EYE CANCER IN CATTLE - Bovine Ocular Squamous Cell Carcinoma (BOSCC) and its Surgical Management.

Animals also  battle with cancer. This segment  is on Eye cancer in cattle.

Eye cancer in cow is a very painful and a fatal disorder which start as small nodular growth in the adnexa of eye. Squamous cell carcinoma is regarded as the most frequently diagnosed cancerous tumour in the bovines. Bovine ocular squamous cell carcinoma (BOSCC) represents the most economically important neoplasm in large animals. The malignant tendencies of this disease make early recognition critical.

I got opportunity to see  a wide variety of Ocular Squamous cell carcinoma cases in working bullocks and dairy cattle. UV rays from scrotching sunlight could be the main source of eye cancers  in working bullocks and free grazing dairy cattle especially in states like Maharashtra and northern Karnataka. 

Prolonged exposure to ultraviolet light, lack of pigment and lack of  hair at the affected site are common factors associated with the development 

of a squamous  cell carcinoma.These tumours in all species develops through a series of premalignant stages  before proceeding to carcinoma. Squamous cell carcinomas are solitary lesions , however  multiple tumours may develop in conjunction with solar injury.Human negligence and callous attitude can lead to severe inflicting injuries to the eye which ultimately culminates in eye cancer. 

I would like to share my experience during my tenure in Animal Rahat, PETA , the largest working animal welfare organization dedicated for working bullocks. We witnessed many animals in a northern Maharashtra village with eye cancer on the right eye. When enquired , it was a shocking finding that the abuse of the eyes by rubbing a combination of pepper and salt to make the animals run during bullock races and sugarcane season had led to high incidence of eye cancer . I am of the opinion that Willful persuasive extension education should be part and parcel of the veterinary practice and I strongly believe that it is the duty of every vet to educate the animal owner / farmer about what the animal is going through. Thus eye cancer  not only drastically reduce the performance of the animal and considerable economic importance to the farmer , but also has serious welfare constraints in animal ethology point of view.The cancer growth may start at the medial canthus, lateral canthus or on eyelid . 

Third eyelid is the most common site of origin of eye cancer.  The stage of presentation of the case decides the chances of saving an affected eye.

Cases presented in initial stages can be fully recovered and the eyes can be saved. But many cases come in advanced chronic stage with extensive tumor mass eating up the entire globe.

Treatment of cancer eye depends on its location and the degree of involvement of ocular  structures. Veterinarians easily remove lesions on the third eyelid by cutting out the free  border of the third eyelid using local anesthesia and tranquilization. Lesions removed in this way are very unlikely to recur. Applying hyperthermia (high temperature) or cryotherapy (freezing) to kill the remaining tumor cells in the tissue of the lids but the procedure can not be employed for all cancers.

Three terms are widely used by the veterinarian in this context are Extripation or Exenteration, Evisceration, Enucleation

Enucleation is removal of the entire globe, including the cornea, sclera, and a portion of the optic nerve .

Evisceration surgery involves removal of the contents of the globe while leaving the sclera and optic nerve in place. The cornea can be retained in some evisceration cases.

Exenteration of Eye or  Extripation of Eye ball  is the removal of the globe, as well as the complete or partial removal of the soft tissues of the orbit.

 The ultimate goals of these surgeries are to safely and effectively remove the diseased eye or orbital contents using advanced surgical techniques, eliminate the severe underlying ocular pathology

 Removal of the entire eyeball is indicated when tumors have spread to the extent that the eyeball is blind; the tumor has invaded deeper structures surrounding the globe; or the eyelid is involved to the extent that it cannot be repaired after removal of the tumor. It may appear to be a drastic procedure, but success of the extirpation is to  accomplish it quickly and humanely.

ANETSHESIA AND RESTRAINT

I prefer standing surgery as the wonderful cock tail of Butorphanol, Xylazine Ketamine @ 0.01,0.2 and 0.04 mg/ kg bw Intra muscular troute will give excellent sedation for 30 minutes. Four point retrobulbar block ensures a painless surgical procedure equally rewarding for the surgeon and for the animal.

YOU CAN WATCH THE VIDEO BELOW

Exenteration of Eye ball 

REGIONAL ANESTHESIA OF EYE IN CATTLE

4 Point Retrobulbar Nerve Block: The 4-point retrobulbar block is technically easier and can be done more rapidly as compared with the Peterson eye block. In this technique, an 18 gauge, 9-cm long needle is introduced through the skin on the dorsal, lateral, ventral and medial aspects of the eye, at 12, 3, 6, and 9 o´clock positions, respectively. Introduction of the needle through the

conjunctiva should be avoided to reduce the occurrence of ocular contamination. The needle is directed behind the globe using the bony orbit as a guide. When the needle is introduced into retrobulbar sheath, the eye will move slightly with the tug of the  needle. After this location is reached and aspiration is performed to assure that the needle is not in a vessel, 5-10 milliliters of lidocaine (2%) is deposited at each site. Mydriasis indicates a successful block.

