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Home , Anal sinuses, Epigastrium, Lingual septum, Rectal examination, Sublingual space

11 Digestive tract

J. Rothuizen, E. Schrauwen, L.F.H. Theyse and L. Verhaert

Chapter contents Abdominal lymph nodes96 96 11.1 History87 97 11.2 Physical examination88 Generation of splashing sounds97 11.2.1 Head88 Undulation test97 Introduction 88 11.2.4 and circumanal 97area Chewing musculature88 Introduction 97 Oral cavity88 Inspection 98 , tonsils, and soft Fig. 11.1 ) 90 ( 98 Salivary glandsFig. ( 11.2) 90 11.2.5 and adjacent structures99 Hyoid bones90 Introduction 99 Technique 90 Technique and interpretation99 Teeth 91 Anus 99 Hard palate93 Rectum 99 93 Coccygeal and levator ani muscles99 Pharynx 94 Internal iliac lymph nodes100 11.2.2 Esophagus94 Pelvic bones100 Introduction 94 100 Technique and interpretation94 11.3 Notation100 11.2.3 Abdomen94 11.4 Further examination100 Introduction 94 Inspection 94 Palpation 95 Superficial palpation95 In addition to the symptoms described by the owner in Deep palpation95 the general history (Chapter 6), such as dysphagia (difficult swallowing or complete inability to swallow), Palpation of the kidneys and urinary vomiting, abnormal feces, and abnormal defecation, tract 95 several other symptoms may originate from the Palpation of the 95liver digestive tract. These will be discussed below in the Palpation of the spleen96 specific history. When there is suspicion of aspiration Palpation of the pancreas96 pneumonia, as can occur with swallowing disorders, Palpation of the ovary, uterus, and the history and must be extended prostate 96 to include the respiratory tract (Chapter 9). Palpation of the stomach96 The examination of the digestive tract is usually Palpation of the intestinal 96tract limited to that part relevant to the problem which has now been formulated (Chapter 3). Rectal examination 86 History is not needed when the problem is dysphagia, nor is retrograde expulsion of vomitus. This is often preceded by examination of the upper digestive tract necessary swallowing, salivation, and restlessness (symptoms of when the problem is tenesmus alvi (painful, repeated nausea). Active vomiting is a reflex phenomenon. urgency to defecate). If a complete examination of the Neurogenic stimuli which lead to vomiting stimulate the digestive tract is indicated, then the examination vomiting center in the brainstem. Humoral stimuli that proceeds in sequence: , pharynx, , lead to vomiting stimulate the chemoreceptor center, from , anus and , and rectum. which the vomiting center is then stimulated. Stimulation of the vomiting center leads to coordinated muscle 11.1 History activity, of which the contractions of the muscles of the abdominal wall are the most striking. The best known manifestations of abnormal functioning of The term diarrhea is used when the characteristics the digestive tract are vomiting and diarrhea. These of the feces are changed by an increase in the volume symptoms will be discussed in detail below and a series of and/or percentage of water. Diarrhea is also often specific questions will be presented together with examples. used to describe an increased defecation frequency, with These questions also illustrate the importance of a careful or without an increase in volume or water content. history for further specifying the problem definition. Similar to the important distinction between vomiting In ‘vomiting’ animals, questions must be asked to and regurgitation, it is essential to distinguish between differentiate between regurgitation and active vomiting. small bowel diarrhea and large bowel diarrhea. Regurgitation is the passive, retrograde expulsion of A small bowel diarrhea occurs when the effluent contents from the , esophagus, or . The act from the small bowel to the large bowel is so changed of regurgitation is ‘passive’ in the sense that it is not a in volume and composition that in spite of the reserve recognizable, reflex-determined phenomenon. Expulsion capacity of the colonic mucosa to absorb water, the occurs under the influence of the position of the head final contents and hence the feces are too voluminous and , gravity, the intrathoracic pressure, the and/or too watery. This form of diarrhea can be caused pressure relation between the and abdomen, and by an increased osmotic value of the intestinal the pressure in the abdomen. The manifestation of contents, or by increased secretion and/or exudation of regurgitation can vary greatly with regard to the nature of the intestinal mucosa, and/or by abnormal motility. the regurgitated material, the amount, and the time after Large bowel diarrhea occurs as the result of abnormal eating. Regurgitation of food during eating can indicate an colon motility, reduction of the absorptive surface of the inability to relax the proximal esophageal colonic mucosa, or increased secretion and/or exudation (cricopharyngeal achalasia) or the presence of pharyngeal in the colon. The most characteristic features are paralysis. Regurgitation of large amounts of mucus or summarized in Table 11.1.Thetableoncemoreillustrates food, independent of food intake (thus both before that the distinction between small bowel diarrhea and and after), is usually related to esophageal paralysis. large bowel diarrhea relies on findings in the history. Regurgitation of large amounts of food may occur with pyloric stenosis. Occasionally, regurgitation is Questions that can be asked about problems that may characterized by belching of fluid, which can be due to involve the digestive tract are given below, with a few dysfunction of the cardia or it can be due to pyloric stenosis. examples to illustrate their relevance. We speak of active vomiting when there are active Development. After determining the age at which the contractions of the abdominal muscles before the animal was acquired by the present owner, the next step

Table 11.1 Most characteristic differences between small bowel diarrhea and large bowel diarrhea. This distinction is only important in chronic diarrhea. Not all of the criteria have to be present for either type and there can be some overlapping

small bowel diarrhea large bowel diarrhea Defecation frequency Low High Tenesmus Rare Often (persisting) Volume of feces Large Small Mucus in feces Rare Often Blood in feces Rare Often Polydipsia Often Rare Polyphagia Often Rare Borborygmi and flatulence Often Rare Weight loss Often Rare

