RADIOGRAPHIC IMAGING OF THE CANINE INTERCONDYLAR FOSSA

The intercondylar fossa is believed to play an important role in the pathology of cranial cruciate ligament rupture and therefore has received considerable attention in the last decade. Accurate radiographic imaging of the intercondylar fossa requires that the central x-ray beam pass through the center of the intercondylar "tunnel". The anatomy of the canine intercondylar fossa is similar to humans, however, the orientations of the intercondylar fossa's differ. Consequently, the positioning techniques described for humans are not appropriate for the dog. To pass through the center of the dog, intercondylar fossa, the central x-ray beam should be 12° (S.D. 1.7°) caudal from the femoral diaphysis in the sagittal plane and obliqued caudolateral to craniomedial 7° (S.D. 0.60°) (caudo78°proximo7° lateralcraniodistomedial oblique). Cross table positioning was used with the hip flexed and the radiograph cassette placed on the cranial surface of the stifle. However, superimposition of the tuber ischii and soft tissues caudal to the femur made 15° to 20° the best angle obtainable. There was not a significant difference (p = 0.17) in the notch width index between a 12° versus 20° angle of the central x-ray beam caudal to the femoral diaphysis, both with 7° of external rotation of the stifle. The notch width index of 0.252 obtained from radiographic measurements was not significantly different from measurements obtained grossly of 0.254 (n = 26; p = 0.69). Failure to oblique the central x-ray beam caused a significant (p = 0.0008) decrease in the apparent fossa width radiographically.     

COLOR DOPPLER AND DOPPLER SPECTRAL ANALYSIS IN THE SPINAL CORD OF NORMAL DOGS

Doppler ultrasonography of the spinal cord was performed in 34 normal, anesthetized dogs following hemilaminectomy. This study was part of an investigation to evaluate the efficacy of a 21-aminosteroid compound and high dose methylprednisolone for the treatment of spinal cord trauma. Grey-scale images of the canine spinal cord were similar to those described for the spinal cord of people. Doppler waveforms of intraparenchymal spinal arteries exhibited high end diastolic blood flow velocities, indicating low resistance to flow. Doppler values (mean ± SD) for arteries immediately ventrolateral to the central canal were: Peak Systolic Velocity = 5.78 ± 2.5 cm/sec, Minimum Diastolic Velocity = 3.5 ± 1.62 cm/sec, Mean Velocity = 4.45 ± 1.96 cm/sec, Minimum Diastolic Velocity = 3.5 ± 1.62 cm/sec, Mean Velocity = 4.45 ± 1.96 cm/sec, Systolic/Diastolic ratio = 169 ± 0.19, Pulsatility Index = 0.53 ± 0.09, and Resistance Index = 0.4 ± 0.06.     

Treatment of Perianal Fistulas With ND: YAG Laser—Results in Twenty Cases

Excision of perianal fistulas using a 1.064 micron wavelength neodymium:yttrium aluminum garnet (ND:YAG) contact tipped laser with primary wound closure was used to treat 20 dogs with perianal fistulas. Overall, 19 of 20 (95%) dogs had resolution of fistulas after one or more ND:YAG treatments. The period of resolution ranged from 10 to 42 months with a mean of 22.9 months. Sixteen of 20 (80%) dogs had resolved fistulas after one laser excision. Three of the four recurrences underwent additional laser treatments with successful results. The total number of laser procedures ranged from one to three with a mean of 1.2 procedures. Postoperatively, anal tone as judged by digital rectal examination was reduced in about 60% of the cases, but clinical evidence of fecal incontinence only occurred in four of 20 cases. This was managed effectively with diet modification. The tendency toward loss of anal tone or fecal incontinence depended on the severity of preexisting anal stenosis. On a client survey, 19 of 20 owners believed that their animals experienced less pain during defecation after surgery and rated the results as excellent or good. The overall success rate using ND:YAG laser excision compared very favorably with previously reported studies of other methods of treatment for perianal fistulas in dogs.     

Sequence of the canine c-yes proto-oncogene

Cloning of the canine yes oncogene was attempted from a c library derived from a healthy canine spleen using a human c-yes-1 probe. The nucleotide and amino acid sequences revealed that the canine yes gene contained an open reading frame consisting of 539 amino acids. Its product had a molecular mass of 60,368 Daltons and showed 95·9 per cent and 90·4 per cent homology with human and chick p61^c-yes, respectively. Moreover, the product had a myristylation signal, src homology region (SH) 3, SH2, and tyrosine kinase domains showing 98·8 per cent and 96·0 per cent homology with those of human beings and chickens, respectively. These findings indicate that the products of the canine yes gene may have non-receptor-type tyrosine kinase activity on the cell membrane, as is the case in human and chick p61^c-yes     

Occipitoatlantoaxial malformation with atlantoaxial subluxation in a cat

Occipitoatlantoaxial malformation and atlantoaxial subluxation was diagnosed in a three-year-old castrated male domestic shorthair cat. Clinical signs included ataxia, postural reaction deficits, abnormal spinal reflexes, and behaviour changes. Radiographic examination revealed malformation and hypoplasia of the occipital condyles, hypoplasia of the dens, and atlantoaxial subluxation. Electroencephalographic (EEG) findings included high voltage slow activity and sharp waves with superimposed low voltage fast activity in the occipital leads and sinusoidal beta waves in the frontal leads. Basilar artery compression as a result of atlantoaxial instability is suspected to have caused the behavioural changes and EEG abnormalities in this patient. The cat was treated by stabilisation of the atlantoaxial subluxation by ventral cross pin fixation, odontectomy, and arthrodesis of the atlantoaxial articulation. The patient responded well to treatment and was neurologically normal 18 months after surgery.     

Effect of acetylsalicylic acid on vascular damage and myointimal proliferation in canine pulmonary arteries subjected to chronic injury by Dirofilaria immitis

The effect of aspirin (ASA) on pulmonary artery response to chronic injury induced by Dirofilaria immitis was assessed in the dog. Eight dogs were studied for 30 days after adult heartworms were transplanted into the pulmonary arteries. Four dogs were treated with ASA (325 mg/day given orally) starting 3 days before the transplantation was done. Evan's blue dye was used to locate areas of vascular damage. Vascular morphology was assessed by scanning electron microscopy and light microscopy. According to results of the morphologic studies, nontreated dogs had extensive endothelial damage and significant adhesion of leukocytes and blood platelets. Blood vessels of ASA-treated dogs had less endothelial damage. Platelet adhesion on areas of vascular damage was less than that observed in nontreated dogs. Myointimal proliferative lesions were observed in both nontreated and ASA-treated dogs. However, the lesions in nontreated dogs were larger (means 68 +/- 7 mm2) and more complex than those in ASA-treated dogs (means 20 +/- 1 mm2). The results indicated that aspirin may protect against development of myointimal proliferation resulting from chronic vascular injury. The mechanism of the ASA protection may result from a combination of antiplatelet and anti-inflammatory effects, as well as a direct protective effect on vascular endothelium.     

Parvovirus-like enteropathy in Missouri turkeys

A viral enteric disease of young turkeys characterized by stunting of affected birds, diarrhea, and increased mortality is described. Eosinophilic intranuclear inclusion bodies were found in the absorptive epithelial cells of the ileum. Electron microscopy of formalin-fixed tissue revealed that the intestinal inclusions contained numerous loosely packed 15-to 20-nm hexagonal particles. The size, shape, and intranuclear location have been used to tentatively identify these particles as parvoviruses.