Cardiovascular conditions
1. Patent ductus arteriosus
1. Patent ductus arteriosus
- Common congenital abnormality
- Relative risk 4.6
- Females predisposed
- Mode of inheritance polygenic
“Patent
ductus arteriosus :The ductus arteriosus carries blood from thepulmonary artery
to the aorta in the foetus to bypass the lung, which is not in use. It normally
closes within the first week after birth. It is prob-ably the ommonest
congenital heart condition of dogs, but is less common in cats. Females are at
a higher risk of developing the condition than males. Symptoms range from none,
to congest-ive heart failure and poor body condition, to weakness, collapse and
seizures”
2. Sick sinus syndrome
2. Sick sinus syndrome
- Middle-aged to old dogs
- Relative risk 3.5 in this breed
- No sex predisposition in this breed
“Sick sinus
syndrome : This dysrhythmia often involves periods of bradycardia and
tachycardia, leading to syncope”
Dermatological conditions
Adult-onset growth-hormone-responsive dermatosis
“A poorly-understood syndrome of unknown cause. Basal growth hormone levels are low and unresponsive to stimulation. Other pituit-ary functions seem normal. The condition is characterised by bilaterally symmetrical areas of alopecia and hyperpigmentation initially in the areas of friction, e.g. the neck.”
Endocrine conditions
Adult-onset growth-hormone-responsive dermatosis
- Breed predisposition
- Males maybe predisposed
- Clinical signs usually seen at 1–5 years
“A
poorly-understood syndrome of unknown cause. Basal growth hormone levels are
low and unresponsive to stimulation. Other pituit-ary functions seem normal.
The condition is characterised by bilaterally symmetrical areas of alopecia and
hyperpigmentation initially in the areas of friction, e.g. the neck.”
1. Hypothyroidism
1. Hypothyroidism
- Reported in some texts to be at increased risk
- Often middle-aged (2–6 years)
“Hypothyroidism
is a common endocrine disease in the dog. There is a deficiency in the
secretion of thyroid hormone either as a result of thyroid gland destruction
(primary hypo-thyroidism), inadequate pituitary production of thyroid
stimulating hormone (TSH) (secondary hypothyroidism) or inadequate hypothalamic
secretion of thyrotropin releasing hormone (TRH) (tertiary hypothyroidism).
Many breeds seem predisposed to hypothyroidism, most notably Dobermann
Pinschers and Golden Retrievers.
Immune-mediated destruction of the thyroid gland (Lymphocytic thyroiditis) is a common cause of primary hypothyroidism and has been demonstrated to be hereditary in laboratory Beagles and a family of Borzois.”
Musculoskeletal conditions
1. Congenital elbow luxation
Immune-mediated destruction of the thyroid gland (Lymphocytic thyroiditis) is a common cause of primary hypothyroidism and has been demonstrated to be hereditary in laboratory Beagles and a family of Borzois.”
Musculoskeletal conditions
1. Congenital elbow luxation
- Type II luxation is seen in this breed (prox-imal radius displaced caudolaterally)
- Usually 4–5 months old at presentation
This condition is uncommon. There are two re-cognised types: type I is more severe and results in a 90° outward rotation of the proximal ulna. Lateral deviation of the antebrachium is seen, with marked reduction in elbow extension. The cause is unknown. Diagnosis is by radiography. Closed reduction is the treatment of choice, but some cases require open reduction. In type II luxation, the proximal radius is displaced cau-dolaterally. This type is less severe than type I. Some animals require no treatment, while others may require surgery, such as osteotomy of the radius or ulna
2. Medial patellar luxation
- Significant hereditary component suspected
This
condition usually presents as an intermitt-ent lameness, although in bilateral
cases it may present as a hind-limb gait abnormality. It is usually seen from
six months of age, although in some cases may not cause clinical signs until
the animal is older
3. Shoulder luxation
3. Shoulder luxation
- Congenital
This
condition usually occurs at three to four months. Flexed and rotated views of
the shoulders can reveal the abnormality on radiography Inguinal/scrotal
herniation Females predisposed Females are over-represented in this common
condition. An inguinal mass or swelling is usu-ally seen, although occasionally
gastrointestinal signs are present
4. Odontoid process dysplasia
4. Odontoid process dysplasia
- Congenital
This
condition results in atlantoaxial subluxa-tion causing signs ranging from neck
pain to quadraplegia. See also Atlantoaxial subluxation under Neurological
conditions
Neoplastic conditions
1. Testicular neoplasia
· Believed to be a breed at increased risk Testicular neoplasia is common in the dog. There are three main tumour types: Sertoli cell tumours, seminomas and interstitial cell tum-ours. Certain breeds seem at increased risk. The incidence of Sertoli cell tumour and seminoma is higher in undescended testes than normally descended testes
Neurological conditions
1. Hydrocephalus
Neoplastic conditions
1. Testicular neoplasia
· Believed to be a breed at increased risk Testicular neoplasia is common in the dog. There are three main tumour types: Sertoli cell tumours, seminomas and interstitial cell tum-ours. Certain breeds seem at increased risk. The incidence of Sertoli cell tumour and seminoma is higher in undescended testes than normally descended testes
Neurological conditions
1. Hydrocephalus
- Congenital
- Relatively common
- Onset of signs: usually 4–5 months
“Hydrocephalus occurs where there is dilation of all or part of the ventricular system of the brain, and may be congenital or acquired (usually sec-ondary to neoplasia or inflammatory disease). Symptoms include a domed cranium, seizures and altered mental status.”