87 Chapter 11: DIGESTIVE TRACT

is to ask when gastrointestinal problems were first through the pharynx and esophagus to the stomach. noticed. Food intolerance generally appears at a young Dogs and cats hold large pieces of food with the front age, whereas enteritis is most often seen in young adult feet and then tear off pieces mainly with the incisor to middle-aged animals. Neoplasia is more likely to be and canine teeth. Larger pieces can be cut off with the involved in gastrointestinal problems in older animals. carnassials (fourth premolars in upper jaw and first Course. Knowing whether the problem is continuous molars in lower jaw). The incisor teeth are used to or episodic is often helpful. Enteritis is often episodic, pick up smaller pieces of food or to tear them loose. while exocrine pancreatic insufficiency (EPI) results in Dogs and cats only marginally chew their food. The continuous problems without spontaneous remission. premolars are mainly suited for holding the food (prey). Further characterization of the problem. The iatrotropic The teeth of cats are characteristic of a real carnivore, problem (} 3.1.1) is documented and further described. whereas those of dogs have some characteristics of an Apart from vomiting and/or diarrhea (see above) there omnivore. In dogs the upper and lower molars have a may be associated problems such as anorexia, dysphagia grinding occlusal surface. (swallowing problems), or bloody feces. By means of the short ‘catching’ movements of the Additional symptoms may include: head, which are very noticeable in the dog, the food, – Decreased appetite, which is considered to be very which is held and guided by the , serious if associated with weight loss. Malignancy and tongue, is moved caudally. Saliva is added while (gastric carcinoma, malignant lymphoma) should the food is broken or ground into slightly smaller be considered. pieces by the molars. The bolus of food formed in this – Weight loss may not only be caused by decreased way is pressed against the hard palate by the tongue food intake, but may also be the result of and then by contraction of the muscles of the pharynx maldigestion/malabsorption. it is brought into the esophagus. – Pica is the tendency to eat things that are The closes off the nasopharynx in this inedible for dogs and cats, such as potato process. The larynx is pulled more or less under the peelings or cloth. It may be the result of extreme root of the tongue and together with tension on the hunger, as can occur in EPI. Eating grass or vocal folds, the airway is closed off. other plants may be a prodrome (forerunner) of vomiting and may be one of the manifestations Chewing musculature of nausea. Of these muscles the masseter and temporal muscles are – General signs of illness. Lethargy associated with a accessible for physical examination. The masseter gastrointestinal problem usually indicates a serious muscle is on the lateral surface of the ramus of the disorder. It can also be secondary to one of the , ventral to the zygomatic arch. The temporal consequences of , such as muscle is the largest and strongest muscle of the head dehydration. Conversely, a problem outside the and lies in the temporal fossa. Both muscles are may lead to general illness important in opening and closing the mouth. with vomiting, as occurs in renal disease when accumulating waste products trigger the vomiting Oral cavity center. – Manifestations of . Conditions such The mouth or oral cavity lies between the mouth opening as acute pancreatitis and intestinal foreign body and the entrance to the throat. The hard palate forms the with may give rise to striking dorsal border; the form the rostral, the cheeks form manifestations of pain. Dogs often assume a the lateral, and the tongue and form ‘praying’ position in which the front legs are the ventral border of the oral cavity. extended forward so that the ventral thoracic wall The teeth separate the mouth into the oral cavity touches the floor, while the hind legs remain proper (inside the teeth) and the labial vestibule and vertical. During attacks of pain the animal may buccal vestibule (outside the teeth), bordered by the suddenly leap up, trembling, and then restlessly lips and cheeks, respectively. walk around. The mouth opening is closed by the lips. There is a sharp border between skin and . The upper (maxillary) makes a transition to the nasal plane. 11.2 Physical examination The lower (mandibular) lip is much shorter than the 11.2.1 Head upper, so that the upper lip hangs over the lower, especially at the angle of the mouth. The buccal mucosa Introduction changes to gingiva at the . The Maintenance of the organism requires that food be cheeks are between the angle of the mouth opening and taken in, reduced to smaller pieces, and transported the mucosal fold that runs behind the last molar 88 Physical examination between the palate and the lower jaw. The openings of the ducts of the parotid and zygomatic salivary glands are in the caudodorsal mucosa of the . The opening of the is situated dorsal to the fourth premolar and the opening of the zygomatic duct is dorsal to the first molar. The mucosa of the cheeks also changes to gingiva at the mucogingival junction. The most common head shape in dogs is described as mesocephalic or mesaticephalic. Dogs with short skulls, such as boxers, are called brachycephalic, and those with long skulls (greyhound type) are called dolichocepahlic. Brachygnathia refers to an abnormally 1 short lower jar or mandible and prognathism refers to relative elongation or protrusion of the mandible. In 2 3 brachycephalic breeds there is shortening of the upper 4 jaw, termed maxillary brachygnathia, so that the lower 5 incisors protrude beyond the upper (‘undershot’). 6 When the lower jaw is shorter than normal we speak of an overbite (‘overshot’) or mandibular brachygnathia. The terms overshot and undershot do not describe jaw length per se but rather the relative 7 proportions of the jaws. Especially with an overbite, mucosal damage can be expected due to the pressing of the lower canines into the hard palate. 8 The set of teeth is described by dental formulas (Table 11.2). The incisors (I), canines (C), premolars (P), and molars (M) are grouped according to the quadrants of the mouth (upper right ¼ 1, upper left ¼ 2, lower left Fig. 11.1 The opened mouth of a dog with the base of the tongue ¼ 3, and lower right ¼ 4) and the tooth number is depressed: 1 soft palate, 2 tonsillar sinus, 3 epiglottis, 4 palatoglossal fold, 5 vallate papillae, 6 conical papillae, 7 filiform and fungiform counted from the central incisor (based on a complete papillae, 8 median sulcus of the tongue. set of teeth). Thus, the fourth premolar of the upper right jaw is indicated as 108 and the second molar of the lower left jaw as 310. mandibular and sublingual salivary glands open into the The hard palate has 6–10 slightly angled ridges (palatine mouth in the sublingual caruncles, lateral to the frenulum. rugae), which help in moving the food backward in the The ducts from these two glands lie in a small mucosal mouth. Behind the first incisor teeth lies the incisive fold (sublingual plica) that runs caudally from the caruncles. papilla, separated from the palate by two grooves. On In addition to its role in taking up and transporting both sides the nasopalatine duct opens here, the duct food, the tongue also has the function of sorting and being a connection between the mouth and the nasal cavity. testing food. In the cat the tongue also fills an important The bottom of the mouth (apical sublingual cavity) is role in cleaning the body. The tongue is also used in heat under the tongue. The frenulum divides the space into two regulation, communication, and caring for the young. elongated lateral sublingual recesses. The ducts of the The tongue (Fig. 11.1) is a strongly muscled that fills a large part of the bottom of the mouth and the oral part of the pharynx. The tip of the tongue lies completely Table 11.2 Dental formulas per quadrant in the upper and free while the body of the tongue is attached on its ventral lower jaws in the dog and the cat side to the bottom of the mouth by the frenulum. The root of the tongue, of which only the upper surface is dog cat free, is attached near the epiglottis. The palatoglossal Deciduous 3i, 1c, 3p 3i, 1c,3p folds or plicae are mucosal folds which run from the 3i, 1c, 3p 3i, 1c, 2p side of the root of the tongue to the soft palate. On the Permanent 3I, 1C, 4P, 2M 3I, 1C, 3P, 1M flat upper surface of the tongue there is a longitudinal 3I, 1C, 4P, 3M 3I, 1C, 2P, 1M groove, the median sulcus of the tongue. I ¼ Incisor, C ¼ Canine, P ¼ Premolar, M ¼ Molar (deciduous teeth in On the mucosa of the tongue various types of papillae lower-case letters). can be recognized: filiform, fungiform, vallate, foliate, and conical (Fig. 11.1). The filiform papillae have a 89 Chapter 11: DIGESTIVE TRACT

