Stephen B. Adams

Degree of antigen adsorption in the vaccine or interstitial fluid and its effect on the antibody response in rabbits

The effect of the degree of adsorption of lysozyme by aluminium hydroxide adjuvant on the immune response in rabbits was studied. The surface charge of the adjuvant was modified by pretreatment with phosphate anion to produce five vaccines having degrees of adsorption ranging from 3 to 90%. The degree of adsorption of vaccines exhibiting 3, 35 or 85% adsorption changed to 40% within 1 h after each vaccine was mixed with sheep interstitial fluid to simulate subcutaneous administration. The mean anti-lysozyme antibody titers produced by the vaccines were the same and were four times greater than that produced by a lysozyme solution. Thus, the degree of adsorption of lysozyme in sheep interstitial fluid rather than the degree of adsorption in the vaccine correlated with the immune response.

Comparison of two tourniquets and determination of amikacin sulfate concentrations after metacarpophalangeal joint lavage performed simultaneously with intravenous regional limb perfusion in horses

OBJECTIVE To determine whether joint lavage performed simultaneously with IV regional limb perfusion (IVRLP) reduces the effectiveness of IVRLP and to compare 2 types of tourniquets used for this procedure in horses. ANIMALS 11 adult horses. PROCEDURES 2 groups of 6 horses were tested by use of a pneumatic or an Esmarch tourniquet (1 horse was tested twice [once in each group]). Standing IVRLP with amikacin (500 mg) was performed for 30 minutes. Simultaneously, the metacarpophalangeal joint was lavaged with 2 L of lactated Ringers solution and the egress fluids were collected. Samples of the distal interphalangeal joint synovial fluid and blood from the digital and jugular veins were collected at set time intervals. Amikacin concentrations in all fluids were determined via fluorescence polarization immunoassay. RESULTS Less amikacin was measured in the systemic circulation with the Esmarch tourniquet than with the pneumatic tourniquet. Amikacin concentrations in the synovial fluid from the distal interphalangeal joints of the Esmarch tourniquet group ranged from 45.1 to 1,968 μg/mL and in the pneumatic tourniquet group ranged from 1.7 to 92.3 μg/mL after 30 minutes of IVRLP. Total loss of amikacin in the egress fluids from the joint lavage ranged from < 1.36 to 7.72 mg for the Esmarch tourniquet group and from < 1.20 to 1.75 mg for the pneumatic tourniquet group. CONCLUSIONS AND CLINICAL RELEVANCE On standing horses, IVRLP performed simultaneously with joint lavage resulted in negligible loss of amikacin in the egress lavage fluids. The Esmarch tourniquet was more effective in preventing loss of amikacin from the distal portion of the limb, easier to use, and less expensive than the pneumatic tourniquet.

Recognition and management of ileus.

Ileus may occur in horses of all ages secondarily to drug administration, colic, exhaustion, peritonitis, or metabolic disorders. Ileus most commonly occurs following abdominal surgery for colic and is a significant cause of postoperative mortality in these horses. The most common clinical signs of ileus are decreased or absent intestinal sounds and gastric reflux. Ileus is treated by eliminating the initiating causes, correcting metabolic imbalances, decompressing distended bowel, providing analgesia, stimulating motility with drugs, and regulating exercise and feed and water intake.

Contamination of Joints with Tissue Debris and Hair after Arthrocentesis: The Effect of Needle Insertion Angle, Spinal Needle Gauge, and Insertion of Spinal Needles with and without a Stylet

OBJECTIVE To assess fetlock joint contamination with tissue debris and hair after arthrocentesis. STUDY DESIGN Experimental. ANIMALS Fetlock joint tissues (n = 10 horses). METHODS Soft tissue flaps including the joint capsule were dissected from the dorsal fetlock joints of 7 anesthetized horses leaving an intact proximal base. Needles inserted through the tissue flaps were flushed into tissue cell culture plates and examined for debris. Studies were repeated on excised fetlock tissue preparations after being stored for 5 days. Variables included gauge and type of needle, insertion of spinal needles with and without a stylet, angle of insertion, length of hair, and ante- and postmortem needle insertion. Tissue fragments collected from 3 horses were cultured for bacteria. RESULTS Compared to 20 g disposable needles inserted perpendicularly through unclipped skin, the odds ratios (ORs) for hair contamination were significantly greater for 20 g spinal needles without a stylet, and significantly less for 22 g spinal needles inserted with a stylet and for angled insertion of disposable needles. Tissue contamination OR was significantly less for 20 g spinal needles inserted without a stylet, angled insertion, and clipped hair. Bacteria were isolated from 2.6% of tissue fragments. CONCLUSIONS Angled needle insertion reduces joint contamination with tissue and hair. Spinal needles should be inserted with a stylet in place and 22 g spinal needles are preferable to 20 g spinal needles. Joints may be contaminated with bacteria after routine surgical preparation of skin.Objective To assess fetlock joint contamination with tissue debris and hair after arthrocentesis. Study Design Experimental. Animals Fetlock joint tissues (n = 10 horses). Methods Soft tissue flaps including the joint capsule were dissected from the dorsal fetlock joints of 7 anesthetized horses leaving an intact proximal base. Needles inserted through the tissue flaps were flushed into tissue cell culture plates and examined for debris. Studies were repeated on excised fetlock tissue preparations after being stored for 5 days. Variables included gauge and type of needle, insertion of spinal needles with and without a stylet, angle of insertion, length of hair, and ante- and postmortem needle insertion. Tissue fragments collected from 3 horses were cultured for bacteria. Results Compared to 20 g disposable needles inserted perpendicularly through unclipped skin, the odds ratios (ORs) for hair contamination were significantly greater for 20 g spinal needles without a stylet, and significantly less for 22 g spinal needles inserted with a stylet and for angled insertion of disposable needles. Tissue contamination OR was significantly less for 20 g spinal needles inserted without a stylet, angled insertion, and clipped hair. Bacteria were isolated from 2.6% of tissue fragments. Conclusions Angled needle insertion reduces joint contamination with tissue and hair. Spinal needles should be inserted with a stylet in place and 22 g spinal needles are preferable to 20 g spinal needles. Joints may be contaminated with bacteria after routine surgical preparation of skin.

