAMP excretion was unaffected by acid infusion. In separate experiments lambs made acidotic by feeding a diet containing NH4Cl were given infusions of PTH at the rate of 1 microgram/h. Infusion of the hormone was accompanied by a rise in plasma Ca and an increase rather than a decrease in urinary Ca excretion and no change in urinary cAMP excretion. These results point to the kidney as the primary site of response to acid loading in the lamb, a failure to reabsorb Ca in these conditions necessitating the release of PTH and an increase in bone resorption in order to maintain normal plasma Ca levels.