**4. Results of the study**

### **4.1 Macroscopic changes**

Various macroscopic lesions/disorders were observed in the claws collected from the abattoir and from the slaughter slab. These included claw deformities (consisting of overgrown claws, flattened claws, concave dorsal wall and corkscrew claws) at a prevalence of 78.0% (n = 248) of the claws. Sole bruising (erosion) was seen in 44.0% (n = 140) of the claws and heel erosion at 41.5% (n = 132) of the claws. Others included subclinical laminitis (only evidenced by localised sole haemorrhages after a thin layer of the sole was trimmed-off), which was found in 34.6% (n = 110) of the claws, double (underrun) soles in 23.2% (n = 74) and chronic laminitis (evidenced by some types of claw deformities and more diffuse severe sole haemorrhages) in 21.4 (n = 68) of the claws. The rest of the lesions with low prevalence can be seen in **Table 1**.

Severe congestion of the sole corium was observed in the claws that had subclinical laminitis as well as those that had chronic laminitis. The congestion was more severe in the claws that had chronic laminitis than in those that had subclinical laminitis. On sagittal section, the pedal bone appeared dark red in claws with laminitis when compared to the normal claws.

Sole bruising (erosion) caused severe thinning of the horn of the sole, which made the corium to be positioned extremely close to the surface of the sole. This was clearly evident after the sagittal section in comparison to the normal claw (**Figure 1**). The thinning of the horn was more evident in sole bruising than in heel bruising (erosion). The claws that had sole bruising were also found to manifest sole haemorrhages. When the necrotic appearing horn of the bruised sole was trimmed, the protective function of the remaining horn was compromised due to the degree of thinness. Double soles and the degree of sole erosion became clearer after claw trimming was done (**Figure 2**).

Claw deformities ranged from mild to severe and usual deformities that clearly impaired the normal gait causing the cows to show obvious signs of lameness. Depending on the extent and degree of deformity, weight distribution on the claws was grossly unequal and not according to the natural normalcy.

**43**

**4.2 Radiographic features**

*corium very close to the treading surface (brace and arrow).*

**Table 1.**

**Figure 1.**

The claws that were collected from the abattoir and the slaughter slab had varying prevalence of radiographic changes that occurred in the distal phalanges, particularly in those that had chronic laminitis. Other radiographic changes seen affected the blood vessels. Out of the 159 abattoir feet samples examined, 25.8% (n = 41) had more than one radiographic lesion. The most prevalent and consistently seen radiographic features were: prominently dilated vascular channels in 60.8% (n = 97), prominent but not dilated vascular channels in 24.1% (n = 38), irregular pedal bone margins in 13.9% (n = 22), pedal bone exostoses in 9.4% (n = 15) and narrowed/ tapering pedal bone in 5.7% (n = 9) of the 159 dairy cow feet samples. Other radiographic features seen occurred in less than 5% (**Table 2**). Radiographic changes in

*Sagittal section of a normal claw (A) showing adequate thickness of the horn of the sole (double-headed arrow); and a claw with severe sole bruising (erosion) (B) showing extremely thinned horn of the sole with the* 

*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis…*

**(n = 159)**

Sole bruising 124 248 78.0 Claw deformities 70 140 44.0 Heel erosion 66 132 41.5 Subclinical laminitis 55 110 34.6 Double (underrun) sole 37 74 23.3 Chronic laminitis 34 68 21.4 White line separation 26 52 16.4 Foreign bodies 5 10 3.1 Sole ulcer 1 2 0.6 Claw infection 1 2 0.6

*Percentage occurrence of macroscopic lesions/disorders out of 159 dairy cow feets (318 claws) collected from Kiserian abattoir and Wangige Slaughter slab in Kajiado County and Kiambu County, Kenya, respectively.*

**Number of claws (n = 318)**

**Prevalence (%)**

*DOI: http://dx.doi.org/10.5772/intechopen.81255*

**Claw lesions/disorders Number of cow feet** 


*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis… DOI: http://dx.doi.org/10.5772/intechopen.81255*

#### **Table 1.**

*Veterinary Anatomy and Physiology*

evaluation.

