Matrix metalloproteinase activity in stifle synovial fluid of cranial cruciate ligament deficient dogs and effect of postoperative doxycycline treatment.

This prospective clinical study investigated the activity of matrix metalloproteinases (MMPs) in stifle synovial fluid (SF) of 13 dogs with acute cranial cruciate ligament (CCL) rupture, and the effect of a postoperative doxycycline treatment. MMP-2, 3, 9 and 13 activities were compared with respect to the time of sampling (preoperatively or 1 month after surgical stabilisation) and the type of postoperative adjuvant treatment (doxycycline or not). No significant activity was detected for both MMP-3 and MMP-13. MMP-2 and MMP-9 activities were found to be significantly highly increased in SF of CCL ruptured stifles compared to control stifles of unaffected dogs. No significant effect from surgical stabilisation and postoperative doxycycline treatment on MMP-2 and MMP-9 activities was found, indicating that doxycycline may not be an appropriate postoperative medical treatment after CCL rupture.

Haematogenous osteomyelitis: clinical presentation and outcome in three dogs.

Haematogenous osteomyelitis is a rare form of bone infection in adult dogs. Most commonly the infection is iatrogenic or traumatic in origin. The authors report three different presentations of haematogenous osteomyelitis: a focal pelvic localisation in a growing dog, a vertebral lesion in an adult dog with associated neurological signs and a multifocal affection in another adult dog with concomitant pathological fractures. Clinical signs included pyrexia of undetermined origin, focal pain and lameness. Diagnostic investigation included radiographic imaging, bone scintigraphy, magnetic resonance imaging, surgical biopsy, and bacteriological culture with sensitivity testing of biopsy specimens as well as of peripheral blood samples. Treatment consisted of long-term antimicrobial therapy and surgical debridement with curettage of the pelvic abscess of the young dog and decompressive hemilaminectomy of the second dog, with excellent recovery. The dog affected by polyostotic bone involvement and suffering pathological fractures was euthanatized. Haematogenous osteomyelitis may be a diagnostic and therapeutic challenge and may present as a devastating skeletal condition, even in adult dogs, and should be considered amongst the differential diagnoses early on to allow effective treatment.

Effects of autologous platelet rich plasma gel and calcium phosphate biomaterials on bone healing in an ulnar ostectomy model in dogs.

The aim of the study was to evaluate the bone healing properties of an osteopromotive platelet rich plasma (PRP) gel in combination with osteoconductive calcium phosphate (CaP) ceramic granules in a long-bone critical size defect in dogs. A standardised 2 cm long ulnar ostectomy was performed bilaterally in four dogs to compare new-bone formation by CaP matrix with and without association with PRP. Radiographic and histological evaluations were performed blindly. Radiographic evaluation was performed at three, six, nine, 12 and 16 weeks postoperatively. Quantitative measurements of new-bone formation were compared using statistical analysis. At explantation 16 weeks after surgery, no significant ossification was present, neither with CaP granules alone nor in association with PRP gel, and there was no difference of radiodensity between the groups. Qualitative histological evaluation demonstrated for both types of implants the presence of non-mineralised fibrous connective tissue around the CaP granules. New-bone formation was only present to a very small extent within the macropores of the CaP granules at the distal bone-implant interface. In our model which exhibited very limited osteoconduction, neither the CaP granules alone nor in association with PRP were sufficient to stimulate bone healing. In this canine model employing a critical size ulnar gap, the combination of CaP granules and PRP did not effectively promote bone regeneration.

Mycoplasma felis arthritis in two cats.

This report describes the occurrence of non-weightbearing lameness caused by Mycoplasma felis monoarthritis in two, immunocompetent, European, shorthair adult cats with a suspected history of trauma. Clinical signs recurred after conservative treatment. The joints were treated surgically and M felis was identified as the causative agent for the monoarthritis. Medication with 10 mg/kg doxycycline twice daily was initiated according to susceptibility testing. One cat underwent further joint flushing after two weeks; both the cats recovered completely after eight and nine weeks, respectively. The findings suggest that M felis, in addition to being an agent associated with conjunctivitis in cats, is able to act as a pathogen in other tissues and cause arthritis even in immunocompetent cats.

