Paralysis in Dairy Cattle - A Comprehensive Overview

1. PARTURIENT PARESIS (Milk Fever / Hypocalcaemic Paralysis)

Aetiology & Pathophysiology

• Occurs at or within 72 hours of parturition, most commonly in high-producing cows (3rd lactation and beyond)
• At calving, calcium demand for colostrum/milk production suddenly surges, outpacing the cow's ability to mobilize calcium from bone or absorb it from the gut
• Serum calcium falls from normal ~2.4 mmol/L to below 1.5 mmol/L (clinical hypocalcaemia)
• Calcium is essential for neuromuscular transmission. As levels fall:
  • Early (Stage I): Hypersensitivity, restlessness, trembling of muscle, hypersensitivity to touch, tetany
  • Stage II: Flaccid paresis - the cow becomes unable to rise and sits in sternal recumbency; heart rate slows, muffled heart sounds, loss of rumen motility, dry muzzle, cold extremities, skin insensitivity
  • Stage III (severe): Lateral recumbency, coma, bloat, death if untreated

Breeds at Risk

Diagnosis

Treatment

• IV calcium borogluconate (400 ml of 25% solution slowly IV) - response typically within 10-30 minutes
• Can also be given SC/IM for maintenance

Prevention

• Negative DCAD (Dietary Cation-Anion Difference) prepartum diets
• Anionic salts (ammonium chloride, ammonium sulfate) in dry cow period
• Vitamin D supplementation
• Low calcium dry cow diet to prime homeostatic mechanisms

2. PERIPHERAL NERVE PARALYSES (Calving Paralysis / Obturator Nerve Paralysis)

2a. Obturator Nerve Paralysis

• Hindlimbs slide outwards (abduction) when the cow tries to stand - the "splits" position
• Inability to adduct the hindlimbs
• Cow can bear weight if limbs are manually adducted and supported
• Usually bilateral; worse on slippery floors
• No loss of skin sensation (sensory fibers not affected)

• Anti-inflammatory (dexamethasone, flunixin meglumine)
• Vitamin B12, Vitamin E/Selenium to aid nerve regeneration
• Deep bedding, non-slip flooring (ropes/hobbles to prevent excessive abduction)
• Sling support
• Physiotherapy - assisted rising 2-3x/day

2b. Sciatic Nerve Paralysis

• Complete hindlimb paralysis
• Stifle and hock joints extend, distal joints (fetlock) flex
• When supported, the cow bears weight on the fetlocks (knuckling)
• Loss of sensation below the stifle

2c. Common Peroneal (Fibular) Nerve Paralysis

• Fetlock knuckling (flexion of fetlock, extension of stifle)
• Dorsal surface of the digit dragged on the ground
• Loss of sensation over dorsal cannon and digit
• Cow walks on the dorsum of the hoof

• Bandaging/splinting the limb in extension
• NSAIDs, turning/rolling the cow every 4-6 hours

2d. Tibial Nerve Paralysis

• Hyperextension of the fetlock (opposite of peroneal)
• Partial flexion of the hock
• Loss of sensation on the caudal and plantar surface of the limb

2e. Femoral Nerve Paralysis

• Inability to extend the stifle joint
• Quadriceps atrophy
• Calf lies recumbent with affected hindlimb flexed
• Characteristic "dropped stifle" appearance
• Cannot bear weight

2f. Radial Nerve Paralysis

• Inability to extend the elbow, carpus, and digit
• Forelimb dragged on the dorsum (knuckling)
• Characteristic "dropped elbow" appearance
• Foreleg cannot be advanced normally

2g. Combined Obturator + Sciatic Nerve Paralysis

• Produces characteristic "frog-leg posture" - hindlimbs extended cranially in lateral recumbency
• Rising is impossible
• Extremely poor prognosis

3. SPINAL CORD PARALYSIS

3a. Vertebral Fractures

• Most common at lumbar/sacral junction or thoracolumbar junction
• Caused by: falls during calving, mounting behaviour, trauma
• Clinical Signs: Sudden onset hindlimb paralysis (paraplegia) with intact forelimbs; pain at the fracture site; bladder/bowel dysfunction
• Diagnosis: Deep pain response assessment; radiography; myelography
• Prognosis: Grave; euthanasia usually indicated

