Cattle (Bovine) Anatomy for Vet Students
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The complete bovine body plan from horns to hooves — palpable landmarks, common surgical sites, unique anatomical features, and the clinical anatomy every bovine practitioner must know.
- Cattle are unguligrade, artiodactyl (even-toed) ruminants that bear weight on digits III and IV. Digits II and V are vestigial (dewclaws). The fused metacarpals (Mc III+IV — the 'canon bone') and the fused metatarsals (Mt III+IV) form a single weight-bearing column in each limb.
- The bovine skull is characterised by the frontal bone, which is pneumatised (contains the frontal sinus) and extends caudally to form the base of the horns in horned breeds. The frontal sinus communicates with the horn's cornual process in horned cattle — dehorning opens the frontal sinus, which must be protected from contamination.
- The bovine udder has four quarters (mammary glands), each with its own teat and separate duct system. The udder is suspended by the medial and lateral suspensory ligaments. The supramammary lymph nodes (palpable at the dorsal base of the udder) are the sentinel nodes for mastitis.
- The bovine liver is entirely on the right side of the abdomen (unlike the dog, where it spans both sides). It is not palpable per rectum — if you palpate a firm, irregular mass in the right cranioventral abdomen on rectal examination, it is not the liver; consider a liver abscess or neoplasia.
- The bovine reproductive tract is suspended by the broad ligament (mesometrium). The uterus is bicornuate — the fetal calf develops in the uterine horn ipsilateral to the corpus luteum. Pregnancy diagnosis per rectum is performed by palpating the asymmetric uterine horns, the amniotic vesicle, and (from 35–40 days) the fetal membranes.
- A cow that cannot rise (downer cow) for >24 hours has a guarded prognosis regardless of the primary disease — secondary ischaemic muscle necrosis (compartment syndrome) of the pelvic limb muscles begins within 6–12 hours of recumbency and is irreversible after 24–48 hours.
- A cow with a rapidly enlarging, unilateral swelling in the paralumbar fossa that 'pings' on percussion has a pneumoperitoneum or abomasal/cecal volvulus until proven otherwise — the 'ping' location differentiates the source.
- A bull or steer with a swollen, painful, prolapsed prepuce that cannot retract the penis has a preputial prolapse, penile haematoma ('broken penis'), or persistent penile frenulum until proven otherwise — these are surgical emergencies because prolonged exposure causes penile desiccation and necrosis.
- A cow with a retained placenta for >24 hours postpartum and a fever has septic metritis until proven otherwise — the open cervix is a direct portal for uterine infection, and systemic illness can develop rapidly.
The Bovine Body Plan: Artiodactyl, Unguligrade, Ruminant
Cattle (Bos taurus and Bos indicus) are large (400–900 kg adult), herbivorous, ruminant mammals that have been domesticated for milk, meat, and draught for over 10,000 years. Their anatomy reflects three key adaptations: (1) an unguligrade, artiodactyl limb structure for weight-bearing on soft and hard ground, (2) a four-compartment forestomach for cellulose fermentation, and (3) a large, gravid uterus that occupies most of the abdominal cavity in late pregnancy.
