Using Teat Endoscopy (Theloscopy) to Diagnose and Treat Milk Flow Disorders in Cows

Teat endoscopy ( theloscopy) is an effective method to diagnose milk flow disorders, to visualize the cistern during surgery and to monitor response to treatment. The necessary equipment consists of a small wireless battery-operated theloscope for air insufflation and en doscopy, and appropriate sized surgical instruments. The patient should be sedated and properly restrained, in cluding the tail and hindlimbs, prior to and during the procedure. Following cleaning and disinfection of the teat, an anesthetic should be injected into a teat vein. The affected teat should be drained, a clamp should be placed at the teat base, and the cistern flushed with sterile saline.


Introduction
Historically it has been difficult to accurately diagnose the cause of milk flow disorders in teats of cows. Inspecting, palpating, blind probing and hand milking the affected teat were helpful, but often sonography, 4 reports have been published on this subject.2,3,s-s,12-11,24,2s-21,32-3 The objective of this paper is to describe endoscopic examination (theloscopy) of the bovine teat.

General Considerations
Theloscopy is a method to more accurately diagnose and treat milk flow disorders. Two approaches have been successfully used; through the teat canal or through the lateral teat wall. When the approach is made through the teat canal (axial theloscopy), the view is directed upwards into the teat canal (Figure 1 and 2) or the teat cistern (Figure 3 and 4). When the approach is through the lateral teat wall (lateral theloscopy), the view is directed downwards into the teat cistern and onto the inner opening of the teat canal (Furstenberg rosette) ( Figure 5 and 6). In our experience, the most frequent disorders of the teat are located in the area of the inner opening of the teat canal, which are best visualized using the approach through the lateral teat wall.

Equipment Necessary for Theloscopy
The basic piece of equipment is a small, wireless, battery-operated theloscope used to inflate and examine the the teat. Our preferred theloscopea consists of a rigid scope, a blow pipe and a handle ( Figure 7). The design of the scope allows for straight insight (0°) into the teat, and has a working length of 10 cm (3.9 in). The scope runs in a blow pipe which has an outer diameter of 3.0 mm. Air is blown through the blow pipe into the teat cistern to dilate the teat for examination. The scope and blow pipe are attached to the handle. The handle contains a lamp, an air pump and two batteriesh (or rechargables) which will power the lamp and the pump for several hours. The lamp and pump may be operated separately.

Preparation of the Cow
Following evaluation of the case history and a brief physical examination, the cow is prepared for examination of the affected teat while she is in the standing position. 9 The cow can be restrained in a claw trimming device. This device can be lifted up with a lifting table or it can be left on the ground and the cow examined from a pit ( Figure 8). Another option is to · put the cow on a tilt table 0 • Prior to examination of the teat, the cow is sedated with xylazine (0.2 ml of a 2% solution per 100 kg [220 lb] body weight IV) and administered oxytocin (30 IU IV). It is important to properly restr-ain the head, tail, and the leg of the cow that is next to the examiner ( Figure 9). The teats should be thoroughly cleaned with warm water and soap, dried, degreased with 70% isopropyl alcohol, and a suitable surgical disinfectant applied. Strict aseptic technique is essential to minimize contamination and mastitis.

Preliminary Examination of the Teat
The external surface of the teat should be examined first. The teat canal, teat cistern and teat wall should be carefully palpated. 9 Patency of the teat canal is determined by expressing a few streams of milk from the teat. Teat canal length can be determined with aTHELOSCOPE -teat endoscope, The Butler Company, Dublin OH hEnergizer LR 14, 1,5 V, 8000 mAh, www.energizer.com. There is also a 110 V power supply available for the THELOSCOPE cTHELOMETER -probe for measuring teat canal length, The Butler Company, Dublin OH dSTERIL -disposable milking tube, The Butler Company, Dublin OH eTHELOKAL -wide milking tube, The Butler Company, Dublin OH robturator, The Butler Company, Dublin OH gSlide pipe, The Butler Company, Dublin OH hHUG's teat lancet, The Butler Company, Dublin OH iTHELOTOM -teat punch, The Butler Company, Dublin OH iTHELAB -teat foreign body forceps, The Butler Company, Dublin OH kNIT® -natural teat insert, The Butler Company, Dublin, OH         Figure 11. (right) The teat is anesthetized by puncturing a teat vein with a 0.6 mm needle, draining blood and injecting 5 to 10 ml of a 2% lidocaine solution. a thelometer, and the length compared to the contralateral teat. An increase in teat canal length of more than 2 mm is suggestive of a rupture in the teat canal area with inversion of tissue into the teat cistern. 6 The course of the teat canal can be examined with a round-ended probe. A sterile milking tube may be used to test the patency of the teat canal and to obtain a milk sample. The CMT should be performed on each milk sample. Culture of milk and antimicrobial sensitivity testing are advisable if the CMT results suggest that the quarter is infected.

Preparation of the Teat for Theloscopy
Following initial examination of the teat canal, a rubber ring is placed around the base of the teat to prevent milk from entering the teat cistern, and to reduce blood flow to the teat wall. The teat is anesthetized by injecting 5 to 10 ml of 2% lidocaine solution into a teat vein ( Figure 10 and 11). 40 The teat cistern is then rinsed with sterile saline through a milking tube until the draining saline is clear.

Axial Theloscopy
For axial theloscopy, the scope and blow pipe are inserted into the teat cistern through the teat canal. After activating the pump, air is blown into the teat to dilate the cistern, and with the lamp illuminated, the teat cistern is examined ( Figure 12). The teat canal may be examined as the scope and blow pipe are removed.