primarily mechanical function, while the others play a to the skull. The structure consists of a single basihyoid role in the sensation of taste. A very rough mucosal bone, paired thyrohyoid, keratohyoid, epihyoid, and surface is characteristic in the cat. On the ventral side stylohyoid bones, and paired tympanohyoid cartilages. of the tongue of the dog, beginning at the tip and The thyrohyoid is attached to the thyroid cartilage of running caudally in the , is the lyssa. It the larynx. The tympanohyoid is attached to the was once thought that there was a relation between mastoid process of the skull. this ‘string’ and rabies¼ lyssa ( in Greek). Possibly it Examination of the head is necessary in animals that are fills a role as a stretch receptor. troubled by problems in eating or by dysphagia. The Phary nx, tonsils, and soft Fig.palat 11.1 )e ( examination includes the muscles of mastication, oral cavity, pharynx, salivary glands, and hyoid bones. The pharynx is a space that connects the mouth with the esophagus, and the nasal cavity with the larynx. The soft Technique palate divides the pharynx into the nasopharynx The examination begins with inspection of the head, taking dorsally and the oropharynx ventrally. The oropharynx special notice of the masseter and temporal muscles for is divided into the isthmus of (throat opening) atrophy, swelling, or asymmetry. Note the closure of the and a laryngeal part. The isthmus of fauces is bordered lips and any deformities of them. Salivation and the by the root of the tongue, the palatoglossal folds, and absence of closure of the mouth can be important findings. the soft palate. The laryngeal part of the oral pharynx The muscles of mastication are then palpated, with extends from the base of the epiglottis to the entrance attention to painfulness, consistency, warmth, and size. to the esophagus. In the side walls of the isthmus of The oral mucosa (labial and gingival) was examined fauces lie the tonsils (palatine tonsils). They lie in the in the general examination by lifting of the upper lip tonsillar sinuses and are covered on the medial side by (Chapter 8). This can also be done now to examine the a thin wall, the semilunar fold. buccal side of the teeth. Saliv ary glan Fig.ds 11.2( ) For further examination of the oral cavity the mouth must be opened. Standing in front of the dog, a right- The dog has four pairs of major salivary glands: the handed person places the left hand over the top of parotid, mandibular, sublingual, and zygomatic glands. the nose with the thumb and forefinger curving down The partly encloses the base of the each side of the upper lip just behind the canine teeth. ear and is covered on the outer surface by muscles The forefinger of the right hand is used to open of the ear. On the ventromedial side the gland overlaps the mouth by pressing on the lower incisor teeth. If this the dorsal edge of the mandibular . The is done slowly and quietly, most dogs will allow the mandibular gland is more or less rounded and lies in mouth to be opened in this manner. In order to examine the angle formed by the internal and external maxillary the caudal part of the oral cavity and the isthmus of veins; it is always easily palpated. This salivary gland is fauces, the right hand is moved so that the forefinger sometimes mistaken for the mandibular lymph nodes and middle finger press the base of the tongue forward } (see 8.2.6). The is connected to the and downward. The left hand can now be shifted to mandibular gland by a connective tissue sheath. The encircle the nose, with the thumb resting against the zygomatic gland lies within the orbit. hard palate (Fig. 11.3). This stimulates a reflex which Hyoid bones causes the dog to keep the mouth open. Together the hyoid bones form the supporting and connecting structure which joins the tongue and larynx

1 4

3 2

Fig. 11.3 Inspection of the oral cavity. The mouth is held open by Fig. 11.2 Salivary glands in the dog: 1 parotid, 2 mandibular, holding the thumb of one hand against the hard palate and using a 90 3 sublingual, 4 zygomatic. finger of the other hand to press down on the base of the tongue. Physical examination

incisor teeth (Fig. 11.5). It is usually necessary to restrain the front legs, as most cats resist the opening of the mouth. While the mouth is being opened, attention is given to the ease or difficulty of passive movement of the temporomandibular joints. The animal’s breath should be noted; a fetid odor may indicate necrotic tissue. Inspection of the mucosa of the buccal cavity is aided by stretching the cheek laterally with a finger. The teeth, hard palate, ventral part of the central area of the oral cavity, and the tongue are then examined. To close this description of the technique of oral inspection we emphasize once more that this method can only provide global information about oral pathology. For thorough inspection and palpation, general anesthesia is required.

