DESORPTION OF PHOSPHATE FROM SOILS USING ANION EXCHANGE RESINS

After 100h reaction with Cl-resin and 300h reaction with HCO₃-resin (approaching equilibrium), the concentration of anions complementary to phosphate was the critical variable affecting the transfer of P from soil to resin. Solution concentrations of H₃0⁺, Ca²⁺ and phosphate indicated that desorption of P by OH^-, and dissolution of Ca phosphates, controlled P release from soils. P extracted by HCO₃-resin was much greater than by Cl-resin from an acid soil, due to lower total anion and higher desorbing anion concentrations, but there was little difference between the two resins with a calcareous soil. HCO₃-resin extracted a constant proportion of isotopically-exchangeable P from different soils whereas Cl-resin did not. Anion exchange resins provide a convenient means for producing P desorption curves for soils.     

Extensive resection and anastomosis of the descending (small) colon in a mare following strangulation by a mesenteric lipoma

A 17-year-old Quarter Horse, Arabian crossbred mare presented with a history of having had abdominal pain for 2 d. At surgery there was 2.6 m of descending colon strangulated within the pedicle of a mesenteric lipoma. The lipoma was resected and the descending colon appeared viable so was replaced, and the mare recovered from anaesthesia. Post-operatively, the mare failed to stabilise so was taken back to surgery. There was 2 m of infarcted descending colon which was resected and anastomosed. A drain and stainless steel stay sutures were incorporated into the ventral suture line. Post-operatively the ventral wound became infected but was resolved with therapy. The diagnosis, surgical and post-operative management and outcome are discussed.     

Malassezia dermatitis in the dog: a retrospective histopathological and immunopathological study of 86 cases (1990–95)

A retrospective histopathological and immunopathological study was conducted on 86 dogs with Malassezia dermatitis. West Highland White terriers, English Setters, Shih Tzus, Basset Hounds, American Cocker Spaniels, spayed females, and castrated males were found to be at increased risk. The histopathological reaction pattern of lymphocytic superficial perivascular to interstitial dermatitis with parakeratotic hyperkeratosis, irregular epidermal hyperplasia, diffuse intercellular oedema and lymphocytic exocytosis was found to be consistent with a diagnosis of Malassezia dermatitis whether yeast were histologically visible (73.3% of the cases) or not (26.7%). Immunopathological studies revealed that 60– > 90% of the inflammatory cells within the epidermis, and 25–75% of those within the dermis were CD3+T lymphocytes, and that the only immunoglobulin-positive cells were dermal plasma cells.     

The life history of Haplorchis pumilio (Looss, 1896) from cultured tilapias

Abstract. The metacercaria of Haplorchis pumilio (Looss, 1896) (Digenea: Hetero-phyidae) was found to occur commonly in intensively reared tilapias ( Tilapia, Sarotherodon ) in an East African fish farm. The life cycle on the farm was found to involve the gastropod Melanoides tuberculata (Müller) as the first intermediate host. The infection was experimentally transmitted to fish in fresh water from naturally infected molluscs. The salinity of the water on the farm varied with season from 0 to 3%₀, but cercariae were shown to remain infective up to 10%₀ although longevity was reduced at 7.5%₀. Piscivorous predators, Ardea cinerea L., Phalocrocorax sp. and Varanus sp., which were resident or regular visitors to the farm were heavily infected with the parasite. Mice, hamsters and pigeons were found to be convenient laboratory hosts. H. pumilio shows a lack of specificity at the second intermediate and final host level as well as a wide geographic range and has been reported to infect man. Its potential as a possible cause of zoonoses, and control methods are discussed.     

Caecal disease in equids

Objective To review the breed, age, gender, clinical and laboratory findings, treatment and outcome of horses with caecal disease presented to a referral centre. Design Retrospective study of 96 cases. Procedure The breed, age, and gender of the study population were compared with the corresponding hospital population for the same period. The means (± SD) for clinical and laboratory findings were recorded for each caecal disorder. Treatment was categorised as medical or surgical, and outcome was recorded. Results Caecal diseases included impaction (40% of total cases), rupture associated with concurrent unrelated disease (13%), rupture with parturition (9%), rupture with no associated disease (5%), infarction (11%), torsion (9%), abscess or adhesion (7%), tumour (3%), and miscellaneous conditions (3%). The breed or gender of affected horses did not differ from the hospital population, although horses > 15 years were more frequently represented (P < 0.05). This age group was specifically more predisposed to caecal impaction (P < 0.05), as were Arabian, Morgan, and Appaloosa breeds (P < 0.05). In horses with caecal impaction transrectal examination was the most useful diagnostic procedure; 90% of affected horses treated medically were discharged while horses treated by typhlotomy alone, or typhlotomy and blind end ileocolostomy, had survival rates to discharge of 71% and 86%, respectively. Horses with caecal rupture associated with concurrent un-related disease showed no signs of impending rupture; all were receiving phenylbutazone, all were euthanased, and 50% had caecal ulceration at necropsy. Of horses with caecal rupture with parturition 56% had prior dystocia; in two-thirds the site of rupture was the ileocaecal junction and all were euthanased. Horses with caecal rupture with no associated disease died or were euthanased; rupture was idiopathic. Horses with caecal infarction usually had signs of abdominal pain and abdominal fluid changes consistent with peritonitis; transrectal examination was nonspecific, and typhlectomy was successful in seven of eight horses. Horses with caecal torsion had signs of severe, acute abdominal pain and typhlectomy was successful in three of five horses. Diagnosis of caecal adhesion or abscess was assisted by transrectal palpation in two of seven horses and surgical treatment was successful in two of five horses. A caecal tumour was diagnosed in three horses aged 20 years or older that presented with chronic weight loss. Other caecal diseases were uncommon. Conclusion Caecal disease is uncommon in equids but some specific features of the history and physical findings can alert the veterinarian to the possibility of caecal involvement in horses with gastrointestinal dysfunction. Medical or surgical therapy can be effective in horses where caecal rupture has not occurred.     

Conservative management of minimally displaced radial fractures in three horses

Minimally displaced, spiral, radial fractures were diagnosed in three adult horses. Two horses had open fractures and in one horse the fracture was closed. A diagnosis was made on radiographs taken 24 h, 5, and 9 days after the fracture. There was minimal displacement of the fracture fragments despite the considerable time which had elapsed between fracture and diagnosis and an unfavourable prognosis with internal fixation, so conservative therapy was the preferred method of treatment. One horse developed a sequestrum and draining sinus, which was treated surgically under general anaesthesia 3 months after diagnosis of the fracture. Other complications were minimal and transient. Two horses were being used for pleasure riding 12 months after fracture and one horse was pasture sound at 8 months.