Feline Top 5 Genetic Diseases

Question 1

what breeds are predisposed to HCM?

Answer 1

maine coons, ragdolls, persian, sphynx, norwegian forest cat, & DSH

Question 2

what clinical signs can be seen with HCM?

Answer 2

can be asymptomatic to CHF with tachypnea, dyspnea, thromboembolic disease with cyanotic nail beds, paraplegia, & sudden death

Question 3

what is seen on thoracic rads of a cat with HCM?

Answer 3

normal or cardiomegaly, dilated left atrium (valentine shape on VD), pulmonary edema/congestion, & pleural effusion

Question 4

what is seen on an echo of a cat with HCM?

Answer 4

atrial dilation, left ventricular wall thickening/papillary muscle hypertrophy, & systolic anterior motion of the mitral valve if obstructive cardiomyopathy

Question 5

how is HCM treated?

Answer 5

only treat if symptomatic - oxygen, furosemide, & ACE inhibitor

Question 6

what is the genetic hereditary seen in HCM in maine coon & ragdool cats?

Answer 6

autosomal dominant with incomplete penetrance

Question 7

what gene is affected in cats with HCM?

Answer 7

mutation affects the cardiac myosin binding c gene (MYBPC3)

Question 8

what breeds are predisposed to polycystic kidney disease?

Answer 8

persian, exotic, himalayan, ragdoll, & british shorthairs

Question 9

what clinical signs can be seen in cats with polycystic kidney disease?

Answer 9

asymptomatic to signs of chronic renal failure with pu/pd, lethargy, weight loss, & vomiting at around 3-10 years of age (hypertension is uncommon)

Question 10

how is polycystic kidney disease diagnosed?

Answer 10

azotemia, genetic testing, & the presence of single to multiple cysts

Question 11

how is polycystic kidney disease treated?

Answer 11

supportive care if renal failure is present

Question 12

what are the genetics involved & affected in cats with polycystic kidney disease?

Answer 12

autosomal dominant mutation of the PKD1 gene results in abnormal production of polycystin proteins causing abnormal dilations or renal tubules which causes the cysts

Question 13

what cat breed is affected with sacrocaudal dysgenesis?

Answer 13

manx cats

Question 14

what clinical signs are seen in cats with sacrocaudal dysgenesis?

Answer 14

urinary or fecal incontinence, pelvic limb weakness, & bunny hopping

Question 15

how is sacrocaudal dysgenesis diagnosed?

Answer 15

physical exam, abdominal rads may show megacolon, spinal rads, CT, MRI showing malformation of the sacrum, & spina bifida may be associated with sacrocaudal dysgenesis

Question 16

how is sacrocaudal dysgenesis treated?

Answer 16

bladder management

Question 17

what are the genetics involved & affected in cats with sacrocaudal dysgenesis?

Answer 17

autosomal dominant of the manx gene M, all manx cats are heterozygous Mm & MM is lethal, mm cats are tailed and therefore not a manx

Question 18

what is the prognosis for recovery of normal function for a manx cat with sacrocaudal dysgenesis?

Answer 18

poor

Question 19

what does polydactyly mean? what is the most common form? least common?

Answer 19

greater than 5 digits on a limb, most common - preaxial, so extra toes on the medial paw, least common - lateral with extra toes on the lateral side

Question 20

how is polydactyly diagnosed?

Answer 20

physical exam, abdominal rads may show megacolon, spinal rads, CT, MRI showing malformation of the sacrum, & spina bifida may be associated with sacrocaudal dysgenesis

Question 21

how is polydactly treated?

Answer 21

keep claws trimmed - claws may curve around & puncture the paw pad requiring amputation

Question 22

what is polydactyly also known as?

Answer 22

hemingway mutant - ernest hemingway kept many of them at his home

Question 23

what other animals may be affected by polydactyly?

Answer 23

horses, ruminants, & pigs

Question 24

what cats are commonly affected by hereditary deafness?

Answer 24

white cat with blue eyes that is unresponsive to auditory stimuli

Question 25

how is hereditary deafness diagnosed?

Answer 25

no response to whistles/loud noises in the exam room, be careful with metal tables because vibrations can cause the cat to react

Question 26

how is hereditary deafness treated?

Answer 26

none - don’t let them go outside

Question 27

what is the pathogenesis of hereditary deafness?

Answer 27

autosominal dominant (epistatic white masking gene W) caused by the degeneration of the stria vascularis which is necessary for endolymph production & endocochlear potential required for cochlear hair cell function at 1-3 weeks of age

Question 28

is the vestibular apparatus affected in cats with hereditary deafness?

Answer 28

nope

Question 29

what is necessary to detect unilateral deafness in a cat?

Answer 29

brainstem auditory evoked response