**3.1 Prevalence of claw disorders found in the study**

The results of this study revealed that cows from the varied smallholder zero-grazing dairy units had a high (88%) prevalence of claw lesions, 69% of which did not manifest lameness but had subclinical disorders and only 31% were lame. Some of the cows had more than one claw disorders concurrently. Laminitis had the highest prevalence (70.3%), with subclinical laminitis at 49.3% and chronic laminitis at 21%. Other non-infectious claw disorders with high prevalence were sole bruising (erosion) at 45%, claw overgrowth at 30%, heel erosion at 27.3%, white line separation at 18% and underrun (double) soles at 17%. Infective lesions had very low prevalence of 4.7% (Table 1).


(NB: *Some of the cows had more than one claw disorders concurrently, hence percentage totals of more than 100*).

Table 1. Prevalence of claw disorders and lesions and their prospective risk factors as found during a cross-sectional study in dairy cows in varied smallholder zero-grazing dairy units in Kenya.

Among the cows that had chronic laminitis, 85% had more than two other concurrent claw disorders such as underrun (double) soles, sole bruising, heel erosion and white line separation. In addition, all the cases of chronic laminitis invariably had one or more ways in

Risk (Predisposing) Factors for Non-Infectious

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 399

A B

C

Fig. 1. Sole haemorrhages exposed after trimming of the horn of the sole signifying presence of subclinical laminitis in the claws of dairy cows examined in smallholder zero-grazing

haemorrhages; B: slight haemorrhages in zone 4 (bold arrow); C: moderate haemorrhages in

dairy units in the peri-urban areas of Nairobi, Kenya. A: normal claw with no

(dotted arrow).

the abaxial and a bit of axial white line (dashed arrows), as well as on zones 4 and 5

which the claw was misshaped such as excessive elongation, abnormal widening, excessive flattening, concavity of the dorsal wall and deep horizontal grooves (ridges) on the dorsal and the lateral walls. When chronic laminitis was found in any cow, it was always bilateral affecting all the claws but more often the hind limbs. Such cows were invariably lame.

#### **3.2 Description of the non-infectious claw disorders found in this study**

Lesions on the weight-bearing surface of the claw were described mainly according to the zones they affected. The six zones on the weight-bearing surface of the claw were universally described previously denoted as zone 1 (white line at the toe), zone 2 (abaxial white line), zone 3 (abaxial wall-bulb junction), zone 4 (sole-bulb junction), zone 5 (apex of the sole) and zone 6 (the bulb) (Greenough & Vermunt, 1991).

#### **3.2.1 Subclinical laminitis**

Cows with subclinical laminitis had normal gait. The only way of confirming subclinical laminitis was by trimming-off a thin layer of the horn of the sole. The main sign of subclinical laminitis was sole haemorrhages seen as reddish or yellow-waxy discolourations after trimming of the superficial layers of the horn of the sole. The haemorrhages in subclinical laminitis appeared in one or at most two zones of the weight-bearing surface of the claw (Fig. 1). In a few instances, the haemorrhages were visible on the surface of the horn of the sole even before trimming. Sole haemorrhages were scored according a universally suggested scale denoted as score 0 (no haemorrhages), score 1 (slight haemorrhages), score 2 (moderate haemorrhages), score 3 (severe haemorrhages), and score 4 (exposed corium) (Greenough & Vermunt, 1991). The haemorrhages were highly prevalent in zone 4 (34.7%), moderately prevalent in zones 3(14.3%), 6 (14.1%) and 2 (13.6%), and least prevalent in zones 5 and 1 at 8.7% and 0.7% respectively (Nguhiu-Mwangi et al., 2007). Haemorrhage score and the number of haemorrhagic zones had a strong positive correlation (r = 0.546, O.R. = 21.24) with subclinical laminitis and this correlation was highly significant (χ2 = 89.45, p < 0.05). Subclinical laminitis was mainly associated with haemorrhages in zone 4 and the abaxial whilte line (Fig. 1) and these associations were significant (χ2 = 22.83, p < 0.05). Occurrence of sole haemorrhages was significantly (χ2 = 86.5, p < = 0.001) higher in the hind lateral claws than the medial claws. Among the cows with subclinical laminitis, 32.4% manifested with only sole haemorrhages but 67.6% concurrently manifested sole haemorrhages as well as one or two of the other claw lesions such as sole bruising, heel erosion and white line separation.

