Diseases of the Canine and Feline I

What are some reasons diseases of the musculoskeletal system may occur?

Trauma

Degenerative disease

Inflammation

Poor conformation (luxating patella)

Neoplasia

DJD

Degenerative Joint Disease

OCD

Osteochondritis dissecans

What are some causes of long bone fractures?

Car accident

Indirect violence

Bone disease

Repeated stress

Classifications of long bone fractures

Open v.s. closed

Simple v.s. comminuted

Stable v.s. unstable

Clinical signs of long bone fractures

Hx of trauma

Pain or localized tenderness

Lameness

Deformity of the bone

Loss of function

Crepitus

Localized swelling or bruising

How to diagnose long bone fractures?

Radiographs- at least 2 views

How to treat long bone fractures?

Reduction

Fixation

What are some methods of fixation?

Splints

Casts

Intramedullary pins

Bone plates

How long does it usually take for a long bone fracture to heal?

5-8 weeks

What does CCL mean?

Cruciate Ligament Disease

What is the most common stifle injury in a dog?

CCL rupture (Cruciate Ligament Injury)

What is a CCL rupture?

Sudden hyperextension of the stifle while exercising. major cause of DJD.

Rupture v.s. tear

Major v.s. minor insability

~50% of CCL injury also results in _____ injury

meniscal

Clinical signs of CCL injury

Acute onset

Non-weight bearing, limping

Internal rotation of tibia when weight bearing is attempted

±/- stifle effusion

How to diagnose a CCL injury?

Cranial drawer movement

Tibial compression test (Tibial thrust)

Radiographs

Cranial drawer movement

Tibia abnormally slides forward with respect to the femoral condyles

Tibial compression test (tibial thrust)

Tibia moves forward with respect to the femur when the hock is flexed

Radiographs

Cranial displacement of the tibial plateau

A bony avulsion at the tibial attachment of the ligament

Treatment of CCL injury

Surgical stabilization

Extraarticular

Intraarticular

Cage rest for 3-4 weeks with gradual reintroduction to use of the limb

Extraarticular

Small animals - <15 pounds

Use of suture to stabilize the joint

Intraarticular

Larger patients

TPLO = tibial plateau leveling osteotomy

Medial Patellar Luxation

Medial bowing of the distal third of the femur

Shallow trochlear sulcus and a poorly developed medial ridge

Medial bowing of the proximal tibia

Lateral Patellar Luxation

Affected by hip dysplasia

Medial rotation of the femur

Lateral displacement of the patella

Diagnosis of patellar luxation

Palpation

Grading system —> DVM

Radiographs

Treatment of patellar luxation

Surgical

Soft tissue treatment for patellar luxation

Fascia latae overlap

Quadriceps release

Patellar and tibial antirotational sutures

Bone reconstruction treatment for patellar luxation

Trochleoplasty

Transposition of the tibial tubercle

Arthrodesis

Contributing factors of hup dysplasia

Genetic predisposition

Environmental and dietary factors

Disparity between muscle mass and the developing skeletal system

Forms of hip dysplasia

Acetabular

Femoral

Osteophyte formation

Acetabular hip dysplasia

Shallow acetabulum

Most common

Femoral hip dysplasia

Shortened femoral neck

Osteophyte formation hip dysplasia

Joint damage and instability

Diagnosing hip dysplasia

Radiographs

OFA certification- > 2yrs

Treatment for hip dysplasia

Conservative

Surgical

Conservative tx for hip dysplasia

Moderate exercise, weight control

Anti-inflammatories

Nutraceuticals

Surgical tx for hip displasia

Femoral head ostectomy (FHO)

Total hip replacement

Triple pelvic osteotomy (TPO)

What is Osteochondrosis dissecans (OCD)

Degeneration or septic necrosis of bone and cartilage

 Followed by reossification

 Results in a dissecting cartilage flap w/

inflammatory joint changes

 Underlying defect in endochondral

ossification

Clinical signs of OCD

Lameness in large-breed dogs (3-18 mos of age)

How to diagnose OCD

Radiographs

Tx of OCD

Rest and weight control

Surgical

Panosteitis

Common disease that causes intermittent lameness in medium and large-breed dogs. Degenerates medullary bone marrow and thickens endosteal bone. Affects long bones.

Signs of panosteitis

Lameness is acute, not trauma, may seem to shift from leg to leg

Diagnosis of panosteitis

Pain elicited on palpation of long bone(s)

Radiographs: areas of increased radiodensity in the medullary cavity of long bone(s)

Tx for panosteitis

Analgesics and anti-inflammatories

What does idiopathic mean?

The origin or cause of the disease is unknown

Tumors of bones most commonly affect…

Distal radius

Proximal humerus

Distal femur

Proximal tibia

Clinical signs of osteosarcomas

Lameness

Weight loss

Severe pain, especially over the affected bone

Swelling in the affected limb

Diagnosis of osteosarcomas

Radiographs

Biopsy – required for definitive diagnosis

Thoracic radiographs – r/o metastasis

Tx for osteosarcomas

Amputation of the affected limb

Follow-up with chemo can increase survival time

Radiation – can help with pain control

(T/F) There is no cure for osteosarcomas

TRUE

Idiopathic Vestibular Disease

Acute disorder of dogs and cats

Clinical signs of idiopathic vestibular disease

Incapacitating loss of balance

Nystagmus

Disorientation

Ataxia

Vomiting

Anorexia

Diagnosis of idiopathic vestibular disease

Clinical signs

Bloodwork to r/o other nervous system diseases

Otic examination to rule out inner ear problems

Idiopathic epilepsy

seizures- no apparent cause

Diagnosis of idiopathic epilepsy

Bloodwork to r/o hypocalcemia, hypoglycemia, infection, hepatic encephalopathy, lead poisoning