| Body Region | Bovine Feature | Comparison to Horse | Comparison to Dog | Clinical Significance |
|---|---|---|---|---|
| Forelimb | Fused Mc III+IV ('canon bone'); two weight-bearing digits (III+IV); two dewclaws (II+V) | Horse: single digit (Mc III), two splint bones (Mc II+IV) | Dog: five digits, separate metacarpals, digitigrade | Cattle have a wider weight-bearing surface than horses, making them more stable on soft ground but more prone to interdigital lesions (foot rot, interdigital fibroma) |
| Hindlimb | Fused Mt III+IV; two weight-bearing digits; the fibula is vestigial (proximal head only) | Horse: Mt III only; fibula is a proximal head + distal remnant | Dog: separate metatarsals, full fibula | The bovine hock (tarsus) has a prominent calcaneal tuber — the insertion of the gastrocnemius tendon. Hock injuries are less common in cattle than in horses because cattle spend less time at speed |
| Skull | Frontal bone is pneumatised and forms the horn base; the frontal sinus is large and communicates with the horn in horned breeds | Horse: frontal sinus is smaller; no horns | Dog: frontal sinus is minimal; skull shape varies by breed | Dehorning exposes the frontal sinus — the sinus must be packed or left open to drain, and the corium (horn-producing tissue) must be completely removed to prevent regrowth |
| Vertebral column | C7, T13, L6, S5, Cd18–20 | C7, T18, L6, S5, Cd15–21 | C7, T13, L7, S3, Cd20–23 | The bovine lumbar transverse processes are long and palpable — L5 is used as a landmark for paravertebral anaesthesia in the standing cow. The sacrum is fused and is the palpable landmark for caudal epidural anaesthesia (Co1–2) |
| Tail | Long, mobile, used for fly-swatting; the tail switch (Cd tip) is a tuft of long hair; the caudal vertebrae are palpable along the entire length | Horse: shorter, with long hair from the base; the tail is used for fly-swatting and communication | Dog: variable length; used for communication | Tail amputation (docking) is banned in many jurisdictions. The tail is a useful site for venipuncture (coccygeal vein) in cattle when the jugular veins are inaccessible (e.g., in a down cow) |
The Bovine Udder: Anatomy of the Mammary Gland
The bovine udder is a complex, four-quartered mammary gland suspended from the ventral abdomen and pelvic floor by the medial and lateral suspensory ligaments. Each quarter is a separate gland with its own secretory tissue, duct system, gland cistern, teat cistern, and teat canal. There is no communication between quarters — infection in one quarter (mastitis) does not directly spread to the adjacent quarter through the duct system.
| Structure | Location | Function | Clinical Significance |
|---|---|---|---|
| Mammary parenchyma (secretory tissue) | Dorsal portion of each quarter; soft, glandular on palpation in a lactating cow | Produces milk — the alveolar epithelial cells synthesise milk components (fat, protein, lactose) from blood precursors | Mastitis destroys the secretory epithelium, replacing it with fibrous tissue → permanent reduction in milk production in that quarter. Chronic mastitis → 'fibrosed quarter' that is hard and non-productive on palpation |
| Gland cistern (sinus lactiferous) | Within each quarter; the space into which milk drains from the ducts | Stores milk before it enters the teat cistern for milking; capacity: 100–400 mL per quarter | The gland cistern is continuous with the teat cistern — an annular ring separates them but does not prevent milk flow. The cisterns can be visualised by ultrasound |
| Teat cistern (sinus papillaris) | Within the teat; the distal continuation of the gland cistern | Stores milk immediately before milking; the teat canal (streak canal) at the distal end is the only opening of the teat | The teat canal is the primary barrier against ascending bacterial infection (mastitis). A patent or damaged teat canal → increased risk of environmental mastitis (Streptococcus uberis, Escherichia coli) |
| Suspensory apparatus | Medial suspensory ligament (elastic, from the linea alba); lateral suspensory ligament (fibrous, from the pubic symphysis and prepubic tendon) | Supports the weight of the udder (up to 50 kg in a high-producing Holstein); the medial ligament is elastic, allowing the udder to distend with milk | Rupture of the medial suspensory ligament → 'dropped udder' — the udder floor descends below the hocks, making it vulnerable to trauma, contamination, and teat damage. This is a common reason for culling older dairy cows |
| Blood supply | External pudendal artery (from the internal iliac) — the primary arterial supply to the udder; the subcutaneous abdominal vein ('milk vein') drains the udder | The udder receives approximately 400–500 L of blood per litre of milk produced (a high-producing Holstein producing 40 L/day has ~20,000 L of blood flowing through the udder daily) | The external pudendal artery runs through the inguinal canal. During mastectomy (udder removal), this artery must be ligated securely — it is a large vessel (5–8 mm diameter) that retracts into the inguinal canal when cut |
Palpation Landmarks: The Rectal Examination
Rectal palpation is the single most important diagnostic procedure in bovine practice — it is used for pregnancy diagnosis, reproductive tract evaluation, gastrointestinal assessment, and urinary tract evaluation. The bovine rectum is capacious and the cow tolerates the procedure well when performed gently.
