Anal sphincter pressure and the rectosphincteric reflex in the dog

Anal sphincter pressure (ASP) was measured in healthy conscious dogs, and the rectosphincteric reflex that causes inhibition of the internal sphincter was identified. Pressures were measured in 6 dogs by use of a perfused miniature 4-lumen catheter. To identify the rectosphincteric reflex, a balloon (fitted over the distal opening of the catheter) was insufflated with 25 ml of air. Mean (+/- SE) ASP was 74.7 +/- 4.2 mm of Hg. When the rectosphincteric reflex was stimulated by balloon distension, ASP decreased to 35.9 +/- 4.9 mm of Hg. The reduction in pressure persisted for 22 +/- 1.5 s, and ASP returned to predistension values, despite the maintenance of balloon distension. Atropine did not affect ASP or its reduction during balloon distension.     

Effects of thiopentone and propofol on lower oesophageal sphincter and barrier pressure in the dog

The effects of thiopentone and propofol on oesophageal pressures were examined in 39 bitches. The dogs were premedicated with either atropine (n = 13), acepromazine maleate (n = 13) or a combination of atropine and acepromazine. Anaesthesia was induced with either thiopentone (15 dogs) or propofol (24 dogs), both given intravenously. Immediately following the induction of anaesthesia, gastric pressure and lower oesophageal sphincter pressure (LOSP) were measured and oesophageal barrier pressure determined. There were no significant differences attributable to the premedication regimens used but both LOSP and barrier pressure were significantly lower in the dogs anaesthetised with propofol compared to the animals given thiopentone (LOSP 12-2 ± 4-2 cm H₂O propofol group versus 26-8 ± 6-5 cm H₂O thiopentone group).     

Semitendinosus muscle transfer flap for external anal sphincter incompetence in a dog

A 5-year-old sexually intact female Yorkshire Terrier was referred with a history of fecal incontinence of at least 2 years and chronic intermittent colitis. The external anal sphincter to the left of the anus was intact; the external anal sphincter was not detectable to the right of the anus. To repair the defect, the semitendinosus muscle was isolated and severed 2 cm proximal to its insertion on the tibia. Care was taken to preserve the integrity of the vasculature and nerve supply in the proximal third of the muscle body. The body of the muscle was passed around the ventral and right aspects of the rectum; the cut end was secured with simple interrupted sutures dorsal to the levator ani and coccygeus muscles to simulate the external anal sphincter. After surgery, the dog could defecate normally. Absence of a portion of the external anal sphincter may be congenital or the result of anorectal trauma, rectal prolapse, severe perineal disease, or surgical resection. The use of a semitendinosus muscle flap for treatment of fecal incontinence secondary to sphincter incompetence in dogs may be a viable alternative to euthanasia.     

Management of urethral sphincter mechanism incompetence in a male dog with laparoscopic-guided deferentopexy

Urethral sphincter mechanism incompetence is uncommon in the male dog. Diagnosis is made on the basis of the history (full bladder intermittent incontinence with persistence of normal micturitions), clinical examination and by exclusion of other causes of incontinence, such as prostatic disease, lower urinary tract abnormalities and cystitis. This report describes a case in an 11-year-old male poodle in which positive contrast urethrocystography showed no anatomical abnormalities. Surgical treatment by fixation of both ductus deferens to the abdominal wall under laparoscopic guidance with cranial displacement of the urinary bladder improved the incontinence.     

Effects of atropine, acepromazine, meperidine, and xylazine on gastroesophageal sphincter pressure in the dog

Gastroesophageal sphincter (GES) pressure was 47.9 +/- 1.2 mm of Hg in nontreated dogs. Treatment with atropine, acepromazine, and xylazine reduced GES pressure to 13.2 +/- 2.03, 18.6 +/- 2.14, and 11.7 +/- 1.19 mm of Hg, respectively. Treatment with meperidine resulted in phasic contractions with minimum and maximum pressures of 27.9 +/- 4.55 and 98.9 +/- 9.16 mm of Hg, respectively. Drugs used in anesthetic procedures can reduce GES pressure in dogs.     