3b. Spinal Cord Abscess

• Secondary to septicaemia (especially in calves via navel infection), TB, or localized infection
• Clinical Signs: Progressive hindlimb weakness and ataxia, spinal pain, fever, progressive ascending paralysis
• Treatment: Long-course antibiotics (penicillin, ampicillin); guarded prognosis

3c. Spinal Cord Compression from Lymphoma (Lymphosarcoma)

• Enzootic bovine leucosis (BLV) can cause peridural lymphoma compressing the spinal cord
• Typical presentation: adult dairy cow with progressive hindlimb paresis/paralysis, no fever
• Other lymphoma masses may be palpable rectally
• Diagnosis: BLV ELISA/AGID test, rectal palpation, CSF cytology
• Prognosis: Fatal; no treatment; slaughter recommended

4. METABOLIC/NUTRITIONAL PARALYSES

4a. Hypomagnesaemic Tetany (Grass Tetany / Hypomagnesaemia)

• Occurs in spring/autumn when cows graze lush pastures low in magnesium
• Serum Mg falls below 0.5 mmol/L
• Stage I: Apprehension, hypersensitivity, muscle tremors
• Stage II: Ataxia, staggering, recumbency
• Stage III: Tetanic convulsions, opisthotonus, nystagmus, death
• Unlike milk fever, cows are hyperexcitable and may be tetanic rather than flaccid
• Treatment: IV/SC magnesium sulfate + calcium borogluconate (combined solutions available); must give slowly to avoid cardiac toxicity
• Prevention: Magnesium supplementation in feed/water

4b. Hypophosphataemia

• Can contribute to downer cow syndrome alongside hypocalcaemia
• Severe hypophosphataemia causes haemolytic anaemia and severe muscle weakness
• Treatment: IV sodium acid phosphate; oral supplementation

4c. Hypokalemia

• Rare; can occur with prolonged anorexia, diarrhoea, or excessive salivation
• Severe hypokalemia causes generalized flaccid muscle weakness
• Treatment: Oral/IV potassium supplementation

5. TOXIC CAUSES OF PARALYSIS

5a. Botulism

• Caused by Clostridium botulinum toxins (Types C, D most common in cattle)
• Toxin blocks acetylcholine release at neuromuscular junction
• Sources: contaminated silage, carcasses in feed/water, soil
• Clinical Signs: Progressive ascending flaccid paralysis starting from hindlimbs, then forelimbs, neck, tongue (dysphagia), eyelids (ptosis), ultimately respiratory paralysis and death
• Treatment: Supportive only (no antitoxin commercially available for cattle); vaccination with toxoid effective for prevention

5b. Organophosphate/Carbamate Poisoning

• Inhibit acetylcholinesterase -> excess ACh at both muscarinic and nicotinic receptors
• Clinical Signs: Salivation, lacrimation, urination, diarrhoea (SLUD signs) PLUS muscle fasciculations, weakness, seizures
• Treatment: Atropine (for muscarinic signs) + pralidoxime (2-PAM) if given early

6. INFECTIOUS CAUSES OF PARALYSIS

6a. Listeriosis

• Listeria monocytogenes - most commonly causes encephalitis (brainstem), not true paralysis
• Signs: Circling, unilateral facial nerve paralysis (drooping ear/lip, deviation of tongue), dysphagia, head tilt
• Treatment: High-dose penicillin early; poor prognosis if severe

6b. Polioencephalomalacia (Thiamine Deficiency)

• Seen in calves/young cattle on high-concentrate diets; thiaminases in rumen
• Cortical necrosis leads to blindness, head pressing, opisthotonus, recumbency
• Treatment: IV thiamine (Vitamin B1) - dramatic response if given early

6c. Bovine Spongiform Encephalopathy (BSE)

• Prion disease; causes progressive CNS degeneration
• Signs: Apprehension, progressive ataxia, trembling, recumbency, death
• Diagnosis: Brain histopathology (post-mortem only); notifiable disease
• No treatment; notifiable/reportable

6d. Rabies

• Progressive ascending paralysis form ("dumb rabies") can occur in cattle
• Pharyngeal paralysis, drooling, ataxia
• Zoonotic - all suspect cases must be handled with extreme caution