Increases in circulating insulin-like growth factor I levels by the oral growth hormone secretagogue MK-0677 in the beagle are dependent upon pituitary mediation.

It has been well established that the spiroindoline sulfonamide MK-0677 stimulates GH secretion from the pituitary both in vitro and in vivo. MK-0677 has also been shown to increase serum insulin-like growth factor I (IGF-I) and cortisol levels in vivo; these increases are assumed to be driven by the increased serum GH and ACTH levels, respectively. However, such increases could also be due to a direct stimulatory action of MK-0677 at the level of the liver and adrenal cortex. To address this possibility, we investigated whether MK-0677 increased IGF-I and cortisol levels in hypophysectomized dogs. Baseline GH, IGF-I, and cortisol responses to MK-0677 (1 mg/kg, orally) were initially determined. Hypophysectomy (hypox; n = 7) or sham surgery (sham; n = 5) was then carried out. Six days postsurgery, the GH and cortisol responses to MK-0677 were reevaluated in each dog. In addition, each dog was treated with porcine GH (PST; 0.1 IU/kg, s.c.) to confirm the responsiveness of the GH-IGF-I axis. The mean peak GH increases in response to MK-0677 in the presham dogs (83.7 +/- 19.2 ng/ml), post-sham dogs (108 +/- 26.2 ng/ml), and pre-hypox dogs (121.2 +/- 13.6 ng/ml) were not significantly different. Mean peak GH levels were unchanged after MK-0677 administration in the hypox dogs (2.3 +/- 0.7 ng/ml). Before surgery, serum IGF-I levels increased to 243 +/- 27 and 224 +/- 47 ng/ml in the sham and hypox groups, respectively, after MK-0677 administration. Surgery was associated with a marked (> or =50%) decrease in serum IGF-I levels. MK-0677 administration increased IGF-I levels in the sham dogs from 78 +/- 14 to 187 +/- 31 ng/ml, whereas IGF-I levels remained unchanged (17.7 +/- 2.4 ng/ml) in the-hypox dogs. PST treatment increased IGF-I levels in the sham dogs from 162 +/- 30 to 325 +/- 32 ng/ml. In the hypox dogs PST treatment restored IGF-I to physiological levels (from 17.7 +/- 2.4 to 199 +/- 41 ng/ml). Cortisol was increased after MK-0677 administration 3.7-fold in the pre-sham, 3.6-fold in the post-sham, and 3.6-fold in the pre-hypox dogs, but no increase was seen in the post-hypox dogs. ACTH GEL administration (2.2 U/kg, i.m.) to hypox dogs returned cortisol to normal physiological levels, demonstrating the functional integrity of the adrenal cortex. This study demonstrates that the GH secretagogue MK-0677 does not directly stimulate an increase in serum IGF-I or cortisol levels, but depends upon the presence of an intact pituitary.

Transorbital approach to the porcine pituitary.

A transorbital approach to the pituitary gland is described in domestic swine weighing between 40 and 70 kg. A transpalpebral eye exenteration is performed and the optic canal is enlarged caudally, using a bone drill. An operating microscope is used to improve visualization of the surgical site as the pituitary stalk and anterior pituitary are exposed to the level of the optic chiasm. This approach exposes the pituitary sufficiently to perform either a hypophyseal stalk transection or a hypophysectomy or to implant cannulas for hypothalamic-hypophyseal portal blood sampling. This technique has been performed in more than 50 pigs without major complications. Postoperative recovery has been rapid and uneventful. The transorbital approach is a significant refinement of the frontal craniotomy and cerebral elevation technique previously described in the pig, and results in shortened surgery time, minimal brain manipulation, and greatly decreased morbidity.

Arteriovenous fistula of the jejunum associated with gastrointestinal hemorrhage in a dog.