Teeth Depending on the age of the animal, oral inspection will reveal deciduous or permanent teeth, or a mixture of the two. Deciduous teeth are much smaller than permanent Fig. 11.4 Cloth straps can be used to hold open the mouth of a dog that teeth (Fig. 11.6). In both dogs and cats, the eruption of resists the usual method. It is very important to remain aware of the permanent teeth is complete by the age of 5 to 7 forces involved and for this reason both cloth bands should be in the months, a variation that is somewhat breed dependent. hands of one person. The molars are the last to appear. In most dogs, molar 3 only erupts at the age of 7 months. The dentition is It is clear that oral inspection as just described can only examined for completeness. If teeth are found to be be carried out in cooperative dogs. If a dog resists having missing during oral inspection, radiographic its mouth opened, an attempt can be made to bring examination is needed to differentiate between absence strips of strong cloth between the teeth in order to and lack of eruption. Deciduous teeth found to be spread the jaws. This usually succeeds if the dog is held present after eruption of the permanent teeth are called quite securely, even if it is necessary to use tissue forceps retained or persistent deciduous teeth (Fig. 11.7). Their between the canine tooth and first premolar to open the presence can lead to malocclusion, mucosal damage, mouth just enough to place the cloth strips. The mouth trapping of food particles, early deposition of dental can then be slowly opened with the cloth strips, but this calculus, and periodontitis. should always be done by just one person (Fig. 11.4). The occlusion or closure of the teeth is considered next. In cats the oral cavity can be inspected in a similar way. The With correct (scissors) occlusion, the incisive border of mouth is opened by pressing downward on the lower the lower incisors touches the palatal side of the upper

Fig. 11.5 Left: Opening the mouth of a cat. Right: Close-up view of the tongue, showing the large and markedly keratinized conical papillae, characteristic of this species. 91 Chapter 11: DIGESTIVE TRACT

Fig. 11.6 A The deciduous teeth of a pup (left) and the permanent teeth of a 1-year-old dog (right). B Frontal and side views of the teeth of an adult cat. The incisors are smaller than in the dog and the canine teeth are longer and sharper. These pictures also illustrate the sharp cutting premolars.

Fig. 11.7 A 7-month-old dog with persistent deciduous teeth (upper Fig. 11.8 A 9-year-old dog with plaque (cremor dentium) on the canine and lower canines). teeth. There is also wearing of the central cusp of 101 and 201, while the cusps of 301 and 401 are still intact. incisors. The lower canines occlude halfway between (e.g., canine, incisive, or maxillary P )(Fig. 11.10), the third incisors and the canine teeth of the upper 4 enamel defects, and other tooth abnormalities. jaw. With correct occlusion, the premolars and Finally, the gingiva is examined for the presence of molars interdigitate with one another (‘pinking shears redness, swelling, and hemorrhages (gingivitis, effect’). If the occlusion is abnormal, there may be periodontitis). This inventory provides a first impression mucosal damage. For example, a lower canine tooth of the condition of the dentition. An extensive inspection that is more lingual in position can damage the hard of the complete set of teeth is only possible with palate, leading to pain and difficulty in eating. anesthesia and the use of a sharp probe and a The teeth are examined for the presence of plaque periodontal probe. Radiographic examination is usually (cremor dentium) (Fig. 11.8), dental calculus (calculus necessary, since only the crown, which is just one-third of dentium), and foreign material between them, such as the tooth, is visible. hair or food residues (Fig. 11.9). The examination also In principle, the changes in dentition during growth and includes a check for possible damage, such as fractures adult life (deciduous teeth, permanent teeth, wear of 92 Physical examination

Fig. 11.9 Side view of the mouth of a 10-year-old greyhound with large amounts of dental calculus, before (left) and immediately after (right) treatment. There is loss of gingival attachment to the mesial root of 108 (periodontitis).

hair), eyes (cataract), and teeth may suggest a certain age, but it is still only a rough estimate and may actually be off by several years. The same holds true for cats. In fact, estimating age from the wearing away of the teeth is even less accurate in cats than in dogs.

Hard palate The hard palate is inspected for mucosal lesions and deformities, as described for the general examination (} 8.3.5), and to confirm that it is closed (no cleft palate).

Tongue Fig. 11.10 Complicated (open pulp) fracture of crown and root of the first molar in the right lower jaw (409). Examination of the tongue concerns its color, surface appearance, the presence of papillae, localized thickening, and foreign bodies. It is important to be lobules on the incisors, and the development of plaque and conscious of the possibility of foreign bodies. Foreign dental calculus) aid in estimation of the age of the animal. bodies around the tongue cause swelling due to However, in adult dogs no reliable estimate can be made. congestion of the entire tongue and such a tongue can The wear of the incisors can vary greatly, depending on become necrotic and then slough. In cats, needles can use and occlusion of the teeth. Some dogs only eat soft become embedded in the root of the tongue. The food, while others gnaw bones and/or play with hard frenulum should be given special attention to be materials (Fig. 11.11). The first appearance and the certain that no string or thread is caught there. Foreign progress of plaque and dental calculus may also vary bodies may also cause lesions under the tongue. greatly between individual animals. The lateral sublingual recesses and the apical In the adult dog, the combined impression of the sublingual cavity can be examined by using one finger posture, behavior, body proportions, haircoat (gray to move the tongue to one side and lift it slightly.

Fig. 11.11 Pronounced wearing down of the teeth of a 5-year-old male bull terrier that enjoys playing with tennis balls and stones (left). In viewing this dog’s maxilla from below (right), we can see that this has resulted in exposure of the pulp of the canine teeth (104 and 204) and teeth 103 and 203. Tooth 105 is missing, which could be a congenital abnormality. 93 Chapter 11: DIGESTIVE TRACT