| Structure | Palpation Finding (Non-Pregnant Cow) | Abnormal Finding | Diagnosis |
|---|---|---|---|
| Cervix | A firm, cylindrical structure (5–10 cm long, 3–5 cm diameter) with 3–4 palpable annular rings; located on the pelvic floor or just cranial to the pelvic brim | Cervix is enlarged, soft, and doughy → pregnancy (from ~30 days); cervix is hard and immobile → chronic cervicitis or cervical adhesions | Normal non-pregnant cervix is firm and mobile. A cervix that is pulled cranially and ventrally (ventral to the pelvic brim) is a sign of a large, gravid uterus in mid-to-late pregnancy |
| Uterine body | A short (2–4 cm) segment between the cervix and the uterine bifurcation; the uterine horns diverge from the bifurcation | Uterine body is distended and fluctuant → pyometra or mucometra; uterine body is thickened and nodular → uterine neoplasia (lymphoma, adenocarcinoma) | The uterine body is the target site for artificial insemination — the semen is deposited in the uterine body, just cranial to the cervix. Depositing semen in the cervix or one uterine horn reduces conception rates |
| Uterine horns | Two horns, each 20–30 cm long in a non-pregnant cow; the horns are symmetrical in non-pregnant cattle | Asymmetry of the horns (one horn is larger) → early pregnancy (the gravid horn enlarges from ~30 days); both horns are thin-walled and atonic → postpartum uterine atony; the horns are thickened and oedematous → metritis | The bovine placenta is cotyledonary — the fetal cotyledons attach to maternal caruncles. Caruncles are palpable per rectum as small, firm bumps on the uterine wall from ~90 days of pregnancy. The number of caruncles is consistent (80–120) regardless of pregnancy status |
| Ovaries | Small (2–3 cm), oval structures; a corpus luteum (CL) is palpable as a firm, liver-like structure on one ovary if the cow is cycling; a follicle is palpable as a smooth, fluctuant, blister-like structure | Ovary is enlarged (>5 cm), cystic → follicular cyst (thin-walled, >2.5 cm) or luteal cyst (thick-walled, >2.5 cm), both of which cause anoestrus; ovary is hard and nodular → ovarian neoplasia (rare in cattle) | The CL is the most commonly palpated ovarian structure. A mature CL has a palpable 'crown' (the ovulation fossa) and is the source of progesterone that maintains pregnancy. If the CL is absent, the cow is not pregnant and is either cycling or anoestrus |
| Left kidney | The left kidney is NOT in a fixed position — it is pushed to the right of the midline by the rumen. It is palpable per rectum as a lobulated (the bovine kidney is multipyramidal, unlike the smooth kidney of the dog and horse), mobile structure in the right dorsal abdomen | Kidney is enlarged and painful → pyelonephritis; kidney is small and firm → chronic renal disease; kidney is absent from its normal position → nephroptosis or displacement by a mass | The bovine kidney is multipyramidal (lobulated) — each pyramid (renal lobule) has its own cortex and medulla. This lobulated appearance is NORMAL — do not mistake it for polycystic kidney disease |
| Rumen | Palpable in the left dorsal abdomen as a large, gas-filled viscus with doughy ingesta ventral to the gas cap; the dorsal sac is palpable per rectum | Rumen is distended and tense → bloat (free-gas or frothy); rumen is collapsed and cannot be palpated → ruminal atony or starvation; rumen is displaced medially → left displaced abomasum (the distended abomasum occupies the space between the rumen and the left body wall) | The rumen should contract 1–3 times per 2 minutes — this can be assessed by palpating the dorsal sac per rectum and counting the contractions |
Common Surgical Sites in Cattle
Bovine surgery is predominantly performed in the standing animal under local anaesthesia — this avoids the risks of general anaesthesia (regurgitation, aspiration, bloat) and the challenges of recumbency in a 600 kg animal. The key surgical sites and their landmarks are essential knowledge for any bovine practitioner.