#### **3.2.2 Chronic laminitis**

Claws with chronic laminitis had severe and widespread haemorrhages affecting several zones of the weight-bearing surfaces of the claws (Fig. 2). Haemorrhages in chronic laminitis could be visible on the surface of the sole before trimming. Haemorrhage score and the number of haemorrhagic zones had a positive correlation (r = 0.41) and the correlation was highly significant (χ2 = 50.16, p < 0.05). Haemorrhages in chronic laminitis significantly affected mainly zones 3 (χ2 = 23.45, p < 0.05), and 2 (χ2 = 18.23, p < 0.05) and occasionally but weakly zone 6 (χ2 = 4.48, p < 0.05). In addition to haemorrhages, 84.8% of the cows with chronic laminitis also had more than two other claw lesions such as double soles, sole bruising, heel erosion and white line separation. All cases of chronic laminitis, almost

which the claw was misshaped such as excessive elongation, abnormal widening, excessive flattening, concavity of the dorsal wall and deep horizontal grooves (ridges) on the dorsal and the lateral walls. When chronic laminitis was found in any cow, it was always bilateral affecting all the claws but more often the hind limbs. Such cows were invariably lame.

Lesions on the weight-bearing surface of the claw were described mainly according to the zones they affected. The six zones on the weight-bearing surface of the claw were universally described previously denoted as zone 1 (white line at the toe), zone 2 (abaxial white line), zone 3 (abaxial wall-bulb junction), zone 4 (sole-bulb junction), zone 5 (apex of

Cows with subclinical laminitis had normal gait. The only way of confirming subclinical laminitis was by trimming-off a thin layer of the horn of the sole. The main sign of subclinical laminitis was sole haemorrhages seen as reddish or yellow-waxy discolourations after trimming of the superficial layers of the horn of the sole. The haemorrhages in subclinical laminitis appeared in one or at most two zones of the weight-bearing surface of the claw (Fig. 1). In a few instances, the haemorrhages were visible on the surface of the horn of the sole even before trimming. Sole haemorrhages were scored according a universally suggested scale denoted as score 0 (no haemorrhages), score 1 (slight haemorrhages), score 2 (moderate haemorrhages), score 3 (severe haemorrhages), and score 4 (exposed corium) (Greenough & Vermunt, 1991). The haemorrhages were highly prevalent in zone 4 (34.7%), moderately prevalent in zones 3(14.3%), 6 (14.1%) and 2 (13.6%), and least prevalent in zones 5 and 1 at 8.7% and 0.7% respectively (Nguhiu-Mwangi et al., 2007). Haemorrhage score and the number of haemorrhagic zones had a strong positive correlation (r = 0.546, O.R. = 21.24) with subclinical laminitis and this correlation was highly significant (χ2 = 89.45, p < 0.05). Subclinical laminitis was mainly associated with haemorrhages in zone 4 and the abaxial whilte line (Fig. 1) and these associations were significant (χ2 = 22.83, p < 0.05). Occurrence of sole haemorrhages was significantly (χ2 = 86.5, p < = 0.001) higher in the hind lateral claws than the medial claws. Among the cows with subclinical laminitis, 32.4% manifested with only sole haemorrhages but 67.6% concurrently manifested sole haemorrhages as well as one or two of the other claw lesions such as sole bruising, heel

Claws with chronic laminitis had severe and widespread haemorrhages affecting several zones of the weight-bearing surfaces of the claws (Fig. 2). Haemorrhages in chronic laminitis could be visible on the surface of the sole before trimming. Haemorrhage score and the number of haemorrhagic zones had a positive correlation (r = 0.41) and the correlation was highly significant (χ2 = 50.16, p < 0.05). Haemorrhages in chronic laminitis significantly affected mainly zones 3 (χ2 = 23.45, p < 0.05), and 2 (χ2 = 18.23, p < 0.05) and occasionally but weakly zone 6 (χ2 = 4.48, p < 0.05). In addition to haemorrhages, 84.8% of the cows with chronic laminitis also had more than two other claw lesions such as double soles, sole bruising, heel erosion and white line separation. All cases of chronic laminitis, almost

**3.2 Description of the non-infectious claw disorders found in this study** 

the sole) and zone 6 (the bulb) (Greenough & Vermunt, 1991).