**3.6 Ethical approval**

University of Nairobi, Kenya.

**4. Results of the study**

**4.1 Macroscopic changes**

lence can be seen in **Table 1**.

trimming was done (**Figure 2**).

laminitis when compared to the normal claws.

analysis tool as the number of dairy cow abattoir feet/claws showing a specific type of lesion divided by the total number of feet/claws examined multiplied by 100 to make it into percentage. Percentages of occurrence of radiographic changes were calculated by dividing the number of claws showing a specific radiographic feature by the total number of claws examined through radiography multiplied by 100. The percentages of histopathologic changes were calculated out of the number of claws with subclinical laminitis and chronic laminitis selected for histological

Permission to collect claws from the abattoir and the slaughter slab was granted by the Director of Veterinary Services, Kenya through the Veterinary Officers in the two places, respectively. The ethical approval of the proposal was given by the Biosafety, Animal Use and Ethics Committee of the Faculty of Veterinary Medicine,

Various macroscopic lesions/disorders were observed in the claws collected from the abattoir and from the slaughter slab. These included claw deformities (consisting of overgrown claws, flattened claws, concave dorsal wall and corkscrew claws) at a prevalence of 78.0% (n = 248) of the claws. Sole bruising (erosion) was seen in 44.0% (n = 140) of the claws and heel erosion at 41.5% (n = 132) of the claws. Others included subclinical laminitis (only evidenced by localised sole haemorrhages after a thin layer of the sole was trimmed-off), which was found in 34.6% (n = 110) of the claws, double (underrun) soles in 23.2% (n = 74) and chronic laminitis (evidenced by some types of claw deformities and more diffuse severe sole haemorrhages) in 21.4 (n = 68) of the claws. The rest of the lesions with low preva-

Severe congestion of the sole corium was observed in the claws that had subclinical laminitis as well as those that had chronic laminitis. The congestion was more severe in the claws that had chronic laminitis than in those that had subclinical laminitis. On sagittal section, the pedal bone appeared dark red in claws with

Sole bruising (erosion) caused severe thinning of the horn of the sole, which made the corium to be positioned extremely close to the surface of the sole. This was clearly evident after the sagittal section in comparison to the normal claw (**Figure 1**). The thinning of the horn was more evident in sole bruising than in heel bruising (erosion). The claws that had sole bruising were also found to manifest sole haemorrhages. When the necrotic appearing horn of the bruised sole was trimmed, the protective function of the remaining horn was compromised due to the degree of thinness. Double soles and the degree of sole erosion became clearer after claw

Claw deformities ranged from mild to severe and usual deformities that clearly

impaired the normal gait causing the cows to show obvious signs of lameness. Depending on the extent and degree of deformity, weight distribution on the claws

was grossly unequal and not according to the natural normalcy.

**42**

*Percentage occurrence of macroscopic lesions/disorders out of 159 dairy cow feets (318 claws) collected from Kiserian abattoir and Wangige Slaughter slab in Kajiado County and Kiambu County, Kenya, respectively.*

#### **Figure 1.**

*Sagittal section of a normal claw (A) showing adequate thickness of the horn of the sole (double-headed arrow); and a claw with severe sole bruising (erosion) (B) showing extremely thinned horn of the sole with the corium very close to the treading surface (brace and arrow).*

#### **4.2 Radiographic features**

The claws that were collected from the abattoir and the slaughter slab had varying prevalence of radiographic changes that occurred in the distal phalanges, particularly in those that had chronic laminitis. Other radiographic changes seen affected the blood vessels. Out of the 159 abattoir feet samples examined, 25.8% (n = 41) had more than one radiographic lesion. The most prevalent and consistently seen radiographic features were: prominently dilated vascular channels in 60.8% (n = 97), prominent but not dilated vascular channels in 24.1% (n = 38), irregular pedal bone margins in 13.9% (n = 22), pedal bone exostoses in 9.4% (n = 15) and narrowed/ tapering pedal bone in 5.7% (n = 9) of the 159 dairy cow feet samples. Other radiographic features seen occurred in less than 5% (**Table 2**). Radiographic changes in