| Procedure | Surgical Site | Landmarks | Anaesthesia | Key Surgical Points |
|---|---|---|---|---|
| Left flank laparotomy (rumenotomy) | Left paralumbar fossa — vertical or oblique incision midway between the last rib and the tuber coxae, and midway between the lumbar transverse processes and the fold of the flank | Palpate the last rib (cranial boundary), lumbar transverse processes (dorsal boundary), tuber coxae (caudal boundary), and the fold of the flank (ventral boundary). The incision is made in the centre of this rectangle | Paravertebral block (T13, L1, L2) or inverted-L block (local infiltration along the dorsal and cranial borders of the incision site) | The rumen wall is sutured to the skin edges ('rumenostomy') before opening it to prevent peritoneal contamination with ingesta. Use a continuous inverting pattern (Cushing or Lembert) to close the rumen — the serosa-to-serosa closure is critical for a watertight seal |
| Right flank laparotomy (RDA/RTA correction, cecal dilatation) | Right paralumbar fossa — same landmarks as the left flank | Same as left flank, on the right side | Same as left flank — paravertebral or inverted-L block | The abomasum (RDA) or cecum (cecal dilatation) is identified, decompressed with a needle and tubing, and the abomasum is fixed to the ventral body wall (omentopexy or pyloropexy). For RTA/AV, the volvulus must be derotated before decompression — decompressing a volvulated abomasum without derotation further compromises the blood supply |
| Dehorning (adult cattle) | The horn is removed at its base, flush with the frontal bone (cosmetic dehorning) or with a 1–2 cm rim of skin (open-sinus dehorning) | The horn base is the junction of the horn with the frontal bone; the cornual artery and nerve run along the temporal ridge toward the horn base | Cornual nerve block (local anaesthetic injected along the temporal ridge, midway between the lateral canthus of the eye and the horn base) + ring block around the horn base | The frontal sinus is opened during dehorning of adult cattle — the sinus must be packed with sterile gauze or left open to drain. The cornual artery is a branch of the superficial temporal artery and can cause significant haemorrhage — it can be ligated or the horn artery can be grasped with forceps and twisted (artery torsion) for haemostasis |
| Cesarean section (left flank) | Left paralumbar fossa — the gravid uterus is accessed through a left flank laparotomy in the standing cow | Same landmarks as left flank laparotomy; the gravid uterus is identified deep to the rumen (the rumen is retracted cranially) | Paravertebral block + local infiltration of the uterine wall (the uterus is insensitive to incisional pain but sensitive to stretch and manipulation) | The uterus is exteriorised through the flank incision (if possible — in late pregnancy, the calf is too large to exteriorise and the uterine incision is made within the abdominal cavity). The uterine incision is made on the greater curvature of the gravid uterine horn, avoiding the large uterine vessels. The calf is delivered, the fetal membranes are removed or left in situ, and the uterus is closed with an inverting suture pattern |
| Caudal epidural anaesthesia | First intercoccygeal space (Co1–2) or sacrococcygeal space (S5–Co1) | Raise and lower the tail — the moving joint is the first intercoccygeal space. The sacrococcygeal space is the depression between the last sacral vertebra and the first coccygeal vertebra, approximately 2–3 cm cranial to the tail head | The local anaesthetic (2 % lidocaine, 5–8 mL for a 500 kg cow) is injected into the epidural space after the needle 'pops' through the interarcuate ligament | Caudal epidural anaesthesia desensitises the perineum, vulva, anus, and tail — it is used for obstetrical procedures (dystocia correction, prolapsed uterus replacement), perineal surgery, and tail amputation. It does NOT provide abdominal or pelvic limb anaesthesia — the cow remains standing |
Unique Bovine Anatomical Features
Several bovine anatomical features are unique among domestic mammals and are clinically important:
- Multipyramidal kidney: The bovine kidney is lobulated — it has 15–25 renal lobules, each with its own cortex, medulla, and calyx. The calyces drain into the renal pelvis via the ureter. This lobulated appearance is normal on ultrasound and palpation — do not mistake it for polycystic kidney disease. Cattle are the only domestic mammals with a multipyramidal kidney.
