Spastic paresis
The term spastic paresis identifies a sporadic neuromuscular bovine disease that is clinically characterised by hyperextension of the hind limbs (“straight hock”) due to a contraction of the muscles that form the Achilles tendon. The symptoms of spastic paresis generally appear at 3-8 months of age, although they can be seen as early as the first weeks of life. Cases of the disease appearing later, up to 3 years of age, are much rarer.
In the initial stages, the clearest clinical sign is hyperextension of the hock, with an increase in the tibiotarsal joint angle (“straight hock”). Although the pathology is progressive, it does not follow a predictable course; sometimes a few weeks or months. Hyperextension of the limbs worsens and the heel tends to straighten. The stifle joint may be slightly bent and the animal may experience muscle tremors in the affected limbs. The gait is rigid and the hock cannot be flexed normally. The limbs are held in such a way that the tip of the foot touches the ground or else they remain completely raised and extended backwards.
In these cases, the animal uses only three limbs to walk on, with the affected limb kept permanently extended and the contracted state causes a typical “pendulum” movement, with increased activity of the coxofemoral joint. This symptom is more evident just after the animal gets up, when it is also possible to notice an arching of the back and an elevation of the tip of the tail. In most cases, only one leg is affected; when both limbs are affected, the animal supports its body weight alternatively on one and then the other limb. Note than during decubitus the animal seems normal and even muscle tone in the affected limbs is normal, as electromyographic studies show.
Spastic paresis is caused by spastic contraction of the anti-gravitational extensor muscles of the foot - the gastrocnemius muscle and superficial flexors of the toes. Other muscles may also be affected, such as the leg biceps, the semitendinosus, the semimembranosus, the femoral quadriceps muscle and the adductors. Contraction of the femoral quadriceps muscle is an atypical form of spastic paresis of the femoral quadriceps that has been described recently. It was first seen in Belgian Blue calves, but has also been found in Romagnola breed cattle; in these cases, the hind limbs swing forward.
Muscular spasticity could be attributed to hyperexcitability of the myotatic reflex (“stretch reflex”). The alteration is primarily localised in the gamma pathway due to an anomalous functioning of the gamma motor neurons. On the basis of this pathogenic hypothesis it is however, still not known if hyperstimulation of the gamma pathway is due to an intrinsic hyperactivity of the gamma motor neurons or a lack of inhibitor mechanisms. In the latter case, an important role could be played by a flaw in controlling the descending pathway that originates from the red nucleus (rubro-spinal tract) or the lateral vestibular nucleus (vestibular-spinal tract).
Although a hereditary component seems evident, it has as yet not been possible to clarify definitively the type of hereditariness (dominant or recessive) or the entity of penetrance of the responsible gene or genes. According to many experts, it could be a recessive gene with scarce or incomplete penetrance. It can be assumed that environmental (toxic plants?), nutritional (a deficit of trace elements, Mn, Ca, P, Cu, Zn, Co, I, Se? or vitamins, vitamin A?), metabolic (Cu/Zn imbalances?) or individual factors may play an important role in the onset of the disease.
Some therapies have been suggested, such as tenotomy of the gastrocnemius tendon and neuroctomy of branches of the tibial nerve responsible for the innervation of the gastrocnemius muscle. Our experience is limited to neuroctomy of the tibial nerve, which has given satisfactory results although not complete recovery.Achondroplasia syndrome/Ascites/Congenital hepatic fibrosis
When considering achondroplasia in the Romagnola breed, thoughts inevitably return to one of the genetic diseases affecting this breed that dominated in the past. At the time, it was a form characterised by dysmorphic dwarfism that in the majority of cases was nevertheless compatible with life, so much so that some animals reached adulthood and were even used as breeders. It was a form that evolved with the development of the animal and was therefore, considered a growth abnormality.
More recently we have outlined another form of achondroplasia in Romagnola breed calves which we have named the congenital “paunch calf” syndrome; a term breeders use to identify animals that present abnormal abdominal relaxation, as well as facial defects. Facial deformities are characterised by a shortening and flattening of the muzzle and in some cases a widening of the head.
The characteristic aspect is an abnormal dilatation of the abdomen caused by the presence of an abundant quantity of liquid. Post-mortem tests demonstrate significant subcutaneous oedemas, particularly in the ventral parts of the abdominal wall and the abdominal cavity is distended due to a large quantity of ascitic liquid (up to 10 litres); which can be cloudy and yellow or red in colour.
Another characteristic aspect is the presence of widespread hepatic fibrosis, associated with the presence of hepatic cysts containing a red, serum-like liquid. A histological test of the liver highlights extensive alteration of the lobular architecture with fibroses in the periportal regions and around the centrilobular veins. In some lobules, fibrosis extends to the perisinusal regions. Some cardiac abnormalities have also been observed, such as flaws in the atrial and interventricular septum and persistence of the arterial duct.
At present, we have not pinpointed any family line that can be considered responsible for the hereditariness of the pathology, however a genetic cause is strongly suspected.