The mucosa of the ventral surface of the tongue and of Inspection and palpation of the neck can sometimes the bottom of the oral cavity can thus be examined be helped by standing before the dog and raising its and the frenulum can be inspected adequately. head with one hand. Special attention is then given to Inspection of the frenulum and the ventral surface of the thoracic inlet, to look for signs of a dilated the tongue can be improved by pressing upward esophagus. This is indicated by a slight bulging of the slightly between the while the mouth is inlet, synchronous with expiration. If the esophagus is open. The location of the sublingual salivary glands dilated, the left side of the thoracic inlet will probably (Fig. 11.2) can be examined. A salivary cyst () feel full when palpated. By causing some movement in may be found under the tongue. Under normal this area with the hand (rapidly opening and closing conditions, only the mandibular and part of the the hand or grasping and sliding the hand cranially and sublingual salivary gland is palpable. caudally), sloshing sounds may be heard (fluid and air). Although the thoracic portion of the esophagus is not Pharynx directly accessible for examination, it can be examined Unless the dog or cat is anesthetized, the pharynx can be only radiographically if necessary. partially inspected for a few moments while the tongue is The most frequent cause of obstructed passage through depressed with the fingers. The isthmus of fauces, soft the esophagus is a foreign body. If it has been present for palate, and tonsils can be examined. The soft palate can more than a few hours, there can be serious damage to usually be seen if the base of the tongue is depressed. the wall of the esophagus due to pressure necrosis. If the tonsils are hidden by the semilunar folds in an Because of the risk of perforation, the blind use of a probe adult dog, it can be assumed that there is no or tube has no place in the examination of the esophagus. abnormality; if they are visible, they are enlarged. If they are enlarged, the shape, color, presence of hyperemia, 11.2.3 Abdomen and appearance of the surface should be noted. In young animals the somewhat more active lymphoid tissue in Introduction the tonsils usually causes them to be visible. For purposes of physical examination of the , A thorough examination of the oropharynx requires , stomach, and intestines, the entire abdomen general anesthesia. Additional information about the is examined. For this examination a good knowledge of pharynx can be obtained by palpating the area between the anatomic relationships is an important requirement. the caudal edge of the mandible and the larynx. One To describe and communicate our findings, we can hand is used to hold the dog’s nose slightly elevated so divide the abdomen into 18 compartments (Fig. 11.12): that the area can be more easily palpated with the other the epigastrium, mesogastrium, and ; hand. The hyoid bones can also be examined in this dorsal, medial, and ventral; left and right. manner to detect deformities or pain. The border between epigastrium and mesogastrium is a transverse plane just caudal to the 13th rib. The border 11.2.2 Esophagus between mesogastrium and hypogastrium is a transverse Introduction plane just cranial to the thigh musculature. Two horizontal planes equally divide the space between the The oral esophageal sphincter lies dorsal to the larynx. In lumbar muscles and the ventral abdominal wall into the neck the esophagus passes on the left of the trachea dorsal, medial, and ventral parts. A median plane and in the thorax it is more dorsal. Under normal divides the abdomen into left and right halves. conditions it is empty, completely collapsed, and thus does not contain air. When a bolus of food is swallowed Inspection it is transported to the stomach by primary and sometimes secondary peristalsis. If peristalsis is reduced, We begin by inspecting the abdomen, giving attention to its the esophagus loses its tonus and becomes dilated, size and form. The observations are interpreted in leading to the accumulation of fluid, food, and air. In the connection with other information, such as anorexia or neck the esophagus is covered by musculature and is not pregnancy. An increase in abdominal size can lead to a palpable in healthy animals. specific form or shape. Hence a marked increase in the size of the liver or overfilling of the stomach will increase the size of the epigastrium and mesogastrium. Sometimes Technique and interpretation great overfilling of the intestinal tract can result in During inspection, attention is given to the position of the segments of intestine being noticeable by inspection. neck, for pain caused by an abnormality in the esophagus A large amount of free fluid usually results in bulging of can be manifested by keeping the neck stretched and the the ventral part of the abdomen and falling inward of the head low. Loss of saliva from the mouth can result from upper part. Thus in the transverse plane the abdomen ineffective or inadequate swallowing. becomes pear shaped (see also } 10.2.3). 94 Physical examination

Superficial palpation Meso- Hypogastrium Epi- Experience teaches that a little discipline is required not to forget superficial palpation of the abdomen. It can 5 9 provide valuable information. Superficial palpation 12 means that the abdominal wall is pressed in as little as possible. The entire abdomen is explored in this manner. 1 7 10 14 It allows the abdominal organs to be examined in place, that is, without affecting their position by palpating. 13 3 6 11 Abnormal muscular tension may indicate resistance 2 by the animal due to unwillingness or pain. A tense and painful abdomen may be observed in association with acute and severe abdominal lesions. It can also be due to abnormalities in the spinal column that cause pressure on the spinal cord and/or spinal nerves. During superficial palpation, overfilled intestinal loops

5 and abnormal masses are not so displaced or changed in 9 8 Dorsal 12 form that they are no longer recognized. Yet to be detected by superficial palpation, the abnormal structures 4 Medial must be more or less in contact with the abdominal wall. 10 7 21

Deep palpation Ventral 3 Deep palpation can be performed in different ways. It should always be approached slowly and performed carefully. The examiner must remain aware of and responsive to the reactions of the patient. One method is to palpate by repeated movements Fig. 11.12 Lateral view of the abdomen, divided into compartments: 1 diaphragm, 2 liver, 3 stomach, 4 pancreas, 5 kidneys, 6 spleen, with the fingers of both hands from a superficial level 7 intestine, 8 ovary, 9 ureter, 10 bladder, 11 , 12 rectum, to as deep as possible. At many places in the 13 scrotum, 14 prostate. abdomen the fingers from the two sides can come in Palpation contact. Another method of deep palpation is to bring the This is the most important part of the abdominal fingers of the two hands as close to each other as examination. It should if possible be performed while the possible and then to slowly move them simultaneously animal is standing. The examiner takes a position at the dorsally or ventrally so that the abdominal contents end of the table and the person who is holding the animal pass between them. stands at the side. All compartments are examined The objective of palpation is to discover abnormal systematically and an effort is made to form an opinion structures, enlarged organs, pain, a thickened intestinal about all organs in the abdomen. These findings must wall, abnormal intestinal contents, etc. be directly translated into words and recorded. In general, the palpation is done with both hands, using Palpation of the kidneys and urinary tract the fingertips of more or less flat hands. The abdomen is This is described in Chapter 12. thereby approached from its two sides for examination of the epigastrium and mesogastrium. Certainly in large Palpation of the liver dogs the hypogastrium can also be palpated from below by standing behind the dog and bringing the hands The liver lies in the epigastrium, completely within the forward between the rear legs. In small dogs and in cats, costal arch and slightly to the right. In most dogs it it may be easier to hold one hand on the animal’s back cannot be palpated, though it may be in those with a and use the other hand to palpate from underneath. broad thorax. In a dog with a deep thorax, such as Palpation begins in the dorsal epigastrium and greyhounds, the liver lies completely within the costal proceeds to the hypogastrium. Palpation can be arch and cannot be reached. In healthy cats the caudal performed from dorsal to ventral and/or from ventral to borders of the liver can usually just be touched. dorsal. Full examination of the mesogastrium requires As can be appreciated from Figure 11.12, diffuse many repetitions of palpation movements. It may be enlargement of the liver is first detectable in the ventral very difficult to perform abdominal palpation in obese epigastrium by superficial palpation. With further animals. Diagnostic imaging may provide a solution. enlargement it can also be found by deep palpation in 95 Chapter 11: DIGESTIVE TRACT

