Thunder
Monday, August 3, 2026 at 1:09 PM
Subjective
Chief Complaint
Thunder, a 9-year-old Quarter Horse gelding used for trail riding, presented for evaluation of left forelimb lameness first noticed after a ride on rocky ground two days ago.
History
- Owner reported Thunder favoring his left front leg, particularly at the trot; no lameness was noticed before the ride.
- Owner noted Thunder is typically stoic, so any sign of discomfort is unusual for him.
- Mild swelling at the back of the left front fetlock noticed the following morning.
- Eating and drinking normally; passing normal manure.
- No medications given before the visit. Shod in front 5 weeks ago. Vaccinations and deworming current.
Objective
Vital Signs
- Temperature: 100.2°F (37.9°C)
- Weight: 520 kg (weight tape)
- Heart Rate: 40 bpm
- Respiratory Rate: 14 breaths/min
- Mucous Membranes / Capillary Refill Time: Pink and moist; CRT < 2 seconds
- Gut Sounds: Present and normal in all four quadrants
- Body Condition Score: 5/9 (Henneke)
Physical Exam
- General: Bright and alert; bearing weight on all four limbs but resting (pointing) the left forelimb at rest.
- Cardiovascular: Regular rhythm, no murmurs; jugular refill normal.
- Respiratory: Normal breath sounds bilaterally; no nasal discharge or cough.
- Gastrointestinal: Normal borborygmi in all four quadrants; normal manure in the stall.
- Digital Pulses: Normal in all four limbs; not increased in the left forelimb.
- Hooves: Shoes secure; no heat at the coronary bands; hoof testers negative on both front feet.
- Left Forelimb: Mild heat and soft swelling of the palmar fetlock region with distension of the digital flexor tendon sheath; pain on palpation of the superficial digital flexor tendon (SDFT) in the distal metacarpus. Suspensory ligament branches and the fetlock joint capsule non-painful.
- Other Limbs: No heat, swelling or pain on palpation.
Lameness Examination
- Straight line, trot on firm ground: Left forelimb lameness, AAEP grade 2/5, with a consistent head nod as the left forelimb lands.
- Lunging on a hard surface: Lameness more evident with the left forelimb on the inside of the circle (grade 3/5); mild on the right rein.
- Lower limb (fetlock) flexion test, left forelimb, 60 seconds: Positive — lameness worsened for the first 8–10 strides. Right forelimb negative.
- Diagnostic analgesia: Palmar digital nerve block — no improvement. Low four-point (low palmar) nerve block — approximately 80% improvement, localizing pain to the fetlock and distal metacarpal region.
Assessment
- Left forelimb lameness (AAEP grade 2/5) localized to the fetlock and distal metacarpal region.
- Findings consistent with digital flexor tendon sheath tenosynovitis with a suspected mild injury of the superficial digital flexor tendon.
- Differentials: SDFT tendinitis, deep digital flexor tendon lesion within the sheath, suspensory ligament branch desmitis, fetlock joint or proximal sesamoid bone injury.
- Foot pain considered unlikely (negative hoof testers, normal digital pulses, no response to the palmar digital nerve block).
Plan
- Stall rest with 10 minutes of hand-walking twice daily; no turnout, lunging, trotting or riding.
- Cold hosing or ice of the left forelimb for 20 minutes twice daily for 5–7 days.
- Standing support bandages on both forelimbs, reset twice daily.
- Phenylbutazone 2.2 mg/kg (about 1 g) PO q12h for 5 days, given with feed.
- Ultrasonography of the palmar metacarpal and pastern region of the left forelimb (SDFT, DDFT, tendon sheath and suspensory branches) at the recheck in 7 days, when the lesion is better defined.
- Radiographs of the left fetlock if the ultrasound does not explain the lameness, to rule out bone involvement.
- Rehabilitation plan and timeline for return to work to be based on the ultrasound findings.
- Owner to call if the lameness worsens, the swelling increases, or Thunder stops eating or shows signs of colic.
- Preventative measures discussed: gradual warm-ups, regular hoof and shoeing checks, and protective boots for trail riding on rocky or hard ground.
Client Discharge Note
Thank you for bringing Thunder in today, Mrs. Thompson. It was a pleasure to see you both.
Summary
Thunder was evaluated for lameness in his left front leg, which was most noticeable at the trot. His temperature, heart rate, breathing and gut sounds were all normal. He showed a mild (grade 2 out of 5) lameness with a head nod at the trot, which became worse after his fetlock was flexed and when he was lunged on a hard surface. His hooves were not sore with hoof testers and the pulses to his feet were normal, so a foot problem such as a bruise or abscess is unlikely. Nerve blocks showed that the pain is coming from the fetlock area, where we also found mild heat, swelling of the tendon sheath and soreness of the tendon at the back of the leg. The most likely cause is inflammation of the tendon sheath with a possible mild tendon strain.
Key Topics We Discussed
- Stall Rest: Thunder should stay on stall rest. Hand-walk him for 10 minutes twice a day, but avoid turnout, lunging, trotting or riding until his recheck.
- Cold Therapy: Cold hose or ice the left front leg for 20 minutes twice a day for the next 5–7 days.
- Bandaging: Keep standing support bandages on both front legs and reset them twice a day.
- Medication: Give phenylbutazone (about 1 gram) by mouth twice a day with feed for 5 days.
- Monitoring: Watch for increased swelling, heat, or worsening lameness at the walk. Contact us right away if any of these occur, or if Thunder stops eating or shows signs of colic.
- Follow-Up: We will recheck Thunder in one week and perform an ultrasound of the tendons and tendon sheath to see exactly what is injured. X-rays may be needed if the ultrasound does not explain the lameness. His return-to-work plan will depend on these results.
- Preventative Measures: Once Thunder has recovered, use gradual warm-ups before exercise, keep up regular hoof and shoeing checks, and consider protective boots for trail riding on rocky or hard ground.
Thank you for entrusting us with Thunder's care! Please do not hesitate to contact us if you have any questions or concerns.
— Dr Kim Lee