Effect of Needle Size and Type, Reuse of Needles, Insertion Speed, and Removal of Hair on Contamination of Joints with Tissue Debris and Hair after Arthrocentesis

OBJECTIVE To assess joint contamination with tissue and hair after arthrocentesis of equine fetlock joints. STUDY DESIGN Experimental. ANIMALS Limb specimens from 8 equine cadavers. PROCEDURES Soft tissues including the joint capsule were harvested from the dorsal aspect of the fetlock joints and mounted on a wooden frame. Needles inserted through the joint tissue preparation were flushed into tissue culture plates that were examined for tissue and hair debris. Variables evaluated were gauge and type of needle (16, 18, 20, and 22 G sharp disposable needles and 20 G disposable spinal needles with stylet), number of times each needle was used (1, 2, 3, 4), length of hair (unclipped, clipped, shaved with razor), and needle insertion speed (fast, slow). Descriptive and statistical evaluations were performed. RESULTS Tissue contamination was identified in 1145 of 1260 wells and hair contamination was identified in 384 of 1260 wells. Twenty gauge needles inserted through unclipped hair resulted in the least amount of hair contamination. Compared with 20 G needles with fast insertion 1 time through unclipped hair the odds ratios for contamination with hair were significantly greater for 16 G sharp disposable needles, 20 G spinal needles, clipped hair, shaved hair, and reuse of the needles. Spinal needles inserted through unclipped hair transferred many long hairs into the joint space. CONCLUSION Reuse of needles for arthrocentesis should be avoided. Removal of hair is not indicated for arthrocentesis with sharp injection needles but is recommended when using spinal needles with stylets. CLINICAL RELEVANCE Joint contamination with hair and tissue debris will be decreased by specific needle insertion techniques. Decreased contamination of joints may reduce the frequency of joint infections after arthrocentesis.

The role of external fixation and emergency fracture management in bovine orthopedics.

External fixation is a very useful method of treating selected fractures in cattle. The economics of therapy and the availability of the techniques to all veterinarians will continue to make external fixation the most frequently used method of fracture repair in cattle.

Treatment of Fractures of the Tibia and Radius-Ulna by External Coaptation

External coaptation of radial-ulnar and tibial fractures with casts or modified Thomas splint-cast combinations is a useful treatment. The economics of therapy make this method of treatment feasible for commercial animals. Current estimates for the cost of treatment of tibial fractures with Thomas splint-cast combinations are

Cryptorchidectomy in equids: 604 cases (1977–2010)

225.00 for calves and

Decision making in ruminant orthopedics.

410.00 for cattle if the metal splints are reused. Casts have similar costs. The availability of external coaptation techniques to all veterinarians and the success of treatment make external coaptation a good method for the treatment of many tibial and radial-ulnar fractures in cattle.

Effect of needle brand, needle bevel grind, and silicone lubrication on contamination of joints with tissue and hair debris after arthrocentesis

OBJECTIVE To evaluate the management of equids undergoing cryptorchidectomy at a referral hospital. DESIGN Retrospective case series. ANIMALS 604 client-owned equids. PROCEDURES Medical records of all equids undergoing surgical treatment of cryptorchidism from 1977 to 2010 were retrospectively reviewed. Analyses of breed, location of retained testes, accuracy of palpation per rectum for determining the location of retained testes, surgical technique, and postoperative complications were performed. RESULTS The most frequently affected breed was the Quarter Horse (282/604 [47%]), which was significantly overrepresented. Of the 604 equids, 90 (15%) had undergone previous surgical attempts at castration. Preoperative palpation per rectum was performed in 395/604 (65.4%) patients, and was accurate in predicting the location of the retained testes in 354/395 (89.6%). Surgeons were significantly more likely to be incorrect in determining the location of the retained testis by means of palpation per rectum in patients that had undergone a prior attempt at castration. For equids with abdominal cryptorchidism (360/604 [59.6%]), the most common surgical technique was noninvasive cryptorchidectomy (298/360 [82.8%]). In unilateral cryptorchids (521/604 [86.3%]), the 2 most common sites were left abdominal (184/521 [35.3%]) and right inguinal (148/521 [28.4%]). For bilateral retention (80/604 [13.2%]), abdominal cryptorchidism was most common (48/80 [60%]). Fever was present in 138/324 (43%) equids on the first day after surgery. Postoperative fever was not significantly associated with any variables evaluated. Including postoperative (≤ 24 hours) fever, 150 of 604 (25%) patients developed postoperative complications. Excluding postoperative fever, 18 of 604 (3%) patients developed major postoperative complications; complications in 10 of 604 patients were deemed surgically related, and 3 of 604 patients died. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that cryptorchidectomy in equids performed with a variety of surgical approaches was associated with minimal postoperative complications. A history of previous attempts at castration decreased the ability to accurately predict the location of the retained testis.