the medial epigastrium, certainly if one palpates with the ‘supple loops’, which indicates no abnormality of the fingers inside the costal arch. This can usually be carried wall and little luminal contents. During palpation of the out quite well in cats. The enlarged liver will be found intestine, the contents may give a crepitating or sooner on the right side than on the left. One can crackling sensation. The of the cat feels attempt by palpation to determine the texture of the more firm and solid. Local thickening and/or surface and the presence of pain, although these features irregularities can be an indication of foreign bodies, are rarely found to be abnormal. adhesions, granulomas, or tumors. Signs of obstructed passage through the intestine can also be found: too Palpation of the spleen much material in the lumen, distended loops, splashing sounds. Pain associated with this may indicate peritonitis. The spleen is normally located in the epigastrium against In most animals the colon is felt in the dorsomedial the major curvature of the stomach. Since it is entirely mesogastrium and hypogastrium as a somewhat stiff within the costal arch, it cannot be palpated. The tube of variable diameter. By careful palpation this spleen and the stomach are loosely connected by the structure can be followed almost from the epigastrium gastrosplenic ligament, so that when the spleen to the hypogastrium. Its diameter is determined by the enlarges, and thus becomes heavier, it easily shifts amount of feces it contains. It is usually filled, unless ventrally and caudally. Enlargement of the spleen the animal has not been eating for several days. The (splenomegaly) can usually be detected by superficial colon contents are usually more segmented in cats than palpation in the ventral and medial mesogastrium and in dogs. and megacolon can result in with slightly deeper palpation it can usually be extreme enlargement of the colon and extreme recognized as the spleen because of a more or less oval hardness of the fecal material. The wall of an empty cross-sectional profile. In contrast to the liver, the colon feels more stiff than the wall of the small spleen can be displaced caudally by palpation. intestine. The diameter of the empty colon is also If the spleen is palpable, an attempt is made to larger than that of the small intestine. When the determine whether its shape is still normal. contents are not too hard, careful pressure may cause an indentation. This indicates feces rather than a solid Palpation of the pancreas foreign body or a soft-tissue structure such as a lymph In general the pancreas is not palpable, even if abnormal. node. Solid feces also indicate there is no diarrhea. It lies in the right ventromedial mesogastrium. A diffuse and generalized pathologic change in the colon can lead to palpable thickening and stiffness of Palpation of the ovary, uterus, and prostate its wall and the palpation can be painful for the See Chapters 13 and 14. animal.

Palpation of the stomach Abdominal lymph nodes If the liver is of normal size, the stomach, if empty, is The mesenteric and colonic lymph nodes can only be completely within the costal arch and is not palpable. identified if enlarged. The mesenteric nodes and the After a large meal, the epigastrium gives an impression right and middle colonic lymph nodes are in the medial of fullness because of a poorly defined mass that can mesogastrium. The left colonic node is nearer the be compressed. junction of the mesogastrium and the hypogastrium. In exceptional situations a markedly thickened gastric wall or a foreign body in the ventral part of the stomach Percussion can be palpated. An attempt to palpate the stomach can Percussion is only attempted if the abdomen is enlarged. be made by lifting up the cranial end of the dog, in the The results may provide some information about the expectation that the stomach will move somewhat cause. Finger-on-finger percussion is used. It is caudally. The results are almost always disappointing. performed along three vertical lines over the abdominal wall of the mesogastrium. Attention is given to the Palpation of the intestinal tract tone and possible local damping or a horizontal Severe overfilling of the small intestine can sometimes be damping line. The presence of a horizontal damping detected by superficial palpation. By deep palpation line can be confirmed by repeating the percussion but the small intestine can be evaluated by letting the with the dog in another position, such as sitting. If abdominal structures pass between the fingers of the there is ascites, a horizontal line will also be found in two hands. This allows evaluation of the thickness of this position. The percussion tone is determined by the the intestinal wall, the contents of the lumen, the abdominal contents: excessive gas in the intestine gives diameter, local thickening, and the presence of pain. a tympanic tone, fluid gives a dull tone. Localized In most healthy animals the small intestine is felt as space-occupying processes cause a local damping. 96 Physical examination

