Table 2.
Comparative pathology of different feline myopathies reporting sarcoplasmic inclusions
| Myopathy | Nemaline rods myopathy | Glycogen storage IV | Tubulin reactive inclusions | Oval amphophilic inclusion bodies |
|---|---|---|---|---|
| Authors’ description | Cooper et al, 6 Kube et al 9 | Fyfe 7 | Shelton et al 15 | The present study |
| Underlying effects | Possible surplus of Z-band material | Glycogen branching enzyme deficiency | Unknown | Unknown |
| Inheritance | Possibly autosomal recessive | Autosomal recessive | Unknown | Unknown |
| Epidemiology | DSH (USA, Belgium) | Norwegian Forest Cat (USA, Europe) | Devon Rex, DSH (USA) | DSH (France) |
| Onset | 6–18 months | <5 months | <8 months | 16 months |
| Age of death | <2 years | 9–13.5 months | >4 years | >20 months |
| Clinical signs | ||||
| Abnormal gait | Wobbly hypermetric | Bunny hopping | Loss of balance and collapse | Loss of balance and collapse |
| Muscular weakness | Exercise intolerance Recumbency after walking (Cooper et al6) |
Prolonged decubitus | Mild cervical ventroflexion Prolonged decubitus |
Muscular weakness Prolonged decubitus |
| Muscle atrophy | Progressive | Progressive | Mild to moderate | – |
| Difficulties in feeding | + (Kube et al9) | + | + | + |
| Tremor | + | + | – | – |
| Myotatic reflexes | Decreased | Decreased | Normal | Decreased to normal |
| Comorbidities | Weak voice (Cooper et al6) | Stillbirth Cardiomyopathy Persistent hyperthermia |
Upper respiratory infection | Intermittent aphonia |
| Histological lesions | ||||
| Atrophy | + | + | – | + |
| Necrosis | + (Cooper et al6) | + | – | + |
| Fibrosis | + (Cooper et al6) | + (myocardium) | – | – |
| Elevated centronucleation | + (Cooper et al6) | + | – | + |
| Fibre type mostly affected | 2A | Unspecified | 2B | Both equal |
| Inclusion morphology | Rod-like: very few to filling the whole fibre H&E: not obvious Gomori trichrome: red (Cooper et al6) to blue (Kube et al9) |
Numerous clusters of round shapes H&E: pale blue PS: red purple |
Oval: mostly 1 to a few in a fibre H&E: eosinophilic Gomori trichrome: bright red PAS: positive around the inclusions NADH/SDH: dark blue rim around the inclusions |
Oval: 1 to a few in a fibre H&E: amphophilic Gomori trichrome: purple NADH: unstained halo around inclusions |
| Immunofluorescences abnormalities | Sarcoplasmic accumulation of dystrophin, desmin and spectrin Diffuse alpha-actinin distribution |
Not realised | Tubulin reactive inclusion Normal distribution of desmin, amyloid, ubiquitin and MLF1 |
Normal distribution of desmin, tubulin, spectrin, laminin, LAMP and LC3 Positive LC3 activated macrophages |
DSH = domestic shorthair; H&E = haematoxylin and eosin; PAS = periodic acid–Schiff; NADH = nicotinamide adenine dinucleotide dehydrogenase; SDH = succinic deshydrogenase; MLF1 = succinic deshydrogenase; + = present; – = absent