- Retinal tapetum lucidum: Like dogs and cats, cattle have a tapetum lucidum — a reflective layer behind the retina that enhances night vision. The bovine tapetum is blue-green (fibrous tapetum, unlike the cellular tapetum of carnivores). The corpora nigra (granula iridica) are pigmented masses on the iris margin that are NORMAL — they may be cystic in some individuals but are not neoplastic.
- Cervical annular rings: The bovine cervix has 3–4 palpable transverse folds (annular rings) that create a tortuous cervical canal. These rings are the major obstacle to artificial insemination — the AI pipette must negotiate each ring to deposit semen in the uterine body. During oestrus, the cervix relaxes and the rings become softer and more open.
- Caruncular (cotyledonary) placentation: The bovine placenta is cotyledonary — the fetal cotyledons (which develop from the chorion) attach to maternal caruncles (which are pre-existing structures on the endometrium). The placentome (the cotyledon-caruncle complex) is the functional unit of nutrient and gas exchange. There are 80–120 caruncles, arranged in two dorsal and two ventral rows along each uterine horn. Retained fetal membranes occur when the cotyledons fail to separate from the caruncles postpartum.
- Pneumatic frontal sinus and horn: The frontal sinus extends into the cornual process of the frontal bone in horned cattle. Dehorning opens the frontal sinus — the communication between the sinus and the nasal cavity means that the sinus is colonised by nasal bacteria. The sinus must be protected from contamination during dehorning, and any packing material must be sterile. The sinus drains into the nasal cavity, and nasal discharge from the dehorning site is normal for several days postoperatively.
- Nictitating membrane (third eyelid): Like all domestic mammals except primates, cattle have a nictitating membrane — a fold of conjunctiva at the medial canthus that moves across the cornea to remove debris and distribute tears. The nictitating membrane contains a T-shaped cartilage and the gland of the third eyelid (which produces a portion of the tear film). Prolapse of the gland ('cherry eye') is less common in cattle than in dogs.
Clinical Decision Table: The Downer Cow
A 'downer cow' — a cow that is recumbent and cannot or will not rise — is one of the most common and challenging bovine emergencies. The differential diagnosis is broad, but the anatomical approach — what system has failed? — provides a systematic framework.
| System | Condition | Key Clinical Signs | Diagnostic Test | Treatment / Prognosis |
|---|---|---|---|---|
| Metabolic | Hypocalcaemia (milk fever) | Recumbency within 24–72 hours of calving; cold extremities, depressed mentation, 'S'-shaped neck bend; ruminal atony | Serum calcium (<2.0 mmol/L; normal: 2.1–2.8 mmol/L); response to IV calcium borogluconate is diagnostic | IV calcium borogluconate (500 mL of 23 % solution for a 500 kg cow, slowly over 10–15 minutes with cardiac auscultation). >80 % of cows rise within 1–2 hours. If the cow does not rise after 2 doses of calcium, it has become a 'downer cow' with secondary muscle necrosis |
| Metabolic | Hypomagnesaemia (grass tetany) | Hyperexcitability, muscle tremors, convulsions, recumbency; often occurs in lactating cows on lush spring pasture | Serum magnesium (<0.5 mmol/L; normal: 0.7–1.2 mmol/L); response to IV magnesium sulphate | IV magnesium sulphate (200–400 mL of 25 % solution slowly) + SC magnesium sulphate (200 mL at multiple sites — the SC route provides a depot for continued absorption). Must be treated within hours — fatality rate is >50 % without treatment |