Auscultation The examiner stands behind the animal with a flat The objective of auscultation is the detection of sounds hand against one side of the abdomen, while using the occurring in the gastrointestinal tract, called fingers of the other hand to give a short, sharp tap borborygmi. They require the presence of fluid and gas against the abdomen below the line of damping. The as well as peristalsis. Their frequency says something pressure wave which this causes is transmitted through indirectly about the character of the peristalsis, if it is the fluid and is felt by the flat hand at almost the same known whether the animal is fasting or is in a digestive moment. If the dog does not have a very heavy coat, phase. A completely empty intestine can be completely the pressure wave can also be seen to cause slight silent. When the intestine is in a digestive phase of movement of the abdomen (see Chapter 10). activity, the sounds are intermittent, infrequent, low- In a dog with a large amount of abdominal fat, the fat toned, and not very loud. can give a slight pressure wave, but it is not so clear as Auscultation is performed by placing the stethoscope that in ascites. Either a full bladder or a large fluid- on the ventral abdominal wall and listening for a few filled cyst that is in contact with both sides of the minutes. Frequent, loud borborygmi with an extremely abdomen can give a quite clear undulation, but it variable high tone indicate a very strong peristalsis. should be possible to differentiate either of these from The absence of borborygmi, even though fluid and ascites by abdominal palpation. other material can be detected in the intestine by palpation or the presence of splashing sounds, indicates lack of peristalsis. This may be observed in intestinal 11.2.4 Anus and circumanal area obstruction, which is called ileus. Introduction Generation of splashing sounds The coccygeal muscle and levator ani muscle are important to the structure and function of the anus Splashing sounds can be induced if there is a closed space and rectum. The rectum is so enclosed by these muscles containing gas and a large amount of fluid. Fluid that they can be thought of as its supporting structures. accumulation without gas, such as ascites, an overfilled The anus is the terminal opening of the alimentary bladder, or pyometra, does not result in splashing sounds. canal, but we also use this term for the combination of Splashing sounds can be generated when there are large the internal and external anal . The anal sacs amounts of gas and fluid in the stomach and/or intestines. are located between the two sphincters and their Using the hands placed lower down on the abdomen on excretory ducts pass along the caudal edge of the both sides, the abdomen is quickly moved up and down, internal sphincter and exit ventrolaterally in the internal while the ear is placed as close as possible or the part of the cutaneous zone of the . The anal stethoscope is placed against the abdominal wall. If sacs form a reservoir for the secretion of the anal glands, splashing sounds are heard, an effort is made to which is thin or pasty, gray, and for humans has a very determine the area from which they are coming and objectionable odor. The anal sacs are emptied in hence the part of the gastrointestinal tract that is defecation and during sudden contraction of muscles in involved. Splashing sounds from the epigastrium usually the anal area, as in fright and resistance. arise in the stomach, suggesting poor gastric emptying. The anal canal is about 1 cm long and lies between Splashing sounds from the entire abdomen indicate an the termination of the rectum and the anal orifice. The accumulation of gas and fluid in the small intestine. This mucosa of the anal canal is divided into three zones: suggests poor passage in the intestine, which could be due cutaneous, intermediate, and columnar (Figs 11.13 and to a local obstruction or a generalized loss of peristalsis. 11.14). The cutaneous zone has an external and an Splashing sounds in the mediodorsal mesogastrium can internal part. The external part does not actually arise from the colon and can therefore suggest the belong to the anal canal. The border between the two presence of watery contents, i.e., diarrhea. Interpretation parts, i.e., the anus, is not sharp but varies with the of splashing sounds must be related to findings in the position of the tail. If the tail is hanging, the anus is history and the rest of the physical examination. visible as a transverse groove. The external part of the cutaneous zone does not have hair. The circumanal Undulation test glands lie in the wall. The extent of this zone is largely The cause of abdominal enlargement may be found by determined by the degree of development of the palpation if it is a tumor or an abnormal organ, or by circumanal glands. In older male dogs the external percussion if it is accumulation of gas. If the percussion zone can be very broad, so that the external, dorsal tone is dull, the undulation test is performed to (longer) part hangs ventrally. The shorter ventrolateral determine whether the damping is due to accumulation part runs ventrally in a slightly V-form. The internal of free fluid in the abdomen (ascites) or enlargement of part of the cutaneous zone is about 4 mm wide and has abdominal organs or accumulation of fat. a slightly moist surface. 97 Chapter 11: DIGESTIVE TRACT

Dorsal to the rectum is the ventral part of the sacrococcygeal muscle and laterally the rectum is mainly bordered by the levator ani muscle. Ventrally it is bordered by the vagina in the female and by the urethra in the male.

Inspection When the rectal temperature is being measured, several observations can be made, as described in Chapter 8. In dogs with defecation problems or other problems in this area, the inspection is more extensive. The following questions are a guide. – Is the area beside the tail thickened? A loss of 5 4 3 1 2 support by the coccygeus and/or levator ani muscle can lead to bulging out in this area, or perineal Fig. 11.13 Almost horizontal section of the anus of a dog: 1 cutaneous . It can be on one or both sides. zone, 2 opening from the anal sac, 3 anocutaneous line, 4 columnar zone, 5 anal sac. – Are there perineal fistulas? Fistulas indicate extensive inflammation of the anus and sometimes also of the rectum. The inflammation and its The intermediate zone has a width of no more than consequences can cause problems in defecation. 1 mm and forms an irregular, fairly sharp edge, the The openings of fistulas can be very small and anocutaneous line. This follows a more or less sinus therefore not readily seen. wave form. The anal glands empty out into this zone. – Are there circumanal tumors? If so, they are Their secretion is slightly fatty. described in the usual manner (} 4.1.2). The wall of the columnar zone consists of longitudinal – Are there proglottids of tapeworms, in the anus or or slightly transverse ridges separated by the . among the hairs of the adjacent skin? The size of the latter is related to the course of the wave- – Are the anal sacs overfilled? shaped anocutaneous line. Most anal sinuses end cranially in a line which forms the cranial border of the Palpation anal canal, called the anorectal line. The rectum is the caudal part of the colon that is located within the pelvic Palpation of the perineal area is done with one hand canal, up to the anorectal line. while the other hand holds the tail up slightly. First,

Fig. 11.14 Anus and circumanal area. Left: Raising the tail provides a view of the external part of the cutaneous zone. Right: dilation of the anus reveals the internal part of the cutaneous zone and the columnar zone. The internal sphincter is closed. The opening of the left anal sac is indicated by the arrow, while the opening of the right anal sac is hidden behind a small fold.