Icthyosis
Found in various species, icthyosis is a rare skin disease characterised by extensive cutaneous hyperkeratosis that looks like fish scales. At the moment, two forms of icthyosis have been described in cattle; foetal icthyosis and congenital icthyosis.
Foetal icthyosis (harlequin foetus) is the more serious form and is incompatible with life: affected calves are either still-born or die a few days after birth. The skin is covered in large cutaneous scales divided by deep fissures that recall “leather armour” and there is generally no hair present whatsoever. The skin, which is thick and inelastic, causes a subversion of the mucocutaneous joints, eclabium and entropium. This form is similar to human harlequin icthyosis (HI), which is also incompatible with life and presents skin formations similar to scales all over the body.
Congenital icthyosis is the less serious form and is compatible with life. Indeed, the general state is good. Lesions are represented by hyperkeratosis that can be present at birth or may appear later. Although lack of hair is not an initial flaw, over time, areas affected by alopecia may appear. Skin thickening and scales are present above all on the limbs, the abdomen and the muzzle. Cases of cataracts, microtia and thyroid abnormalities have been reported. Congenital bovine icthyosis is similar to human lamellar icthyosis (LI).
Despite differences in anatomical localization and seriousness, in both types of icthyosis the histological alteration is always represented by orthokeratotic lamellar hyperkeratosis of the epidermis and hair follicle. As in humans, the scales are probably caused by defective desquamation, along with an increase in the cohesion of the keratinocytes. In both forms of bovine icthyosis a hereditary base linked to a recessive autosomal gene is suspected. The University of Milan has devised a genetic test that can be used to identify animals that are carriers of the flaw. However, it is fundamental to report any affected animals and guarantee their correct identification in order to proceed to their analysis and to thus pinpoint the genetic lines that carry the disease.