2. Atlantoaxial subluxation
- Congenital
- Relatively common in this breed
- Age of clinical onset: <1 br="" year="">
- This is seen primarily in young dogs of Toy
breeds which present with neck pain and neuro-logical deficits in all four limbs due to cervical spinal cord compression. A variety of congenital defects including a lack of or hypoplasia of the dens and shortening of the axis lead to instabil-ity of the atlantoaxial articulation. The condi-tion may also be acquired in any breed as a result of fracture of the dens or damage to the ligamentous support. (See also Odontoid process dysplasiaunder Musculoskeletal conditions.)
3. Ocular conditions
1. Entropion (usually medial canthal area of the lower lid)
- Breed predisposition; polygenic inheritance likely
An inward rolling of all or part of the eyelid margin resulting in irritation of the conjunctival and corneal surfaces
2. Cataract
- Inheritance suspected
- Localisation: posterior cortical
- Age of onset: 4 years; may progress to completion
“lens or lens capsule, unilaterally or bilaterally. Cataracts may be primary (where a hereditary basis is suspected) or secondary, e.g. to ocular inflammation, metabolic disease or congenital anomalies such as persistent pupillary mem-branes or persistent hyaloid artery. Cataracts may be detected first in a variety of different areas of the lens and may progress at different rates. A complete cataract involves the whole lens and obscures the fundus, resulting in blindness in the affected eye
3. Generalised progressive retinal atrophy (GPRA)
- Autosomal recessive inheritance suspected
- Clinically apparent by 6 years
Degeneration of the retinal cells. An autosomal recessive inheritance is suspected in most breeds. Different breeds are affected at different ages by different types of GPRA. however, all cases are bilateral and progress to blindness. The earliest clinical sign is night blindness with day vision being lost a variable time later. Ophthalmoscopically there is attenuation of retinal vessels and tapetal hyper-reflectivity. In the later stages, the condition is often accom-panied by cataracts. More than 100 breeds of dog have been identified as suffering from GPRA; however, only those where the condition is seen relatively frequently, or is well-described, have been included in Part I
Reproductive conditions
1. Cryptorchidism
- Developmental defect believed to be inherited as a sex-limited, autosomal recessive trait
- Believed to be a breed at increased risk of the condition
“both testes to descend into the scrotum. The undescended testis may be found in the inguinal canal or abdomen. Non-genetic factors may play a part, but the high incidence in some breeds of dog, and in families within those breeds, suggests a genetic influence. A sex-limited autosomal mode of inheritance has been suggested"
2. Testicular neoplasia
- Believed to be a breed at increased risk
"Testicular neoplasia is common in the dog. There are three main tumour types: Sertoli cell tumours, seminomas and interstitial cell tum-ours. Certain breeds seem at increased risk. The incidence of Sertoli cell tumour and seminoma is higher in undescended testes than normally descended testes"
Respiratory conditions
1. Tracheal collapse
- Aetiology unknown
- Usually affects middle-aged to old dogs This condition can occur in young dogs with a severe form of the condition, or later in life in those less severely affected. Clinical signs include coughing and inspiratory stridor. A character-istic ‘goose-honk’ cough may be heard