Hemorrhage from the gastrointestinal tract of a young dog resulted in melena with concurrent anemia. Exploratory laparotomy revealed the hemorrhage originated from an arteriovenous fistula in the jejunum. Resection of the abnormal part of the jejunum was curative. The arteriovenous fistula in the dog was probably congenital in origin, but may have been the result of gastrointestinal tract trauma.

Evaluation of craniotomy in dogs and cats.

Over a reporting period of 5 years, craniotomy was performed in 26 dogs and 5 cats with various intracranial lesions. X-ray computed tomography was performed in all animals prior to surgery. Twenty dogs and all cats had intracranial neoplasms; of these, 14 were meningioma, and 11 represented a wide variety of brain tumors and skeletal tumors. Three dogs were treated surgically for traumatic, open-skull fractures with cerebral damage, and 3 underwent biopsy to evaluate chronic inflammatory brain disease. The overall medium survival time was 212 days, the 1-year survival rate was 39%, and the 2-year survival rate was 20%. Dogs and cats with meningioma survived a mean 198 and 485 days, respectively, with 1-year survival rates of 30% for dogs and 50% for cats. The overall median survival time for animals with tumors other than meningeal intracranial neoplasms was 414 days, with a 1-year survival rate of 40%. The death of 19% of all animals could be related to the combination of advanced brain disease and surgery. Because fatality seldom occurred as a direct result of surgery, morbidity and mortality associated with craniotomy in pet animals can be seen as acceptably low. In 29 of 34 craniotomies, dura mater defects were left unsutured and no adverse effects were seen.

Macrohematuria and life-threatening anemia attributable to subepithelial vascular ectasia of the urinary bladder in a dog.

Hematuria leading to life-threatening anemia was evaluated in a 9-year-old male dog. At surgery, an abnormal vessel resembling an ulcerated varicose vein was found on the surface of the bladder mucosa. After removal of the lesion, hematuria ceased and had not recurred 22 months later.

Study of long-term survival after transsphenoidal hypophysectomy in clinically normal dogs.

Experimental hypophysectomies were performed in 7 clinically normal dogs, using a new modification of the transsphenoidal approach. This approach facilitated centering of the sphenoid bone trephination and allowed safe exposure of the hypophysis regardless of the size or shape of a dog's skull. Complications did not occur during surgery and all dogs recovered well from surgery. Growth hormone secretory capacity was measured over a 3-month period to assess completeness of hypophysectomies. One dog was euthanatized 2 months after surgery, 4 dogs were euthanatized at 3 months after surgery, and 2 dogs were allowed to survive and their progress was followed for 2.5 years. Soft palate dehiscence and keratoconjunctivitis sicca developed in 2 of the dogs. The technical deficiencies responsible for these complications were corrected shortly after the beginning of the study. In 4 of the 5 necropsied dogs, minute remnants of adenohypophyseal tissue were found in the sellae turcica. Measurement of in vivo growth hormone secretory capacity revealed that these remnants had an altered stage of functional activity. Although complete hypophysectomy was not achieved consistently, the main technical obstacle of hypophysectomy, the reliable identification and the avoidance of the vascular structures surrounding the hypophysis, has seemingly been overcome. The surgical technique proved to enhance the safety of hypophysectomy, and the procedure can be recommended to treat clinical cases of canine pituitary-dependent hyperadrenocorticism. The clinical significance of potential subtotal hypophysectomy remains yet to be evaluated.

Simultaneous use of microfibrillar collagen hemostat and blood saving devices in a canine kidney perfusion model.

Intraoperative autotransfusion and topical microfibrillar collagen hemostats have been increasingly used, often simultaneously, in various surgical procedures to minimize intraoperative blood loss and thus reduce the inherent risks of homologous blood transfusion. As moderate amounts of small particles have been shown to pass through filtering devices during intraoperative autotransfusion, concern has been raised over the amount of heterologous collagen fibrils transfused and their effect on the host. We found that 2% of microfibrillar collagen hemostat particles pass through the 20-microns millipore filter contained in the tested autotransfusion device (William Harvey H-4700 cardiotomy reservoir). Using a canine kidney perfusion model, we found multifocal perivascular inflammatory reactions within the renal parenchyma five days after transfusion of filtered autologous blood containing minute amounts of microfibrillar collagen hemostat. The findings demonstrate a strong inflammatory foreign body response to heterologous collagen particles trapped in the microcirculation of the perfused kidneys. It is concluded that despite using filters with a pore size of 20 microns, using intraoperative autotransfusion and microfibrillar collagen hemostats simultaneously creates a potential risk because adverse reactions can be elicited especially within the microvasculature of tissues containing end-arterial circulation.

