EQUINE CLINICAL PATHOLOGY - Rossdale & Partners

More documents

Recommendations

Info

T h e B e a u f o r t c o t t a g e l a b o r a t o r i e s accidental cervical injury. With the hand holding the forceps held against the mare’s buttocks (to avoid injury to the uterus if the mare moves suddenly) maintaining the forceps in the uterus, the manipulating hand and arm are then withdrawn from the vagina and placed in the rectum. The forceps are then palpated and advanced into one or other of the uterine horns. The jaws of the forceps are then opened and a fold of endometrium is gently pushed into the jaws, which are then closed, the biopsy is completed and the forceps are withdrawn from the uterus and vagina. Tissues are carefully removed from the forceps with fine forceps to avoid artefactual damage and are fixed immediately in Bouin's fluid. A fine-tipped sterile swab may be used to sample the inside of the jaws of the biopsy instrument for bacterial culture. Sometimes more than one endometrial fold is removed and then the smaller one may be placed into transport medium for bacterial culture. Endometrial biopsy samples should be referred to a laboratory that is specifically experienced in both equine endometrial histopathology and equine gynaecology, in order to receive a meaningful interpretation. Testicular Biopsy Testicular biopsies are best obtained by conventional wedge resection with the horse under general anaesthesia in order to provide adequately interpretable tissues and to avoid accidental injury to the testicular artery, by blind needle biopsy, which may have fatal consequences. The testicle is examined by ultrasound scan for visible pathology and best site for sampling and the scrotum is prepared as for surgical intervention. Automated punch biopsy and ultrasound guided techniques are available but the relatively small tissue samples are better suited to specific research requirements. Great care must be taken to avoid injuring the testicular artery. Testicular tissues should be fixed immediately in Bouin's fluid. Ileal biopsy Using our state-of-the-art microwave processing system, same day results can be provided for fixed tissue specimens. Ileal biopsies may be indicated to attempt to confirm or deny a clinical diagnosis of equine dysautonomia (‘grass sickness’), where exploratory laparotomy is indicated. At exploratory laparotomy, a transmural, i.e. full-thickness, longitudinal ellipse of ileum, approximately 15mm by up to 10mm is excised at the proximal end of the ileocaecal fold, midway between the mesenteric and antimesenteric borders. The tissue is placed immediately into 10% formol saline and processed for histopathological examination. The ganglia in the myenteric plexus between the 54
G u i d e t o e q u i n e c l i n i c a l p a t h o l o g y muscular layers are examined for normal and abnormal neurones. In ‘typical’ cases of equine dysautonomia, these ganglia are devoid of normal neurones and appear ‘skeletal’. The occasional degenerate neurone, with nuclear degeneration and cytoplasmic vacuolar degenerative changes are seen in some cases. Also, clusters or normal neurones are seldom seen in the submucosal layers and again, the occasional degenerate neurone, with nuclear degeneration and cytoplasmic vacuolar degenerative changes are seen in some cases. Ileal biopsies should be referred to a laboratory that is specifically experienced with examining these tissues. Rectal biopsy Rectal biopsies are useful for the investigation of weight loss and diarrhoea cases or where haematological and serum biochemical results suggest enteropathy. Samples are best obtained with mare endometrial biopsy forceps (Yeoman's basket-jawed), inserted just a hand's length through the anus. A rectal fold (mucosa and submucosa only) is removed laterally on either side (dorsal or ventral biopsies are more prone to puncture blood vessels and result in worrying haemorrhage). One sample is fixed in 10% formol saline and the other placed into Amies’ charcoal transport medium for bacteriological examinations. NOTES 55
Page 1 and 2:
the beaufort cottage laboratories G
Page 3 and 4: G u i d e t o e q u i n e c l i n i
Page 53: G u i d e t o e q u i n e c l i n i
show all

EQUINE CLINICAL PATHOLOGY - Rossdale & Partners

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?