#### **Figure 2.**

*Claw with double (underrun) soles whose margins are clearly distinct as shown (bold arrows) in A. The thin inner sole in B is exposed (bold arrow) after trimming-off part of the outer superficial sole (dotted arrow). This occurred concurrently with chronic laminitis in some dairy cow claws.*

laminitis and other claw disorders were only observed in the distal phalanx. The middle and proximal phalanges did not show any changes. Vascular channels were markedly prominent in the distal ends of pedal bones of the claws that had laminitis.

These were more prominently dilated in claws with chronic laminitis, visible in claws with subclinical laminitis and hardly visible in claws without laminitis (**Figure 3**). The margins of the pedal bone from claws with chronic laminitis were small irregular serrations towards the distal end of the bone. The pedal bones from claws with subclinical laminitis and other laminitis-related disorders did not show any irregular margins (**Figure 4**).

Slight osseous overgrowths were seen on the periosteum at the distal parts of distal phalanges in some of the claws with chronic laminitis. Similar findings were seen in some of the claws with severe deformities. This radiographic feature seemed like exostosis (**Figure 5**). One of the claws with chronic laminitis had pedal bone with exostosis on the plantar surface (**Figure 5**). None of the claws with subclinical laminitis and other laminitis-related lesions had bone periosteal overgrowths.


#### **Table 2.**

*Radiographic changes observed out of the 159 dairy cow feet examined from Kiserian abattoir, Kajiado County and Wangige slaughter slab, Kiambu County, Kenya.*

**45**

*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis…*

*Prominently dilated vascular channels (arrows) seen in claws with chronic laminitis (A), compared with* 

Extreme tapering of the distal parts of the pedal bone was observed in some of the claws that had chronic laminitis with severe deformities such as twisted toe. The pedal bone was markedly narrowed (**Figure 6**). The other laminitis-related disorders including subclinical laminitis did not show this radiographic feature.

*Periosteal-like exostosis (bold arrow) with definite margin (dotted arrow) on the medial side of pedal bone in A. Exostosis (bold arrow) on the plantar surface of pedal bone with definite margin (dotted arrow) in B.* 

*These exostoses were found in some of the pedal bones from claws of dairy cows with laminitis.*

*Irregular serrations of the distal margin of the pedal bone (area with brace enclosure) in some of the claws that had chronic laminitis. Compare with the ipsilateral claw, which shows no serrations on the distal margin.*

Another radiographic feature seen in claws with chronic laminitis and extreme twisting of the toe is absence of the sharp apex of the distal phalanx. The apex of the bone appeared more rounded than the normal ipsilateral claw (**Figure 7**). Claws with chronic laminitis but without deformity of the toe did not have this pedal apical feature. One of the radiographic features observed in claws with excessive sole bruising and heel erosion coupled with claw deformities was fracture-like fissures of the distal

*DOI: http://dx.doi.org/10.5772/intechopen.81255*

*unnoticeable vascular channels in a normal non-laminitis claw (B).*

**Figure 3.**

**Figure 4.**

**Figure 5.**

*Macroscopic, Radiographic and Histopathologic Changes of Claws with Laminitis… DOI: http://dx.doi.org/10.5772/intechopen.81255*

#### **Figure 3.**

*Veterinary Anatomy and Physiology*

any irregular margins (**Figure 4**).