Other ocular nerve blocks in cattle are

Auriculopalpebral Nerve Block: The  auriculopalpebral nerve can be palpated as it crosses the zygomatic arch, roughly 5-6 centimeters behind the supraorbital process. Inject 5 milliliters of 2% lidocaine HCl subcutaneously on the dorsal aspect of the zygomatic arch at this location.

Peterson Nerve Block: This is a complicated one .

After performing a small local skin block over the intended site of puncture, a 3.8-cm long 14 gauge needle is inserted through the skin as a cannula for introduction of an 18-gauge 9-cm long needle for the nerve block. The cannula is inserted caudal to the junction of the supraorbital process and zygomatic arch and is introduced through the skin. Then, the 18-gauge, 9-cm long needle is introduced through the cannula needle and is directed in a horizontal and slightly dorsal direction until the  coronoid process is encountered. The needle is “walked off” the rostral aspect of the coronoid process and advanced in a ventromedial direction along the caudal aspect of the orbit until the needle encounters the bony plate encasing the foramen orbitorotundum. Once the needle is advanced to the foramen, it is advised that the needle be drawn back  a few millimeters to reduce the risk of intrameningeal injection. After aspirating to assure the needle is not in the internal maxillary artery, 10-15 milliliters of lidocaine (2%) is deposited, with an additional 5 milliliters of lidocaine deposited as the needle is slowly withdrawn. Mydriasis indicates a successful block.

Retrobulbar block: An alternative to the 4-point retrobulbar block is the single retrobulbar block In this technique, the 9-cm long 18-gauge needle is bent into a ½ circle. The needle is inserted immediately ventral to the dorsal orbital rim and directed such that the needle impacts into the bone of the orbit. Then the needle is advanced as it is rotated ventrally in a progressive

manner such that the needle remains in close proximity to the bone. After the needle is inserted to the caudal aspect of the eye, 20 ml of 2% lidocaine HCl is administered after aspiration to ensure that the needle is not positioned in a vessel or other fluid structure. Successful deposition of lidocaine causes mild proptosis of the globe.

Ring Block: Additional local anesthesia of the eyelids is recommended as the Peterson and retrobulbar blocks typically  result in incomplete analgesia of the eyelids. Five to ten milliliters lidocaine (2%) is infiltrated subcutaneously 2.5 centimeters from the eyelid margins as a ring block.

Surgical procedure of Exenteration

A transpalpebral ablation technique is utilized to remove the eye. The upper and lower eyelids are sutured closed or  alternatively, eyelids can be closed using multiple towel . A circumferential skin incision is made approximately 1 centimeter from the edges of the eyelids . Using a combination of blunt and sharp dissection, Mayo scissors are used to dissect through the orbicularis oculi muscle, fascia, and subcutaneous tissue surrounding the eye. The interior of the bony orbit is used as a guide. The medial and lateral canthal ligaments are sharply transected to allow access to the caudal aspect of the orbit.

As there is a large vessel associated with the medial canthus and optic stalk which need to be ligated after the resection. A vascular clamp can aid in hemostasis while additional excision

of remaining orbital tissue is undertaken. In cases where neoplastic infiltration of the bony orbit has occurred, affected areas of ocular periosteum should be thoroughly excised. I had not encountered any bony lesions extending from BOSCC so far.

The skin incision can be closed in a variety of patterns with a nonabsorbable suture such as No. 3 nylon. Common patterns include the Ford interlocking, cruciate or simple continuous after sufficiently obliterating the dead space with iodine impregnated gauze rolls. This needs to be changed for 5 dyas till the cavity dries and heals up.   

Post-operative Care: The animal should be kept in a confined area for several days after surgery to allow for appropriate hemostasis to occur. Daily observation of the surgical site and assessment of general well being is recommended until suture removal. Sutures should be removed in 14 to 21 days to allow for complete healing of the skin. 

Histopathologically infiltrating tumour cells characterized by  numerous mitotic figure, diffusely dilated lymphatics along with Multifocal necrosis and haemorrhages throughout  the neoplasm is a common feature

CESAREAN SECTION IN COWS -TWO COMPLICATED CASES - TWINNING AND FETAL MONSTER

Greetings to all well wishers and visitors  of my blog. 

