McAdd - medium chain acyl-CoA dehydrogenase deficiency

Do you have a dog that has any sort of seizure ? That collapses after exercise ? 

He/she could well have a newly discovered condition. Specific to Cavalier King Charles Spaniels. It's a bit of a mouthful but is know as “McAdd” for short you may have even heard of it as it's a “hot” topic of conversation on some pet facebook pages atm. Sadly there are arm chair experts giving out a lot of incorrect information.

McAdd is a medium chain acyl-CoA dehydrogenase deficiency (MCADD), a fatty acid oxidation disorder, is an inherited disease affecting the CKCS breed. This condition prevents the normal use of fat as an alternative source of energy during times of fasting or increased metabolic demands. Affected animals cannot burn fat for energy when their bodies run out of glucose, and as a result they may be affected by low blood sugar, altered central nervous system function, coma, or sudden death. 

McAdd can easily be diagnosed by a simple cheek swab. Available from Either Laboklin or CAGT. Cost £48. The dog will be either clear, carrier or affected.

Even IF “affected” the dog may never be symptomatic which makes it so dangerous as these dogs can pass these genes on to successive generations. 

With an early diagnosis, MCADD can be managed successfully by diet.

There's very little known about the condition with most vets never hearing of it, same with neurologists. 

However once a dog has begun to have seizures management can be very difficult. These dogs must NOT under any circumstances be given MCT's . (MCTs) are fats derived from coconut oil and palm kernel oil. They have been found to be more rapidly absorbed into the canine digestive system than other dietary oils. 

These foods containing MCTs are marketed specifically for epileptic dogs, advertising that the MCTs will reduce seizure frequency. Other dog foods are advertised that the MCTs in its ingredients “support cardiac function in dogs”. However in dogs with McAdd they are very dangerous increasing seizure frequency.

The Swiss genetics lab who developed the test litmus tested a sample of some 162 dogs. The allele frequency within the CKCS population tested in the publication was 23.5%, which means that 5.52% of the tested CKCS were affected, Recent stats from Laboklin of over 100 European dogs have the incident as 35% clear, 53% carriers and 12% affected. Current known status of some 140 UK/overseas dogs have a similar incident, not all affected dogs with be symptomatic in fact many remain asymptomatic throughout their lives.

DNA test for MCAD deficiency ( MCADD ) 

Laboklin do a DNA test for McAdd.

Full details here

https://www.laboklin.co.uk/laboklin/showGeneticTest.jsp?testID=8288

This is from their website 

Medium chain acyl-CoA dehydrogenase deficiency (MCADD), a fatty acid oxidation disorder, is an inherited disease affecting the CKCS breed. This condition prevents the normal use of fat as an alternative source of energy during times of fasting or increased metabolic demands. Affected animals cannot burn fat for energy when their bodies run out of glucose, and as a result they may be affected by low blood sugar, altered central nervous system function, coma, or sudden death. With an early diagnosis, MCADD can be managed successfully by diet.

In a recent study, affected dogs showed complex focal seizures with prolonged lethargy, lower responsiveness and proprioceptive ataxia. These conditions occurred several times a week and lasted from 20 minutes up to 24 hours. Urine and blood analysis showed an elevated level of medium chain fatty acids. The symptoms improved under medical treatment and diet change towards low fat diet leading to several month without major seizures. The allele frequency within the CKCS population tested in the publication was 23.5%, which means that 5.52% of the tested CKCS were affected.