Radiographs to r/o head trauma, hydrocephalus

CT scan or MRI to r/o brain lesions

Tx for idiopathic epilepsy

Start treating if seizures occur more than once per month

Drugs

Drugs that may be given to treat idiopathic epilepsy

Phenobarbital

 Take 7-10 days to reach steady-state serum

concentration

 Labs – pre pill, 2 hrs post pill

KBr

Zonisamide

Status Epileptics

MEDICAL EMERGENCY

Prolongs, uninterrupted seizure activity

Diagnosis of status epileptics

Seizure history

Clinical signs

Tx for status epileptics

Drugs

Establish and airway, O2 therapy

IV catheter, fluids

Monitor body temp

Drugs that may be given to treat status epilepticus

Diazepam

Anesthetize (propofol)

Intervertebral Disk Disease

One of the most common disorders involving the spinal cord of small animals

Type 1 disc herniations

Common in younger animals

Acute rupture into the spinal canal

Type 2 disc herniations

Common in older (>5yrs) large-breed dogs

Extrusion occurs over a longer period

Less acute and less severe clinical signs

How to determine severity of spinal cord injury

Speed at which the disk is deposited into the spinal canal

Degree of compression

Duration of compression

Clinical signs of intervertebral disk disease

Apparent pain: +/- motor or sensory deficits

Acute onset (type 1)

Paresis or paralysis – unilateral or bilateral

Decreased panniculus reflex 1-2 vertebral spaces caudal to the lesion

Altered deep pain response

Diagnosis for intervertebral disk disease

Age, breed, clinical signs, history

Complete neuro exam

Radiographs (anesthetized)

Myelogram – definitive localization of lesion

Medical tx for intervertebral disc disease

Cage rest

Corticosteroids

Recurrence common

Intensive nursing care for intervertebral disc disease

Padded cage

U-cath or bladder expression

Prevention of bed sores

Proper nutrition and hydration

Surgical tx for intervertebral disc disease

Deep pain should be present – poor prognosis

ASAP to prevent further damage to spinal cord

Cervical Spondylomyelopathy (Wobbler Syndrome)

Cervical spinal cord compression

 Caudal vertebral (C5-C7) malformation or

misarticulation

 Common in Great Danes and Doberman pinschers

Clinical signs of Cervical Spondylomyelopathy (Wobbler Syndrome)

History of progressive pelvic limb ataxia

Abnormal wearing of the dorsal surface of the rear paws, nails, or both

Swinging, wobbly gait – rear limbs

Gait worse on rising

Similar signs in front limbs

+/- atrophy of scapular muscles

Rigid flexion of neck without neck pain

Diagnosis of Cervical Spondylomyelopathy (Wobbler Syndrome)

Bloodwork to rule out metabolic defects

Radiographs – may be useful

Myelography – essential in locating regions of compression

CT and MRI – excellent diagnostic tools

Medical tx for Cervical Spondylomyelopathy (Wobbler Syndrome)

Antiinflammatories

Neck brace

Cage confinement

Surgical tx for Cervical Spondylomyelopathy (Wobbler Syndrome)

High potential for morbidity and postsurgical complications

Decompression and stabilization

Degenerative myelopathy

Symptoms slowly progress until the animal is unable to support weight with the rear limbs

 Progressive incurable disease

 Degeneration of spinal nerve

Most commonly seen in GSD and GSD mixes

Usually affects older dogs

Exact cause unknown

Clinical signs of degenerative myelopathy

Slowly progressive hid limb paresis and ataxia

Muscle atrophy

Neuro exam for degenerative myelopathy

Lesion in the region of T3-L3

Decreased or absent proprioception

Increased to normal patellar reflex

Lack of pain

Normal sphincter tone

Normal panniculus reflex

Diagnosis for degenerative myelopathy

Neuro exam

Radiographs- narrowed disk spaces

CSF collection- May show increase protein concentrations

What should you not use with dogs/cats with laryngeal paralysis?

DO NOT use neck leads

Forms of laryngeal paralysis

Hereditary: 4-6 months old

Acquired: 1.5-13 years old

 Lead poisoning, rabies, trauma, inflammation of the vagus nerve

Idiopathic: middle-age to old, large and giant breed dogs

 Castrated male dogs and cats > female and non- neutered animals

Clinical signs of laryngeal paralysis

Inspiratory stridor

Respiratory distress

Loss of endurance

Voice change

Dyspnea

Cyanosis

Complete respiratory collapse

Tx for laryngeal paralysis

Surgical- Unilateral arytenoid tie-back

Megaesophagus

Lack of esophageal peristalsis —> dilation of the esophagus and regurgitation

Congenital megaesophagus

Usually evident around weaning time

Chronic regurgitation, weight loss, respiratory signs, pneumonias

Great Danes, GSD, Irish setters, Newfoundlands,Shar-Peis, greyhounds

Inherited – wire-haired fox terriers, mini

schnauzers

Acquired megaesophagus

Any age

Linked to: metabolic neuromuscular disease,

distemper, tick paralysis, lead poisoning, lar-par