I would like to dedicate this segment to the large animal field veterinarians who are the real heroes in field. They are the guardian angels and saviors addressing  silent cries of "expectant mothers", attending Dystocia cases  in odd hours . Animals are also exactly like us in evincing labour pain.No species can deliver a young one without pain and that is the rule of life. Even though the act of  parturition is much more independent in animals, assistance is inevitable in cases where the mother won't be able to deliver due to various well reasonable causes. To many of my fellow veterinarians , especially to those who are posted in remote villages this is a routine. 
Cesarean section is potentially indicated in cases of difficulty in parturition or dystocia  when a calf cannot be delivered by manual extraction. The decision on whether to perform a  cesarean section is based on the facts whether the calf is alive, the availability of operating space in the cow’s pelvis, whether the cervix is open, access to restraint facilities and the importance of future cow fertility.
It is very unfortunate that 9 out of 10 cases presented to a  surgeon will be in last stage of handling with excess tear to the vaginal mucosa, excessive intra uterine bleeding and in some cases severe injuries to the calf and mother by unscientific manipulations using wrong traction, excessive and misplaced hooks and snares done by less trained para vets and local animal handlers . 
I strongly believe the zen saying  "Even though pain is inevitable.. suffering is certainly optional"  and much awareness is needed in Indian village conditions to educate the para vets and animal handlers to carefully and cautiously handle cases of dystocia so as to present the cases well in advance to a qualified vet and  thus save the mother and calf .

I had a very eventful week with two interesting C- sections performed at field level

I AM POSTING TWO CASES OF CAESAREAN SECTION PERFORMED AT FIELD LEVEL WITH VIDEOS FOR THE BENEFIT OF THE BUDDING LARGE ANIMAL PRACTITIONERS . 
Also a brief discussion on the methodologies and procedures is also added to this segment. You are free to post your comments and suggestions.
The surgeon usually has little choice when selecting the operating environment for a caesarean operation. Many successful operations have been performed under less than ideal circumstances in pastures,sheds, and fields . If a hospital facility is  not available, attention must be given to choosing the cleanest possible surroundings, as the operating environment has been shown to be a significant source of organisms that contaminate the wound. Also the location for surgery should be selected carefully with the objectives of ensuring good lighting, facilities for restraint and a suitable floor surface.

CASE NO -1              
CESAREAN SECTION TO RELIEVE DYSTOCIA – TWINNING
A triparous cow was presented on terminal gestation with severe straining. A para vet had tried to relieve the foetus and two limbs were found locked inside the birth canal with severe trauma to the vagina. Extensive use of snares and hook resulted in severe stress to that animal . An emergency C- Section relieved two calves . One was a live male calf and the other a still born  freemartin twin.

                        CLICK TO  WATCH THE VIDEO  BELOW 

                                           
CASE NO -2

CESAREAN SECTION TO RELIEVE DYSTOCIA – MALFORMED FOETAL MONSTER- SCHISTOSOMUS REFLEX

A 6 yr old biparous cow was presented with intermittent straining after 9^th month of gestation  propelling tortuos intestinal loops from the vagina. On examination foetal intestines were  identified. Per rectal examination revealed foetal parts locked inside the uterus leading to dystocia and pervaginal examination identified rib cage and forelimbs struck in the birth canal . An emergency C- section relieved the mother . An 18 kg weighing malformed dead  foetus abnormal limbs and (two under developed ) and concurrent schistosoma reflex leading to protrusion of intestines with ill developed thorax was removed. Timely C- Section saved the mother and post operatively the animal had an uneventful recovery. Schistosoma reflex is a monster and cause of dystocia requiring a cesarean section. Charecterised by acute angulation of the spine so that the head lies close to the tail , thoracic and abdominal cavities have no ventral wall.

CLICK TO  WATCH THE VIDEO  BELOW   

SURGICAL  APPROACHES TO CESAREAN SECTION IN COWS  

The options of patient positioning for caesarean operation are:

1. Standing (suitable for left or right paralumbar fossa and lateral oblique approach)

2. Dorsal recumbency (suitable for ventral midline and paramedian approach)
3. Sternal recumbency (suitable for left or right paralumbar fossa)
4. Lateral recumbency (suitable for ventrolateral and low-flank approach).

Standing left paralumbar celiotomy

The standing left paralumbar celiotomy is the most commonly used approach for an uncomplicated cesarean section . The incision is made vertically in the middle of the paralumbar fossa, starting approximately 10 cm ventral to the transverse processes of the lumbar vertebrae and continuing ventrally, far enough to allow removal of the calf .Closure of the abdominal wall is straightforward and relatively easy.

Standing right paralumbar celiotomy

This approach has all the indications and contraindications of the left paralumbar approach The additional and perhaps most important difference between the left and right paralumbar approach is the difficulty in keeping viscera in the peritoneal cavity with the right paralumbar approach. Most practitioners studiously avoid this approach; however, some practitioners feel right horn pregnancies are more manageable with the right paralumbar approach.

