Modern veterinary practice最新文献

Cats with mild urethral obstruction are anesthetized, the obstruction removed and the bladder lavaged. Moderately affected cats are sedated and given IV fluids, and usually return to normal soon after the obstruction is removed. Severely affected cats are given IV fluids, NaHCO3 and Ca gluconate, sedated or anesthetized and unblocked. Fluid administration is continued to avoid renal failure. The bladder can be expressed 3-4 times daily or bethanechol given to aid recovery of detrusor muscle function. Halothane, 1% thiopental or thiamylal, or ketamine-acepromazine can be used to anesthetize blocked cats. An 18- or 20-ga, 2 1/2-inch over-the-needle catheter or a lacrimal needle is used to relieve the obstruction, after which a 3 1/2-Fr Silastic or vinyl catheter is used for catheterization and bladder lavage with sterile saline. Cystotomy allows recuperation before definitive corrective surgery.

Many beef herds with less than ideal reproductive efficiency have an 85-90% pregnancy rate, a breeding season longer than 90 days, and less than 60% of the calf crop born in the first 21 days of the calving season. The previous years' fertility levels should be used as a guideline for estimating calf losses and assessing improvement after implementation of reproductive programs. Acute infectious causes of reproductive inefficiency tend to be expressed as abortion or delayed conception. Management-related reproductive problems are common and involve inadequacies in nutrition, replacement heifer development, bull fertility and cow culling.

Egg binding most often affects budgerigars, cockatiels, finches and canaries. Causes include oversized or malpositioned eggs, lack of exercise, nesting too early or late, excessive egg laying, uterine damage or infection, obesity, malnutrition, sudden drops in ambient temperature and genetic factors. Clinical signs are perching unsteadily with ruffled feathers and half-closed eyelids, frequent tail-wagging or straining, swelling over the tail base, and sitting on the cage bottom. Diagnosis is by physical examination and radiography. Treatment may involve increasing the ambient temperature to 85-90 F, lubricating the vent, IM injections of Ca solution and/or oxytocin, egg aspiration and laparotomy.

Patent ductus arteriosus (PDA) is thought to be inherited and occurs twice as often in females as in males, most commonly in Poodles, Collies, Cocker Spaniels and Shetland Sheepdogs. About half of untreated dogs develop left-sided heart failure by 8 months of age. Clinical signs include coughing, decreased exercise tolerance, pulmonary edema, a "machinery" murmur in the pulmonic-aortic region, and a bounding pulse. An ECG may reveal an increased amplitude of the R wave and a lengthened P wave. Plain LAT films reveal loss of the cranial and caudal cardiac waists, increased sternal contact of the heart, increased width and straightened caudal border of the cardiac silhouette, elevated carina, and an enlarged left atrium. Changes on plain DV films include an elongated cardiac silhouette, enlarged right ventricle, and 3 bulges on the left side of the cardiac silhouette. Nonselective angiocardiography can be used for a definitive diagnosis and to demonstrate a reverse right-to-left PDA, in which the ascending aorta, brachiocephalic trunk and left subclavian artery are not opacified by contrast medium. Animals with a right-to-left shunt PDA are cyanotic in caudal body parts. Treatment of left-to-right shunt PDA involves ligation with 2 nonabsorbable sutures. A right-to-left shunt PDA should not be ligated but is treated by restricted exercise and periodic phlebotomy.

Pleural effusions can cause dyspnea and cyanosis, and are caused by cardiomyopathy, pyothorax, FIP, FeLV-related disease and trauma. Thoracentesis is used to obtain fluid samples for cytologic examination and culture. Radiographs made after thoracentesis may reveal the cause. Lymphosarcoma causes a sterile exudate containing neoplastic cells. Congestive cardiomyopathy causes a transudate or modified transudate. The sterile exudate of FIP has a proteinaceous background on cytologic examination. The exudate of pyothorax is septic. Treatment depends on the cause but generally includes thoracentesis and supportive care. Cardiomyopathy causes dyspnea, cyanosis, murmurs, gallop rhythms and other arrhythmias. Radiography reveals a globoid heart in the congestive form and a "valentine-shaped" heart in the hypertrophic form. Treatment of congestive cardiomyopathy involves use of furosemide, but is usually unrewarding. Hypertrophic cardiomyopathy is treated with propranolol. Fever may be caused by infection, immune-mediated disease, neoplasia and unknown causes. Treatment is aimed at removal of the underlying cause.

Initial treatment of colic is aimed at maintaining hydration and acid-base balance, controlling pain and reestablishing peristalsis. A poor response to medical treatment in the first 12-18 hours suggests the need for laparotomy. Other indications for surgery include: rising pulse rate, exceeding 60/minute for several hours; congested mucosae; delayed capillary refill; silent abdomen; gastric reflux; distended or displaced loops of bowel on rectal examination; intractable pain; and adverse laboratory findings. Postoperative care should consist of hand-walking for 30 days, followed by confinement in a small paddock for another 60 days, and reduced grain intake.

A genetically engineered monoclonal antibody, given PO to calves within 12 hours of birth, reduced the severity of diarrhea caused by enterotoxigenic K99 E coli. In challenge studies, dehydration and deaths were markedly reduced in treated calves vs untreated controls (29% vs 82%, 28% vs 82%). Use of the antibody in double-blind field trials on dairy calves in 9 herds in 5 states markedly reduced the severity of E coli diarrhea.