**3.2.1 Subclinical laminitis** 

erosion and white line separation.

**3.2.2 Chronic laminitis** 

Fig. 1. Sole haemorrhages exposed after trimming of the horn of the sole signifying presence of subclinical laminitis in the claws of dairy cows examined in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: normal claw with no haemorrhages; B: slight haemorrhages in zone 4 (bold arrow); C: moderate haemorrhages in the abaxial and a bit of axial white line (dashed arrows), as well as on zones 4 and 5 (dotted arrow).

Risk (Predisposing) Factors for Non-Infectious

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 401

C1

C2

D

Fig. 3. The different forms of misshaping of the claws with chronic laminitis observed in dairy cows during a study on prevalence of claw disorders and the possible risk factors in

smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: irregularly widened claws; B: elongated flattened claws, reduced toe angle and heel height and presence of deep prominent horizontal ridges on the dorsal and lateral walls; C1 and C2: elongated overlapping claws with extreme concavity of dorsal wall and convex weight-bearing surface; D: elongated flattened claw, toe angle greatly reduced and

concavity of dorsal walls of the claw.

Fig. 2. Severe widespread haemorrhages affecting most zones of the weight-bearing surfaces of the claws in one of the cows examined during the study of claw disorders and their prospective risk factors in the smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. The haemorrhages are seen as reddening of the horn of the sole. A: haemorrhages seen after trimming of the horn of the sole; B: haemorrhages seen superficially on the weight-bearing surface before trimming.

invariably had misshapen claws resulting from either overgrown, elongated, widened, flattened or concaved claws and all of them with deep prominent horizontal ridges of the dorsal and lateral walls (Fig. 3). Chronic laminitis in each cow was invariably bilateral, which together with misshaped claws exacerbated poor locomotion and hence the animals were found to always have moderate degree of lameness. Some of the claws were extremely misshapen to the extent that re-shaping them back to normal would be impossible. On trimming some of the claws with chronic laminitis, they were found to have weak whitish crumbling horn (Fig. 4).

Fig. 2. Severe widespread haemorrhages affecting most zones of the weight-bearing surfaces of the claws in one of the cows examined during the study of claw disorders and their prospective risk factors in the smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. The haemorrhages are seen as reddening of the horn of the sole. A: haemorrhages seen after trimming of the horn of the sole; B: haemorrhages seen

A B

A B

invariably had misshapen claws resulting from either overgrown, elongated, widened, flattened or concaved claws and all of them with deep prominent horizontal ridges of the dorsal and lateral walls (Fig. 3). Chronic laminitis in each cow was invariably bilateral, which together with misshaped claws exacerbated poor locomotion and hence the animals were found to always have moderate degree of lameness. Some of the claws were extremely misshapen to the extent that re-shaping them back to normal would be impossible. On trimming some of the claws with chronic laminitis, they were found to have weak whitish

superficially on the weight-bearing surface before trimming.

crumbling horn (Fig. 4).

Fig. 3. The different forms of misshaping of the claws with chronic laminitis observed in dairy cows during a study on prevalence of claw disorders and the possible risk factors in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: irregularly widened claws; B: elongated flattened claws, reduced toe angle and heel height and presence of deep prominent horizontal ridges on the dorsal and lateral walls; C1 and C2: elongated overlapping claws with extreme concavity of dorsal wall and convex weight-bearing surface; D: elongated flattened claw, toe angle greatly reduced and concavity of dorsal walls of the claw.

Risk (Predisposing) Factors for Non-Infectious

of sole bruising at the same time.

**3.2.5 Underrun (double) soles** 

**3.2.4 Heel erosion** 

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 403

Heel erosion like sole bruising appeared as dark necrotic areas of the horn predominantly in zone 6. However, when deeply invasive, it occasionally extended to zones 3 and 4 (Fig. 6). Heel erosion was invariably bilateral and in the hind limbs it affected either lateral claws only, or medial claws only, but occasionally it affected both lateral and medial claws concurrently. When present in any herd, it was observed to affect all the cows in the zerograzing unit without any exception. Some of the claws with heel erosion had some degrees

Fig. 6. Severely erosive and invasive heel erosion involving zones 6, 4 and 3 in both claws of a cow seen during the study of prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in Kenya. There is also sole bruising affecting the axial part of zone 5.