| Musculoskeletal | Traumatic injury (fracture, hip luxation, stifle injury) | Recumbency after a fall, bulling injury, or dystocia; palpable fracture or joint instability; crepitus on manipulation of the affected limb | Physical examination of all four limbs (palpation, manipulation, crepitus assessment); radiographs if available (often impractical in the field) | Femoral neck fracture or coxofemoral luxation → euthanasia (the cow will never rise). Tibial fracture → external coaptation (cast) ± internal fixation (if the fracture is distal and the cow is valuable). Stifle injury → conservative management (rest, anti-inflammatories) if the cruciate ligament is intact; if the stifle is unstable (cranial drawer positive), euthanasia may be indicated |
| Musculoskeletal | Secondary recumbency (downer cow syndrome) | The cow initially went down for a metabolic reason (milk fever) but did not rise promptly → ischaemic muscle necrosis of the pelvic limb muscles due to prolonged recumbency (>6–12 hours) | Creatine kinase (CK) >50,000 U/L (massive muscle necrosis); firm, swollen pelvic limb muscles (especially the quadriceps and gluteals); the cow cannot rise even after the metabolic problem is corrected | The prognosis is grave if recumbency exceeds 24–48 hours. Treatment: deep, soft bedding, frequent turning (every 4–6 hours to prevent pressure necrosis), NSAIDs for pain and inflammation, and assisted lifting (hip lifters, flotation tank). If the cow does not rise within 5–7 days, euthanasia is indicated on welfare grounds |
| Neurological | Brain or spinal cord disease (listeriosis, thromboembolic meningoencephalitis, spinal abscess, trauma) | Recumbency with neurological signs: head tilt, circling (listeriosis), opisthotonos (meningitis), flaccid paralysis of the pelvic limbs (spinal cord lesion) | CSF analysis (listeriosis: mononuclear pleocytosis); neurological examination to localise the lesion; post-mortem if euthanised | Listeriosis: high-dose penicillin G (44,000 IU/kg IM q12h for 2–4 weeks) — early treatment can be successful. Spinal abscess: guarded-to-poor prognosis. Thromboembolic meningoencephalitis (Histophilus somni): oxytetracycline + anti-inflammatories — early treatment can be successful |
| Cardiovascular | Septic shock (acute septic metritis, mastitis, peritonitis) | Recumbency, fever, tachycardia, injected mucous membranes, cold extremities; the primary source of sepsis is often obvious (purulent vulvar discharge, gangrenous mastitis) | Complete blood count (leukopaenia or leukocytosis with left shift); serum biochemistry (azotaemia, elevated liver enzymes); blood culture (identify the organism) | Aggressive IV fluid therapy (hypertonic saline + crystalloids), broad-spectrum IV antibiotics (penicillin + gentamicin or ceftiofur), NSAIDs (flunixin meglumine), and surgical drainage/removal of the septic focus. Mortality is >50 % even with aggressive treatment |
- The paralumbar fossa is the most important palpable landmark in the cow — it is the triangle bounded by the last rib, the lumbar transverse processes, and the tuber coxae. The left paralumbar fossa is the site for rumenocentesis, rumenotomy, and LDA correction; the right paralumbar fossa is the site for RDA/RTA correction and cecal dilatation surgery.
- The ventral abdominal veins (subcutaneous abdominal vein, 'milk vein') are large, tortuous vessels that drain the udder and course cranially along the ventral abdomen. These veins can be used for intravenous access in an emergency (e.g., a down cow with no accessible jugular vein) — but they are fragile and easily haematoma.
- The bovine eye has a tapetum lucidum (like the dog and cat) and a corpora nigra (granula iridica) — pigmented masses on the iris margin that are normal anatomical structures, not neoplasia. The corpora nigra may be cystic in some cattle, but they are benign.
- The bovine cervix has 3–4 annular rings (transverse folds) that must be negotiated during artificial insemination. The rings are palpable per rectum as firm, doughnut-shaped structures. The cervical canal is tortuous, and the AI pipette must be advanced through each ring to deposit the semen in the uterine body.