Congenital pseudomyotonia
This is a congenital form characterised by a state of contraction of all the skeletal muscles, particularly accentuated in the hind limbs. Muscular contraction usually only appears when animals are subjected to mild/medium effort (a fast pace or a sudden change of direction) or when frightened. Muscular stiffening “blocks” muscular activity in the execution phase (contraction) not permitting it to be taken through to its completion (contraction-relaxation cycle) and determining, if it is a motor movement, a stumbling or hopping gait (like “bunny hopping”). Realising the difficulty of continuing, the animal tends to spontaneously limit its activity, avoiding any acceleration or rapid movements. The animal thus manages to prevent any cramp-like attacks. However, if the animal is forced to move rapidly or to continue walking - either due to a spontaneous occurrence or following prolonged stimulation - then its movements will be completely blocked (“stuck”) and it will be able to do nothing other than “collapse” to the ground.
The fall can give the animal another fright and if stimulated to get up quickly it will stiffen again and fall to the ground once more. On the other hand, if the animal is allowed to relax and get up slowly then it will recover its station as if nothing has happened. If led slowly the animal does not show any kind of cramp-like attack nor does it show any signs of fatigue, even after long “walks”. Uneven terrain, the presence of obstacles or even steep climbs or descents may cause muscle stiffening and a subsequent fall. Animals also tend to stiffen if they are frightened; in this case, retraction of the eyeball and procidence of the third eyelid are common. Symptoms are present from birth and remain more or less unaltered for the entire life of the animal. Although growth indexes are penalised, animals can reach a useful weight for slaughter.
The muscular base of the disease is confirmed by haematic-biochemical case histories, characterised by an increase in the concentration of “muscle-specific” enzymes (CPK, AST) and levorotatory lactate. In contracted states, electromyographic tests do not highlight the elements typical of myotonias, orienting the myopathic case history towards so-called forms of pseudo-myopathy. In both routine staining and in those more specifically addressing metabolic-type assessments, histological tests exclude forms of muscular dystrophy, as well as mitochondrial states of suffering.
To date, studies of the pedigree of animals that have been found affected by the disease (all Chianina breed) show close family links, meaning we can assume the genetic/hereditary nature of the disease. The particular type of distribution in the families of sick animals and uniformity of the phenotypical expression of the flaw warrant a suspected monogenic Mendelian transmission.
As far as is known, the pathology in question does not have any nosographic overlap among bovine pathologies or even with other veterinary medicine. When compared to human medicine, “congenital pseudomyotonia of the Chianina breed” finds notable overlap with so-called “Brody's disease”. This is a rare hereditary muscular disease linked to a flaw in the reuptake of calcium by the sarcoplasmatic reticulum during the muscle relaxation phase due to a mutation of the gene codifying the SERCA1 pump (sarco-endoplasmic reticulum Ca-ATPase-1), the sarcoplasmatic reticulum pump that recovers calcium from the sarcoplasm after muscle contraction. This causes a slowing down of the contraction-relaxation cycle, which leads to a persistence of the contracted state of the muscle.
As in humans, in our animals clinical case histories are characterised by muscular rigidity that is painless and provoked by vigorous and/or sudden physical exercise. The symptoms disappear after a few seconds rest. The University of Berne, in collaboration with the University of Bologna, has devised a genetic test that can be used to identify carriers of the flaw. However, it is fundamental to report any affected animals and guarantee their correct identification in order to proceed to their analysis and to thus pinpoint the genetic lines that carry the disease.

Anomalies in coat colour
This anomaly, reported towards the end of 2002 in Romagnola breed animals, leads to the presence of red hair on the coat. This phenomenon is due to the mutation of the MC1R gene (melnocortic-1 receptor) in its fundamental role in controlling melanogenesis.
With regards to the polymorphism of this gene, as well as the wild allele E+ that codifies for a functional receptor, two alleles have been described that have a known phenotypical effect on the colour of the coat:
- the dominant allele Ed characterised by a T296C replacement that causes a change in the 99th amino acid in prolin and determines the production of high quantities of black eumelanin.
- the allele is characterised by the deletion of a guanine in position 310 that causes a frameshift mutation, with the appearance of a premature stop codon. This allele leads to the formation of a non-functional receptor that leads to poor production of tyrosinase and the formation of pheomelanin. This is a recessive allele and in the homozygote state is generally associated with the pheomelanic (red) pigmentation of the coat.

“Paunch calf syndrome”
The “paunch calf syndrome” (PCS) in the Romagnola breed is a complex malformation, mainly characterized by facial deformities, an enlarged abdomen full of fluid and liver fibrosis. For all of these features, this genetic anomaly is known by farmers as “paunch calf”. The study of affected animals revealed common ancestors and suggested a genetic etiology with a high probability that the defect could be controlled by a single autosomal locus acting in a recessive way. The DNA alteration that is causative of the disease was identified on gene KDM2B on the chromosome 17 and the test to check carriers was then developed. From June 2011 all the animals selected for Performance Test are checked for this anomaly.

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