Underrun sole involved separation of the horn of the sole into two distinct layers constituting a superficial thicker harder sole and a thinner softer underlying sole. It was diagnosed by thoroughly washing the claws, which made it possible to see dung and debris stuck underneath the superficial sole. In some of the cases, it was only diagnosed during trimming by incidental finding of a superficial horn layer completely detached from a thinly forming underlying horn layer (Fig. 7). A claw that had double soles appeared grossly wider than both the normal ipsilateral and contralateral claws. Double sole phenomenon was common in zones 4 and 5. In some of the cows it was unilateral while in others it was bilateral affecting the contralateral claw on the opposite limb. Superficially traumatized horn of the sole was encountered in two cows in which the top sliced horn still attached to the underlying remaining horn at some point (Fig. 8), which erroneously can be diagnosed as underrun sole. The margins of the traumatized horn of the sole cleared appeared as distinct cut edges compared to those of underrun sole, and the underlying horn in the case

of trauma was hard compared to the thin horn of the underrun sole.

Fig. 4. Softened whitish crumbling horn of the sole in a claw with chronic laminitis found in one of the cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

#### **3.2.3 Sole bruising**

Sole bruising was seen as erosive areas of black necrotic-like horn. In the cows with less erosive sole bruising, it involved zone 5 only. The more invasive erosions of the sole involved zones 1, 4 and 5 simultaneously. In the less severe sole bruising, there was erosion of only the superficial parts of the horn of the sole, but in the severe sole bruising, there was invasive erosion deeper into the horn of the sole, which when trimmed revealed that only a very thin layer of the horn was left intact (Fig. 5). Sole bruising was always found to be bilateral affecting either only the lateral claws, or only the medial claws. It very occasionally involved lateral and medial claws simultaneously. It was observed to affect the claws of all the feet, but particularly common on the hind feet claws.

Fig. 5. Sole bruising in claws of cows observed during a study of prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in Kenya. A: superficial noninvasive sole bruising mainly in zone 5; B: deeper erosive and invasive sole bruising involving zones 1, 4 and 5, with only a small part at the centre remaining not eroded; C: thin layer of the horn left in a section of the sole after trimming areas that had sole bruising

#### **3.2.4 Heel erosion**

402 A Bird's-Eye View of Veterinary Medicine

Fig. 4. Softened whitish crumbling horn of the sole in a claw with chronic laminitis found in

Sole bruising was seen as erosive areas of black necrotic-like horn. In the cows with less erosive sole bruising, it involved zone 5 only. The more invasive erosions of the sole involved zones 1, 4 and 5 simultaneously. In the less severe sole bruising, there was erosion of only the superficial parts of the horn of the sole, but in the severe sole bruising, there was invasive erosion deeper into the horn of the sole, which when trimmed revealed that only a very thin layer of the horn was left intact (Fig. 5). Sole bruising was always found to be bilateral affecting either only the lateral claws, or only the medial claws. It very occasionally involved lateral and medial claws simultaneously. It was observed to affect the claws of all

Fig. 5. Sole bruising in claws of cows observed during a study of prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in Kenya. A: superficial noninvasive sole bruising mainly in zone 5; B: deeper erosive and invasive sole bruising

A B C

involving zones 1, 4 and 5, with only a small part at the centre remaining not eroded; C: thin layer of the horn left in a section of the sole after trimming areas that had sole bruising

one of the cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

the feet, but particularly common on the hind feet claws.

**3.2.3 Sole bruising** 

Heel erosion like sole bruising appeared as dark necrotic areas of the horn predominantly in zone 6. However, when deeply invasive, it occasionally extended to zones 3 and 4 (Fig. 6). Heel erosion was invariably bilateral and in the hind limbs it affected either lateral claws only, or medial claws only, but occasionally it affected both lateral and medial claws concurrently. When present in any herd, it was observed to affect all the cows in the zerograzing unit without any exception. Some of the claws with heel erosion had some degrees of sole bruising at the same time.

Fig. 6. Severely erosive and invasive heel erosion involving zones 6, 4 and 3 in both claws of a cow seen during the study of prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in Kenya. There is also sole bruising affecting the axial part of zone 5.