**Figure 2.**

Prominent but not dilated vascular channels

**Radiographic lesion Number of feet** 

*and Wangige slaughter slab, Kiambu County, Kenya.*

laminitis and other claw disorders were only observed in the distal phalanx. The middle and proximal phalanges did not show any changes. Vascular channels were markedly prominent in the distal ends of pedal bones of the claws that had laminitis. These were more prominently dilated in claws with chronic laminitis, visible in claws with subclinical laminitis and hardly visible in claws without laminitis (**Figure 3**). The margins of the pedal bone from claws with chronic laminitis were small irregular serrations towards the distal end of the bone. The pedal bones from claws with subclinical laminitis and other laminitis-related disorders did not show

*This occurred concurrently with chronic laminitis in some dairy cow claws.*

*Claw with double (underrun) soles whose margins are clearly distinct as shown (bold arrows) in A. The thin inner sole in B is exposed (bold arrow) after trimming-off part of the outer superficial sole (dotted arrow).* 

Slight osseous overgrowths were seen on the periosteum at the distal parts of distal phalanges in some of the claws with chronic laminitis. Similar findings were seen in some of the claws with severe deformities. This radiographic feature seemed like exostosis (**Figure 5**). One of the claws with chronic laminitis had pedal bone with exostosis on the plantar surface (**Figure 5**). None of the claws with subclinical laminitis and other laminitis-related lesions had bone periosteal overgrowths.

**samples (n = 159)**

Dilated vascular channels 96 192 60.4

Irregular pedal bone margins 22 44 13.8 Exostoses of pedal bone 15 30 9.4 Narrowed (tapering) pedal bone 9 18 5.7 Absent pedal bone apex 4 8 2.5 Fractured pedal bone 3 6 1.9 Periostitis of pedal bone 2 4 1.3 Osteolysis of pedal bone 1 2 0.6

*Radiographic changes observed out of the 159 dairy cow feet examined from Kiserian abattoir, Kajiado County* 

*The changes were observed in claws with laminitis and/or laminitis-related lesions/disorders.*

**Number of claws (n = 318)**

38 76 23.9

**Percentage occurrence (%)**

**44**

**Table 2.**

*Prominently dilated vascular channels (arrows) seen in claws with chronic laminitis (A), compared with unnoticeable vascular channels in a normal non-laminitis claw (B).*

#### **Figure 4.**

*Irregular serrations of the distal margin of the pedal bone (area with brace enclosure) in some of the claws that had chronic laminitis. Compare with the ipsilateral claw, which shows no serrations on the distal margin.*

#### **Figure 5.**

*Periosteal-like exostosis (bold arrow) with definite margin (dotted arrow) on the medial side of pedal bone in A. Exostosis (bold arrow) on the plantar surface of pedal bone with definite margin (dotted arrow) in B. These exostoses were found in some of the pedal bones from claws of dairy cows with laminitis.*

Extreme tapering of the distal parts of the pedal bone was observed in some of the claws that had chronic laminitis with severe deformities such as twisted toe. The pedal bone was markedly narrowed (**Figure 6**). The other laminitis-related disorders including subclinical laminitis did not show this radiographic feature.

Another radiographic feature seen in claws with chronic laminitis and extreme twisting of the toe is absence of the sharp apex of the distal phalanx. The apex of the bone appeared more rounded than the normal ipsilateral claw (**Figure 7**). Claws with chronic laminitis but without deformity of the toe did not have this pedal apical feature. One of the radiographic features observed in claws with excessive sole bruising and heel erosion coupled with claw deformities was fracture-like fissures of the distal

#### **Figure 6.**

*Narrowed pedal bone (arrow) whose extent of tapering is shown (brace). The pedal bone of the ipsilateral claw is normal width. This radiographic change was observed in dairy cow claws with laminitis.*

phalanx. The fissure was small and the part that appeared like bone fragment was still aligned to the entire bone (**Figure 8**). One distal phalanx was found to have osteolysis, which was clearly manifested by radiolucency of the bone appearing like the bone has a large medullary cavity (**Figure 9**), which is naturally absent in the pedal bone.