Frequently asked questions
The paravertebral block desensitises the flank for standing laparotomy. Landmarks: palpate the lumbar transverse processes — the needle is inserted at the caudal border of the transverse processes of T13, L1, and L2. Technique: insert a 14G, 5 cm needle just caudal to each transverse process, at the lateral border of the epaxial muscles. Advance the needle ventrally until it contacts the vertebral body (4–6 cm deep in a 500 kg cow), then withdraw 0.5–1 cm and inject 10–15 mL of 2 % lidocaine at each site. The block desensitises the dorsal and lateral abdominal wall from T13 to L2 — the entire paralumbar fossa. Onset is 10–15 minutes. Wait for complete anaesthesia (test by pricking the skin with a needle — the cow should not flinch). The block typically lasts 1.5–2 hours. The major pitfall is injection into the subarachnoid space (if the needle is advanced too far dorsally toward the intervertebral foramen) — if cerebrospinal fluid is aspirated, withdraw the needle and redirect.
The bovine kidney is multipyramidal (lobulated) — it comprises 15–25 renal lobules (pyramids), each with its own cortex, medulla, and calyx. The calyces drain into the renal pelvis, which drains into the ureter. On palpation per rectum, the kidney feels like a cluster of grapes — this is NORMAL. On ultrasound, the lobulated cortical surface and the individual medullary pyramids are visible. In contrast, the dog and horse have a smooth (unipyramidal or unilobar) kidney — the renal cortex is smooth on the surface, and there is a single renal papilla (dog) or a renal crest (horse) that drains into the renal pelvis. The lobulated bovine kidney should NOT be mistaken for polycystic kidney disease (which causes discrete, anechoic cysts throughout the parenchyma) or renal lymphoma (which causes nodular, hypoechoic masses).
A uterine prolapse is an immediate postpartum emergency — the entire gravid uterine horn is everted and protruding from the vulva. The cow is in danger of haemorrhagic shock (from tearing the uterine vessels), uterine rupture, and peritonitis. Management: (1) caudal epidural anaesthesia (Co1–2, 5–8 mL of 2 % lidocaine) to reduce straining. (2) Clean the prolapsed uterus with warm, sterile saline or very dilute antiseptic (chlorhexidine 0.05 %). Remove gross contamination but do NOT scrub — the endometrium is fragile. (3) Elevate the uterus to the level of the vulva (use a clean sheet or board) to reduce venous congestion. (4) Starting at the cervical end (the most proximal portion), use the flat of your hands to push the uterus back through the vulva — work gradually, and the cow's contractions will help. (5) Once the uterus is fully replaced, ensure both uterine horns are fully everted back to their normal position (palpate per rectum to confirm). (6) Administer oxytocin (40–60 IU IM) to promote uterine involution and reduce the risk of re-prolapse. (7) Place vulval retention sutures (Buhner or modified Caslick technique) if the cow continues to strain. (8) Systemic antibiotics (penicillin or ceftiofur) for 3–5 days because the uterine wall is bruised and oedematous, predisposing to metritis.
In the horse, the right kidney is located in the right paralumbar fossa, ventral to the lumbar transverse processes — it is not palpable per rectum but can be imaged with ultrasound in the right flank. In the cow, the right kidney is NOT located in the right flank — it is pushed medially by the massive rumen, and the left kidney is pushed entirely to the right of the midline. Both kidneys are located in the right dorsal abdomen: the right kidney is ventral to the last rib and the first 2–3 lumbar transverse processes, and the left kidney is caudal to the right kidney, ventral to L3–L5. Both kidneys are palpable per rectum — the right kidney is more cranial and more fixed, while the left kidney is more caudal and more mobile. The bovine kidney is the only kidney among domestic mammals that can be palpated per rectum in the live animal.