#### **3.2.5 Underrun (double) soles**

Underrun sole involved separation of the horn of the sole into two distinct layers constituting a superficial thicker harder sole and a thinner softer underlying sole. It was diagnosed by thoroughly washing the claws, which made it possible to see dung and debris stuck underneath the superficial sole. In some of the cases, it was only diagnosed during trimming by incidental finding of a superficial horn layer completely detached from a thinly forming underlying horn layer (Fig. 7). A claw that had double soles appeared grossly wider than both the normal ipsilateral and contralateral claws. Double sole phenomenon was common in zones 4 and 5. In some of the cows it was unilateral while in others it was bilateral affecting the contralateral claw on the opposite limb. Superficially traumatized horn of the sole was encountered in two cows in which the top sliced horn still attached to the underlying remaining horn at some point (Fig. 8), which erroneously can be diagnosed as underrun sole. The margins of the traumatized horn of the sole cleared appeared as distinct cut edges compared to those of underrun sole, and the underlying horn in the case of trauma was hard compared to the thin horn of the underrun sole.

Risk (Predisposing) Factors for Non-Infectious

**3.2.6 White line separation** 

unilateral involving only one claw.

**3.2.7 Sole ulcer** 

**3.2.8 Claw deformity disorders** 

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 405

White line separation was seen as clear separation of the horn of the sole and the wall. It was more discernible after thorough washing of the claws and trimming the horn of the sole (Fig. 9). The gap between the avulsed horn of the sole and the wall was usually filled with dung and debris, and in addition it could also oozed infective exudates if sepsis had set into the separated white line. White line separation involved mainly zone 2, but also very occasionally the axial part of zone 4 and 5, and sometimes zone 3. It was invariably

Fig. 9. Various degrees of white line separation seen after trimming of the horn of the sole in some of the cows examined during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units of the peri-urban areas of Nairobi, Kenya. A: moderate separation on the abaxial white line (arrow); B: moderate separation on the axial white line (arrow); C: extensive avulsion of the white line with invasive infection (arrow).

A B C

Occurrence of sole ulcers exposes the corium. In this study, it occurred in 3% of the cows and invariably resulted in severe lameness. All the sole ulcers occurred at the inner part of zone 4 and were unilateral affecting only one claw in each case. Each sole ulcer had a mass of protruding granulation tissue growing out of the site of the exposed corium (Fig. 10).

In this study, 43.7% of the cows examined had one or more types of claw deformities. There were several types of claw deformities and a number of them occurred concurrently in the same cow. Cows with claw overgrowth had entire toe, sole and walls overgrown ranging from slight to extreme overgrowth and with subsequent misshaping or deformity of the claw (Fig. 11) and consequently abnormal gait. The deformities observed were upward (dorsal) turning or crookedly shaped toe (Fig. 12), irregularly widened claw (Fig. 3 and 11), concaved claw (Fig. 3), elongated flattened claw (Fig. 3 and 11), lateral claw wall turned sole-ward (ventral) to the treading surface (Fig. 13), which was observed in 3 cows, crossed toes or scissor feet (Fig. 14) and prominent deep horizontal ridges on the dorsal wall of the claw (Fig. 3). Claws that had these characteristics in most cases also had chronic laminitis as

Fig. 7. The left claw in A and B has underrun (double) soles and is wider than the normal ipsilateral claw. This was seen in a cow examined during a study on prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A:underrun sole before trimming with the margins of the superficial sole clearly demarcated (arrows); B: underrun sole after trimming, the dung matting underlying thin sole can be seen (dashed arrow).

Fig. 8. Traumatized horn of the claw observed in 2 cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: plantero-dorsal view with the metallic quitter knife pointer between the detached horn and underlying horn; B: lateral view with the metallic quitter knife pointer between the detached horn and underlying horn.

#### **3.2.6 White line separation**

404 A Bird's-Eye View of Veterinary Medicine

Fig. 7. The left claw in A and B has underrun (double) soles and is wider than the normal ipsilateral claw. This was seen in a cow examined during a study on prevalence and risk factors of claw disorders in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A:underrun sole before trimming with the margins of the superficial sole clearly demarcated (arrows); B: underrun sole after trimming, the dung matting underlying

A B

Fig. 8. Traumatized horn of the claw observed in 2 cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: plantero-dorsal view with the metallic quitter knife pointer between the detached horn and underlying horn; B: lateral view with the metallic quitter knife pointer

A B

thin sole can be seen (dashed arrow).

between the detached horn and underlying horn.