7. DOWNER COW SYNDROME

1. Primary recumbency: The initial cause (most often milk fever, nerve injury, or fracture)
2. Secondary recumbency: When the cow fails to rise after 12 hours despite IV calcium; ischemic muscle/nerve damage from lying too long compounds the problem
3. Tertiary recumbency: Progressive muscle necrosis (creeper cow), compartment syndrome, total loss of limb function

• Alert, eating, but unable to rise
• "Creeper cow" - paddling attempts, gradual scooting
• Serum CK/AST markedly elevated (muscle damage)
• Poor prognosis after >4-5 days recumbency

• Identify and treat primary cause
• Systemic anti-inflammatories (flunixin meglumine)
• Vitamins (B12, E/Se)
• Deep bedding (sand or straw)
• Roll cow every 4-6 hours to prevent pressure sores and contralateral muscle ischemia
• Hip lifters/slings 2-3x/day
• Hydrotherapy (float tanks) if available - greatly improves prognosis

Summary Table

Key Distinguishing Points

• Flaccid + periparturient + responds to Ca = Milk fever
• Hindlimbs splaying + after calving = Obturator nerve
• Knuckling on dorsum of fetlock = Peroneal nerve
• Hyperextended fetlock = Tibial nerve
• Dropped elbow, forelimb = Radial nerve
• Hyperexcitable + tetanic convulsions = Hypomagnesaemia (NOT hypocalcaemia)
• Progressive ascending flaccid + dysphagia + silage fed = Botulism
• Alert cow, can't rise, high CK = Downer cow syndrome
• Circling + unilateral facial droop = Listeriosis

Treatment of Teat Injuries in Dairy Cattle - From the Teat Skin to the Inner Teat Canal (Streak Canal)

Anatomy First - Understanding What Gets Injured

OUTSIDE → INSIDE

Teat Skin (epidermis + dermis)
        ↓
Teat Wall (connective tissue, smooth muscle)
        ↓
Teat Cistern (teat sinus) - inner milk-holding chamber
        ↓
Annular Fold - junction between teat and gland cistern
        ↓
Streak Canal (Teat Canal / Teat Tube) - 8-12 mm long
        ↓
Teat Orifice (Teat Opening / Papillary Duct) - external opening

Classification of Teat Injuries by Depth/Location

STEP 1: IMMEDIATE FIRST AID (Before the Vet Arrives)

1. Cold hydrotherapy - Apply cold water/ice packs wrapped in cloth to the injured teat immediately
   • Reduces inflammation, controls swelling, decreases pain
   • Also helps clean the wound
   • Continue for 15-20 minutes
2. Stop milking machine on the affected quarter - do NOT apply teat cups over a fresh wound
3. Control bleeding - apply gentle pressure with a clean cloth
4. Prevent contamination - keep the cow away from mud/dirty bedding; apply a clean bandage loosely
5. Do NOT hand-milk a lacerated teat - hand milking causes wound dehiscence (pulling apart of sutured edges)

STEP 2: VETERINARY ASSESSMENT

• Location: Proximal (base), body (middle), or apex (tip/streak canal)
• Thickness: Partial vs. full thickness
• Shape: Longitudinal, transverse/horizontal, V-shaped, inverted-V
• Age of wound: Fresh (< 6 hours) vs. contaminated (> 6-12 hours)
• Degree of tissue loss
• Streak canal involvement

• A sterile metal teat cannula is gently passed through the streak canal into the cistern to check for full-thickness penetration
• A teat probe checks if the laceration enters the cistern
• Ultrasonography or contrast radiography for complex internal lesions
• Theloscopy (teat endoscopy) for internal cistern/canal lesions

STEP 3: PRE-OPERATIVE / PRE-TREATMENT PREPARATION

Antibiotics

• Procaine Penicillin G - 22,000 IU/kg IM, twice daily
• Alternatively: Ceftriaxone-Tazobactam @ 10 mg/kg body weight for 7 days
• Start BEFORE surgery; continue post-operatively for 5-7 days
• Intramammary antibiotic tubes are also infused after surgery to prevent mastitis