Transsphenoidal hypophysectomy in the dog. A new technique.

A technique for localizing the canine hypophysis regardless of the shape or size of a dog's skull was evaluated. Using known anatomic landmarks, the approximate location of the hypophysis was estimated, and three small self-threading screws were placed as radiographic markers in the exposed sphenoid bone. A cranial sinus venogram was performed and the hypophysis was outlined by the contrast-filled cavernous sinus. A circular ostectomy was centered over the hypophysis, using the previously placed screws as reference points. The technique was evaluated in eight dogs in a nonsurvival procedure. In seven dogs, hypophysectomy was complete and the ostectomy sites were centered precisely over the hypophysis.

Evaluation of immune complexes and collagen type-specific antibodies in sera and synovial fluids of horses with secondary osteoarthritis.

Thirty-one horses with secondary osteoarthritis as a sequel of trauma (chip fractures) or osteochondritis dissecans were screened for immune complexes (IC) and anticollagen antibodies. Eighty-two percent of horses with joint disease had circulating C1q-binding IC; 77% of those horses had IC in synovial fluids of affected joints. Although only a few horses had anticollagen type-II antibodies, anticollagen type-I antibodies were found in sera of 25% of the horses and in 41% of their synovial fluids. This correlated well with the clinical data and suggested that antibodies might have been elicited by antigens derived from detached intra-articular osteochondral fragments. Immunologic reactivity is a new concept in equine secondary osteoarthritis and might be involved in the mechanisms of chronic inflammation and progressive collagen destruction in degenerative joint disease.

Antibodies to canine collagen types I and II in dogs with spontaneous cruciate ligament rupture and osteoarthritis.

Antibodies to homologous collagens, types I and II, have been found in the sera and synovial fluids of dogs with spontaneous cruciate ligament rupture and osteoarthritis. Samples from 30 dogs with degenerative joint disease of the knee and from 15 healthy dogs were investigated by enzyme-linked immunosorbent assay. Fifty-three percent of dogs with joint disease showed significant levels of anti-type I collagen antibodies in their sera, and 56% had anti-type II reactivity. Ninety-one percent of the dogs with joint disease exhibited antibody reactivity to type I collagen in their synovial fluid, and 88% showed reactivity to type II collagen. Correlation of these results with the clinical data indicated that the antibodies had been elicited by antigens derived from cruciate ligaments (type I collagen) and from altered joint cartilage (type II collagen). Immunologic reactivity in this form of canine osteoarthritis is a new concept, and it should be considered in our attempts to understand the pathogenesis of this disease.

Immunological changes in canine cruciate ligament rupture.

Samples of sera (39) and synovial fluid (36) from 58 dogs suffering from inflammatory arthropathy of the stifle joints, 47 of them in combination with unilateral or bilateral rupture of the anterior cruciate ligaments (CLR), were investigated for C1q-binding immune complexes (IC) using a solid phase radioimmunoassay. In 31 out of 39 sera (79 per cent) and 25 out of 36 synovial fluids (69 per cent) significant IC concentrations could be detected. As controls 21 healthy dogs were used. The radioimmunoassay was standardised with aggregated dog gamma globulin. The sera of the dogs were also investigated for anticollagen antibodies to denaturated type 1 or type 2 dog collagens. No evidence of the presence of these antibodies could be obtained. In a small percentage of sera and, or, synovial fluids rheumatoid factor could be demonstrated. These results indicate that the CLR in dogs is accompanied by immunological mechanisms.