White line separation was seen as clear separation of the horn of the sole and the wall. It was more discernible after thorough washing of the claws and trimming the horn of the sole (Fig. 9). The gap between the avulsed horn of the sole and the wall was usually filled with dung and debris, and in addition it could also oozed infective exudates if sepsis had set into the separated white line. White line separation involved mainly zone 2, but also very occasionally the axial part of zone 4 and 5, and sometimes zone 3. It was invariably unilateral involving only one claw.

Fig. 9. Various degrees of white line separation seen after trimming of the horn of the sole in some of the cows examined during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units of the peri-urban areas of Nairobi, Kenya. A: moderate separation on the abaxial white line (arrow); B: moderate separation on the axial white line (arrow); C: extensive avulsion of the white line with invasive infection (arrow).

#### **3.2.7 Sole ulcer**

Occurrence of sole ulcers exposes the corium. In this study, it occurred in 3% of the cows and invariably resulted in severe lameness. All the sole ulcers occurred at the inner part of zone 4 and were unilateral affecting only one claw in each case. Each sole ulcer had a mass of protruding granulation tissue growing out of the site of the exposed corium (Fig. 10).

#### **3.2.8 Claw deformity disorders**

In this study, 43.7% of the cows examined had one or more types of claw deformities. There were several types of claw deformities and a number of them occurred concurrently in the same cow. Cows with claw overgrowth had entire toe, sole and walls overgrown ranging from slight to extreme overgrowth and with subsequent misshaping or deformity of the claw (Fig. 11) and consequently abnormal gait. The deformities observed were upward (dorsal) turning or crookedly shaped toe (Fig. 12), irregularly widened claw (Fig. 3 and 11), concaved claw (Fig. 3), elongated flattened claw (Fig. 3 and 11), lateral claw wall turned sole-ward (ventral) to the treading surface (Fig. 13), which was observed in 3 cows, crossed toes or scissor feet (Fig. 14) and prominent deep horizontal ridges on the dorsal wall of the claw (Fig. 3). Claws that had these characteristics in most cases also had chronic laminitis as

Risk (Predisposing) Factors for Non-Infectious

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 407

Fig. 12. Crookedly twisted and upward (dorsal) turning of the claw of a cow observed during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing

Fig. 13. Spiraling of the lateral wall of the claw of a cow with abaxial aspect turning to face ventral toward the treading surface and the axial aspect turning to face dorsally. This was observed during the study of prevalence and risk factors of claw lesions in smallholder zero-

grazing dairy units in the peri-urban areas of Nairobi, Kenya.

dairy units in the peri-urban areas of Nairobi, Kenya.

evidenced by underlying sole haemorrhages on trimming of the horn of the sole and some even before trimming (Fig. 2). Splaying of the claws was found independent of other deformities but occasionally concurrent with claw overgrowth (Fig. 15). Corkscrew claw was not common but when encountered, it was bilateral involving only medial claws or only lateral claws of fore or hind limbs (Fig. 16).

Fig. 10. Sole ulcer with protruding mass of granulation tissue (arrow) seen clearly after trimming of the horn of the sole in some cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. The affected claw also has sole haemorrhages, thus indicating presence of laminitis.

Fig. 11. Regular overgrowth showing claw widening (A), toe elongation (B), as well as widening, flattening and change of treading angle of the claw to more proximal parts toward the heel (C). These were observed in some of the cows examined during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

evidenced by underlying sole haemorrhages on trimming of the horn of the sole and some even before trimming (Fig. 2). Splaying of the claws was found independent of other deformities but occasionally concurrent with claw overgrowth (Fig. 15). Corkscrew claw was not common but when encountered, it was bilateral involving only medial claws or

Fig. 10. Sole ulcer with protruding mass of granulation tissue (arrow) seen clearly after trimming of the horn of the sole in some cows during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. The affected claw also has sole haemorrhages, thus indicating presence of

Fig. 11. Regular overgrowth showing claw widening (A), toe elongation (B), as well as widening, flattening and change of treading angle of the claw to more proximal parts toward the heel (C). These were observed in some of the cows examined during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the

A B C

only lateral claws of fore or hind limbs (Fig. 16).

laminitis.

peri-urban areas of Nairobi, Kenya.