Anti-inflammatory / Pain Relief

• Flunixin meglumine (Finadyne) - 1 mg/kg IV
• Reduces swelling, pain, inflammation - improves tissue viability and healing
• May continue with meloxicam orally for 3-5 days post-op

Analgesia / Sedation for Surgery

• Teat ring block (local anesthesia): Lidocaine 2% injected circumferentially around the base of the teat (ring block), OR
• Caudal epidural: 5 ml of 2% lidocaine at the sacrococcygeal (Co1-Co2) space - provides perineal and udder analgesia
• Neuroleptanalgesia (preferred over alpha-2 agonists alone, which worsen bloat): e.g., xylazine + butorphanol combination

Positioning

• Lateral or dorsal recumbency
• Dorsal recumbency gives better visibility and reduces milk contamination of the wound

Wound Preparation

• Thorough cleaning with dilute chlorhexidine or povidone-iodine solution
• Debridement of devitalized/necrotic tissue
• A sterile teat cannula is placed to maintain the lumen during suturing

STEP 4: WOUND CLOSURE (SURGERY) BY INJURY TYPE

A. Superficial Skin Lacerations (Partial Thickness, Not Entering Cistern)

• Simple interrupted sutures or horizontal mattress sutures using absorbable suture (e.g., 2-0 or 3-0 Polyglycolic Acid / Vicryl)
• Sutures placed through skin and subcutaneous tissue only
• Do NOT penetrate the teat mucosa/cistern from outside
• Wound edges must be closely apposed without excessive tension
• A sterile cannula placed inside the teat during suturing prevents inadvertent narrowing of the lumen

B. Full-Thickness Lacerations (Penetrating the Teat Cistern)

• Fine absorbable suture, 3-0 or 4-0 Polyglycolic Acid
• Simple continuous (running) suture or Cushing pattern
• Sutures must be placed carefully to avoid narrowing the cistern lumen
• A cannula is placed inside to act as a stent/guide during suturing

• Interrupted horizontal mattress sutures using 2-0 Nylon or Polyglycolic Acid
• This closes the skin over the first layer

C. Injuries Involving the Streak Canal (Teat Tube / Teat Canal) and Sphincter

• Cannula with a lid (capped teat cannula) is carefully inserted through the streak canal at each milking to allow milk drainage
• Keep the capped cannula in place for no more than 2-3 days (longer duration = high mastitis risk)
• After removing the cannula, a natural teat insert (wax implant) is placed in the streak canal between milkings
• The wax insert maintains the canal lumen open, prevents fibrotic stenosis, and promotes healing of the damaged sphincter

• Extremely difficult due to the small size (8-12 mm) and the functional importance of the sphincter
• If the sphincter is disrupted, milk leakage (oozing) will occur
• Repair using very fine 4-0 or 5-0 sutures to reappose the canal mucosa
• Post-repair: cannula stenting between milkings for 7-10 days

• If the streak canal is obstructed/stenotic due to scar tissue after injury: a teat bistoury (Hug's knife) or teat knife is used to carefully incise the stenotic streak canal under local anesthesia
• After incision, a teat cannula or teat insert is placed to keep the canal open during healing
• Risk: re-stenosis is common; may need repeated procedures

D. Internal Teat Cistern Injuries / Obstructions (Teat Peas, Granulation Tissue)

• Teat peas (lumen clots/masses): Floating masses of granulation tissue, fibrin, fat, or mineral deposits inside the cistern or canal - obstruct milk flow
• Membranous obstructions: Thin fibrous membranes at the annular fold - poor treatment success
• Adhesions: Extensive fibrosis filling the cistern after severe trauma - permanent; quarter should be dried off

• Teat cannula: Short-term use to allow milking; high mastitis risk with prolonged use
• Manual crushing: Mobile, discrete masses may sometimes be broken down by external palpation
• Theloscopy (endoscopic surgery): For complex internal lesions - endoscope passed through the streak canal; lesions removed under direct visualization with miniature instruments
• Contrast radiography / ultrasound: Guides approach for deeply placed lesions