The goal of AI is to deposit semen in the uterine body, just cranial to the cervix. Technique: (1) The cow is restrained, and the rectum is evacuated of faeces. (2) The cervix is grasped per rectum and held in the hand — the cervix is the landmark; the AI pipette is guided through the cervix by manipulating the cervix around the pipette (NOT by pushing the pipette through the cervix — this causes cervical trauma). (3) The pipette is advanced through the cervical annular rings — each ring is negotiated by gently manipulating the cervix with the rectal hand while advancing the pipette with the other hand. (4) Once the pipette passes the last annular ring, it is in the uterine body. The pipette should NOT be advanced into one uterine horn — depositing semen in a single horn reduces conception rates because sperm must be distributed to both horns. (5) The semen is deposited slowly, and the pipette is withdrawn. (6) The entire procedure should take <2 minutes from the start of pipette insertion — prolonged manipulation causes cervical and uterine trauma and reduces conception rates.
Self-check quiz
Test yourself. Answers are below each question — cover them first if you are studying.
- A) Persistent hypocalcaemia
- B) Secondary ischaemic muscle necrosis (downer cow syndrome)
- C) Pelvic fracture
- D) Hypomagnesaemia
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Answer: B) Secondary ischaemic muscle necrosis (downer cow syndrome)
Prolonged recumbency (>6–12 hours) causes ischaemic necrosis of the pelvic limb muscles (especially the quadriceps and gluteals) due to the cow's body weight compressing the muscle compartments against the ground. The massively elevated CK confirms muscle necrosis. Even after the primary metabolic problem (milk fever) is corrected, the muscle damage prevents the cow from rising. The prognosis is grave if recumbency exceeds 24–48 hours.
- A) Smooth, unipyramidal surface
- B) Lobulated (multipyramidal) surface
- C) Hydronephrosis (dilated renal pelvis)
- D) Renal calculi (nephroliths)
Show answer
Answer: B) Lobulated (multipyramidal) surface
The bovine kidney is multipyramidal — it has 15–25 renal lobules, each with its own cortex, medulla, and calyx. On palpation per rectum, the kidney feels like a cluster of grapes. This is the normal anatomy of the bovine kidney — do not mistake it for polycystic kidney disease or renal lymphoma. The dog, cat, and horse have smooth, unipyramidal kidneys.
- A) Spleen
- B) Rumen (dorsal sac)
- C) Abomasum
- D) Left kidney
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Answer: B) Rumen (dorsal sac)
The left paralumbar fossa incision enters the abdominal cavity immediately over the dorsal sac of the rumen. The rumen wall is sutured to the skin edges (rumenostomy) before opening it to prevent ingesta contamination of the peritoneal cavity. The spleen is located on the left but is more cranial. The abomasum is on the right side of the abdomen. The left kidney is pushed to the right of the midline by the rumen.
- A) Cervix (mid-cervical)
- B) Uterine body
- C) Left uterine horn
- D) Right uterine horn
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Answer: B) Uterine body
The semen should be deposited in the uterine body, just cranial to the cervix. Depositing semen in the cervix reduces conception rates because sperm cannot traverse the cervical mucus efficiently. Depositing semen in one uterine horn reduces conception rates because the sperm must distribute to both horns for fertilisation. The pipette is advanced through the cervix until it passes the last annular ring, and the semen is deposited immediately cranial to that point.
- A) Left displaced abomasum (LDA)
- B) Right displaced abomasum (RDA) or cecal dilatation
- C) Pneumoperitoneum from a perforated ulcer
- D) Bloat (ruminal tympany)
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Answer: B) Right displaced abomasum (RDA) or cecal dilatation
A 'ping' in the right paralumbar fossa on simultaneous auscultation and percussion is pathognomonic for a right-sided gas-filled viscus — most commonly an RDA or cecal dilatation. An LDA pings on the LEFT side. Bloat (ruminal tympany) pings in the left paralumbar fossa (the rumen gas cap). Pneumoperitoneum from a perforated ulcer produces a more generalised 'ping' that is higher-pitched and extends further cranially.
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