Fig. 12. Crookedly twisted and upward (dorsal) turning of the claw of a cow observed during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

Fig. 13. Spiraling of the lateral wall of the claw of a cow with abaxial aspect turning to face ventral toward the treading surface and the axial aspect turning to face dorsally. This was observed during the study of prevalence and risk factors of claw lesions in smallholder zerograzing dairy units in the peri-urban areas of Nairobi, Kenya.

Risk (Predisposing) Factors for Non-Infectious

spiraling toward the normal claw.

**3.3 Description of risk factors 3.3.1 Cow housing factors** 

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 409

Fig. 16. Two stages of corkscrew claw seen in the cows examined during a study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: shows severe bilateral corkscrew on both lateral claws, while both medial claws are normal and, B: mild corkscrew on one of the claws

A B

Good concrete floors (with firm ground-grip, non-slip and without pot-holes) were present in 68.8% of the zero-grazing units. The rest (31.2%) of the units had floors that were concreted but with loose stones, over-smoothened and slippery, grossly worn out with small to large pit-like patches, or earthen (bare soil). Among these floors, 62% had slight to moderate floor slope (< 3% gradient), while 9% had steep slope (> 3% gradient) and 29% had no slope at all but were flat. A total of 59% of the zero-grazing units were stocked to capacity (cubicle to cow ratio 1:1). The other 41% were over-stocked (more cows than cubicles). The proportion of the zero-grazing units without cubicle bedding was 38%, in which the animals lay directly on bare concrete and in some of them there were loose stones present on the cubicle floor (Fig. 17a). In those with cubicle bedding, the bedding was wood

The neck-bar height of 0.6 m from the upper-level of the feeding bunk was considered to be optimal. Only in 57% of the zero-grazing units were the neck-bars ≥ 0.6 m high, but in the other 43% of the units the neck-bars were < 0.6 m high. In 63% of the zero-grazing units, the lunging space (for the forward head movement during the act of standing) was ≥ 0.4 m, but in 37% of the units, it was < 0.4 m and the cow's head was in contact with the wall of the cubicle. In 72% of the units, the bob zone (for up-down movement of the head during the act of standing) was adequate between 0.4 m and 0.6 m from the ground to the cubicle crossbar, while in 28% of the zero-grazing units, the bob zone was inadequate at < 0.4 m in which the cows struggled during the act of standing with the dorsal part of the neck coming into

Presence of a curb (kerb) on the rear end of a cubicle was considered as a possible risk factor for development of non-infective claw disorders. Cubicle curb-height of 10-15 cm was

shavings, sawdust, soil, sand, rice husks, or rubber mats (Fig. 17b).

contact with the cross bar before fully standing (Fig. 18).

Fig. 14. Bilateral crossed toes or scissor feet in cows due to overgrown claws overlapping over each other. These were observed during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

Fig. 15. Splayed toes observed in cows examined during a study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

Fig. 16. Two stages of corkscrew claw seen in the cows examined during a study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya. A: shows severe bilateral corkscrew on both lateral claws, while both medial claws are normal and, B: mild corkscrew on one of the claws spiraling toward the normal claw.

#### **3.3 Description of risk factors**

#### **3.3.1 Cow housing factors**

408 A Bird's-Eye View of Veterinary Medicine

Fig. 14. Bilateral crossed toes or scissor feet in cows due to overgrown claws overlapping over each other. These were observed during the study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi,

Fig. 15. Splayed toes observed in cows examined during a study of prevalence and risk factors of claw lesions in smallholder zero-grazing dairy units in the peri-urban areas of

Kenya.

Nairobi, Kenya.

Good concrete floors (with firm ground-grip, non-slip and without pot-holes) were present in 68.8% of the zero-grazing units. The rest (31.2%) of the units had floors that were concreted but with loose stones, over-smoothened and slippery, grossly worn out with small to large pit-like patches, or earthen (bare soil). Among these floors, 62% had slight to moderate floor slope (< 3% gradient), while 9% had steep slope (> 3% gradient) and 29% had no slope at all but were flat. A total of 59% of the zero-grazing units were stocked to capacity (cubicle to cow ratio 1:1). The other 41% were over-stocked (more cows than cubicles). The proportion of the zero-grazing units without cubicle bedding was 38%, in which the animals lay directly on bare concrete and in some of them there were loose stones present on the cubicle floor (Fig. 17a). In those with cubicle bedding, the bedding was wood shavings, sawdust, soil, sand, rice husks, or rubber mats (Fig. 17b).