98 Physical examination the condition of the coccygeal and levator ani muscles is In general, animals do not strongly resist rectal noted. The area under the skin just to the left and right palpation and the examiner should therefore recognize of the anus should be firm if these muscles are present that resistance can be due to pain. Circumanal and and of normal size. Atrophy of these muscles can rectal disorders can lead to pain that is so great that contribute to development of perineal hernia. When a rectal palpation cannot be continued unless the animal perineal hernia is present, the skin can be pushed with is anesthetized. This may especially be required in the fingers of the palpating hand inward along the animals with perianal fistulas. rectum, unless this is prevented by the accumulation of The tonus of the anus must also be assessed. In general feces in the rectum. the tonus is such that the sphincters close firmly upon the Next, the circumanal area is palpated. Note is taken finger. Either a reduced or an increased tonus is of of the fullness of the anal sacs, thickening that could importance. A reduced tonus can indicate a disturbance be due to tumor, or the presence of pain. of innervation of the anus. If the tonus is reduced, both the anal reflex and the bulbocavernosus reflex should be 11.2.5 Rectum and adjacent structures checked. In the bulbocavernosus reflex, pressure on the bulb of the penis results in contraction of the anal Introduction sphincters. An increased anal tonus can indicate an Rectal examination is included in examination of the increased sensitivity of the defecation reflex, which digestive tract only when there are specific indications could be the reason for abnormal defecation behavior, for it. Important indications related to the digestive such as defecation in the house. system are: constipation (obstruction or stricture), The structures of the anus are then examined: the blood in the feces (tumor, inflammation), diarrhea mucosa of the anal canal, the sphincters, the anal sacs, (differentiation of small bowel and large bowel and the circumanal region. The examination can be diarrhea), , and tenesmus. Because carried out by palpating the entire area between the cats tend to resist this examination, it is sometimes thumb and the finger in the anus. This main purpose of neglected even though there are indications for it, but this palpation is to detect irregularities and thickening. this neglect is a mistake. The anal sac can be felt as a circumscribed thickening ventrolateral to the anal sphincter on each side. Technique and interpretation Rectum The examiner stands at the end of the table and the assistant stands at the side to hold the animal. The Now attention is given to the rectum and its contents. examiner uses one hand to hold the animal’s tail When the finger is inserted further and meets feces, the slightly elevated. An excess of lubricating cream is amount and consistency are assessed. The presence of a applied to the gloved forefinger of the other hand. A large amount of hard feces can be important (Why small amount of lubricating cream is applied to the wasn’t there a defecation reflex, or why did it not lead anus, which gives the animal some warning and allows to emptying of the rectum and colon?). a little time for it to be calmed, if necessary. The Examination of the rectal mucosa is of great palpating finger is then placed against the anus with importance in animals with signs of large bowel light pressure and this should allow it to pass through diarrhea. In healthy animals the mucosa is supple, the sphincters. No force may be used, and no turning slightly folded and uniform. Inflammation can make or boring motion, since this can cause extreme pain. the mucosa less supple and the surface finally becomes Rectal examination may provide much useful irregular. In addition, the palpation can be very information. In order not to miss abnormalities, the painful. examiner should take the time needed for careful Palpation should also reveal whether there is any attention to the following structures. thickening of the rectal wall or narrowing of the lumen by compression outside the wall of the rectum, Anus or a rectal stricture. During palpation there may be a rectal contraction and this ring should not be A normally functioning anus can be distended easily. The misinterpreted as a stricture. Soft pressure will usually diameter of the anal canal should easily accommodate the cause it to relax. palpating finger (assuming that this has been considered in advance and that the size of the finger is not too great for the size of the animal). Circumanal abnormalities can Coccygeal and levator ani muscles result in narrowing of the anal canal, sometimes to the After examination of the rectal wall, attention is given to extent that the finger cannot pass the anus. This should the muscles bordering the rectum on the left and right have been anticipated from a history of tenesmus together sides, namely, the coccygeal and levator ani muscles. with the production of feces of very small diameter. As mentioned above, a defect in these muscles leads to 99 Chapter 11: DIGESTIVE TRACT

a perineal hernia. If these muscles are intact, palpation result in a diagnosis, in which case a therapeutic plan will reveal a firm wall beside the rectum on both sides. will be made. More often they do not lead to a diagnosis If the muscles have atrophied, the palpating finger can but allow formulation of the problem to be sharpened so reach directly to the subcutis. Because the lateral that a plan for further diagnostic studies can be made. support for the rectum has been lost, there is usually a Sometimes it is necessary to start symptomatic therapy dilatation of the rectum and as a result the rectum is in the meantime. incompletely emptied by defecation. Since the feces remain longer in the dilated rectum, more fluid is removed and they may become hard. 11.4 Further examination There are many possibilities for further examination. Internal iliac lymph nodes Their applicability depends very much on the cost of apparatus, the anticipated number of patients to be The internal iliac lymph nodes are only palpable if examined in a given period, and the opportunity for enlarged. Enlargement is usually due to tumor. The the veterinarian to develop and maintain knowledge caudal border of the enlarged nodes can be felt and experience. dorsally through the wall of the rectum, below the – blood examination (routine clinical chemistry, lumbosacral junction. Enlargement of the nodes can trypsin-like immunoreactivity) also displace the colon and rectum ventrally. – urine examination – fecal examination (parasites) Pelvic bones – plain radiography – ultrasonography The bones of the pelvic canal can be palpated. – contrast radiography Abnormalities of the can lead to narrowing of – thin-needle aspiration biopsy and cytologic the canal, via which the passage of feces can be examination severely obstructed and constipation can develop. – diagnostic , also for full thickness biopsies of the gastrointestinal tract Prostate – (esophagus, stomach, , colon) with biopsies } Examination of the prostate is described in 12.2.3. The – prostate should be palpated in any male dog with a large – tolerance tests bowel problem in which there is tenesmus or with any – pH measurements in the esophagus signs suggesting obstruction of fecal passage. – pressure measurements in the esophagus – measurement of gastric juice secretion, with 11.3 Notation stimulation – The results of the examination can be recorded on a form such as that shown on the DVD. The observations might

References 1 Bistner S, Ford RB. Handbook of veterinary procedures and 5 Tams TR. Handbook of small animal gastroenterology. Philadelphia: emergency treatment. Philadelphia: Saunders; 1995. Saunders; 1996. 2 van Foreest A. Tandheelkunde bij Gezelschapsdieren. Maarssen: 6 Thomas DA, Simpson JW, Hall EJ. Manual of canine and feline Elsevier/Bunge; 1999. gastroenterology. Shurdington (Cheltenham). British Small Animal 3 Guilford WG, Center SA, DA Strombeck, et al. Strombeck’s Small Veterinary Association; 1996. animal gastroenterology. Philadelphia: Saunders; 1996. 4 McCurnin DM, Poffenbarger EM. Small animal physical diagnosis and clinical procedures. Philadelphia: Saunders; 1991.

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