By I. Yussuf. University of Alaska, Anchorage.
This area is highly vascular cheap cipro 750 mg without a prescription, and laser purchase generic cipro online, if avail- able cheap 1000 mg cipro with mastercard, is best for providing hemostasis. Bipolar radio- surgical units on higher coagulation settings may also be effective. Pressure may be applied to the area with a cotton-tipped applicator to allow visualization of the vessels. Its major disadvan- sinus that cannot be accessed using nasal flushes and tage is the risk of ocular injury. This pro- cedure is repeated so that each of the four sutures To create an opening in the supraorbital sinus, the passes through the skin, one hole of the stent, dou- skin is incised exposing the frontal bone. Holes are bles back, passes through the other hole of the stent made in the bone with a sterile rotary toolf about and exits the skin. The four sutures should be placed one-half to two-fifths the distance between the ros- one on each of the four sides of the incision. Cortical bone is removed problem is a transient occlusion of the stent with until the cancellous bone above the supraorbital si- dried tissue fluids, which is easily resolved using a nus is visualized. Samples for cytology and culture are This syndrome has also been treated in an Amazon obtained, and the sinus is flushed with irrigation parrot using a one-way valve connecting the cervico- solution. The passage of irrigation solution through cephalic air sac to the clavicular air sac. The ap- the choana and into the oral cavity confirms that the proach is through the left lateral thoracic inlet, and hole is properly placed. It bulge when fluids are introduced, and these tissues is then directed caudally along the esophagus, should not be over-distended. If indicated, this proce- through the thoracic inlet and into the cranial aspect dure may be performed bilaterally in some Passeri- of the clavicular air sac. The tube is sutured to the formes, whereas a single trephination site is suffi- longus coli muscles to prevent migration. No attempt cient in Psittaciformes in which the infraorbital is made to suture the air sac around the tube. The trephination sites may be irrigated as often as Thoracic Surgery indicated with appropriate antimicrobial solutions. The incisions heal rapidly and may need to be opened Tracheal/Syringeal Obstruction periodically. When therapy is no longer indicated, the 9,19 Seed or other foreign body aspiration, fungal trephination sites heal with minimal scarring. Some birds present with no premoni- This condition is thought to occur secondary to trauma, tory signs, while others have a history of voice change but the location of leakage of air into the subcutaneous and a more gradual onset of dyspnea. Generalized subcu- taneous emphysema usually occurs in small birds, Therapy depends upon the size of the patient and the while in larger species the emphysema is generally configuration of the trachea. A birds such as swans and cranes is coiled and encased procedure for surgically implanting a cutaneous stent within the sternum, making retrieval of distal tra- at the poll of the head to allow the air to escape (in a cheal foreign bodies extremely difficult (see Figure location where the bird cannot remove the device) has 12. In a that allows the skin to be placed under its edge to Sarus Crane, a 22 ga spinal needle was passed trans- prevent the dermis from closing over the opening, is versely through the trachea to prevent a kernel of used for the procedure. Sutures are pre-placed through generally cartilaginous, although calcified rings have the four pairs of holes in the flange of the stent such been reported in adult Amazon parrots and adult that the suture enters one hole from the external 19 40 cranes. Once all four sutures are cartilage) may be present, providing an additional placed, the stent is implanted. Place- moval of tracheal or syringeal foreign bodies (Figure ment of an air sac cannula will allow the patient to 41. The patient is positioned in dorsal recumbency ventilate through an alternate airway until the ob- on a surgical restraint board. It may be beneficial to in the esophagus to allow for its easy identification to place the bird in an oxygen-enriched environment prevent iatrogenic trauma. The skin is incised from prior to manipulating the patient for placement of the right clavicular/sternal junction to the clavicu- the air sac cannula. The skin is elevated from the crop, and the right lateral aspect In small birds (cockatiels and smaller), the tracheal of the crop is gently dissected from surrounding tis- diameter (approximately 1. Major blood vessels are easily avoided using cludes use of an endoscope to retrieve a foreign body blunt dissection. If the obstruction is the result of a vicular attachments, it should be reflected to the granuloma or inspissated cells and mucus, a suction right. The trachea is identified by its complete carti- tube (urinary