Effect of gastrin, histamine, serotonin, and adrenergic amines on gastroesophageal sphincter pressure in the dog

In nonrestrained dogs that had not been given chemicals and that were in the fasted and fed state, gastroesophageal sphincter pressure (GESP) was measured; results were compared with GESP induced in the same dogs by drugs that modified activity at cholinergic, adrenergic, histaminic, and gastrin receptors. Atropine reduced GESP from 38.5 +/- 1.3 (mean +/- SE) and 55.5 +/- 2.0 mm of Hg to 11.3 +/- 2.0 and 14.5 +/- 2.4 mm of Hg in fasted and fed dogs, respectively. Histamine induced phasic contractions that were not affected by anticholinergics or cimetidine. Iphenhydramine eliminated the phasic contractions and reduced GESP to 18.2 +/- 3.9 mm of Hg. In fed dogs, diphenhydramine reduced GESP to 37.0 +/- 2.5 mm of Hg, but cimetidine did not. Pentagastrin induced increases in GESP that were inversely related to basal GESP. Pentagastrin given during histamine infusion eliminated histamine-induced phasic contractions. In fed dogs, metoclopramide increased GESP from 48.8 +/- 4.0 mm of Hg to 76.0 +/- 4.0 mm of Hg; this increment was eliminated by diphenhydramine. Administration of atropine after metoclopramide reduced GESP the same as for dogs given atropine alone. An adrenergic amine with only alpha-adrenergic effects induced phasic contractions, and an adrenergic amine with only beta-adrenergic effects reduced GESP. Blockers of alpha and beta effects did not change GESP in fed dogs. Domperidone induced phasic contractions that were eliminated by feeding. Serotonin increased GESP. Canine GESP may be maintained in fed dogs by chemicals interacting with cholinergic, histaminic, gastrin, and serotonin receptors, but not by chemicals interacting with adrenergic receptors.     

Urethral sphincter mechanism incompetence in the male dog: importance of bladder neck position, proximal urethral length and castration

The radiographs of 37 incontinent adult male dogs with urethral sphincter mechanism incompetence were compared with those of 28 control dogs to determine if, as in the bitch, differences in bladder neck position and urethral length were implicated in the pathophysiology of urethral sphincter mechanism incompetence. Bladder neck position was significantly different; compared with continent dogs, incontinent animals were significantly more likely (P<0.005) to have intrapelvic than intra-abdominal bladder necks. However, after allowing for the influence of body size, and unlike the situation in the bitch, there was no significant difference in proximal urethral length between the two groups. Bladder neck position was significantly related to prostate size (P<0.001) and it is suggested that this is one reason why castrated male dogs are more prone to urethral sphincter mechanism incompetence than entire animals. A logistic regression analysis revealed that both bladder neck position and castration status were significant risk factors for incontinence and that they appeared to be acting independently of each other.     

Bacteriuria in the dog

The results of a retrospective study of 85 bacteriological cultures on urine samples from 64 dogs is presented. Fifty-three of the samples produced a pure growth of bacteria and Proteus spp was grown from 24 of those samples while Escherichia coli was grown from 13 samples and Staphylococcus spp from six samples. It was noted that a large majority of the Proteus spp isolates (87.5 per cent) were from females and conversely a large majority of the E. coli isolates 92.3 per cent came from males. A study of conditions concurrent with the urinary tract infection showed that many animals had underlying problems that could compromise the ability of their urinary tracts to withstand invasion by micro-organisms. The antibiotic sensitivity patterns of E. coli and Proteus spp are discussed and the value of various antimicrobial agents considered.     

Discospondylitis in the dog

Five cases of bacterial discospondylitis in dogs are described. The clinical features included spinal pain, stiffness, lameness and in some cases a neurological deficit. Radiography proved the best aid to diagnosis and demonstrated bony destruction adjacent to an irregular disc space with sclerosis of the centra. Surgical curettage of the infected disc was carried out in conjunction with antibiotic therapy.     

Ureteroneocystostomy in the dog

A satisfactory technique of ureteroneocystostomy in the dog, which was devised experimentally, is described. It was used successfully on clinical cases of ureteral ectopia.
Résumé. Il est décrit une technique satisfaisante d'urétéronéocystosomie du chien, qui fut découverte expérimentalement. Elle fut avec succés utilisée sur des cas cliniques d'ectopie urétérale.
Zusammenfassung. Eine experimentalisch-ausersinnte Methode der Ureteroneozystostomie, ist beschrieben. Diesse Technique wurde an klinischen Fällen von uretaler Ektopie, erfolgreich vorgenommen.     

Cystourethroscopy in the dog

The cystourethroscopic examination with cold light cystoscopes forms an essential part of a complete urological examination and is useful for diagnostic as well as surgical procedures. The fast and non-invasive character of the procedure limits the inconvenience to the patient. With the rigid non-flexible scope its use is, however, limited to female dogs, unless in the male dog a urethro(s)tomy is performed.     

Gonioscopy in the dog

Gonioscopy is the examination of the iridocorneal angle of the eye utilizing a corneal contact lens. The technique is extensively practised in human ophthalmology and is particularly important in the differential diagnosis of the glaucoma complex. The author has practised the technique extensively in dogs, and his findings on the appearance of the normal canine iridocorneal angle are reported in this paper.