STEP 5: POST-OPERATIVE / POST-TREATMENT CARE

Milking Management

• Use a larger teat cup if milking machine is used (reduces suction trauma on the wound)
• Never hand-milk a recently sutured teat - causes dehiscence
• If machine milking is not possible, use a sterile teat cannula at every milking (every 8-12 hours)
• Milk the injured quarter gently and completely to prevent milk accumulation and pressure

Mastitis Prevention

• Intramammary antibiotic tubes after every milking (first 3-5 days): e.g., cloxacillin, penicillin, or cephapirin intramammary preparations
• Teat dipping with effective iodine-based teat dip (pre and post milking) on the injured teat - but dilute (avoid concentrated dips on raw tissue)
• California Mastitis Test (CMT) monitoring every 2-3 days post-repair

Local Wound Care

• Wound sprays: Oxytetracycline wound spray (terramycin spray) or aluminum spray on the sutured area twice daily
• Avoid thick greasy ointments that harbor bacteria
• Keep the area clean and dry
• Fly repellent sprays in fly season to prevent wound myiasis

Systemic Support

• Continue antibiotics for 5-7 days
• NSAIDs for 3-5 days (meloxicam, flunixin)
• Vitamin E/Selenium injection to support tissue healing

Bandaging

• A loose teat bandage using sterile gauze + cohesive bandage can protect the wound between milkings
• Must NOT be so tight as to restrict blood supply
• Change bandage every 12-24 hours

Suture Removal

• Non-absorbable skin sutures (nylon): removed at 10-14 days
• Absorbable inner layer sutures dissolve on their own

STEP 6: SPECIAL SITUATIONS

Hard Milker / Teat Stenosis After Healing

• Teat bistoury (Hug's knife): A guarded knife inserted through the canal to incise the stenotic ring
• Teat dilators: Graduated metal dilators inserted progressively over days to stretch open the stenosis
• Teat insert/wax implant: Placed between milkings after dilation to maintain patency
• Antibiotic injection directly into the teat canal region to prevent secondary mastitis

Avascular Necrosis of Teat Tip

• The tip may become cold, black, and gangrenous
• Amputation of the necrotic portion under local anesthesia may be needed
• Prognosis for the quarter is guarded

Severe/Unrepairable Injuries

• If the teat cistern is completely destroyed or the injury is too old/contaminated for repair:
• Permanently dry off the quarter: Infuse a long-acting intramammary antibiotic (e.g., cloxacillin long-acting dry cow tube), seal the teat canal with a teat sealant or colophony wax, and abandon the quarter
• The cow can continue producing from the remaining 3 quarters

Summary - Treatment by Injury Layer

Prognosis

• Superficial/partial thickness: Excellent - heals with primary intention
• Full thickness, fresh, clean: Good with proper two-layer repair
• Apex/streak canal involvement: Guarded - high risk of re-stenosis and mastitis
• Old/contaminated wound (>12 hours): Poor for first intention; secondary intention healing attempted
• Cistern adhesions/complete destruction: Poor - quarter often permanently lost

• Proper anatomical and pharmacological terminology
• Pathophysiology explained in depth
• Drug names with doses, routes, and mechanisms
• Surgical techniques described with correct procedure names
• Differential diagnoses and diagnostic reasoning included
• References to veterinary clinical science where relevant

• Anatomical layers (teat cistern, streak canal, Furstenberg's rosette, teat sphincter)
• Surgical repair (two-layer closure, cannula stenting, theloscopy)
• Pharmacology (procaine penicillin dosing, flunixin meglumine, epidural anesthesia at Co1-Co2, ring block with 2% lidocaine)
• Complications (avascular necrosis, cistern fibrosis, re-stenosis)
• Prognosis by injury classification

• Identify the type of injury - laceration, contusion, avulsion, stenosis, necrosis, etc.
• Classify it - superficial / partial thickness / full thickness; proximal / body / apex
• Assess the streak canal involvement if visible
• Suggest the appropriate treatment protocol based on what I can see
• Discuss prognosis for that specific injury pattern