catheter) slightly smaller than the di- lage rings. The sternotracheal muscles are identified ameter of the trachea may be utilized to remove traversing obliquely to their caudolateral attach- material from the trachea and syrinx (see Chapter ments, and both sets of sternotracheal muscles are 22). A large blood vessel between the muscle cannula, the trachea may be occluded with the suc- bellies should be coagulated prior to transection of tion tube without compromising respiration. A small canine vaginal speculum may squamous metaplasia secondary to hypovitaminosis aid in visualization. A is suspected, dietary modification and vitamin A supplementation should be instituted. The restraint board should be elevated In medium to large birds, a rigid or flexible endoscope at the cranial end such that the operating microscope can be used to evaluate the cause of an obstruction can be used to visualize the structures deep in the and potentially aid in its removal. It may take some time and patience to endoscope may allow visualization of the object, but achieve proper positioning and focus, but this tech- the tracheal diameter may be too small to use a wire nique allows the surgeon to visualize critical structures basket or grasping forceps to remove the object. In Amazon samples obtained from the suction tube, or the end of parrots, small macaws and smaller birds, this proce- the endoscope, may be used to determine the identity dure may result in avulsion of the bronchi from the of an etiologic agent. For these patients, a left lateral approach to the patient should be treated using nebulization, intra- syrinx is recommended as a last desperate attempt. A transverse tracheotomy (50% of diameter) can also be created on the ventral surface to allow retrieval of In some cases, tracheal foreign bodies may be re- the foreign material. Foreign bodies have been re- trieved using grasping forceps, a Foley catheteri or a moved through longitudinal tracheal incisions;35,36,44 Fogarty catheter28 with the aid of an endoscope. The however, these incisions provide limited visibility size of the patient’s tracheal diameter will determine and access due to the inward twisting of the cut rings, which catheter is most appropriate. The catheter is and are more prone to iatrogenic trauma during passed beyond the foreign body and the balloon is manipulation, are more difficult to close than a trans- inflated sufficiently to occlude the airway but not to verse tracheotomy and are more prone to stricture prevent it from being withdrawn. Those located endoscope-guided biopsy for diagnosis of a respira- caudal to the tracheotomy site can be removed by tory disease. If the trachea completely separates during manipulations, anastomosis may be performed. The In birds, there is no distinct pleural space, and the incision should be closed with a small-sized, mon- visceral and parietal pleura are in close approxima- ofilament, absorbable suture material encompassing tion. The pulmonary parenchyma is contoured to the at least one tracheal ring on each side of the trache- dorsal aspect of the ribs and the intercostal spaces. Compared with mammalian lungs, those of birds are Knots should be placed external to the tracheal lu- more vascular and the intrinsic clotting mechanism men. Soft tissue, skin and subcutaneous The lungs can be approached through the caudal tho- closure are routine.
In contrast to other birds buy cipro 750 mg with amex, the feathers of the ostrich function to shade the body purchase cheap cipro on line, rather than insulate it cheapest cipro, and an ostrich will erect the feathers when hot and flatten them when cold. Musculoskeletal System The rhea, emu and cassowary have three toes (digits 2, 3 and 4), each with four phalanges. The ostrich is the most specialized runner and has only two toes (digits 3 and 4); the metatarsal-phalangeal joint is suspended so that the standing weight is born en- tirely by the digits (Figure 48. The pubic bones of the ostrich form a solid ventral symphysis to support the weight of the abdomen (Figure 48. Because there is no need for flight, the thoracic sus 2) metatarsal phalangeal pad 3) digital cushion 4) phalangeal pad 5) toenail (modified with permission from Murray Fowler19). In the ostrich and emu, one of the tarsal bones remains unfused to the contiguous bones, which should not be misinterpreted as the knee radiographically. A surgical incision made along the midline penetrates the skin, sub- cutaneous fat (minimal) and a dense fibrous abdominal tunic. The next layer is retroperitoneal fat, which may be two to eight centimeters thick, especially in the emu. When a laparotomy is performed, the bulk of this adipose tissue should be peeled away prior to closing the body wall (Color 48. Respiration occurs by lateral excursions of the chest wall, which must be considered during an- esthesia and recovery. The normal respiratory rate in adult ostriches is 6 to 12 bpm, which may