Lateral Theloscopy
For lateral theloscopy, a small opening is made in the lateral teat wall by passing an obturator through the teat canal into the teat cistern, and pushing it through the lateral teat wall (Figure 13) . . Then the slide pipe is insert ed along the obturator into the teat cistern ( Figure 14), and the obturator is removed. The scope and blow pipe are then inserted through the slide pipe into the teat cistern. The slide pipe protects the edges of the opening during the examination. The air pump is switched on to dilate the cistern, and the lamp will illuminate the distal part of the teat cistern and the inner opening of the teat canal for inspection ( Figure 15). To make ruptures in the area of the teat canal more visible, a milking tube can be placed into the teat canal while viewing the inner opening of the teat canal through the scope.

Treatment of Specific Conditions
Theloscopy is used for both diagnosis and surgical treatment. 23 , 25 For treatment of most teat disorders, the 160 Figure 12. Theloscopy through the teat canal. Figure 13. (left) For lateral theloscopy a small opening is made in the lateral teat wall. For this purpose an obturator is run through the teat canal into the teat cistern and pushed through the lateral teat wall. Figure 14. (right) The slide pipe is inserted from outside along the obturator into the teat cistern and the obturator is removed. Then scope and blow pipe are inserted through the slide pipe into the teat cistern. Figure 15. Theloscopy through the lateral teat wall. thelotome ( Figure 16) or Rug's lancet are used. Tissue impeding milk flow can be removed with the thelotome. A general guideline is "remove sick tissue -preserve healthy tissue". Tissue removal can be visualized through the theloscope inserted through the lateral teat wall (Figure 17 and 18). An assistant can hold the theloscope while the surgeon performs the treatment.
Incisions into the teat canal can be made with Rug's lancet to widen a strictured or narrowed teat canal. A general guideline is "one, two (at O and 180°) or three (at 0, 120 and 240°) V-shaped incisions in the area of the inner opening of the teat canal while attempting to preserve the outer teat canal opening" (Figure 19, 20 and 21). The incisions can also be made blindly without visualizing the procedure through the theloscope. For-ceps can be used to remove bodies from the teat cistern that may originiate from either inside (papilloma, blood or milk clots) or outside (foreign bodies) the teat ( Figure  21 and 22).

Aftercare
The opening in the teat can be closed with a diagonal suture. The rubber ring applied at the teat base is best removed with scissors. Milk flow can be tested by hand-milking the teat. Residual milk should be drained from the quarter; normal milk can be drained with a narrow disposable milking tube (Figure 23), while mastitis milk often must be drained with a specially designed wide milking tube ( Figure 24). Drain-     Figure 22. (right) Removal of tissue that had plugged the inner opening of the teat canal by using a forceps inserted through the teat canal. Seen through the theloscope inserted through the lateral teat wall. ing the milk flushes residual tissue from surgery. An intramammary antibiotic should be infused into the teat cistern to prevent or to treat mastitis. Selection of the product should be based on the results of milk culture and sensitivity testing. 42 A sterile silicone implant ( Figure 25) or a sterile natural teat insert ( Figure  26) is inserted into the teat canal to prevent teat canal stenosis. The suture is then removed, and the teat is bandaged by applying a strip of elastic long-lasting adhesive tape in a longitudinal manner (U-shape), (Figure 27) and applying another strip in a circular manner around the teat.
Teats are often rested for nine days after surgical jntervention before routine milking is r~sumed. 10 , 19 , 29 , 42 , 43 Often referred to as the 3x3-day method, milk is drained from the teat, a new teat insert is placed into the teat canal, and the teat is rebandaged on days 1, 4 and 7 postoperatively. A silicone implant is recommended during the first 3-day resting period and a natural teat insert during the second and third 3-day resting period. Beginning on day 10, the teat should be milked normally. If mastitis is present, the teat cannot be rested as the milk needs to be drained twice daily.

Conclusions
The procedure described in this paper was developed as a result of treating hundreds of cases in rural bovine practice. By using theloscopy instead of blind techniques, milk flow disorders can be precisely diagnosed. Recent studies have shown that the reason for the milk flow disorder in teats with undamaged skin can be visualized by theloscopy in 99% of the cases. In 48% of the cases, simple ruptures in the teat canal were diagnosed as reasons for milk flow disorders. In another 4 7%, ruptures in the area of the teat canal with inversion of teat canal skin into the teat cistern (acting like a valve) were found. In 1 % ruptures occured in the teat canal area with eversion of teat canal skin. 2% of the cases were caused by teat cistern papillomas occluding the inner opening of the teat canal, and 1 % by ruptures in the teat cistern area. After precisely diagnosing these conditions the treatment is easy to perform. Another advantage oftheloscopy over blind techniques is that treatment can be visualized and hence performed precisely. Our success rate has increased tremendously since we use theloscopy. In a recent study, cows whose milk flow j ·"· ► ... ' fjl Figure 25. (left) A sterile SIMPL® silicone teat canal implant (yellow -thin, purple -'-thick) is inserted into the teat canal to prevent teat canal stenosis during first 3 day test resting period after surgery. Figure 26. (right) A NIT® natural teat insert keeps the teat canal patent during the second and third 3 day resting period. NIT's adjust to the teat canal and contain no medicaments. They disintegrate within a few days (The Butler Company, Dublin, OH).

Figure 27.
Bandaging the teat by using elastic longlasting teat adhesive tape. One strip is applied longitudinally (U -shaped) and one strip is applied circularly. The bandage protects the teat, prevents the NIT® or SIMPL® from falling out, and indicates to the milker that the teat should not be milked. disorders had been diagnosed and treated by using theloscopy yielded as much milk and stayed as long in the herd as herdmates. 8 This has vastly improved from the past, when using blind treatment techniques often worsened the condition: cows often got mastitis after treatment and were culled.

JUNE, 2001
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