The neck-bar height of 0.6 m from the upper-level of the feeding bunk was considered to be optimal. Only in 57% of the zero-grazing units were the neck-bars ≥ 0.6 m high, but in the other 43% of the units the neck-bars were < 0.6 m high. In 63% of the zero-grazing units, the lunging space (for the forward head movement during the act of standing) was ≥ 0.4 m, but in 37% of the units, it was < 0.4 m and the cow's head was in contact with the wall of the cubicle. In 72% of the units, the bob zone (for up-down movement of the head during the act of standing) was adequate between 0.4 m and 0.6 m from the ground to the cubicle crossbar, while in 28% of the zero-grazing units, the bob zone was inadequate at < 0.4 m in which the cows struggled during the act of standing with the dorsal part of the neck coming into contact with the cross bar before fully standing (Fig. 18).

Presence of a curb (kerb) on the rear end of a cubicle was considered as a possible risk factor for development of non-infective claw disorders. Cubicle curb-height of 10-15 cm was

Risk (Predisposing) Factors for Non-Infectious

in the peri-urban areas of Nairobi, Kenya

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 411

Fig. 17b. E: cubicles with partial rubber mat covering. These were seen during the study of prevalence and risk factors of claw lesions in cows in smallholder zero-grazing dairy units

E

Fig. 18. Inadequate lunging space and bob zone causing difficulties for the cow during standing due to low cross-bar in the cubicle and short length of the cubicle. These were found in some of the zero-grazing units during the study of prevalence and risk factors of

claw lesions in the peri-urban areas of Nairobi, Kenya.

considered as normal. Only 50% of the zero-grazing units had cubicle curbs among which 19% had cubicle curbs that were between 10 cm and 15 cm tall, while 31% had cubicle curbs that were more than 15 cm tall that presented difficulties for the cows to walk backwards off the cubicles. The other 50% of the zero-grazing units had cubicles that did not have any curbs. In 88% of the zero-grazing units, the feeding area was adequate space (≥ 0.8m per cow) for all the cows to feed simultaneously. In most of them the older and the younger stock fed separately. In 12% of the units, the feeding area was inadequate space (< 0.8m per cow) due to overstocking.

Fig. 17a. A: bare cubicle without bedding but with loose stones, B: cubicle with wood shaving bedding. These were seen during the study of prevalence and risk factors of claw lesions in cows in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya.

Fig. 17b. C: cubicles with sand bedding, D: cubicles with soil bedding and

considered as normal. Only 50% of the zero-grazing units had cubicle curbs among which 19% had cubicle curbs that were between 10 cm and 15 cm tall, while 31% had cubicle curbs that were more than 15 cm tall that presented difficulties for the cows to walk backwards off the cubicles. The other 50% of the zero-grazing units had cubicles that did not have any curbs. In 88% of the zero-grazing units, the feeding area was adequate space (≥ 0.8m per cow) for all the cows to feed simultaneously. In most of them the older and the younger stock fed separately. In 12% of the units, the feeding area was inadequate space (< 0.8m per

Fig. 17a. A: bare cubicle without bedding but with loose stones, B: cubicle with wood shaving bedding. These were seen during the study of prevalence and risk factors of claw lesions in cows in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi,

A B

C D

Fig. 17b. C: cubicles with sand bedding, D: cubicles with soil bedding and

cow) due to overstocking.

Kenya.

Fig. 17b. E: cubicles with partial rubber mat covering. These were seen during the study of prevalence and risk factors of claw lesions in cows in smallholder zero-grazing dairy units in the peri-urban areas of Nairobi, Kenya

Fig. 18. Inadequate lunging space and bob zone causing difficulties for the cow during standing due to low cross-bar in the cubicle and short length of the cubicle. These were found in some of the zero-grazing units during the study of prevalence and risk factors of claw lesions in the peri-urban areas of Nairobi, Kenya.

Risk (Predisposing) Factors for Non-Infectious

Claw Disorders in Dairy Cows Under Varying Zero-Grazing Systems 413

A

B

C

Fig. 19. Three different zero-grazing units A, B, and C in the peri-urban areas of Nairobi, Kenya showing slurry that has been left to accumulate for some days and could predispose

the claws of cows to develop lesions.