increase to 40 to 60 bpm during periods of stress, exercise or with high temperatures. The lungs and air sacs are similar to those of other avian species, but the air sac capacity is greatly reduced. The distinct visceral outlines created by the air sacs in the radiographs of psittacines are not present in ratites. Other structures of interest include the first rib (r), The femur is the only pneumatized cartilaginous extension of the sternum (c) and the humerus (h). Other structures include the femur (f), ilium (s), ischium (i) and pubic symphysis (t) Emus have a longitudinal cleft in the (courtesy of Murray Fowler,19 reprinted with permission). This insertion of the muscle on the cnemial crest of the area is particularly well developed in the female. The crest is projected craniodorsally pro- the chick, a thin membrane covers the cleft. Material deposited into the esopha- gus during tube-feeding is routinely regurgitated, creating a risk for aspiration. Consequently, gavage feeding requires that a tube extend into the proven- triculus. The proventriculus of the ostrich is a large, dilated, thin-walled structure that is easy to access surgically because it extends caudal to the ventriculus (Figure 48. In most avian species, the entire inner surface of the proventriculus secretes digestive enzymes. In contrast, the secretory region of the ostrich proven- triculus is restricted to an area of glandular tissue on the greater curvature. The distal extremity of the ostrich proventriculus passes dorsal to the ventricu- lus and empties into this organ through a large open- ing on its caudal aspect. Ventricular foreign bodies can be easily removed through an incision made into the proventriculus. The ventriculus is situated slightly to the left of the midline at the caudal border of the sternum. Though the proven- triculus and ventriculus can normally contain small stones, gastric impaction from the consumption of foreign bodies is a common problem in ratites, par- ticularly in juvenile birds (Color 48. In emus rected into the pouch causes a drumming sound in the female and a growling sound in the male. The presence of this expandable pouch may compli- cate inhalation anesthesia in mature emus. If posi- tive pressure ventilation is used to inflate the air sacs and ventilate the lungs, air may be directed into and thus inflate the pouch. Inflation of the pouch can be prevented by wrapping the lower neck with a self- adhesive bandage, taking care not to place excessive pressure on the major vessels of the neck. Proventriculus (p), ventriculus (v), duodenum (d), jejunum (j), ileum (i), ceca (c), rectum (r) and niche of these large grazing ungulates. Ratites have cloaca (cl) (courtesy of Murray Fowler, reprinted with permission19). The opening from the ventriculus to the duodenum is on the right side in all ratites. The small intestine is most important in the emu, in which it occupies most of the abdomen caudal to the ventricu- lus. In the ostrich and rhea, the elongated, well developed ceca, vis- ible immediately after entering the midline abdominal wall, course di- agonally from right to left in a caudal direction. The lumen of the ceca ap- pears sacculated as a result of spiral folds that increase the surface area in the organ and facilitate the fer- mentive digestion of fiber (Color 48. The large intestine of the ostrich is voluminous and occupies the caudal right abdomen (Figure 48. The long, large intestine is considered necessary to digest high-fiber food items. The gastroin- testinal transit time is slow in ostrich and rheas (36 hours) and much faster in emus (5 to 6 hours). Interestingly, emus produce a large portion of their energy through fermentation even though they have poorly developed ceca, a short colon and a rapid gastro- intestinal transit time. In the ostrich, the urodeum and co- prodeum are separated by a muscu- lar sphincter, making the ostrich the only bird that can urinate inde- pendent of defecation. The coprodeum is a large sac that may be covered by a dark tough membrane similar to koilin. There is no gallbladder in the ostrich, but this organ is present in the emu and rhea. As a hen reaches sexual maturity, the follicles begin to develop, so the ovary has many visible follicles of different sizes at any one time (see Color 29). Cranial division of the left kidney (k), left testicle (t) and left adrenal gland (a) (courtesy of Murray Fowler, reprinted with near the kidney. Male ratites have a phallus that serves to transport semen from the ejaculatory Ratites of both genders possess a genital prominence ducts in the cloaca of the male to the cloaca of the that extends from the ventral aspect of the cloaca. The phallus is shaped differently in ostrich, This prominence may be visualized or palpated to emu and rhea; however, the function is the same, and 25 determine the gender of any aged individual. Venipuncture can be performed using the jugular, brachial and medial metatarsal veins.