Clinical Analysis of the Teat Injury

1. Visual Findings (What I Can See)

2. Clinical Classification

3. Immediate Concerns (Pathophysiology)

• Even though the streak canal appears intact, the wound's proximity to the teat apex means:
  • Edema at the wound site can mechanically compress the streak canal → impaired milk flow → milk stasis → mastitis risk
  • The disrupted skin barrier allows ascending bacterial infection (Staph. aureus, Strep. dysgalactiae, Coliforms) through the damaged area
  • The eschar/necrotic crust harbors bacteria and must be debrided
• Confirm full vs. partial thickness by:
  • Gently inserting a sterile teat cannula through the teat orifice into the cistern
  • Palpate the wound with a sterile gloved finger - check if the probe/cannula tip can be felt or seen through the wound = full thickness
  • Milk the quarter gently - if milk leaks through the wound = full thickness fistula

4. Differential Diagnoses for This Appearance

1. Traumatic laceration/abrasion - most likely (wire, gate edge, hoof, floor)
2. Teat trampling injury - cow stepped on her own teat or another cow stepped on it
3. Calf bite wound - rough suckling by calf causes focal abrasion/laceration at distal teat
4. Pseudocowpox (Paravaccinia virus) - but usually multiple circular lesions with a characteristic horseshoe-shaped scab; less likely here
5. Bovine Herpesvirus-2 (BHV-2) teat skin lesion - vesicles → ulcers; possible differential
6. Black spot / teat-end necrosis - the dark eschar could represent early ischemic necrosis from over-milking or liner-impact injury

5. Treatment Protocol for This Case

Step 1 - Wound Preparation

• Gently clean with dilute chlorhexidine gluconate (0.5%) or povidone-iodine (0.1%) solution using sterile gauze
• Debride the dark eschar/necrotic crust carefully with sterile forceps and scissors - removing it exposes healthy granulation tissue and allows better healing and antibiotic penetration
• Cold hydrotherapy (10-15 min) if swelling is significant - reduces edema, relieves pain

Step 2 - Local/Systemic Anti-inflammatory

• Flunixin meglumine (Finadyne) - 1.1-2.2 mg/kg IV or IM once daily for 3 days
  • Reduces edema at the wound site - very important to prevent streak canal compression
• Meloxicam 0.5 mg/kg SC/IM can be continued orally for 3-5 days

Step 3 - Wound Treatment

• No suturing likely needed - partial thickness wounds heal by secondary intention (granulation + epithelialization)
• Apply topical antibiotic spray:
  • Oxytetracycline aerosol spray (Terramycin spray) - apply twice daily
  • OR Chloramphenicol + gentamicin topical cream in some regions
  • OR Aluminum hydroxide wound spray - protective barrier + antiseptic
• Apply a loose sterile gauze + cohesive bandage (Vetrap) over the wound between milkings to:
  • Protect from contamination/flies
  • Prevent desiccation of the wound bed
  • Prevent self-trauma/licking

Step 4 - Systemic Antibiotics

• Procaine Penicillin G - 22,000 IU/kg IM, BID for 5-7 days
• OR Ceftriaxone 10 mg/kg IM SID for 5-7 days (broader spectrum)

Step 5 - Intramammary Treatment

• Infuse intramammary antibiotic tube (e.g., Cloxacillin 200 mg or Cephapirin intramammary) after EACH milking for 3-5 days
• Use strict aseptic technique for infusion - clean teat end with spirit swab first

Step 6 - Milking Management

• Use machine milking (preferred over hand milking - less wound trauma)
• Use a larger/wider teat cup liner to reduce suction trauma on the wound area
• If the teat is too painful for cup attachment - milk via sterile teat cannula gently at each milking
• Monitor milk at each milking: check for flakes, clots, watery appearance = early mastitis

Step 7 - Fly Control

• Apply cypermethrin-based fly repellent around (not directly on) the wound - flies cause myiasis (maggot infestation) in open wounds in warm climates
• Fly trap/spray in the housing area

6. Monitoring & Follow-Up

• Milk leaking through the wound = full thickness fistula → surgical repair needed
• Purulent discharge from wound or teat canal = mastitis/abscess
• Wound enlarging or blackening = spreading necrosis
• Cow not letting milk down / kicking during milking = pain/mastitis

7. Prognosis

• Streak canal appears intact (primary mastitis barrier preserved)
• Wound is partial thickness
• Well-defined margins (not spreading)
• No evidence of full-thickness fistula visible