Puppies with rigid extension of the hind limbs
Two 9-week-old Labrador puppies from the same litter present with pelvic limb paresis that progresses over days to rigid hyperextension, with muscle atrophy and raised CK. The dam is healthy. A third puppy is starting to show hind limb weakness.
Which statement is correct?
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A. It is toxoplasmosis; the now-immune dam will not pass the infection to future litters
The picture is typical of Neospora caninum. Moreover, a chronically infected bitch can reactivate the infection and transmit it transplacentally in successive pregnancies.
B. It is neosporosis: treat early with clindamycin; once rigidity is established, prognosis is poor
Correct. Neospora caninum radiculoneuritis and myositis in puppies cause ascending paresis and rigid hyperextension of the pelvic limbs. Treatment (clindamycin or trimethoprim-sulfonamide with pyrimethamine) works best before contracture develops; treat and monitor the littermates too.
C. It is neurological distemper; only supportive care is possible, and vaccinate the rest of the litter
Distemper does not typically cause rigid hyperextension with raised CK and myositis; moreover, vaccinating already-exposed puppies does not treat an ongoing infection.
D. It is immune-mediated meningoencephalitis; start immunosuppressive glucocorticoids
Immunosuppressing a protozoal infection worsens the disease. Moreover, the lower motor neuron pattern with myositis and several affected littermates points to an infection transmitted by the dam.
lightbulb Key takeaway
The dog is the definitive host of Neospora caninum (it sheds oocysts and can infect cattle). Confirm with serology (IFAT) or PCR and advise against breeding from that bitch again: transmission can recur in successive litters.
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Updated: November 1, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.