  

Standing left oblique celiotomy

This described variation of the left paralumbar celiotomy approach has distinct advantages . In this approach, the incision starts 4 to 6 cm ventral and cranial to the tuber coxae, extends cranioventrad at a 45 degree angle to the ground, and terminates at the last rib .

Recumbent left paralumbar celiotomy    

This approach differs little from the standing left paralumbar approach .Additional assistance is nearly always needed to cast the cow, if not recumbent already, and to place the cow in right lateral recumbency. The incision is made slightly more ventral than in the standing left paralumbar celiotomy.

Recumbent right paralumbar celiotomy

This approach is very seldom used, as it is very similar to that of recumbent left paralumbar celiotomy and has the additional complication of not having the rumen to retain the abdominal viscera.

Recumbent ventral midline celiotomy

This approach is straightforward and is most commonly used on a recumbent animal . If the incision is appropriately placed, the only body wall layers incised are the skin, subcutis, and the linea alba. Additional assistance is required to cast and position the cow for this approach. The cow is typically positioned in dorsal recumbency, leaning toward the surgeon at a 45 degree angle .

Recumbent ventral paramedian celiotomy

This approach is similar in most respects, including the advantages and contraindications, to the ventral midline approach .The abdominal wall incision is placed parallel and approximately 5 cm lateral to the linea .

Recumbant Ventrolateral celiotomy

This approach is similar to the other ventral approaches, but it may be better suited for the older dairy or beef cow .The cow is positioned in right lateral recumbency. The hindlimbs should be extended caudally and the upper limb abducted for the best exposure to the incision site . 

We tried various approaches in the lower flank with varying degrees of inclination and found that lower flank incision from stifle arch to the milk vein is the best.

Positioning of the patient is very important . It is important to exteriorize the uterus. This aids in limiting peritoneal cavity contamination, thereby aiding in the prevention of peritonitis.  After positioning the limb in the incision, the uterus is incised avoiding cotyledons, the limb is grasped directly and traction is placed on the calf. Uterine incisions should be positioned on the greater curvature of the uterus and the incision should be placed distant from either the cervix or apex of the horn. 

We are getting rewarding results with regional anesthesia Xylazine lignocaine mix(0.5 ml + 2.5ml for 350 kg cow ) as lower epidural nerve block followed by inverted L block

ANESTHESIA 

General anesthesia is practically impossible and an effective lower epidural nerve block and inverted L block with lignocaine give rewarding results in recumbent approach. Unfortunately, xylazine has  an ecbolic effect (i.e. it stimulates contraction in the uterus at term), making surgery more difficult, and can cause rumen tympany, which can obstruct the surgical wound

We had extensively tried a combination of 0.5 ml Xylazine + 2.5 ml lignocaine via lower epidural route( C1- C 2  for cows weighing 350 kg. This is probably the best combination to recommend. 

The uterus should be closed with an absorbable monofilament suture on a tapered needle in a continuous inverting pattern. Cushings followed by continuous Lambert pattern is the best . The muscle layers can be apposed all together or in two layers using No -2 chromic catgut using continuous pattern. A well placed subcuticular suture can renforce the closure and can ensure fast healing due to less dead space . Skin can be apposed using Nylon or Polyamide in mattress pattern. A Stay suture can retain the surgical bandage in position. Three comon complications of C- Section are Subcutaneous emphysema, Metritis and retained fetal membrane, Peritonitis and Adhesions. A deliberate post operative antibiotic therapy , supportive fluid therapy, post operative douching area must for a successful C- Section.

Post-Operative Fertility

Under normal circumstances, the three main goals of the caesarean operation in cattle are: a) survival of the cow; b)  survival of the calf;  and  c)  maintenance of post-operative  productivity, which implies not only the maintenance of body  condition and an acceptable level of lactation, but also the ability to conceive again. In our experience 70 % of the cows operated had conceived in the subsequent A live calf should be dried and the navel dressed with antiseptic immediately after delivery. Once surgery is completed, 2-3 litres of colostrum from the dam should be administered to the calf, using an oesophageal feeding tube if necessary. The dam should be introduced to the calf promptly, particularly in the case of a suckler cow and calf, to form a maternal bond.

Ever since I had actively involved in large animal practice as a surgeon and a teacher  in a state with huge livestock reserve like Karnataka , I had the opportunity to attend a variety  of C-Section cases in odd hours.I am thankful to Dr N Nagaraju, my colleague, together with whom , I  had a great time and learning attending a wide variety of dystocia and C- Sections at field level.

C Sections are really exhaustive for the surgeon too, but it is really beyond the scope of words to see the animal coming back to life and nothing is more rewarding than the sigh of relief that we perceive on the face of the animals that get treated from our hands. It is indeed blessed to work for the silent cries and thank Almighty for giving this opportunity.

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