What are the indications for FHO vs total hip replacement in dogs and cats, and what outcomes can I quote clients?

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FHO is the more commonly performed salvage procedure in cats and small dogs, while total hip replacement (THR) is the gold standard for coxofemoral disease in dogs and is increasingly available for cats. Both procedures are indicated for chronic coxofemoral osteoarthritis, fractures, luxation, and avascular necrosis of the femoral head; THR is additionally indicated for failed FHO.124 For cats, FHO provides good clinical outcomes but objective gait analysis reveals measurable deficits. Cats after FHO show marked clinical gait changes, significantly reduced range of motion on the operated limb, pain with passive hip movements in the majority of cases, and hindlimb muscle circumference asymmetry consistent with limb unloading.2 Despite these objective findings, owners are consistently able to assess their cats accurately, and owner satisfaction remains acceptable.2 THR produces superior objective outcomes in cats compared to FHO. Cats after THR show less lameness, no difference in range of motion between the operated and healthy limb, no pain with passive hip movements, and no significant difference in hindlimb muscle circumference.2 The Feline Musculoskeletal Pain Index (FMPI) score improves from 0.111 preoperatively to 2.111 postoperatively following feline THR, and owner satisfaction is rated "very good" in 90.9% of cases.6 Available feline THR systems include the cemented BioMedtrix CFX Micro and Nano Hip systems, the Zurich Mini Cementless Hip Replacement System (Kyon), and BioMedtrix press-fit cups (BFX).2 The most common indication for THR in cats is slipped capital femoral epiphysis, occurring predominantly in young neutered male cats.6 Median follow-up after feline THR is 752 days.6 In dogs, owner satisfaction after FHO is historically good to excellent for pain-free locomotion, but objective measurements tell a different story. FHO has been reported to carry a 42% incidence of unsatisfactory results at a mean of 4 years after surgery based on objective outco